Initial take on crafting algo Mk.III

Gruntfile.coffee

@@ -132,7 +132,7 @@ module.exports = (grunt)->
             options:
                 bail:     true
                 color:    true
-                reporter: 'dot'
+                reporter: 'list'
                 require: [
                     'coffee-script/register'
                     './src/test_helper.coffee'
@@ -188,7 +188,7 @@ module.exports = (grunt)->
                 tasks: ['sass']
             test:
                 files: ['./src/**/*.coffee', './src/**/*.js', './test/**/*.coffee']
-                tasks: ['test']
+                tasks: ['script:clear', 'test']
 
     # Compound Tasks ###################################################################################################
 
@@ -277,7 +277,7 @@ module.exports = (grunt)->
 
     grunt.registerTask 'script:clear', "clear the current terminal buffer", ->
       done = this.async()
-      grunt.util.spawn cmd:'clear', opts:{stdio:'inherit'}, (error)-> done(error)
+      grunt.util.spawn cmd:'./scripts/clear_buffer', opts:{stdio:'inherit'}, (error)-> done(error)
 
     grunt.registerTask 'script:deploy:prod', "deploy code by copying to the production branch", ->
       done = this.async()

scripts/clear_buffer

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+clear && printf '\e[3J'

src/client/models/crafting/crafting_node.coffee

@@ -1,134 +0,0 @@
-#
-# Crafting Guide - crafting_node.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-########################################################################################################################
-
-module.exports = class CraftingNode
-
-    @::TYPES =
-        INVENTORY: 0
-        ITEM: 1
-        RECIPE: 2
-
-    @::TYPE = null
-
-    constructor: (options={})->
-        if not options.modPack? then throw new Error 'options.modPack is required'
-
-        @modPack = options.modPack
-
-        @_children  = []
-        @_complete  = null
-        @_id        = _.uniqueId 'node_'
-        @_rotations = 0
-        @_valid     = null
-
-    # Public Methods ###############################################################################
-
-    expand: (queue=[])->
-        return unless @valid
-        return queue if @children.length > 0
-
-        for child in @_createChildren()
-            child.parent = this
-            @_children.push child
-            queue.push child
-        return queue
-
-    acceptVisitor: (visitor)->
-        enter = visitor[@ENTER_METHOD]
-        if enter?
-            enter.call visitor, this
-        else
-            enter = visitor['onEnterOtherNode']
-            if enter? then enter.call visitor, this
-
-        for child in @_children
-            child.acceptVisitor visitor
-
-        leave = visitor[@LEAVE_METHOD]
-        if leave?
-            leave.call visitor, this
-        else
-            leave = visitor['onLeaveOtherNode']
-            if leave? then leave.call visitor, this
-
-    pruneInvalidChildren: ->
-        @_pruneInvalidChildren()
-
-    removeChild: (index)->
-        @_children.splice index, 1
-
-    rotateChildren: ->
-        @_children.push @_children.shift()
-        @_rotations += 1
-
-    # Property Methods #############################################################################
-
-    Object.defineProperties @prototype,
-
-        children:
-            get: -> return @_children
-
-        complete:
-            get: ->
-                if not @_complete?
-                    @_complete = @_checkCompleteness()
-                return @_complete
-
-        completeText:
-            get: -> if @complete then "◼︎" else "◻︎"
-
-        depth:
-            get: ->
-                maxDepth = 1
-                for child in @children
-                    maxDepth = Math.max maxDepth, child.depth + 1
-                return maxDepth
-
-        id:
-            get: -> return @_id
-
-        rotations:
-            get: -> return @_rotations
-
-        size:
-            get: ->
-                size = 1
-                for child in @children
-                    size += child.size
-                return size
-
-        valid:
-            get: -> @_checkValidity()
-
-        validText:
-            get: -> if @valid then "✓" else "✗"
-
-
-    # Virtual Methods ##############################################################################
-
-    # Subclasses must override this method to create such children as are appropriate for that kind of node. The new
-    # nodes should be appended to the given array.
-    _createChildren: (result)->
-        throw new Error "#{@constructor.name} must override the _createChildren method"
-
-    # Subclasses must override this method to indicate whether the node has at least one "complete" subtree rooted with
-    # itself. Completeness may be defined differently by different subclasses.
-    _checkCompleteness: ->
-        throw new Error "#{@constructor.name} must override the _checkCompletness method"
-
-    # Subclasses must override this method to determine whether the subtree represented by a node should still be
-    # explored for having a useful crafting plan.
-    _checkValidity: ->
-        throw new Error "#{@constructor.name} must override the _checkValidity method"
-
-    # Subclasses may override this method to remove any children determined to be invalid and therefore unable to be
-    # of any use in finding legitimate crafting plans.
-    _pruneInvalidChildren: ->
-        for child in @children
-            child.pruneInvalidChildren()

src/client/models/crafting/crafting_node.test.coffee

@@ -1,44 +0,0 @@
-#
-# Crafting Guide - crafting_node.test.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-fixtures = require './fixtures.test'
-
-########################################################################################################################
-
-root = null
-
-########################################################################################################################
-
-describe 'crafting_node.coffee', ->
-
-    describe 'acceptVisitor', ->
-
-        it 'can provide a prefix, depth-first traversal', ->
-            root = fixtures.makeTree 'test__iron_ingot'
-
-            visitor =
-                nodes: []
-                onEnterOtherNode: (node)-> visitor.nodes.push node
-
-            root.acceptVisitor visitor
-
-            (v.constructor.name.replace('Node', '') for v in visitor.nodes).should.eql [
-                "Inventory", "Item", "Recipe", "Item", "Item", "Recipe", "Item", "Item", "Recipe", "Item", "Item"
-            ]
-
-        it 'can provide a postfix, depth-first traversal', ->
-            root = fixtures.makeTree 'test__iron_ingot'
-
-            visitor =
-                nodes: []
-                onLeaveOtherNode: (node)-> visitor.nodes.push node
-
-            root.acceptVisitor visitor
-
-            (n.constructor.name.replace('Node', '') for n in visitor.nodes).should.eql [
-                "Item", "Item", "Item", "Recipe", "Item", "Recipe", "Item", "Item", "Recipe", "Item", "Inventory"
-            ]

src/client/models/crafting/crafting_plan.coffee

@@ -5,174 +5,140 @@
 # All rights reserved.
 #
 
-SimpleInventory = require './simple_inventory'
+Inventory       = require "./inventory"
+{StringBuilder} = require "crafting-guide-common"
 
 ########################################################################################################################
 
 module.exports = class CraftingPlan
 
-    constructor: (modPack, want, have, steps)->
+    constructor: (attributes={})->
-        if not modPack? then throw new Error 'modPack is required'
+        @_id    = _.uniqueId "crafting-plan-"
-        if not want? then throw new Error 'want is required'
+        @_make  = null
-        if not have? then throw new Error 'have is required'
-        if not steps? then throw new Error 'steps is required'
-
-        @_have      = have
-        @_made      = null
-        @_modPack   = modPack
         @_need  = null
-        @_rawScores = {}
+        @have   = attributes.have
-        @_scores    = {}
+        @steps  = attributes.steps
-        @_steps     = steps
+        @want   = attributes.want
-        @_tools     = null
-        @_want      = want
 
-        @_numberSteps()
+        @_consolidateSteps()
+        @_computeResources()
 
-    # Public Methods ###############################################################################
+    # Properties ###################################################################################
-
-    computeRequired: ->
-        @_need = new SimpleInventory modPack:@_modPack
-        @_need.addInventory @_want
-
-        @_made = new SimpleInventory modPack:@_modPack
-        @_made.addInventory @_have
-
-        @_tools = new SimpleInventory modPack:@_modPack
-
-        for i in [@_steps.length-1..0] by -1
-            step = @_steps[i]
-            step.multiplier = 0
-            recipe = step.recipe
-
-            for stack in step.recipe.output
-                continue if recipe.isPassThroughFor stack.itemSlug
-                qualifiedSlug = @_modPack.qualifySlug stack.itemSlug
-
-                while @_need.quantityOf(qualifiedSlug) > 0
-                    @_executeStep step
-
-            if step.multiplier > 0
-                for stack in step.recipe.output
-                    qualifiedSlug = @_modPack.qualifySlug stack.itemSlug
-                    continue unless recipe.isPassThroughFor stack.itemSlug
-                    continue if @_made.hasAtLeast qualifiedSlug, 1
-                    continue if @_need.hasAtLeast qualifiedSlug, 1
-                    continue if @_tools.hasAtLeast qualifiedSlug, 1
-                    @_need.add qualifiedSlug, 1
-                    @_tools.add qualifiedSlug, 1
-
-        @_made.addInventory @_want
-        @_made.addInventory @_tools
-        @_pruneEmptySteps()
-        @_numberSteps()
-
-    hasRawScore: (name)->
-        return @_rawScores[name]?
-
-    getRawScore: (name)->
-        return @_rawScores[name]
-
-    setRawScore: (name, rawScore)->
-        @_rawScores[name] = rawScore
-
-    hasScore: (name)->
-        return @_scores[name]?
-
-    getScore: (name)->
-        return @_scores[name]
-
-    setScore: (name, score)->
-        @_scores[name] = score
-
-    # Property Methods #############################################################################
 
     Object.defineProperties @prototype,
-        have:
+
-            get: -> @_have
+        have: # an Inventory specifying what the player already has
-        length:
+            get: -> return @_have
-            get: -> @steps.length
+            set: (have)->
-        made:
+                have ?= new Inventory
-            get: -> @_made
+                if @_have is have then return
-        need:
+                if @_have? then throw new Error "have cannot be reassigned"
-            get: -> @_need
+                @_have = new Inventory have
-        steps:
+
-            get: -> @_steps
+        id: # a string uniquely specifying this crafting plan
-        want:
+            get: -> return @_id
-            get: -> @_want
+            set: -> throw new Error "id is not assignabled"
+
+        make: # an Inventory specifying what the results of executing the plan will be
+            get: -> return @_make
+            set: -> throw new Error "make cannot be assigned"
+
+        need: # an Inventory specifying what the player will need to gather before executing the plan
+            get: -> return @_need
+            set: -> throw new Error "need cannot be assigned"
+
+        want: # an Inventory specifying what the player wants to make
+            get: -> return @_want
+            set: (want)->
+                if not want? then throw new Error "want is required"
+                if want.isEmpty then throw new Error "want cannot be empty"
+                if @_want is want then return
+                if @_want? then throw new Error "want cannot be reassigned"
+                @_want = new Inventory want
+
+        steps: # an array of CraftingPlanSteps detailing the steps of the plan
+            get: -> return @_steps
+            set: (steps)->
+                steps ?= []
+                if steps is @_steps then return
+                if @_steps? then throw new Error "steps cannot be reassigned"
+                @_steps = steps
 
     # Object Overrides #############################################################################
 
-    toString: ->
+    toString: (options={})->
-        result = ["To Make:"]
+        options.full ?= false
-        @_want.each (stack)->
-            result.push "    #{stack}"
 
-        result.push "When you already have:"
+        if options.full
-        @_have.each (stack)->
+            b = new StringBuilder
-            result.push "    #{stack}"
+            b.line "CraftingPlan<", @_id, ">"
+            b.indent()
+            b.line "have: ", @_have.toString full:true
+            b.line "want: ", @_want.toString full:true
+            b.line "need: ", @_need.toString full:true
+            b.line "steps:"
+            b.indent()
+            b.loop @_steps, delimiter:"\n", onEach:(b, step)->
+                b.push step.count, " × ", step.recipe.toString(full:true)
+            b.line()
+            b.outdent()
+            b.line "make: ", @_make.toString full:true
+            b.outdent()
 
-        result.push "Start with:"
+            return b.toString()
-        if @_need?
-            @_need.each (stack)->
-                result.push "    #{stack}"
-
-        result.push "Use these recipes:"
-        for step in @_steps
-            result.push "    #{step}"
-
-        result.push "To produce:"
-        if @_made?
-            @_made.each (stack)->
-                result.push "    #{stack}"
-
-        if _.keys(@_rawScores).length > 0
-            result.push "Scores:"
-            for criteria, score of @_rawScores
-                if @_scores[criteria]?
-                    result.push "    #{criteria}: #{score} (#{@_scores[criteria]})"
         else
-                    result.push "    #{criteria}: #{score}"
+            return "CraftingPlan:#{@_make.toString(full:true)}<#{@_id}>"
-
-        return result.join '\n'
 
     # Private Methods ##############################################################################
 
-    _executeStep: (step)->
+    _computeResources: ->
-        step.multiplier += 1
+        need = new Inventory @_want
-        recipe = step.recipe
+        make = new Inventory @_have
+        steps = @_steps[..].reverse()
 
-        for stack in recipe.input
+        for step in steps
-            qualifiedSlug = @_modPack.qualifySlug stack.itemSlug
+            step.count = 0
 
-            available = @_made.quantityOf qualifiedSlug
+            for productStack in step.recipe.allProducts
-            required  = recipe.getQuantityRequired stack.itemSlug
+                continue unless need.contains productStack.item
-            consumed  = Math.min required, available
+                productCount = Math.ceil need.getQuantity(productStack.item) / productStack.quantity
-            deficit   = required - consumed
+                step.count = Math.max step.count, productCount
 
-            @_made.remove qualifiedSlug, consumed
+            continue unless step.count > 0
-            @_need.add qualifiedSlug, deficit
 
-        for stack in recipe.output
+            for itemId, item of step.recipe.inputs
-            qualifiedSlug = @_modPack.qualifySlug stack.itemSlug
+                amountNeeded    = step.count * step.recipe.computeQuantityRequired item
+                amountAvailable = make.getQuantity item
+                amountUsed      = Math.min amountAvailable, amountNeeded
+                amountMissing   = amountNeeded - amountUsed
 
-            deficit     = @_need.quantityOf qualifiedSlug
+                make.remove item, amountUsed
-            created     = recipe.getQuantityProduced stack.itemSlug
+                need.add item, amountMissing
-            replenished = Math.min deficit, created
-            surplus     = created - replenished
 
-            @_made.add qualifiedSlug, surplus
+            for productStack in step.recipe.allProducts
-            @_need.remove qualifiedSlug, replenished
+                amountCreated   = step.count * productStack.quantity
+                amountNeeded    = need.getQuantity productStack.item
+                amountFulfilled = Math.min amountNeeded, amountCreated
+                amountSurplus   = amountCreated - amountFulfilled
 
-    _numberSteps: ->
+                need.remove productStack.item, amountFulfilled
-        for step, i in @_steps
+                make.add productStack.item, amountSurplus
-            step.number = i + 1
 
