Complete basic crafting functionality

src/scripts/models/inventory.coffee

@@ -17,14 +17,19 @@ module.exports = class Inventory extends BaseModel
         super attributes, options
         @clear()
 
+        Object.defineProperty this, 'isEmpty', get:-> @_names.length is 0
+
     # Public Methods ###############################################################################
 
     add: (name, quantity=1)->
+        return if quantity is 0
+
         item = @_items[name]
         if not item?
             item = new Item name:name, quantity:quantity
             @_items[name] = item
             @_names.push name
+            @_names.sort()
         else
             item.quantity += quantity
 
@@ -32,10 +37,19 @@ module.exports = class Inventory extends BaseModel
         @trigger Event.change, this
         return this
 
+    addInventory: (inventory)->
+        inventory.each (item)=> @add item.name, item.quantity
+        return this
+
     clear: ->
         @_items = {}
         @_names = []
 
+    clone: ->
+        inventory = new Inventory
+        @each (item)-> inventory.add item.name, item.quantity
+        return inventory
+
     each: (onItem)->
         for name in @_names
             item = @_items[name]
@@ -48,7 +62,25 @@ module.exports = class Inventory extends BaseModel
         return false unless item?
         return item.quantity >= quantity
 
+    pop: ->
+        name = @_names.pop()
+        return null unless name?
+
+        item = @_items[name]
+        delete @_items[name]
+
+        @trigger Event.remove, this, item.name, item.quantity
+        @trigger Event.change, this
+        return item
+
+    quantityOf: (name)->
+        item = @_items[name]
+        return 0 unless item?
+        return item.quantity
+
     remove: (name, quantity=1)->
+        return if quantity is 0
+
         item = @_items[name]
         if not item? then throw new Error "cannot remove #{name} since it is not in this inventory"
         if item.quantity < quantity
@@ -63,13 +95,22 @@ module.exports = class Inventory extends BaseModel
         @trigger Event.change, this
         return this
 
+    toList: ->
+        result = []
+        @each (item)->
+            if item.quantity > 1
+                result.push [item.quantity, item.name]
+            else
+                result.push item.name
+        return result
+
     # Object Overrides #############################################################################
 
     toString: ->
         result = [@constructor.name, " (", @cid, ") { items: ["]
 
         needsDelimiter = false
-        for name, item of @_items
+        @each (item)->
             if needsDelimiter then result.push ', '
             result.push item.toString()
             needsDelimiter = true