-    _pruneEmptySteps: ->
+        make.merge @_want
-        index = 0
+
-        while index < @_steps.length
+        @_make = make
-            step = @_steps[index]
+        @_need = need
-            if step.multiplier is 0
+
-                @_steps.splice index, 1
+    _consolidateSteps: ->
-            else
+        steps = []
-                index++
+        stepsByRecipeId = {}
+
+        for step in @_steps
+            priorStep = stepsByRecipeId[step.recipe.id]
+            if priorStep?
+                priorStep.count += step.count
+            else if step.count > 0
+                steps.push step
+                stepsByRecipeId[step.recipe.id] = step
+
+        @_steps = steps

src/client/models/crafting/crafting_plan.test.coffee

@@ -6,118 +6,94 @@
 #
 
 CraftingPlan     = require './crafting_plan'
-fixtures     = require './fixtures.test'
+CraftingPlanStep = require './crafting_plan_step'
-ItemSlug     = require '../game/item_slug'
+Inventory        = require './inventory'
+fixtures         = require './fixtures'
 
 ########################################################################################################################
 
-describe 'crafting_plan.coffee', ->
+describe "CraftingPlan", ->
 
-    it 'requires wanted item if gatherable', ->
+    beforeEach ->
-        plans = fixtures.makePlans [1, 'test__coal']
+        @mod = fixtures.createMod()
-        plans.length.should.equal 1
+        @want = new Inventory
+        @have = new Inventory
 
-        plan = plans[0]
+    describe "with a single step plan", ->
-        plan.computeRequired()
-        plan.need.unparse().should.equal 'coal'
-        plan.made.unparse().should.equal 'coal'
 
-    it 'can compute a single item with one single step plan', ->
+        beforeEach ->
-        plans = fixtures.makePlans [1, 'test__charcoal']
+            @oakPlank = fixtures.configureOakPlank @mod
-        plans.length.should.equal 1
+            @want.add @oakPlank, 11
 
-        plan = plans[0]
+            @plan = new CraftingPlan want:@want, steps:[
-        plan.computeRequired()
+                new CraftingPlanStep @oakPlank.firstRecipe
-        plan.need.unparse().should.equal 'coal:8.oak_wood'
-        plan.made.unparse().should.equal '8.charcoal'
-        (s.toString() for s in plan.steps).should.eql ['1x 8 test__oak_wood,test__coal>.0. ... .1.>>8 test__charcoal']
-
-    it 'can compute a large quantity of a single item with one single step plan', ->
-        plans = fixtures.makePlans [15, 'test__charcoal']
-        plans.length.should.equal 1
-
-        plan = plans[0]
-        plan.computeRequired()
-        plan.need.unparse().should.equal '2.coal:16.oak_wood'
-        plan.made.unparse().should.equal '16.charcoal'
-        (s.toString() for s in plan.steps).should.eql ['2x 8 test__oak_wood,test__coal>.0. ... .1.>>8 test__charcoal']
-
-    it 'can compute a single item with multiple plans', ->
-        plans = fixtures.makePlans [1, 'test__iron_ingot']
-        plans.length.should.equal 2
-
-        plan = plans[0]
-        plan.computeRequired()
-        plan.need.unparse().should.equal 'coal:8.iron_ore:8.oak_wood'
-        plan.made.unparse().should.equal '7.charcoal:8.iron_ingot'
-        (s.toString() for s in plan.steps).should.eql [
-            '1x 8 test__oak_wood,test__coal>.0. ... .1.>>8 test__charcoal'
-            '1x 8 test__iron_ore,test__charcoal>.0. ... .1.>test__furnace>8 test__iron_ingot'
             ]
 
-        plan = plans[1]
+        it "correctly computes the step counts", ->
-        plan.computeRequired()
+            @plan.steps[0].count.should.equal 3
-        plan.need.unparse().should.equal 'coal:8.iron_ore'
+
-        plan.made.unparse().should.equal '8.iron_ingot'
+        it "correctly determines the inputs needed", ->
-        (s.toString() for s in plan.steps).should.eql [
+            @plan.need.toString(full:true).should.equal "3 Oak Wood"
-            '1x 8 test__iron_ore,test__coal>.0. ... .1.>test__furnace>8 test__iron_ingot'
+
+        it "correctly computes the products created", ->
+            @plan.make.toString(full:true).should.equal "12 Oak Planks"
+
+    describe "with a multi-step plan", ->
+
+        beforeEach ->
+            @ironIngot = fixtures.configureIronIngot @mod
+            @ironSword = fixtures.configureIronSword @mod
+            @oakPlank  = fixtures.configureOakPlank @mod
+            @stick     = fixtures.configureStick @mod
+
+            @want.add @ironSword, 20
+
+            @plan = new CraftingPlan want:@want, steps:[
+                new CraftingPlanStep @oakPlank.firstRecipe
+                new CraftingPlanStep @stick.firstRecipe
+                new CraftingPlanStep @ironIngot.firstRecipe
+                new CraftingPlanStep @ironSword.firstRecipe
             ]
 
-    it 'uses the correct amount of passthrough items', ->
+        it "correctly computes the step counts", ->
-        plans = fixtures.makePlans [10, 'test__split_oak_wood'], [10, 'test__split_spruce_wood']
+            @plan.steps[0].count.should.equal 3
-        plan = plans[2]
+            @plan.steps[1].count.should.equal 5
-        plan.computeRequired()
+            @plan.steps[2].count.should.equal 5
+            @plan.steps[3].count.should.equal 20
 
-        plan.need.unparse().should.equal 'coal:8.iron_ore:6.oak_wood:5.spruce_wood'
+        it "correctly determines the inputs needed", ->
-        plan.made.unparse().should.equal '4.iron_ingot:maul:2.oak_planks:10.split_oak_wood:10.split_spruce_wood:stick'
+            @plan.need.toString(full:true).should.equal "5 Coal, 40 Iron Ore, 3 Oak Wood"
-        (s.toString() for s in plan.steps).should.eql [
+
-            '1x test__oak_wood>... .0. ...>>4 test__oak_planks'
+        it "correctly computes the products created", ->
-            '1x test__oak_planks>.0. .0. ...>>4 test__stick'
+            @plan.make.toString(full:true).should.equal "20 Iron Sword, 2 Oak Planks"
-            '1x 8 test__iron_ore,test__coal>.0. ... .1.>test__furnace>8 test__iron_ingot'
+
-            '1x test__iron_ingot,test__stick>001 001 ..1>test__crafting_table>test__maul'
+    describe "with a plan which recycles some items", ->
-            '5x test__spruce_wood,test__maul>.1. .0. ...>>2 test__split_spruce_wood,test__maul'
+
-            '5x test__oak_wood,test__maul>.1. .0. ...>>2 test__split_oak_wood,test__maul'
+        beforeEach ->
+            @bucket     = fixtures.configureBucket @mod
+            @cake       = fixtures.configureCake @mod
+            @ironIngot  = fixtures.configureIronIngot @mod
+            @milkBucket = fixtures.configureMilkBucket @mod
+            @sugar      = fixtures.configureSugar @mod
+
+            @want.add @cake, 2
+
+            @plan = new CraftingPlan want:@want, steps:[
+                new CraftingPlanStep @ironIngot.firstRecipe
+                new CraftingPlanStep @bucket.firstRecipe
+                new CraftingPlanStep @milkBucket.firstRecipe
+                new CraftingPlanStep @sugar.firstRecipe
+                new CraftingPlanStep @cake.firstRecipe
             ]
 
-    it 'can compute multiple items with multiple plans', ->
+        it "correctly computes the step counts", ->
-        plans = fixtures.makePlans [1, 'test__copper_block'], [1, 'test__iron_sword']
+            @plan.steps.length.should.equal 3
-        plans.length.should.equal 4
+            @plan.steps[0].count.should.equal 6
+            @plan.steps[1].count.should.equal 4
+            @plan.steps[2].count.should.equal 2
 
-        for plan in plans
+        it "correctly determines the inputs needed", ->
-            plan.computeRequired()
+            @plan.need.toString(full:true).should.equal "2 Egg, 6 Milk, 4 Sugar Cane, 6 Wheat"
-            plan.need.unparse().should.match /16.copper_ore.*8.iron_ore/
-            plan.made.unparse().should.match /copper_block.*:iron_sword/
 
-        plan = plans[0]
+        it "correctly computes the products created", ->
-        plan.need.unparse().should.match /3.coal.*9.oak_wood/
+            @plan.make.toString(full:true).should.equal "2 Cake"
-        plan.made.unparse().should.match /7.charcoal/
-        "#{plan.steps[3]}".should.equal \
-            '1x 8 test__iron_ore,test__charcoal>.0. ... .1.>test__furnace>8 test__iron_ingot'
-        "#{plan.steps[4]}".should.equal \
-            '2x 8 test__copper_ore,test__coal>.0. ... .1.>test__furnace>8 test__copper_ingot'
-        plan.steps.length.should.equal 7
-
-        plan = plans[1]
-        plan.need.unparse().should.match /3.coal.*:oak_wood/
-        plan.made.unparse().should.not.match /charcoal/
-        "#{plan.steps[2]}".should.equal '1x 8 test__iron_ore,test__coal>.0. ... .1.>test__furnace>8 test__iron_ingot'
-        "#{plan.steps[3]}".should.equal \
-            '2x 8 test__copper_ore,test__coal>.0. ... .1.>test__furnace>8 test__copper_ingot'
-        plan.steps.length.should.equal 6
-
-        plan = plans[2]
-        plan.need.unparse().should.match /^coal.*9.oak_wood/
-        plan.made.unparse().should.match /5.charcoal/
-        "#{plan.steps[3]}".should.equal \
-            '1x 8 test__iron_ore,test__charcoal>.0. ... .1.>test__furnace>8 test__iron_ingot'
-        "#{plan.steps[4]}".should.equal \
-            '2x 8 test__copper_ore,test__charcoal>.0. ... .1.>test__furnace>8 test__copper_ingot'
-        plan.steps.length.should.equal 7
-
-        plan = plans[3]
-        plan.need.unparse().should.match /2.coal.*9.oak_wood/
-        plan.made.unparse().should.match /6.charcoal/
-        "#{plan.steps[3]}".should.equal '1x 8 test__iron_ore,test__coal>.0. ... .1.>test__furnace>8 test__iron_ingot'
-        "#{plan.steps[4]}".should.equal \
-            '2x 8 test__copper_ore,test__charcoal>.0. ... .1.>test__furnace>8 test__copper_ingot'
-        plan.steps.length.should.equal 7

src/client/models/crafting/crafting_plan_step.coffee

@@ -0,0 +1,39 @@
+#
+# Crafting Guide - crafting_plan_step.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+########################################################################################################################
+
+module.exports = class CraftingPlanStep
+
+    constructor: (recipe, count=1)->
+        @_id    = _.uniqueId "crafting-plan-step-"
+        @recipe = recipe
+        @count  = count
+
+    # Properties ###################################################################################
+
+    Object.defineProperties @prototype,
+
+        recipe:
+            get: -> return @_recipe
+            set: (recipe)->
+                if not recipe? then throw new Error 'recipe is required'
+                if @_recipe is recipe then return
+                if @_recipe? then throw new Error 'recipe cannot be reassigned'
+                @_recipe = recipe
+
+        count:
+            get: -> return @_count
+            set: (count)->
+                count = parseInt "#{count}"
+                count = if Number.isNaN(count) then 0 else Math.max 0, count
+                @_count = count
+
+    # Object Overrides #############################################################################
+
+    toString: ->
+        return "CraftingPlanStep:#{@_recipe}×#{@_count}<#{@_id}>"

src/client/models/crafting/crafting_step.coffee

@@ -1,73 +0,0 @@
-#
-# Crafting Guide - crafting_step.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-SimpleInventory = require './simple_inventory'
-
-########################################################################################################################
-
-module.exports = class CraftingStep
-
-    constructor: (recipe, modPack, multiplier=0)->
-        if not recipe? then throw new Error 'recipe is required'
-        if not modPack? then throw new Error 'modPack is required'
-        if multiplier < 0 then throw new Error 'multiplier must be at least 1'
-
-        @number = null
-
-        @_inventory  = null
-        @_modPack    = modPack
-        @_multiplier = multiplier
-        @_recipe     = recipe
-
-    # Public Methods ###############################################################################
-
-    addToolsTo: (targetInventory)->
-        for stack in @_recipe.tools
-            targetInventory.add stack.itemSlug, stack.quantity, insert:true
-
-    completeInto: (targetInventory)->
-        for stack in @_recipe.output
-            continue if @_recipe.isPassThroughFor stack.itemSlug
-            quantity = @_recipe.getQuantityProduced stack.itemSlug
-            targetInventory.add stack.itemSlug, quantity * @_multiplier
-
-    # Property Methods #############################################################################
-
-    Object.defineProperties @prototype,
-
-        inventory:
-            get: ->
-                if not @_inventory?
-                    @_refreshInventory()
-                return @_inventory
-
-        recipe:
-            get: -> @_recipe
-
-        multiplier:
-            get: -> @_multiplier
-            set: (newMultiplier)->
-                @_multiplier = newMultiplier
-                @_refreshInventory() if @_inventory?
-
-        slug:
-            get: -> "#{@multiplier}x #{@_recipe.slug}"
-
-    # Object Overrides #############################################################################
-
-    toString: ->
-        return @slug
-
-    # Private Methods ##############################################################################
-
-    _refreshInventory: ->
-        @_inventory = new SimpleInventory
-        for stack in @_recipe.input
-            qualifiedSlug = @_modPack.qualifySlug stack.itemSlug
-            required = @_recipe.getQuantityRequired(stack.itemSlug) - @_recipe.getQuantityProduced(stack.itemSlug)
-            required = if required > 0 then required * @multiplier else 1
-            @_inventory.add qualifiedSlug, required

src/client/models/crafting/craftsman.coffee

@@ -1,150 +0,0 @@
-#
-# Crafting Guide - craftsman.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-BaseModel     = require '../base_model'
-GraphBuilder  = require './graph_builder'
-Inventory     = require '../game/inventory'
-PlanBuilder   = require './plan_builder'
-PlanEvaluator = require './plan_evaluator'
-
-########################################################################################################################
-
-module.exports = class Craftsman extends BaseModel
-
-    @::ANALYZE_STEP_INCREMENT = 29
-
-    @::GRAPH_STEP_INCREMENT = 59
-
-    @::PLAN_STEP_INCREMENT = 39
-
-    @::STAGE =
-        EMPTY:     'empty'
-        READY:     'ready'
-        GRAPHING:  'examining recipes'
-        PLANNING:  'computing plans'
-        ANALYZING: 'analyzing plans'
-        COMPLETE:  'complete'
-        INVALID:   'invalid'
-        OUTDATED:  'outdated'
-
-    constructor: (modPack)->
-        if not modPack? then throw new Error 'modPack is required'
-        attributes =
-            stage:      @STAGE.READY
-            stageCount: 0
-        super attributes, {}
-
-        @_modPack = modPack
-
-        @_have = new Inventory modPack:@_modPack
-        @_have.on c.event.change, => @_resetStage()
-
-        @_want = new Inventory modPack:@_modPack
-        @_want.on c.event.change, => @_resetStage()
-
-        @on c.event.change + ':stage', => logger.info "Craftsman has started #{@stage}..."
-        @on 'scheduleNextWork', => @_scheduleNextWork()
-        @reset()
-
-    # Public Methods ###############################################################################
-
-    reset: ->
-        @_graphBuilder  = null
-        @_planBuilder   = null
-        @_planEvaluator = null
-        @_plans         = null
-
-        @_resetStage()
-
-    work: ->
-        return if @_want.isEmpty
-
-        if not @_graphBuilder?
-            @_want.localize()
-            @_have.localize()
-            logger.info -> "Craftsman starting to build #{@_want} from #{@_have}"
-
-            @_graphBuilder = new GraphBuilder modPack:@_modPack, want:@_want, have:@_have
-            @stage         = @STAGE.GRAPHING
-            @stageCount    = 0
-        else if not @_graphBuilder.complete
-            @_graphBuilder.expandGraph @GRAPH_STEP_INCREMENT
-            @stageCount = @_graphBuilder.stepCount
-            logger.verbose => "Craftsman is expanding graph: #{@stageCount} nodes"
-        else if not @_graphBuilder.rootNode.valid
-            @stage = @STAGE.INVALID
-            @stageCount = 0
-            logger.warning => "Craftsman could not complete a crafting plan:\n#{@_graphBuilder.rootNode}"
-        else if not @_planBuilder?
-            @_graphBuilder.pruneInvalidNodes()
-            logger.debug => "Craftsman finished computing graph:\n#{@_graphBuilder.rootNode}"
-
-            @_planBuilder = new PlanBuilder @_graphBuilder.rootNode, @_modPack, have:@_have, want:@_want
-            @stage        = @STAGE.PLANNING
-            @stageCount   = 0
-        else if not @_planBuilder.complete
-            @_planBuilder.producePlans @PLAN_STEP_INCREMENT
-            @stageCount = @_planBuilder.plans.length
-            logger.verbose => "Craftsman is producing plans: #{@_planBuilder.plans.length} plans"
-        else if not @_planEvaluator?
-            logger.verbose => "Craftsman finished producing plans: #{@_planBuilder.plans.length} plans"
-            @_planEvaluator = new PlanEvaluator @_planBuilder.plans
-            @stage          = @STAGE.ANALYZING
-            @stageCount     = 0
-        else if not @_planEvaluator.complete
-            @_planEvaluator.scorePlans @ANALYZE_STEP_INCREMENT
-            @stageCount = @_planEvaluator.lastScored
-            logger.verbose => "Craftsman is rating plans: #{@stageCount} plans"
-        else
-            @_plans = [
-                @_planEvaluator.findBestPlan PlanEvaluator::CRITERIA.FEWEST_STEPS
-                @_planEvaluator.findBestPlan PlanEvaluator::CRITERIA.LEAST_MATERIALS
-            ]
-            @stage = @STAGE.COMPLETE
-            @stageCount = 0
-
-            logger.info => "Craftsman has finished with plans: #{(p.toString() for p in @_plans).join('\n\n')}"
-
-        @trigger c.event.change, this
-        @trigger 'scheduleNextWork'
-        return @complete
-
-    # Property Methods #############################################################################
-
-    Object.defineProperties @prototype,
-
-        complete:
-            get: -> @stage in [@STAGE.COMPLETE, @STAGE.INVALID, @STAGE.OUTDATED]
-
-        have:
-            get: -> @_have
-
-        plan:
-            get: -> @_plans?[0]
-
-        want:
-            get: -> @_want
-
-    # Private Methods ##############################################################################
-
-    _resetStage: ->
-        @stageCount = 0
-
-        if @want.isEmpty
-            if @stage isnt @STAGE.EMPTY
-                @stage = @STAGE.EMPTY
-                @reset()
-        else if not @_plans?
-            @stage = @STAGE.READY
-        else
-            @stage = @STAGE.OUTDATED
-
-    _scheduleNextWork: ->
-        return if @want.isEmpty
-        return if @complete
-
-        _.defer => @work()

src/client/models/crafting/evaluation.coffee

@@ -0,0 +1,112 @@
+#
+# Crafting Guide - evaluation.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+########################################################################################################################
+
+module.exports = class Evaluation
+
+    constructor: (attributes={})->
+        @evaluator = attributes.evaluator
+        @item      = attributes.item if attributes.item?
+        @recipe    = attributes.recipe if attributes.recipe?
+        @baseScore = attributes.baseScore
+
+        @_baseEvaluations = []
+        @_includedTools = {}
+        @_toolScore = null
+
+    # Properties ###################################################################################
+
+    Object.defineProperties @prototype,
+
+        baseEvaluations:
+            get: -> return @_baseEvaluations
+            set: -> throw new Error "baseEvaluations cannot be assigned"
+
+        baseScore:
+            get: -> return @_baseScore
+            set: (baseScore)->
+                baseScore = parseFloat "#{baseScore}"
+                baseScore = if Number.isNaN(baseScore) then null else baseScore
+                @_baseScore = baseScore
+
+        evaluator:
+            get: -> return @_evaluator
+            set: (evaluator)->
+                if not evaluator? then throw new Error "evaluator is required"
+                if @_evaluator is evaluator then return
+                if @_evaluator? then throw new Error "evaluator cannot be reassigned"
+                @_evaluator = evaluator
+
+        includedTools:
+            get: -> return @_includedTools
+            set: -> throw new Error "includedTools cannot be assigned"
+
+        item:
+            get: -> return @_item
+            set: (item)->
+                if @_recipe? then throw new Error "this evaluation is for a recipe: cannot set an item"
+                if @_item is item then return
+                if not item? then throw new Error "item cannot be assigned null"
+                if @_item? then throw new Error "item cannot be reassigned"
+                @_item = item
+
+        recipe:
+            get: -> return @_recipe
+            set: (recipe)->
+                if @_item? then throw new Error "this evaluation is for an item: cannot set an recipe"
+                if @_recipe is recipe then return
+                if not recipe? then throw new Error "recipe cannot be assigned null"
+                if @_recipe? then throw new Error "recipe cannot be reassigned"
+                @_recipe = recipe
+
+        toolScore:
+            get: -> @_computeToolScore()
+            set: -> throw new Error "toolScore cannot be assigned"
+
+    # Public Methods ###############################################################################
+
+    addBaseEvaluation: (evaluation)->
+        @_baseEvaluations.push evaluation
+
+    addIncludedTool: (item)->
+        @_includedTools[item.id] = item
+        @_toolScore = null
+
+    computeTotalScore: (quantity=1)->
+        if @item?
+            multiplier = quantity
+        else if @recipe?
+            multiplier = Math.ceil 1.0 * quantity / @recipe.output.quantity
+
+        return @baseScore * multiplier + @toolScore
+
+    isToolIncluded: (item)->
+        return true if @_includedTools[item.id]?
+
+        for baseEvaluation in @_baseEvaluations
+            return true if baseEvaluation.isToolIncluded item
+
+        return false
+
+    # Object Overrides #############################################################################
+
+    toString: ->
+        obj = if @item? then @item else @recipe
+        return "#{@evaluator}=>#{obj}@#{@baseScore}"
+
+    # Private Methods ##############################################################################
+
+    _computeToolScore: ->
+        if not @_toolScore?
+            @_toolScore = 0
+            for id, toolItem of @_includedTools
+                evaluation = @evaluator.evaluateItem toolItem
+                continue unless evaluation?.baseScore?
+                @_toolScore += evaluation.baseScore
+
+        return @_toolScore

src/client/models/crafting/evaluator.coffee

@@ -0,0 +1,102 @@
+#
+# Crafting Guide - evaluator.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+Evaluation = require './evaluation'
+
+########################################################################################################################
+
+module.exports = class Evaluator
+
+    constructor: ->
+        @_id = _.uniqueId "evaluator-"
+        @_evaluations = {}
+
+    # Property Methods #############################################################################
+
+    Object.defineProperties @prototype,
+
+        id:
+            get: -> return @_id
+            set: -> throw new Error "id cannot be assigned"
+
+    # Public Methods ###############################################################################
+
+    evaluateItem: (item)->
+        return null unless item?
+
+        evaluation = @_evaluations[item.id]
+        if not evaluation?
+            evaluation = @_evaluations[item.id] = new Evaluation evaluator:this, item:item
+
+            recipeEvaluation = @_findBestRecipeEvaluationFor item
+            if recipeEvaluation?
+                evaluation.addBaseEvaluation recipeEvaluation
+                evaluation.baseScore = recipeEvaluation.baseScore
+            else
+                @_computeGatherableItemScore item, evaluation
+
+        return evaluation
+
+    evaluateRecipe: (recipe)->
+        return null unless recipe?
+
+        evaluation = @_evaluations[recipe.id]
+        if not evaluation?
+            evaluation = @_evaluations[recipe.id] = new Evaluation evaluator:this, recipe:recipe
+            @_computeRecipeScore recipe, evaluation
+
+            for id, toolItem of recipe.tools
+                evaluation.addIncludedTool toolItem
+
+                for id, toolItem of @evaluateItem(toolItem).includedTools
+                    evaluation.addIncludedTool toolItem
+
+
+        return evaluation
+
+    getOrderedRecipes: (item, quantity=1)->
+        recipes = (recipe for recipeId, recipe of item.recipes)
+
+        recipes.sort (a, b)=>
+            scoreA = @evaluateRecipe(a).computeTotalScore quantity
+            scoreB = @evaluateRecipe(b).computeTotalScore quantity
+
+            if scoreA isnt scoreB
+                return if scoreA < scoreB then -1 else +1
+
+            return 0
+
+        return recipes
+
+    # Object Overrides #############################################################################
+
+    toString: ->
+        return "#{@constructor.name}<#{@id}>"
+
+    # Overrideable Methods #########################################################################
+
+    _computeRecipeScore: (recipe, evaluation)->
+        throw new Error "#{@constructor.name} must override _computeRecipeScore"
+
+    _computeGatherableItemScore: (item, evaluation)->
+        throw new Error "#{@constructor.name} must override _computeGatherableItemScore"
+
+    # Private Methods ##############################################################################
+
+    _findBestRecipeEvaluationFor: (item)->
+        return null if item.isGatherable
+        result = null
+
+        for recipeMap in [item.recipes, item.recipesAsExtra]
+            for id, recipe of recipeMap
+                evaluation = @evaluateRecipe recipe
+                continue unless evaluation?.baseScore?
+
+                if not result? then result = evaluation
+                if evaluation.baseScore < result.baseScore then result = evaluation
+
+        return result

src/client/models/crafting/fixtures.coffee

@@ -0,0 +1,313 @@
+#
+# Crafting Guide - fixtures.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+Item    = require "./item"
+Mod     = require "./mod"
+ModPack = require "./mod_pack"
+Recipe  = require "./recipe"
+Stack   = require "./stack"
+
+# Instance Creation Fixtures ###########################################################################################
+
+exports.createModPack = createModPack = (attributes={})->
+    attributes.id ?= _.uniqueId "mod-pack-"
+    attributes.displayName ?= "Test ModPack"
+    return new ModPack attributes
+
+exports.createMod = createMod = (attributes={})->
+    attributes.modPack ?= createModPack()
+    attributes.id ?= _.uniqueId "mod-"
+    attributes.displayName ?= "Test Mod"
+    return new Mod attributes
+
+exports.createItem = createItem = (attributes={})->
+    attributes.mod ?= createMod()
+    attributes.id ?= _.uniqueId "item-"
+    attributes.displayName ?= _.uniqueId "Test Item "
+    return new Item attributes
+
+exports.createRecipe = createRecipe = (attributes={})->
+    attributes.id ?= _.uniqueId "recipe-"
+    attributes.output ?= createItem()
+    return new Recipe attributes
+
+exports.createStack = createStack = (attributes={})->
+    attributes.item ?= createItem()
+    attributes.quantity ?= 1
+    return new Stack attributes
+
+# Item Configuration Fixtures ##########################################################################################
+
+exports.configureBucket = configureBucket = (mod)->
+    bucket = mod.items["bucket"]
+    if not bucket?
+        ironIngot     = configureIronIngot mod
+        bucket        = createItem mod:mod, id:"bucket", displayName:"Bucket"
+        craftingTable = configureCraftingTable mod
+
+        recipe = createRecipe output:createStack item:bucket
+        recipe.setInputAt 0, 0, createStack item:ironIngot
+        recipe.setInputAt 1, 1, createStack item:ironIngot
+        recipe.setInputAt 0, 2, createStack item:ironIngot
+        recipe.addTool craftingTable
+
+    return bucket
+
+exports.configureCake = configureCake = (mod)->
+    cake = mod.items["cake"]
+    if not cake?
+        bucket        = configureBucket mod
+        cake          = createItem mod:mod, id:"cake", displayName:"Cake"
+        craftingTable = configureCraftingTable mod
+        egg           = configureEgg mod
+        milkBucket    = configureMilkBucket mod
+        sugar         = configureSugar mod
+        wheat         = configureWheat mod
+
+        recipe = createRecipe output:createStack item:cake
+        recipe.setInputAt 0, 0, createStack item:milkBucket
+        recipe.setInputAt 0, 1, createStack item:milkBucket
+        recipe.setInputAt 0, 2, createStack item:milkBucket
+        recipe.setInputAt 1, 0, createStack item:sugar
+        recipe.setInputAt 1, 1, createStack item:egg
+        recipe.setInputAt 1, 2, createStack item:sugar
+        recipe.setInputAt 2, 0, createStack item:wheat
+        recipe.setInputAt 2, 1, createStack item:wheat
+        recipe.setInputAt 2, 2, createStack item:wheat
+        recipe.addTool craftingTable
+        recipe.addExtra createStack item:bucket, quantity:3
+
+    return cake
+
+exports.configureCoal = configureCoal = (mod)->
+    coal = mod.items["coal"]
+    if not coal?
+        coal = createItem mod:mod, id:"coal", displayName:"Coal", isGatherable:true
+    return coal
+
+exports.configureCobblestone = configureCobblestone = (mod)->
+    cobblestone = mod.items["cobblestone"]
+    if not cobblestone?
+        cobblestone = createItem mod:mod, displayName:"Cobblestone", isGatherable:true
+    return cobblestone
+
+exports.configureCraftingTable = configureCraftingTable = (mod)->
+    craftingTable = mod.items["crafting_table"]
+    if not craftingTable?
+        craftingTable = createItem mod:mod, id:"crafting_table", displayName:"Crafting Table"
+        oakPlanks     = configureOakPlank mod
+
+        recipe = createRecipe output:createStack item:craftingTable
+        recipe.setInputAt 0, 0, createStack item:oakPlanks
+        recipe.setInputAt 0, 1, createStack item:oakPlanks
+        recipe.setInputAt 1, 0, createStack item:oakPlanks
+        recipe.setInputAt 1, 1, createStack item:oakPlanks
+
+    return craftingTable
+
+exports.configureEgg = configureEgg = (mod)->
+    egg = mod.items["egg"]
+    if not egg?
+        egg = createItem mod:mod, id:"egg", displayName:"Egg", isGatherable:true
+    return egg
+
+exports.configureFurnace = configureFurnace = (mod)->
+    furnace = mod.items["furnace"]
+    if not furnace?
+        cobblestone   = configureCobblestone mod
+        craftingTable = configureCraftingTable mod
+        furnace       = createItem mod:mod, displayName:"Furnace"
+
+        recipe = createRecipe output:createStack item:furnace
+        recipe.setInputAt 0, 0, createStack item:cobblestone
+        recipe.setInputAt 0, 1, createStack item:cobblestone
+        recipe.setInputAt 0, 2, createStack item:cobblestone
+        recipe.setInputAt 1, 0, createStack item:cobblestone
+        recipe.setInputAt 1, 2, createStack item:cobblestone
+        recipe.setInputAt 2, 0, createStack item:cobblestone
+        recipe.setInputAt 2, 1, createStack item:cobblestone
+        recipe.setInputAt 2, 2, createStack item:cobblestone
+        recipe.addTool craftingTable
+
+    return furnace
+
+exports.configureIronIngot = configureIronIngot = (mod)->
+    ironIngot = mod.items["iron_ingot"]
+    if not ironIngot?
+        coal      = configureCoal mod
+        furnace   = configureFurnace mod
+        ironIngot = createItem mod:mod, id:"iron_ingot", displayName:"Iron Ingot"
+        ironOre   = configureIronOre mod
+
+        recipe = createRecipe output:createStack item:ironIngot, quantity:8
+        recipe.setInputAt 0, 1, createStack item:ironOre, quantity:8
+        recipe.setInputAt 2, 1, createStack item:coal
+        recipe.addTool furnace
+
+    return ironIngot
+
+exports.configureIronBlock = configureIronBlock = (mod)->
+    ironBlock = mod.items["iron_block"]
+    if not ironBlock?
+        craftingTable = configureCraftingTable mod
+        ironBlock = createItem mod:mod, id:"iron_block", displayName:"Iron Block"
+        ironIngot = configureIronIngot mod
+
+        recipe = createRecipe output:createStack item:ironBlock
+        for row in [0..2]
+            for col in [0..2]
+                recipe.setInputAt row, col, createStack item:ironIngot
+        recipe.addTool craftingTable
+
+        recipe = createRecipe output:createStack item:ironIngot, quantity:9
+        recipe.setInputAt 1, 1, createStack item:ironBlock
+
+    return ironBlock
+
+exports.configureIronSword = configureIronSword = (mod)->
+    ironSword = mod.items["iron_sword"]
+    if not ironSword?
+        craftingTable = configureCraftingTable mod
+        ironIngot     = configureIronIngot mod
+        ironSword     = createItem mod:mod, id:"iron_sword", displayName:"Iron Sword"
+        stick         = configureStick mod
+
+        recipe = createRecipe output:createStack item:ironSword
+        recipe.setInputAt 0, 1, createStack item:ironIngot
+        recipe.setInputAt 1, 1, createStack item:ironIngot
+        recipe.setInputAt 2, 1, createStack item:stick
+        recipe.addTool craftingTable
+
+    return ironSword
+
+exports.configureIronShovel = configureIronShovel = (mod)->
+    ironShovel = mod.items["iron_shovel"]
+    if not ironShovel?
+        craftingTable = configureCraftingTable mod
+        ironIngot     = configureIronIngot mod
+        ironShovel    = createItem mod:mod, id:"iron_shovel", displayName:"Iron Shovel"
+        stick         = configureStick mod
+
+        recipe = createRecipe output:createStack item:ironShovel
+        recipe.setInputAt 0, 1, createStack item:ironIngot
+        recipe.setInputAt 1, 1, createStack item:stick
+        recipe.setInputAt 2, 1, createStack item:stick
+        recipe.addTool craftingTable
+
+    return ironShovel
+
+exports.configureIronOre = configureIronOre = (mod)->
+    ironOre = mod.items["iron_ore"]
+    if not ironOre?
+        ironOre = createItem mod:mod, id:"iron_ore", displayName:"Iron Ore", isGatherable:true
+    return ironOre
+
+exports.configureMilk = configureMilk = (mod)->
+    milk = mod.items["milk"]
+    if not milk?
+        milk = createItem mod:mod, id:"milk", displayName:"Milk", isGatherable:true
+    return milk
+
+exports.configureMilkBucket = configureMilkBucket = (mod)->
+    milkBucket = mod.items["milk_bucket"]
+    if not milkBucket?
+        bucket     = configureBucket mod
+        milk       = configureMilk mod
+        milkBucket = createItem mod:mod, id:"milkBucket", displayName:"Milk Bucket"
+
+        recipe = createRecipe output:createStack item:milkBucket
+        recipe.setInputAt 0, 1, createStack item:milk
+        recipe.setInputAt 1, 1, createStack item:bucket
+
+    return milkBucket
+
+exports.configureOakPlank = configureOakPlank = (mod)->
+    oakPlanks = mod.items["oak_planks"]
+    if not oakPlanks?
+        oakPlanks = createItem mod:mod, id:"oak_planks", displayName:"Oak Planks"
+        oakWood   = configureOakWood mod
+
+        recipe = createRecipe output:createStack item:oakPlanks, quantity:4
+        recipe.setInputAt 1, 1, createStack item:oakWood
+
+    return oakPlanks
+
+exports.configureOakWood = configureOakWood = (mod)->
+    oakWood = mod.items["oak_wood"]
+    if not oakWood?
+        oakWood = createItem mod:mod, id:"oak_wood", displayName:"Oak Wood", isGatherable:true
+    return oakWood
+
+exports.configureRedstoneDust = configureRedstoneDust = (mod)->
+    redstoneDust = mod.items["redstone_dust"]
+    if not redstoneDust?
+        redstoneDust = createItem mod:mod, id:"redstone_dust", displayName:"Redstone Dust", isGatherable:true
+    return redstoneDust
+
+exports.configureStick = configureStick = (mod)->
+    stick = mod.items["stick"]
+    if not stick?
+        oakPlanks = configureOakPlank mod
+        stick     = createItem mod:mod, id:"stick", displayName:"Stick"
+
+        recipe = createRecipe output:createStack item:stick, quantity:4
+        recipe.setInputAt 0, 0, createStack item:oakPlanks
+        recipe.setInputAt 1, 0, createStack item:oakPlanks
+
+    return stick
+
+exports.configureSugar = configureSugar = (mod)->
+    sugar = mod.items["sugar"]
+    if not sugar?
+        sugar     = createItem mod:mod, id:"sugar", displayName:"Sugar"
+        sugarCane = configureSugarCane mod
+
+        recipe = createRecipe output:createStack item:sugar
+        recipe.setInputAt 1, 1, createStack item:sugarCane
+
+    return sugar
+
+exports.configureSaw = configureSaw = (mod)->
+    saw = mod.items["saw"]
+    if not saw?
+        craftingTable = configureCraftingTable mod
+        ironBlock     = configureIronBlock mod
+        ironIngot     = configureIronIngot mod
+        oakPlank      = configureOakPlank mod
+        oakWood       = configureOakWood mod
+        redstoneDust  = configureRedstoneDust mod
+        saw           = createItem mod:mod, id:"saw", displayName:"Saw"
+
+        recipe = createRecipe output:createStack item:saw
+        recipe.setInputAt 0, 0, createStack item:oakPlank
+        recipe.setInputAt 0, 1, createStack item:ironIngot
+        recipe.setInputAt 0, 2, createStack item:oakPlank
+        recipe.setInputAt 1, 0, createStack item:oakPlank
+        recipe.setInputAt 1, 1, createStack item:ironBlock
+        recipe.setInputAt 1, 2, createStack item:oakPlank
+        recipe.setInputAt 2, 0, createStack item:oakPlank
+        recipe.setInputAt 2, 1, createStack item:redstoneDust
+        recipe.setInputAt 2, 2, createStack item:oakPlank
+        recipe.addTool craftingTable
+
+        recipe = createRecipe output:createStack item:oakPlank, quantity:8
+        recipe.setInputAt 1, 1, createStack item:oakWood
+        recipe.addTool saw
+
+    return saw
+
+exports.configureSugarCane = configureSugarCane = (mod)->
+    sugarCane = mod.items["sugar_cane"]
+    if not sugarCane?
+        sugarCane = createItem mod:mod, id:"sugar_cane", displayName:"Sugar Cane", isGatherable:true
+    return sugarCane
+
+exports.configureWheat = configureWheat = (mod)->
+    wheat = mod.items["wheat"]
+    if not wheat?
+        wheat = createItem mod:mod, id:"wheat", displayName:"Wheat", isGatherable:true
+    return wheat

src/client/models/crafting/fixtures.test.coffee

@@ -1,189 +0,0 @@
-#
-# Crafting Guide - fixtures.test.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-GraphBuilder = require './graph_builder'
-Inventory    = require '../game/inventory'
-ItemSlug     = require '../game/item_slug'
-Mod          = require '../game/mod'
-ModPack      = require '../game/mod_pack'
-ModVersion   = require '../game/mod_version'
-PlanBuilder  = require './plan_builder'
-
-########################################################################################################################
-
-MOD_VERSION_FILE =
-    """
-    schema: 1
-
-    item: Bed
-        recipe:
-            input: Oak Planks, Wool
-            pattern: ... 000 111
-
-    item: Charcoal
-        recipe:
-            input: 8 Oak Wood, Coal
-            pattern: .0. ... .1.
-            quantity: 8
-
-    item: Crafting Table
-        recipe:
-            input: Oak Planks
-            pattern: .00 .00 ...
-
-    item: Coal
-        gatherable: yes
-
-    item: Cobblestone
-        gatherable: yes
-
-    item: Copper Block
-        recipe:
-            input: Copper Ingot
-            pattern: 000 000 000
-            tools: Crafting Table
-
-    item: Copper Ingot
-        recipe:
-            input: 8 Copper Ore, Coal
-            pattern: .0. ... .1.
-            quantity: 8
-            tools: Furnace
-        recipe:
-            input: 8 Copper Ore, Charcoal
-            pattern: .0. ... .1.
-            quantity: 8
-            tools: Furnace
-        recipe:
-            input: Copper Block
-            pattern: ... .0. ...
-            quantity: 9
-
-    item: Copper Ore
-        gatherable: yes
-
-    item: Furnace
-        recipe:
-            input: Cobblestone
-            pattern: 000 0.0 000
-            tools: Crafting Table
-
-    item: Iron Ore
-        gatherable: yes
-
-    item: Iron Ingot
-        recipe:
-            input: 8 Iron Ore, Charcoal
-            pattern: .0. ... .1.
-            quantity: 8
-            tools: Furnace
-        recipe:
-            input: 8 Iron Ore, Coal
-            pattern: .0. ... .1.
-            quantity: 8
-            tools: Furnace
-
-    item: Iron Sword
-        recipe:
-            input: Iron Ingot, Stick
-            pattern: .0. .0. .1.
-            tools: Crafting Table
-
-    item: Lever
-        recipe:
-            input: Stick, Cobblestone
-            pattern: .0. .1. ...
-
-    item: Maul
-        recipe:
-            input: Iron Ingot, Stick
-            pattern: 001 001 ..1
-            tools: Crafting Table
-
-    item: Oak Planks
-        recipe:
-            input: Oak Wood
-            pattern: ... .0. ...
-            quantity: 4
-
-    item: Oak Wood
-        gatherable: yes
-
-    item: Spruce Wood
-        gatherable: yes
-
-    item: Stick
-        recipe:
-            input: Oak Planks
-            pattern: .0. .0. ...
-            quantity: 4
-
-    item: Split Oak Wood
-        recipe:
-            extras: Maul
-            input: Oak Wood, Maul
-            pattern: .1. .0. ...
-            quantity: 2
-
-    item: Split Spruce Wood
-        recipe:
-            extras: Maul
-            input: Spruce Wood, Maul
-            pattern: .1. .0. ...
-            quantity: 2
-
-    item: String
-        gatherable: yes
-
-    item: Wool
-        gatherable: yes
-        recipe:
-            input: String
-            pattern: 00. 00. ...
-    """
-
-########################################################################################################################
-
-module.exports = fixtures =
-
-    makeGraphBuilder: ->
-        return new GraphBuilder modPack:fixtures.makeModPack(), want:new Inventory
-
-    makeModPack: ->
-        modPack = new ModPack
-
-        mod = new Mod name:'Test', slug:'test'
-        modPack.addMod mod
-
-        modVersion = new ModVersion modSlug:'test', version:'0.0'
-        modVersion.parse MOD_VERSION_FILE
-        mod.addModVersion modVersion
-
-        return modPack
-
-    makePlans: (stacks...)->
-        modPack = fixtures.makeModPack()
-
-        have = new Inventory
-        want = new Inventory
-        for stack in stacks
-            want.add ItemSlug.slugify(stack[1]), stack[0]
-
-        graphBuilder = new GraphBuilder modPack:modPack, want:want
-        graphBuilder.expandGraph()
-
-        planBuilder = new PlanBuilder graphBuilder.rootNode, modPack, want:want, have:have
-        return planBuilder.producePlans()
-
-    makeTree: (itemSlug, quantity=1)->
-        want = new Inventory
-        want.add ItemSlug.slugify itemSlug
-
-        builder = new GraphBuilder modPack:fixtures.makeModPack(), want:want
-        builder.expandGraph()
-
-        return builder.rootNode

src/client/models/crafting/graph_builder.coffee

@@ -1,72 +0,0 @@
-#
-# Crafting Guide - graph_builder.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-Inventory     = require '../game/inventory'
-InventoryNode = require './inventory_node'
-
-########################################################################################################################
-
-module.exports = class GraphBuilder
-
-    constructor: (options={})->
-        if not options.modPack? then throw new Error 'options.modPack is required'
-        if not options.want? then throw new Error 'options.want is required'
-
-        @_maximumGraphSize = c.limits.maximumGraphSize
-        @_modPack          = options.modPack
-        @_stepCount        = 0
-        @_want             = options.want
-
-        @_rootNode = new InventoryNode modPack:@_modPack, inventory:@_want
-        @_queue    = [@_rootNode]
-
-    # Public Methods ###############################################################################
-
-    expandGraph: (steps=null)->
-        maxSteps = if steps? then @_stepCount + steps else Number.MAX_VALUE
-        @_queue ?= []
-
-        while true
-            break if @_queue.length is 0
-            break if @_stepCount >= maxSteps
-
-            node = @_queue.shift()
-            break unless node?
-
-            node.expand @_queue
-            @_stepCount += 1
-
-    pruneInvalidNodes: ->
-        @_rootNode.pruneInvalidChildren()
-
-    reset: ->
-
-    # Property Methods #############################################################################
-
-    Object.defineProperties @prototype,
-
-        complete:
-            get: ->
-                return true if @_stepCount > @_maximumGraphSize
-                return false unless @_rootNode?
-                return false unless @_queue?
-                return false unless @_queue.length is 0
-                return true
-
-        rootNode:
-            get: -> @_rootNode
-
-        stepCount:
-            get: -> @_stepCount
-
-        want:
-            get: -> @_want
-
-    # Object Overrides ############################################################################
-
-    toString: (indent='')->
-        "Build Tree\n#{@_rootNode.toString(indent + '    ')}"

src/client/models/crafting/graph_builder.test.coffee

@@ -1,77 +0,0 @@
-#
-# Crafting Guide - graph_builder.test.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-fixtures = require './fixtures.test'
-ItemSlug = require '../game/item_slug'
-
-########################################################################################################################
-
-builder = null
-
-########################################################################################################################
-
-describe 'GraphBuilder.coffee', ->
-
-    beforeEach ->
-        builder = fixtures.makeGraphBuilder()
-
-    describe 'expand', ->
-
-        it 'can work a few steps at a time', ->
-            builder.want.add ItemSlug.slugify 'test__iron_sword'
-            builder.expandGraph 9
-
-            builder.rootNode.depth.should.equal 6
-            builder.rootNode.size.should.equal 13
-            builder.complete.should.be.false
-
-            builder.expandGraph 9
-
-            builder.rootNode.depth.should.equal 8
-            builder.rootNode.size.should.equal 18
-            builder.complete.should.be.true
-
-        it 'works properly with an empty inventory', ->
-            builder.expandGraph 100
-
-            builder.rootNode.depth.should.equal 1
-            builder.rootNode.size.should.equal 1
-            builder.complete.should.be.true
-
-        describe 'can build a tree for', ->
-
-            runSingleItemTreeBuildingTest = (slug, depth, size)->
-                builder.want.add ItemSlug.slugify slug
-                builder.expandGraph 100
-
-                builder.rootNode.depth.should.equal depth
-                builder.rootNode.size.should.equal size
-                builder.complete.should.be.true
-
-            it 'a gatherable item', ->
-                runSingleItemTreeBuildingTest 'test__oak_wood', 2, 2
-
-            it 'a single-step item', ->
-                runSingleItemTreeBuildingTest 'test__crafting_table', 6, 6
-
-            it 'an item with multiple inputs', ->
-                runSingleItemTreeBuildingTest 'test__lever', 8, 9
-
-            it 'an item with multiple recipes', ->
-                runSingleItemTreeBuildingTest 'test__iron_ingot', 6, 11
-
-            it 'an item with multiple inputs and multiple recipes', ->
-                runSingleItemTreeBuildingTest 'test__iron_sword', 8, 18
-
-            it 'an item with one recursive recipe', ->
-                runSingleItemTreeBuildingTest 'test__copper_ingot', 6, 15
-
-            it 'an item which gatherable and craftable', ->
-                runSingleItemTreeBuildingTest 'test__wool', 4, 4
-
-            it 'an item which requires a gatherable and craftable item', ->
-                runSingleItemTreeBuildingTest 'test__bed', 6, 7

src/client/models/crafting/inventory.coffee

@@ -0,0 +1,90 @@
+#
+# Crafting Guide - inventory.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+Stack = require './stack'
+
+########################################################################################################################
+
+module.exports = class Inventory
+
+    constructor: (inventory=null)->
+        @_id = _.uniqueId "inventory-"
+        @_stacks = {}
+
+        if inventory? then @merge inventory
+
+    # Properties ###################################################################################
+
+    Object.defineProperties @prototype,
+
+        isEmpty:
+            get: -> (id for id, stack of @_stacks).length is 0
+
+        stacks:
+            get: -> return @_stacks
+            set: -> throw new Error "stacks cannot be replaced"
+
+    # Public Methods ###############################################################################
+
+    add: (item, quantity)->
+        return unless item?
+        return if quantity is 0
+
+        existingStack = @_stacks[item.id]
+        if existingStack?
+            if existingStack.quantity + quantity < 0 then throw new Error "cannot have a negative quantity"
+            existingStack.quantity += quantity
+        else
+            if quantity < 0 then throw new Error "cannot have a negative quantity"
+            @_stacks[item.id] = new Stack item:item, quantity:quantity
+
+        if @_stacks[item.id].quantity is 0
+            delete @_stacks[item.id]
+
+    clear: ->
+        @_stacks = {}
+
+    contains: (item)->
+        return @_stacks[item.id]?
+
+    getQuantity: (item)->
+        existingStack = @_stacks[item.id]
+        return 0 unless existingStack?
+        return existingStack.quantity
+
+    merge: (inventory)->
+        for id, stack of inventory.stacks
+            @add stack.item, stack.quantity
+
+    remove: (item, quantity)->
+        @add item, -1 * quantity
+
+    # Object Overrides #############################################################################
+
+    toString: (options={})->
+        options.full ?= false
+
+        if options.full
+            result = []
+            needsDelimiter = false
+
+            stackList = (stack for itemId, stack of @_stacks)
+            stackList.sort (a, b)->
+                if a.item.displayName isnt b.item.displayName
+                    return if a.item.displayName < b.item.displayName then -1 else +1
+                return 0
+
+            for stack in stackList
+                if needsDelimiter then result.push ", "
+                needsDelimiter = true
+
+                result.push stack.quantity
+                result.push " "
+                result.push stack.item.displayName
+            return result.join ""
+        else
+            return "Inventory<#{@_id}>@#{(id for id, item of @_stacks).length}"

src/client/models/crafting/inventory_node.coffee

@@ -1,55 +0,0 @@
-#
-# Crafting Guide - inventory_node.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-CraftingNode = require './crafting_node'
-ItemNode     = require './item_node'
-
-########################################################################################################################
-
-module.exports = class InventoryNode extends CraftingNode
-
-    @::ENTER_METHOD = 'onEnterInventoryNode'
-    @::LEAVE_METHOD = 'onLeaveInventoryNode'
-    @::TYPE = CraftingNode::TYPES.INVENTORY
-
-    constructor: (options={})->
-        if not options.inventory? then throw new Error 'options.inventory is required'
-        super options
-
-        @inventory = options.inventory
-
-    # CraftingNode Overrides #######################################################################
-
-    _createChildren: (result=[])->
-        @inventory.each (stack)=>
-            item = @modPack.findItem stack.itemSlug
-            if not item? then throw new Error "Could not find an item for slug: #{stack.itemSlug}"
-            result.push new ItemNode modPack:@modPack, item:item, ignoreGatherable:true
-        return result
-
-    _checkCompleteness: ->
-        for child in @children
-            return false unless child.complete
-        return true
-
-    _checkValidity: ->
-        for child in @children
-            return false unless child.valid
-        return true
-
-    # Object Overrides #############################################################################
-
-    toString: (options={})->
-        options.indent ?= ''
-        options.recursive ?= true
-
-        parts = ["#{options.indent}#{@completeText} #{@validText} InventoryNode for #{@inventory}"]
-        nextIndent = options.indent + '    '
-        if options.recursive
-            for child in @children
-                parts.push child.toString indent:nextIndent
-        return parts.join '\n'

src/client/models/crafting/item.coffee

@@ -0,0 +1,93 @@
+#
+# Crafting Guide - item.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+########################################################################################################################
+
+module.exports = class Item
+
+    constructor: (attributes={})->
+        @id           = attributes.id
+        @displayName  = attributes.displayName
+        @isGatherable = attributes.isGatherable
+        @mod          = attributes.mod
+
+        @_hasPrimaryRecipe = false
+        @_recipesAsPrimary = {}
+        @_recipesAsExtra = {}
+
+    # Property Methods #############################################################################
+
+    Object.defineProperties @prototype,
+
+        displayName:
+            get: -> return @_displayName
+            set: (displayName)->
+                if not displayName? then throw new Error "displayName is required"
+                @_displayName = displayName
+
+        firstRecipe:
+            get: -> return recipe for id, recipe of @recipes
+            set: -> throw new Error "firstRecipe cannot be assigned"
+
+        id:
+            get: -> return @_id
+            set: (id)->
+                if not id? then throw new Error "id is required"
+                return if @_id is id
+                if @_id? then throw new Error "id cannot be reassigned"
+                @_id = id
+
+        isGatherable:
+            get: ->
+                return true if @_isGatherable is true
+                return false if (id for id, recipe of @_recipesAsPrimary).length > 0
+                return false if (id for id, recipe of @_recipesAsExtra).length > 0
+                return true
+            set: (isGatherable)->
+                @_isGatherable = null unless isGatherable?
+                @_isGatherable = !!isGatherable
+
+        mod:
+            get: -> return @_mod
+            set: (mod)->
+                if not mod? then throw new Error "mod is required"
+                if @_mod is mod then return
+                if @_mod? then throw new Error "mod cannot be reassigned"
+                @_mod = mod
+                @_mod.addItem this
+
+        modPack:
+            get: -> return @_mod.modPack
+            set: -> throw new Error "modPack cannot be replaced"
+
+        recipes:
+            get: -> return if @_hasPrimaryRecipe then @_recipesAsPrimary else @_recipesAsExtra
+            set: -> throw new Error "recipes cannot be assigned"
+
+        recipesAsPrimary:
+            get: -> return @_recipesAsPrimary
+            set: -> throw new Error "recipes cannot be assigned"
+
+        recipesAsExtra:
+            get: -> return @_recipesAsExtra
+            set: -> throw new Error "recipesAsExtra cannot be assigned"
+
+    # Public Recipes ###############################################################################
+
+    addRecipe: (recipe)->
+        if recipe.output.item is this
+            @_recipesAsPrimary[recipe.id] = recipe
+            @_hasPrimaryRecipe = true
+        else if recipe.extras[this.id] is this
+            @_recipesAsExtra[recipe.id] = recipe
+        else
+            throw new Error "recipe<#{recipe.id}> does not produce this item<#{@id}>"
+
+    # Object Overrides #############################################################################
+
+    toString: ->
+        return "Item:#{@displayName}<#{@id}>"

src/client/models/crafting/item_node.coffee

@@ -1,108 +0,0 @@
-#
-# Crafting Guide - item_node.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-CraftingNode = require './crafting_node'
-RecipeNode   = require './recipe_node'
-
-########################################################################################################################
-
-module.exports = class ItemNode extends CraftingNode
-
-    @::ENTER_METHOD = 'onEnterItemNode'
-    @::LEAVE_METHOD = 'onLeaveItemNode'
-    @::TYPE = CraftingNode::TYPES.ITEM
-
-    constructor: (options={})->
-        if not options.item? then throw new Error 'options.item is required'
-        super options
-
-        @item = options.item
-        @_ignoreGatherable = options.ignoreGatherable ?= false
-        @_recipes = null
-
-    # Property Methods #############################################################################
-
-    getRecipes: ->
-        if not @_recipes?
-            @_recipes = @modPack.findRecipes @item.slug, forCrafting:true, onlyPrimary:true
-            if not @_recipes
-                @_recipes = @modPack.findRecipes @item.slug, forCrafting:true
-
-        return @_recipes or []
-
-    isGatherable: ->
-        if not @_ignoreGatherable
-            return true if @item.isGatherable
-        return true if @getRecipes().length is 0
-        return false
-
-    Object.defineProperties @prototype,
-        gatherable: { get:@prototype.isGatherable }
-        recipes: { get:@prototype.getRecipes }
-
-    # CraftingNode Overrides #######################################################################
-
-    _createChildren: (result=[])->
-        recipes = @getRecipes()
-        return [] if @gatherable
-
-        for recipe in recipes
-            child = new RecipeNode modPack:@modPack, recipe:recipe
-            child.parent = this
-            if child.valid
-                result.push child
-
-        return result
-
-    _checkCompleteness: ->
-        return true if @gatherable
-        return false unless @children?
-
-        for child in @children
-            return true if child.complete
-        return false
-
-    _checkValidity: ->
-        return false if @_isRepeatedItem()
-        return true unless @children.length > 0
-
-        for child in @children
-            return true if child.valid
-        return false
-
-    _pruneInvalidChildren: ->
-        index = 0
-        while index < @children.length
-            child = @children[index]
-            if child.valid
-                child.pruneInvalidChildren()
-                index++
-            else
-                @removeChild index
-
-    # Object Overrides #############################################################################
-
-    toString: (options={})->
-        options.indent ?= ''
-        options.recursive ?= true
-
-        parts = ["#{options.indent}#{@completeText} #{@validText} ItemNode for #{@item.name}"]
-        nextIndent = options.indent + '    '
-        if options.recursive
-            for child in @children
-                parts.push child.toString indent:nextIndent
-        return parts.join '\n'
-
-    # Private Methods ##############################################################################
-
-    _isRepeatedItem: ->
-        nextParent = @parent
-        while nextParent?
-            return true if nextParent.item is @item
-            nextParent = nextParent.parent
-
-        return false

src/client/models/crafting/mod.coffee

@@ -0,0 +1,62 @@
+#
+# Crafting Guide - mod.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+########################################################################################################################
+
+module.exports = class Mod
+
+    constructor: (attributes={})->
+        @id = attributes.id
+        @displayName = attributes.displayName
+        @modPack = attributes.modPack
+
+        @_items = {}
+
+    # Properties ###################################################################################
+
+    Object.defineProperties @prototype,
+
+        displayName:
+            get: -> return @_displayName
+            set: (displayName)->
+                if not displayName? then throw new Error "displayName is required"
+                return if @_displayName is displayName
+                @_displayName = displayName
+
+        id:
+            get: -> return @_id
+            set: (id)->
+                if not id? then throw new Error "id is required"
+                return if @_id is id
+                if @_id? then throw new Error "id cannot be reassigned"
+                @_id = id
+
+        items:
+            get: -> return @_items
+            set: -> throw new Error "items cannot be replaced"
+
+        modPack:
+            get: -> return @_modPack
+            set: (modPack)->
+                if not modPack? then throw new Error "modPack is required"
+                if @_modPack is modPack then return
+                if @_modPack? then throw new Error "modPack cannot be reassigned"
+                @_modPack = modPack
+                @_modPack.addMod this
+
+    # Public Methods ###############################################################################
+
+    addItem: (item)->
+        if not item? then return
+        if @_items[item.id] is item then return
+        @_items[item.id] = item
+        item.mod = this
+
+    # Object Overrides #############################################################################
+
+    toString: ->
+        return "Mod:#{@displayName}<#{@id}>"

src/client/models/crafting/mod_pack.coffee

@@ -0,0 +1,52 @@
+#
+# Crafting Guide - mod_pack.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+########################################################################################################################
+
+module.exports = class ModPack
+
+    constructor: (attributes={})->
+        @id = attributes.id
+        @displayName = attributes.displayName
+
+        @_mods = {}
+        @_oreDict = {}
+
+    # Property Methods #############################################################################
+
+    Object.defineProperties @prototype,
+
+        displayName:
+            get: -> return @_displayName
+            set: (displayName)->
+                if not displayName? then throw new Error "displayName is required"
+                if @_displayName is displayName then return
+                @_displayName = displayName
+
+        id:
+            get: -> return @_id
+            set: (id)->
+                if not id? then throw new Error "id is required"
+                if @_id is id then return
+                if @_id? then throw new Error "id cannot be reassigned"
+
+        mods:
+            get: -> return @_mods
+            set: -> throw new Error "mods cannot be replaced"
+
+    # Public Methods ###############################################################################
+
+    addMod: (mod)->
+        if not mod? then return
+        if @_mods[mod.id] is mod then return
+        @_mods[mod.id] = mod
+        mod.modPack = this
+
+    # Object Overrides #############################################################################
+
+    toString: ->
+        return "ModPack:#{@displayName}<#{@id}>"

src/client/models/crafting/plan_builder.coffee

@@ -5,123 +5,88 @@
 # All rights reserved.
 #
 
-CraftingNode = require './crafting_node'
+CraftingPlan     = require "./crafting_plan"
-CraftingPlan = require './crafting_plan'
+CraftingPlanStep = require "./crafting_plan_step"
-CraftingStep = require './crafting_step'
-Inventory    = require '../game/inventory'
 
 ########################################################################################################################
 
 module.exports = class PlanBuilder
 
-    constructor: (rootNode, modPack, options={})->
+    constructor: (evaluator)->
-        if not rootNode? then throw new Error 'rootNode is required'
+        @evaluator = evaluator
-        if not modPack? then throw new Error 'modPack is required'
 
-        @want = options.want
+    # Properties ###################################################################################
-        @have = options.have
-
-        @_choiceNodes  = []
-        @_complete     = false
-        @_maxPlanCount = c.limits.maximumPlanCount
-        @_modPack      = modPack
-        @_plans        = []
-        @_rootNode     = rootNode
-
-        @_isolateChoiceNodes()
-
-    # Public Methods ###############################################################################
-
-    producePlans: (maxPlans=null)->
-        maxPlans = if maxPlans then @plans.length + maxPlans else Number.MAX_VALUE
-
-        if @plans.length >= @_maxPlanCount
-            @_complete = true
-
-        while not @complete and (@plans.length < maxPlans)
-            plan = @_captureCurrentPlan()
-            if plan?
-                @plans.push plan
-
-            @_incrementChoiceNodes()
-
-        return @_plans
-
-    # Property Methods #############################################################################
 
     Object.defineProperties @prototype,
 
-        complete:
+        evaluator:
-            get: -> @_complete
+            get: -> return @_evaluator
+            set: (evaluator)->
+                if not evaluator? then throw new Error "evaluator is required"
+                if @_evaluator is evaluator then return
+                if @_evaluator? then throw new Error "evaluator cannot be reassigned"
+                @_evaluator = evaluator
 
-        have:
+    # Public Methods ###############################################################################
-            get: -> @_have
-            set: (have)-> @_have = have or new Inventory
 
-        maxPlanCount:
+    createPlan: (want, have)->
-            get: -> @_maxPlanCount
+        @_alreadyMaking = {}
-            set: (value)-> @_maxPlanCount = value
+        @_recipesInUse = {}
 
-        plans:
+        stepList = []
-            get: -> @_plans
+        for itemId, stack of want.stacks
+            steps = @_findStepsForItem stack.item, stack.quantity
+            return null unless steps?
 
-        want:
+            stepList.push steps
-            get: -> @_want
+
-            set: (want)-> @_want = want or new Inventory
+        plan = new CraftingPlan want:want, have:have, steps:_.flatten(stepList)
+        return plan
 
     # Private Methods ##############################################################################
 
-    _captureCurrentPlan: ->
+    _findStepsForItem: (item, quantity=1)->
-        toVisit = [@_rootNode]
+        steps = null
-        stepNodes = []
 
-        while toVisit.length > 0
+        if not @_alreadyMaking[item.id]
-            node = toVisit.shift()
+            @_alreadyMaking[item.id] = true
-
-            if node.TYPE is CraftingNode::TYPES.INVENTORY
-                toVisit.push(c) for c in node.children
-            else if node.TYPE is CraftingNode::TYPES.ITEM
-                toVisit.push node.children[0] if node.children.length > 0
-            else if node.TYPE is CraftingNode::TYPES.RECIPE
-                stepNodes.push node
-                toVisit.push(c) for c in node.children
 
+            recipes = @_evaluator.getOrderedRecipes item, quantity
+            if recipes.length is 0
                 steps = []
-        seenRecipes = {}
+            else
-        index = stepNodes.length - 1
+                for recipe in recipes
-        while index >= 0
+                    continue if @_recipesInUse[recipe.id]?
-            node = stepNodes[index]
-            index -= 1
-            return null unless node.valid and node.complete
 
-            recipeSlug = node.recipe.slug
+                    steps = @_findStepsForRecipe recipe, quantity
-            continue if seenRecipes[recipeSlug]?
+                    break if steps?
 
-            seenRecipes[recipeSlug] = true
+            delete @_alreadyMaking[item.id]
-            steps.push new CraftingStep node.recipe, @_modPack
 
-        plan = new CraftingPlan @_modPack, @_want, @_have, steps
+        return steps
-        return plan
 
-    _incrementChoiceNodes: ->
+    _findStepsForRecipe: (recipe, quantity=1)->
-        if @_choiceNodes.length is 0
+        steps = null
-            @_complete = true
-            return
 
-        index = @_choiceNodes.length - 1
+        if not @_recipesInUse[recipe.id]
-        while true
+            @_recipesInUse[recipe.id] = true
-            if index is -1
-                @_complete = true
-                return
 
-            node = @_choiceNodes[index]
+            invalidRecipe = false
-            node.rotateChildren()
+            for itemId, item of recipe.inputs
+                inputSteps = @_findStepsForItem item, quantity * recipe.computeQuantityRequired(item)
+                if not inputSteps?
+                    invalidRecipe = true
+                    break
 
-            return unless node.rotations % node.children.length is 0
+                steps ?= []
-            index -= 1
+                for step in inputSteps
+                    steps.push step
 
-    _isolateChoiceNodes: ->
+            if invalidRecipe
-        @_rootNode.acceptVisitor
+                steps = null
-            onEnterItemNode: (node)=>
+            else
-                if node.children.length > 1
+                steps.push new CraftingPlanStep recipe
-                    @_choiceNodes.push node
+
+            delete @_recipesInUse[recipe.id]
+
+        return steps

src/client/models/crafting/plan_builder.test.coffee

@@ -5,39 +5,154 @@
 # All rights reserved.
 #
 
-fixtures    = require './fixtures.test'
+fixtures           = require './fixtures'
+Inventory          = require './inventory'
 PlanBuilder        = require './plan_builder'
+ResourcesEvaluator = require './resources_evaluator'
 
 ########################################################################################################################
 
-describe 'plan_builder.coffee', ->
+describe.only "PlanBuilder", ->
 
-    printPlan = (plan)->
+    beforeEach ->
-        return '' unless plan?
+        @planner = new PlanBuilder new ResourcesEvaluator
-        return ((s.recipe.slug.replace(/^.*>.*>/, '') for s in plan.steps;;)).join ' > '
+        @mod = fixtures.createMod()
+        @want = new Inventory
+        @have = new Inventory
 
-    it 'generates an empty plan for a gatherable item', ->
+    describe "for a gatherable item, creates a plan that", ->
-        plans = fixtures.makePlans [1, 'test__oak_wood']
 
-        plans.length.should.equal 1
+        beforeEach ->
-        plans[0].length.should.equal 0
+            @oakWood = fixtures.configureOakWood @mod
+            @want.add @oakWood, 2
+            @plan = @planner.createPlan @want
 
-    it 'can find a multi-step plan', ->
+        it "has no steps at all", ->
-        plans = fixtures.makePlans [1, 'test__lever']
+            @plan.steps.length.should.equal 0
 
-        printPlan(plans[0]).should.equal '4 test__oak_planks > 4 test__stick > test__lever'
+        it "demands the item itself as the input", ->
-        plans.length.should.equal 1
+            @plan.need.toString(full:true).should.equal "2 Oak Wood"
 
-    it 'can find multiple plans', ->
+        it "produces the item as the result", ->
-        plans = fixtures.makePlans [1, 'test__iron_ingot']
+            @plan.make.toString(full:true).should.equal "2 Oak Wood"
 
-        printPlan(plans[0]).should.equal '8 test__charcoal > 8 test__iron_ingot'
+    describe "for a single item with a one-step recipe, it creates a plan that", ->
-        printPlan(plans[1]).should.equal '8 test__iron_ingot'
-        plans.length.should.equal 2
 
-    it 'ignores invalid plans', ->
+        beforeEach ->
-        plans = fixtures.makePlans [1, 'test__copper_block']
+            @oakPlank = fixtures.configureOakPlank @mod
+            @want.add @oakPlank, 63
+            @plan = @planner.createPlan @want
 
-        printPlan(plans[0]).should.equal '8 test__copper_ingot > test__copper_block'
+        it "has the recipe as the only step", ->
-        printPlan(plans[1]).should.equal '8 test__charcoal > 8 test__copper_ingot > test__copper_block'
+            @plan.steps.length.should.equal 1
-        plans.length.should.equal 2
+            @plan.steps[0].recipe.output.item.displayName.should.equal "Oak Planks"
+
+        it "demands the right inputs", ->
+            @plan.need.toString(full:true).should.equal "16 Oak Wood"
+
+        it "produces the right results", ->
+            @plan.make.toString(full:true).should.equal "64 Oak Planks"
+
+    describe "for a single item with a complex recipe, it creates a plan that", ->
+
+        beforeEach ->
+            @ironSword = fixtures.configureIronSword @mod
+            @want.add @ironSword, 2
+            @plan = @planner.createPlan @want
+
+        it "has the right steps", ->
+            @plan.steps.length.should.equal 4
+            @plan.steps[0].recipe.output.item.displayName.should.equal "Iron Ingot"
+            @plan.steps[1].recipe.output.item.displayName.should.equal "Oak Planks"
+            @plan.steps[2].recipe.output.item.displayName.should.equal "Stick"
+            @plan.steps[3].recipe.output.item.displayName.should.equal "Iron Sword"
+
+        it "demands the right inputs", ->
+            @plan.need.toString(full:true).should.equal "1 Coal, 8 Iron Ore, 1 Oak Wood"
+
+        it "produces the right results", ->
+            @plan.make.toString(full:true).should.equal "4 Iron Ingot, 2 Iron Sword, 2 Oak Planks, 2 Stick"
+
+    describe "for multiple items with complex recipes, it creates a plan that", ->
+
+        beforeEach ->
+            @ironSword = fixtures.configureIronSword @mod
+            @ironShovel = fixtures.configureIronShovel @mod
+            @want.add @ironSword, 3
+            @want.add @ironShovel, 3
+            @plan = @planner.createPlan @want
+
+        it "has consolidated the common steps", ->
+            (step.recipe.output.item.displayName for step in @plan.steps).should.eql [
+                "Iron Ingot", "Oak Planks", "Stick", "Iron Sword", "Iron Shovel"
+            ]
+
+        it "requires the correct repetitions for each step", ->
+            (step.count for step in @plan.steps).should.eql [ 2, 2, 3, 3, 3 ]
+
+        it "demands the right inputs", ->
+            @plan.need.toString(full:true).should.equal "2 Coal, 16 Iron Ore, 2 Oak Wood"
+
+        it "produces the right results", ->
+            @plan.make.toString(full:true).should.equal(
+                "7 Iron Ingot, 3 Iron Shovel, 3 Iron Sword, 2 Oak Planks, 3 Stick"
+            )
+
+    describe "for an item which has a recursive recipe, it creates a plan that", ->
+
+        beforeEach ->
+            @ironBlock = fixtures.configureIronBlock @mod
+            @want.add @ironBlock, 4
+            @plan = @planner.createPlan @want
+
+        it "avoids the recursive options", ->
+            (step.recipe.output.item.displayName for step in @plan.steps).should.eql [
+                "Iron Ingot", "Iron Block"
+            ]
+
+        it "requires the correct repetitions for each step", ->
+            (step.count for step in @plan.steps).should.eql [ 5, 4 ]
+
+        it "demands the right inputs", ->
+            @plan.need.toString(full:true).should.equal "5 Coal, 40 Iron Ore"
+
+        it "produces the right results", ->
+            @plan.make.toString(full:true).should.equal(
+                "4 Iron Block, 4 Iron Ingot"
+            )
+
+    describe "when making enormous quantities of something simple", ->
+
+        beforeEach ->
+            @oakPlank = fixtures.configureOakPlank @mod
+            @want.add @oakPlank, Number.MAX_VALUE / 2
+            @start = Date.now()
+            @plan = @planner.createPlan @want
+            @duration = Date.now() - @start
+
+        it "doesn't take forever to create the plan", ->
+            @duration.should.be.lessThan 10
+
+    describe "when making an item which can be made with and without a tool, for a", ->
+
+        beforeEach ->
+            @oakPlank = fixtures.configureOakPlank @mod
+            @saw = fixtures.configureSaw @mod
+
+        describe "small batch, the plan", ->
+
+            beforeEach ->
+                @want.add @oakPlank, 2
+                @plan = @planner.createPlan @want
+
+            it "avoids the expensive tool", ->
+                (step.recipe.needsTools for step in @plan.steps).should.eql [ false ]
+
+        describe "large batch, the plan", ->
+
+            beforeEach ->
+                @want.add @oakPlank, 2048
+                @plan = @planner.createPlan @want
+
+            it "uses the tool for efficiency", ->
+                (step.recipe.needsTools for step in @plan.steps).should.eql [ true ]

src/client/models/crafting/plan_evaluator.coffee

@@ -1,98 +0,0 @@
-#
-# Crafting Guide - plan_evaluator.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-########################################################################################################################
-
-module.exports = class PlanEvaluator
-
-    @::CRITERIA =
-        FEWEST_STEPS:    'fewest steps'
-        LEAST_MATERIALS: 'least materials'
-
-    constructor: (plans)->
-        if not plans? then throw new Error 'plans is required'
-
-        @_plans = plans
-        @_lastScored = -1
-        @_normalized = false
-
-    # Public Methods ###############################################################################
-
-    findBestPlan: (mainCriteria)->
-        criteriaList = [mainCriteria].concat (criteria for key, criteria of @CRITERIA when criteria isnt mainCriteria)
-        @_plans.sort (a, b)->
-            for criteria in criteriaList
-                scoreA = a.getScore criteria
-                scoreB = b.getScore criteria
-
-                if scoreA isnt scoreB
-                    return if scoreA > scoreB then -1 else +1
-
-            return 0
-
-        return @_plans[0]
-
-    scorePlans: (count)->
-        count ?= @_plans.length
-        return if @complete
-
-        maxPlanIndex = Math.min @_lastScored + count, @_plans.length - 1
-        for i in [(@_lastScored + 1)..maxPlanIndex]
-            @_plans[i].computeRequired()
-            @_scorePlan @_plans[i]
-            @_lastScored = i
-
-        if @complete then @_normalizeScores()
-
-        return @complete
-
-    # Property Methods #############################################################################
-
-    Object.defineProperties @prototype,
-
-        complete:
-            get: -> @_lastScored is @_plans.length - 1
-
-        lastScored:
-            get: -> @_lastScored
-
-    # Private Methods ##############################################################################
-
-    _computeFewestStepsScore: (plan)->
-        total = 0
-        for step in plan.steps
-            total += step.multiplier
-        plan.setRawScore @CRITERIA.FEWEST_STEPS, total
-
-    _computeLeastMaterialsScore: (plan)->
-        total = 0
-        plan.need.each (stack)->
-            total += stack.quantity
-        plan.setRawScore @CRITERIA.LEAST_MATERIALS, total
-
-    _normalizeScores: ->
-        for key, criteria of @CRITERIA
-            maxScore  = 0
-            minScore  = Number.MAX_VALUE
-
-            for plan in @_plans
-                continue unless plan.hasRawScore criteria
-                maxScore = Math.max maxScore, plan.getRawScore(criteria)
-                minScore = Math.min minScore, plan.getRawScore(criteria)
-
-            adjustedMaxScore = maxScore - minScore
-            for plan in @_plans
-                continue unless plan.hasRawScore criteria
-                if adjustedMaxScore > 0
-                    adjustedRawScore = plan.getRawScore(criteria) - minScore
-                    plan.setScore criteria, 1.0 - (1.0 * adjustedRawScore / adjustedMaxScore)
-                else
-                    plan.setScore criteria, 1.0
-
-    _scorePlan: (plan)->
-        @_computeFewestStepsScore plan
-        @_computeLeastMaterialsScore plan

src/client/models/crafting/plan_evaluator.test.coffee

@@ -1,80 +0,0 @@
-#
-# Crafting Guide - plan_evaluator.test.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-CraftingPlan  = require './crafting_plan'
-fixtures      = require './fixtures.test'
-Inventory     = require '../game/inventory'
-PlanEvaluator = require './plan_evaluator'
-
-########################################################################################################################
-
-criteria = evaluator = planA = planB = planC = plans = wanted = null
-
-########################################################################################################################
-
-describe 'plan_evaluator.coffee', ->
-
-    beforeEach ->
-        criteria = PlanEvaluator::CRITERIA.FEWEST_STEPS
-
-    describe 'findBestPlan', ->
-
-        it 'can find the shortest of two options', ->
-            evaluator = new PlanEvaluator fixtures.makePlans [1, 'test__copper_block']
-            evaluator.scorePlans()
-
-            bestPlan = evaluator.findBestPlan criteria
-            bestPlan.getScore(criteria).should.equal 1.0
-
-        it 'can find the shortest of many options', ->
-            evaluator = new PlanEvaluator fixtures.makePlans [1, 'test__copper_block'], [1, 'test__iron_sword']
-            evaluator.scorePlans()
-
-            bestPlan = evaluator.findBestPlan criteria
-            bestPlan.getScore(criteria).should.equal 1.0
-
-        it 'can break ties using the non-primary criteria', ->
-            evaluator = new PlanEvaluator fixtures.makePlans [2, 'test__iron_ingot'], [1, 'test__charcoal']
-            evaluator.scorePlans()
-
-            bestPlan = evaluator.findBestPlan criteria
-            bestPlan.getScore(criteria).should.equal 1.0
-
-            (p.getRawScore('fewest steps') for p in evaluator._plans).should.eql [2, 2]
-            (p.getRawScore('least materials') for p in evaluator._plans).should.eql [17, 18]
-
-    describe '_normalizeScores', ->
-
-        beforeEach ->
-            modPack   = fixtures.makeModPack()
-            wanted    = new Inventory modPack:modPack
-            have      = new Inventory modPack:modPack
-            planA     = new CraftingPlan modPack, wanted, have, []
-            planB     = new CraftingPlan modPack, wanted, have, []
-            planC     = new CraftingPlan modPack, wanted, have, []
-            plans     = [planA, planB, planC]
-            evaluator = new PlanEvaluator plans
-            criteria  = PlanEvaluator::CRITERIA.FEWEST_STEPS
-
-        it 'does not set scores when none have been evaluated', ->
-            evaluator._normalizeScores()
-            (plan.hasRawScore(criteria) for plan in plans).should.eql [false, false, false]
-
-        it 'assigns a 1.0 when all plans equal', ->
-            for plan in plans
-                plan.setRawScore criteria, 5
-
-            evaluator._normalizeScores()
-            (plan.getScore(criteria) for plan in plans).should.eql [1.0, 1.0, 1.0]
-
-        it 'computes correct scores from raw scores', ->
-            planA.setRawScore criteria, 7
-            planB.setRawScore criteria, 8
-            planC.setRawScore criteria, 9
-
-            evaluator._normalizeScores()
-            (plan.getScore(criteria) for plan in plans).should.eql [1.0, 0.5, 0.0]

src/client/models/crafting/recipe.coffee

@@ -0,0 +1,148 @@
+#
+# Crafting Guide - recipe.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+{StringBuilder} = require 'crafting-guide-common'
+
+########################################################################################################################
+
+module.exports = class Recipe
+
+    constructor: (attributes={})->
+        @id     = attributes.id
+        @height = attributes.height
+        @output = attributes.output
+        @width  = attributes.width
+
+        @_extras    = {}
+        @_inputs    = {}
+        @_inputGrid = []
+        @_tools     = {}
+
+    # Properties ###################################################################################
+
+    Object.defineProperties @prototype,
+
+        allProducts: # an array of Stacks starting the the primary output of this recipe
+            get: -> return [].concat @output, (stack for id, stack of @extras)
+            set: -> throw new Error "allProducts cannot be assigned"
+
+        extras: # a hash of item id to Stack of all the non-primary outputs of this recipe
+            get: -> return @_extras
+            set: -> throw new Error "extras cannot be replaced"
+
+        id: # a string which uniquely identifies this recipe
+            get: -> return @_id
+            set: (id)->
+                if not id? then throw new Error "id is required"
+                if @_id is id then return
+                if @_id? then throw new Error "id cannot be reassigned"
+                @_id = id
+
+        height: # an integer specifying the number of rows needed by this recipe
+            get: -> return @_height
+            set: (height)->
+                height = parseInt "#{height}"
+                height = if Number.isNaN(height) then 0 else Math.max(0, height)
+                @_height = height
+
+        inputs: # a hash of item id to Item containing all the inputs to this recipe
+            get: -> return @_inputs
+            set: -> throw new Error "inputs cannot be replaced"
+
+        needsTools: # a boolean indicating whether this recipe requires a tool
+            get: -> return (id for id, toolItem of @_tools).length > 0
+
+        output: # a Stack specifying the primary output of this recipe
+            get: -> return @_output
+            set: (output)->
+                if not output? then throw new Error "output is required"
+                if @_output is output then return
+                if @_output? then throw new Error "output cannot be reassigned"
+                @_output = output
+                @_output.item.addRecipe this
+
+        modPack: # the ModPack to which this recipe belongs
+            get: -> return @_output.modPack
+            set: -> throw new Error "modPack cannot be replaced"
+
+        tools: # a hash of item id to Item of all the tools required for this recipe
+            get: -> return @_tools
+            set: -> throw new Error "tools cannot be assigned"
+
+        width: # an integer specifying the number of columns needed by this recipe
+            get: -> return @_width
+            set: (width)->
+                width = parseInt "#{width}"
+                width = if Number.isNaN(width) then 0 else Math.max(0, width)
+                @_width = width
+
+    # Public Methods ###############################################################################
+
+    addExtra: (stack)->
+        return unless stack
+        @_extras[stack.item.id] = stack
+
+    addTool: (item)->
+        return unless item
+        @_tools[item.id] = item
+
+    computeQuantityRequired: (item)->
+        result = 0
+
+        for row in [0...@height]
+            for col in [0...@width]
+                stack = @_inputGrid[row]?[col]
+                continue unless stack?
+                continue unless stack.item.id is item.id
+                result += stack.quantity
+
+        return result
+
+    computeQuantityProduced: (item)->
+        result = 0
+
+        if @_output.item.id is item.id
+            result += @_output.quantity
+
+        for itemId, stack of @_extras
+            continue unless itemId is item.id
+            result += stack.quantity
+
+        return result
+
+    getInputAt: (row, col)->
+        return @_inputGrid[row]?[col]
+
+    setInputAt: (row, col, stack)->
+        @_height = Math.max @_height, row + 1
+        @_width = Math.max @_width, col + 1
+
+        @_inputGrid[row] ?= []
+        @_inputGrid[row][col] = stack
+        @_inputs[stack.item.id] = stack.item
+
+    # Object Overrides #############################################################################
+
+    toString: (options={})->
+        options.full ?= false
+
+        if options.full
+            b = new StringBuilder
+            b.loop (item for id, item of @inputs), delimiter:" + ", onEach:(b, item)=>
+                b.push @computeQuantityRequired(item), " ", item.displayName
+            b.push " ="
+            b.onlyIf @needsTools, (b)=>
+                b.push "("
+                b.loop (toolItem for id, toolItem of @tools), onEach:(b, toolItem)-> b.push toolItem.displayName
+                b.push ")"
+            b.push "=> "
+            b.loop @allProducts, delimiter:" + ", onEach:(b, stack)=>
+                b.push stack.quantity, " ", stack.item.displayName
+
+            return b.toString()
+        else
+            return "Recipe:#{@output}<#{@id}>"

src/client/models/crafting/recipe_node.coffee

@@ -1,87 +0,0 @@
-#
-# Crafting Guide - recipe_node.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-CraftingNode = require './crafting_node'
-Item         = require '../game/item'
-# ItemNode   = require './item_node' # don't include here, causes a cycle
-ItemSlug     = require '../game/item_slug'
-
-########################################################################################################################
-
-module.exports = class RecipeNode extends CraftingNode
-
-    @::ENTER_METHOD = 'onEnterRecipeNode'
-    @::LEAVE_METHOD = 'onLeaveRecipeNode'
-    @::TYPE = CraftingNode::TYPES.RECIPE
-
-    constructor: (options={})->
-        if not options.recipe? then throw new Error 'options.recipe is required'
-        super options
-
-        @recipe = options.recipe
-
-    # CraftingNode Overrides #######################################################################
-
-    _createChildren: (result=[])->
-        ItemNode = require './item_node' # include here to avoid a cycle
-
-        for stack in @recipe.input
-            item = @modPack.findItem stack.itemSlug
-            if not item?
-                name = @modPack.findName stack.itemSlug
-                item = new Item name:name, slug:stack.itemSlug, gatherable:true
-            result.push new ItemNode modPack:@modPack, item:item
-        return result
-
-    _checkCompleteness: ->
-        for child in @children
-            return false unless child.complete
-        return true
-
-    _checkValidity: ->
-        return false if @_isRepeatedRecipe()
-        return false if @_requiresToolBeingMade()
-
-        for child in @children
-            return false unless child.valid
-
-        return true
-
-    # Private Methods ##############################################################################
-
-    _isRepeatedRecipe: ->
-        nextParent = @parent
-        while nextParent?
-            return true if nextParent.recipe is @recipe
-            nextParent = nextParent.parent
-
-        return false
-
-    _requiresToolBeingMade: ->
-        for toolStack in @recipe.tools
-            toolSlug = toolStack.itemSlug
-
-            nextParent = @parent
-            while nextParent?
-                if ItemSlug.equal toolSlug, nextParent.item?.slug
-                    return true
-                nextParent = nextParent.parent
-
-        return false
-
-    # Object Overrides ############################################################################
-
-    toString: (options={})->
-        options.indent ?= ''
-        options.recursive ?= true
-
-        parts = ["#{options.indent}#{@completeText} #{@validText} RecipeNode for #{@recipe.slug}"]
-        nextIndent = options.indent + '    '
-        if options.recursive
-            for child in @children
-                parts.push child.toString indent:nextIndent
-        return parts.join '\n'

src/client/models/crafting/resources_evaluator.coffee

@@ -0,0 +1,45 @@
+#
+# Crafting Guide - resources_evaluator.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+Evaluator = require './evaluator'
+
+########################################################################################################################
+
+module.exports = class ResourcesEvaluator extends Evaluator
+
+    # Evaluator Overrides ##########################################################################
+
+    _computeRecipeScore: (recipe, evaluation)->
+        evaluation.baseScore = 0
+
+        for row in [0...recipe.height]
+            for col in [0...recipe.width]
+                stack = recipe.getInputAt row, col
+                continue unless stack?
+
+                inputEvaluation = @evaluateItem stack.item
+                if inputEvaluation?.baseScore?
+                    evaluation.baseScore += inputEvaluation.baseScore * stack.quantity
+                    evaluation.addBaseEvaluation inputEvaluation
+                else
+                    evaluation.baseScore = null
+                    logger.outdent()
+                    return
+
+        for id, extraStack of recipe.extras
+            extraEvaluation = @evaluateItem extraStack.item
+            continue unless extraEvaluation?.baseScore?
+            evaluation.baseScore -= extraStack.quantity * extraEvaluation.baseScore
+
+        for id, toolItem of recipe.tools
+            toolEvaluation = @evaluateItem toolItem
+            evaluation.addBaseEvaluation toolEvaluation
+
+        evaluation.baseScore = evaluation.baseScore / recipe.output.quantity
+
+    _computeGatherableItemScore: (item, evaluation)->
+        evaluation.baseScore = 1

src/client/models/crafting/resources_evaluator.test.coffee

@@ -0,0 +1,125 @@
+#
+# Crafting Guide - resources_evaluator.test.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+ResourcesEvaluator = require './resources_evaluator'
+fixtures           = require './fixtures'
+
+########################################################################################################################
+
+describe "ResourcesEvaluator", ->
+
+    beforeEach ->
+        @evaluator = new ResourcesEvaluator
+        @mod = fixtures.createMod()
+
+    describe 'evaluating a gatherable item', ->
+
+        beforeEach ->
+            @cobblestone = fixtures.configureCobblestone @mod
+            @evaluation = @evaluator.evaluateItem @cobblestone
+
+        it 'should return a score of 1 for each item', ->
+            # 1 cobblestone
+            @evaluation.computeTotalScore().should.equal 1
+
+    describe 'evaluating a first-level recipe', ->
+
+        beforeEach ->
+            @craftingTable = fixtures.configureCraftingTable @mod
+            @evaluation = @evaluator.evaluateItem @craftingTable
+
+        it 'should return a score which is the sum of all resources', ->
+            # 1 oak wood => 4 planks (1/4)
+            # 4 oak planks => 1 crafting table (4 * 1/4 = 1)
+            @evaluation.computeTotalScore().should.equal 1
+
+    describe 'evaluating a recipe which requires a tool', ->
+
+        beforeEach ->
+            @furnace = fixtures.configureFurnace @mod
+            @evaluation = @evaluator.evaluateItem @furnace
+
+        it 'includes the cost of the tool', ->
+            # 1 oak wood => 4 planks (1/4)
+            # 4 oak planks => 1 crafting table (4 * 1/4 = 1)
+            # 8 cobblestone =(crafting table)=> 1 furnace (8 + 1 = 9)
+            @evaluation.computeTotalScore().should.equal 9
+
+    describe 'evaluating a recipe where a tool requires a tool', ->
+
+        beforeEach ->
+            @ironIngot = fixtures.configureIronIngot @mod
+            @evaluation = @evaluator.evaluateItem @ironIngot
+
+        it 'should include both tools in the score', ->
+            # raw ingredients:
+            #     8 iron ore + 1 coal =(furnace)=> 8 iron ingots ((8 + 1) / 8 = 1.125)
+            # tools:
+            #     8 cobblestone =(crafting table)=> 1 furnace (8)
+            #     4 oak planks => 1 crafting table (4 * 1/4 = 1)
+            #         1 oak wood => 4 planks (1/4)
+            @evaluation.computeTotalScore().should.equal 10.125
+
+    describe 'evaluating a recipe which requires a tool multiple times', ->
+
+        beforeEach ->
+            @ironSword = fixtures.configureIronSword @mod
+            @evaluation = @evaluator.evaluateItem @ironSword
+
+        it 'should include the tool only once', ->
+            # raw ingredients:
+            #     1 oak wood ==> 4 planks (0.25)
+            #     2 oak planks ==> 4 sticks (0.125)
+            #     8 iron ore + 1 coal =(furnace)=> 8 iron ingots (1.125)
+            #     2 iron ingot + 1 stick =(crafting table)=> 1 iron sword (2.375)
+            #
+            # tools:
+            #     8 cobblestone =(crafting table)=> 1 furnace (8)
+            #
+            #     1 oak wood => 4 planks (0.25)
+            #     4 oak planks => 1 crafting table (1)
+            #
+            @evaluation.computeTotalScore().should.equal 11.375
+
+    describe 'evaluating a recipe which has a recursive recipe', ->
+
+        beforeEach ->
+            @ironBlock = fixtures.configureIronBlock @mod
+            @evaluation = @evaluator.evaluateItem @ironBlock
+
+        it 'should avoid the recursive recipes', ->
+            # raw ingredients:
+            #     8 iron ore + 1 coal =(furnace)=> 8 iron ingots ((8 + 1) / 8 = 1.125)
+            #     9 iron ingot =(crafting table)=> 1 iron block (10.125)
+            #
+            # tools:
+            #     8 cobblestone =(crafting table)=> 1 furnace (8)
+            #     4 oak planks => 1 crafting table (4 * 1/4 = 1)
+            #         1 oak wood => 4 planks (1/4)
+            @evaluation.computeTotalScore().should.equal 19.125
+
+    describe 'evaluating a recipe with multiple ouputs', ->
+
+        beforeEach ->
+            @cake = fixtures.configureCake @mod
+            @evaluation = @evaluator.evaluateItem @cake
+
+        it 'should discount the extra outputs', ->
+            # raw ingredients:
+            #    8 iron ore + 1 coal =(furnace)=> 8 iron ingot (1.125)
+            #    3 iron ingot =(crafting table)=> 1 bucket (3.375)
+            #    1 milk + 1 bucket ==> 1 milk bucket (4.375)
+            #    1 sugar cane ==> 1 sugar (1)
+            #    3 wheat + 1 egg + 2 sugar + 3 milk bucket =(crafting table)=> 1 cake, 3 buckets (9)
+            #
+            # furnace:
+            #    8 cobblestone =(crafting table)=> 1 furnace (8)
+            #
+            # crafting table
+            #    1 oak wood ==> 4 oak planks (0.25)
+            #    4 planks ==> 1 crafting table (1)
+            @evaluation.computeTotalScore().should.equal 18

src/client/models/crafting/simple_inventory.coffee

@@ -1,212 +0,0 @@
-#
-# Crafting Guide - simple_inventory.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-ItemSlug    = require '../game/item_slug'
-SimpleStack = require './simple_stack'
-
-########################################################################################################################
-
-module.exports = class SimpleInventory
-
-    constructor: (attributes={}, options={})->
-        @clear()
-
-        if options.modPack?
-            @modPack = options.modPack
-
-        if options.clone?
-            @addInventory options.clone
-
-    # Class Methods ################################################################################
-
-    @Delimiters =
-        Item: '.'
-        Stack: ':'
-
-    # Public Methods ###############################################################################
-
-    add: (itemSlug, quantity=1)->
-        return this unless quantity > 0
-
-        @_add itemSlug, quantity
-        return this
-
-    addInventory: (inventory)->
-        inventory.each (stack)=> @_add stack.itemSlug, stack.quantity
-        return this
-
-    clear: (options={})->
-        @_stacks = {}
-        @_itemSlugs = []
-
-    clone: ->
-        inventory = new SimpleInventory
-        inventory.addInventory this
-        return inventory
-
-    each: (callback)->
-        for itemSlug in @_itemSlugs
-            callback @_stacks[itemSlug]
-
-    getSlugs: ->
-        return @_itemSlugs[..]
-
-    hasAtLeast: (itemSlug, quantity=1)->
-        if quantity is 0 then return true
-
-        stack = @_stacks[itemSlug]
-        return false unless stack?
-        return stack.quantity >= quantity
-
-    localize: ->
-        if not @modPack? then throw new Error 'localize requires @modPack'
-
-        changed = false
-        newSlugs = []
-        newStacks = []
-        for itemSlug in @_itemSlugs
-            stack = @_stacks[itemSlug]
-            continue unless stack?
-
-            qualifiedSlug = if itemSlug.isQualified then itemSlug else null
-            if not qualifiedSlug?
-                qualifiedSlug = @modPack.findItem(itemSlug)?.slug
-                changed = qualifiedSlug?
-
-            if qualifiedSlug?
-                newSlugs.push qualifiedSlug
-                newStacks.push new SimpleStack itemSlug:qualifiedSlug, quantity:stack.quantity
-            else
-                newSlugs.push itemSlug
-                newStacks.push stack
-
-        if changed
-            @_itemSlugs = newSlugs
-            @_stacks = {}
-            for stack in newStacks
-                @_stacks[stack.itemSlug] = stack
-
-            @_sort()
-
-    pop: ->
-        itemSlug = @_itemSlugs.pop()
-        return null unless itemSlug?
-
-        stack = @_stacks[itemSlug]
-        delete @_stacks[itemSlug]
-
-        return stack
-
-    quantityOf: (itemSlug)->
-        stack = @_stacks[itemSlug]
-        return stack.quantity if stack
-        return 0
-
-    remove: (itemSlug, quantity=null)->
-        stack = @_stacks[itemSlug]
-        return this unless stack?
-
-        quantity ?= stack.quantity
-        return this unless quantity > 0
-
-        if stack.quantity < quantity
-            throw new Error "cannot remove #{quantity}: only #{stack.quantity} #{itemSlug} in this inventory"
-
-        stack.quantity -= quantity
-        if stack.quantity is 0
-            for currentItemSlug, index in @_itemSlugs
-                if ItemSlug.equal itemSlug, currentItemSlug
-                    @_itemSlugs.splice index, 1
-                    break
-
-        return this
-
-    # Parsing Methods ##############################################################################
-
-    parse: (data)->
-        return this if not data? or data.length is 0
-
-        stacks = data.split SimpleInventory.Delimiters.Stack
-        for stackText in stacks
-            stackParts = stackText.split SimpleInventory.Delimiters.Item
-            if stackParts.length is 2
-                quantity = parseInt stackParts[0], 10
-                itemSlug = ItemSlug.slugify stackParts[1]
-            else if stackParts.length is 1
-                quantity = 1
-                itemSlug = ItemSlug.slugify stackParts[0]
-            else
-                throw new Error "expected #{stackText} to have 0 or 1 parts"
-
-            if itemSlug.qualified.length > 0
-                @add itemSlug, quantity
-
-        return this
-
-    unparse: (options={})->
-        parts = []
-        @each (stack)=>
-            slugText = stack.itemSlug.item
-            if @modPack?
-                item = @modPack.findItem ItemSlug.slugify slugText
-                if item? and item.slug.qualified isnt stack.itemSlug.qualified
-                    slugText = stack.itemSlug.qualified
-
-            if stack.quantity is 1
-                parts.push slugText
-            else
-                parts.push "#{stack.quantity}#{SimpleInventory.Delimiters.Item}#{slugText}"
-
-        return parts.join SimpleInventory.Delimiters.Stack
-
-    # Property Methods #############################################################################
-
-    getIsEmpty: ->
-        return @_itemSlugs.length is 0
-
-    getTotalQuantity: ->
-        total = 0
-        @each (stack)->
-            total += stack.quantity
-        return total
-
-    Object.defineProperties @prototype,
-        isEmpty:       { get:@prototype.getIsEmpty }
-        totalQuantity: { get:@prototype.getTotalQuantity }
-
-    # Object Overrides #############################################################################
-
-    toString: ->
-        result = [@constructor.name, " (", @cid, ") {items: ["]
-
-        needsDelimiter = false
-        @each (stack)->
-            if needsDelimiter then result.push ', '
-            result.push stack.toString()
-            needsDelimiter = true
-        result.push ']'
-
-        result.push '}'
-        return result.join ''
-
-    # Private Methods ##############################################################################
-
-    _add: (itemSlug, quantity=1)->
-        return unless itemSlug?
-        return unless quantity > 0
-
-        stack = @_stacks[itemSlug]
-        if not stack?
-            stack = new SimpleStack itemSlug:itemSlug, quantity:quantity
-            @_stacks[itemSlug] = stack
-            @_itemSlugs.push itemSlug
-            @_sort()
-        else
-            stack.quantity += quantity
-
-    _sort: ->
-        @_itemSlugs.sort (a, b)-> ItemSlug.compare a, b

src/client/models/crafting/simple_stack.coffee

@@ -1,33 +0,0 @@
-#
-# Crafting Guide - simple_stack.coffee
-#
-# Copyright © 2014-2016 by Redwood Labs
-# All rights reserved.
-#
-
-ItemSlug = require '../game/item_slug'
-
-########################################################################################################################
-
-module.exports = class Stack
-
-    constructor: (attributes={}, options={})->
-        if not attributes.itemSlug? then throw new Error 'attributes.itemSlug is required'
-        attributes.quantity ?= 1
-
-        @itemSlug = attributes.itemSlug
-        @quantity = attributes.quantity
-
-    # Class Methods ################################################################################
-
-    @compare: (a, b)->
-        if a? and not b? then return -1
-        if not a? and b? then return +1
-        if a.quantity isnt b.quantity
-            return if a.quantity > b.quantity then -1 else +1
-        return ItemSlug.compare a.itemSlug, b.itemSlug
-
-    # Object Overrides #############################################################################
-
-    toString: ->
-        return "#{@quantity} #{@itemSlug}"

src/client/models/crafting/stack.coffee

@@ -0,0 +1,42 @@
+#
+# Crafting Guide - stack.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+########################################################################################################################
+
+module.exports = class Stack
+
+    constructor: (attributes={})->
+        @item = attributes.item
+        @quantity = attributes.quantity
+
+    # Properties ###################################################################################
+
+    Object.defineProperties @prototype,
+
+        item:
+            get: -> return @_item
+            set: (item)->
+                if not item? then throw new Error "item is required"
+                if @_item is item then return
+                if @_item? then throw new Error "item cannot be reassigned"
+                @_item = item
+
+        modPack:
+            get: -> return @_item.modPack
+            set: -> throw new Error "modPack cannot be replaced"
+
+        quantity:
+            get: -> return @_quantity
+            set: (quantity)->
+                quantity = parseInt "#{quantity}"
+                quantity = if Number.isNaN(quantity) then 0 else Math.max(0, quantity)
+                @_quantity = quantity
+
+    # Object Overrides #############################################################################
+
+    toString: ->
+        return "Stack:#{@item}×#{@quantity}"

src/client/models/crafting/steps_evaluator.coffee

@@ -0,0 +1,43 @@
+#
+# Crafting Guide - steps_evaluator.coffee
+#
+# Copyright © 2014-2016 by Redwood Labs
+# All rights reserved.
+#
+
+Evaluator = require './evaluator'
+
+########################################################################################################################
+
+module.exports = class StepsEvaluator extends Evaluator
+
+    # Evaluator Overrides ##########################################################################
+
+    _computeRecipeScore: (recipe, evaluation)->
+        evaluation.score = 0
+
+        for id, stack of recipe.inputs
+            inputEvaluation = @evaluateItem stack.item
+            if not inputEvaluation?.score?
+                evaluation.score = null
+                return
+
+            evaluation.addBaseEvaluation inputEvaluation
+            evaluation.score = Math.min evaluation.score, inputEvaluation.score + 1
+
+        for id, item of recipe.tools
+            continue if evaluation.isToolIncluded item
+
+            toolEvaluation = @evaluateItem stack.item
+            if not toolEvaluation?.score?
+                evaluation.score = null
+                return
+
+            evaluation.addBaseEvaluation evaluation
+            evaluation.addIncludedTool item
+            evaluation.score += toolEvaluation.score
+
+        return result
+
+    _computeGatherableItemScore: (item, evaluation)->
+        evaluation.score = 0

src/client/models/game/mod_version.coffee

@@ -157,7 +157,7 @@ module.exports = class ModVersion extends BaseModel
         for recipe in primaryRecipes
             result.push recipe
 
-        if not options.onlyPrimary
+        if not options.onlyPrimary and result.length is 0
             for recipe in otherRecipes
                 result.push recipe
 

src/client/models/game/mod_version.test.coffee

@@ -90,12 +90,17 @@ describe 'mod_version.coffee', ->
                     recipe:; input: Cake Slice; pattern: 000 000 000; onlyIf: item Cake Slice
                 item: Bucket
                     recipe:; input: Iron Ingot; pattern: ... 0.0 .0.
+                    recipe:; input: Copper Ingot; pattern: ... 0.0 .0.; extras: Copper Nugget
             """
 
         it 'finds all recipes which list item as output', ->
             recipes = modVersion.findRecipes ItemSlug.slugify('test__bucket')
-            (r.output[0].itemSlug.item for r in recipes).sort().should.eql ['bucket', 'cake', 'cake']
+            (r.output[0].itemSlug.item for r in recipes).sort().should.eql ['bucket', 'bucket']
 
         it 'skip recipes whose conditions are not met', ->
             recipes = modVersion.findRecipes ItemSlug.slugify('test__cake')
             recipes.length.should.equal 2
+
+        it 'finds recipes for items which are only ever extras', ->
+            recipes = modVersion.findRecipes ItemSlug.slugify('test__copper_nugget')
+            recipes.length.should.equal 1