using System;
using System.Linq;
using System.Collections.Generic;
using Oxide.Core;
using UnityEngine;

namespace Oxide.Plugins {
    [Info("PlantBiomeCustomizer", "TungstonMiner", "1.0.0")]
    [Description("Customize placement of plants around the map by biome")]
    public class PlantBiomeTuner : RustPlugin {

        // Config //////////////////////////////////////////////////////////////////////////////////

        PluginConfig configData;

        public class PluginConfig {
            // Key = arbitrary rule name (e.g., "berry_blue", "pumpkins_desert", etc.), value = rule definition.
            public Dictionary<string, PlantRule> rules = new Dictionary<string, PlantRule>();
            public static PluginConfig Default() { return new PluginConfig(); }
        }

        public class PlantRule {
            public bool enabled = true;
            public string[] prefabFilters = Array.Empty<string>(); // case-insensitive substrings matched against population identity
            public string[] biomes = Array.Empty<string>();        // names matching TerrainMeta.BiomeType flags
            public float densityMultiplier = 1.0f;                 // multiply existing density/weights
        }

        protected override void LoadDefaultConfig() {
            configData = PluginConfig.Default();
            SaveConfig();
        }

        protected override void SaveConfig() {
            Config.WriteObject(configData, true);
        }

        protected override void LoadConfig() {
            base.LoadConfig();
            try {
                configData = Config.ReadObject<PluginConfig>();
            } catch {
                PrintError("Config read error; generating new default config.");
                configData = PluginConfig.Default();
            }
            SaveConfig();
        }


        // Hooks ///////////////////////////////////////////////////////////////////////////////////

        void OnServerInitialized(bool initial) {
            NextTick(ApplyAll);
        }


        // Commands ////////////////////////////////////////////////////////////////////////////////

        [ConsoleCommand("plantbiometuner.apply")]
        void CmdApply(ConsoleSystem.Arg arg) {
            if (!arg.IsAdmin) return;
            ApplyAll();
            arg.ReplyWith("PlantBiomeTuner: applied settings and refilled populations.");
        }

        // Core Logic //////////////////////////////////////////////////////////////////////////////

        void ApplyAll() {
            int changed = 0;
            int matched = 0;

            var populations = Resources.FindObjectsOfTypeAll<SpawnPopulation>();
            if (populations == null || populations.Length == 0) {
                PrintWarning("No SpawnPopulation objects found (map not ready yet?). Will retry next tick.");
                NextTick(ApplyAll);
                return;
            }

            if (configData.rules == null || configData.rules.Count == 0) {
                Puts("PlantBiomeTuner: no rules configured.");
                return;
            }

            foreach (var kv in configData.rules) {
                string ruleKey = kv.Key;
                PlantRule rule = kv.Value;
                if (rule == null || !rule.enabled) continue;

                var filters = (rule.prefabFilters ?? Array.Empty<string>())
                              .Where(s => !string.IsNullOrWhiteSpace(s))
                              .Select(s => s.Trim())
                              .ToArray();
                if (filters.Length == 0) continue;

                int biomeMask = BuildBiomeMask(rule.biomes);
                if (biomeMask == 0) {
                    PrintWarning($"[{ruleKey}] Biome mask is empty; skipping.");
                    continue;
                }

                foreach (var population in populations) {
                    if (population == null) continue;

                    string id = GetPopulationIdentity(population);
                    if (string.IsNullOrEmpty(id)) continue;

                    if (!filters.Any(f => id.IndexOf(f, StringComparison.OrdinalIgnoreCase) >= 0)) continue;

                    matched++;

                    try {
                        bool anyChange = false;
                        anyChange |= TrySetBiomeMask(population, biomeMask);
                        anyChange |= TrySetDensity(population, rule.densityMultiplier);

                        if (anyChange) {
                            changed++;
                            Puts($"[{ruleKey}] Updated '{id}' (biomes={string.Join(",", rule.biomes)}, density x{rule.densityMultiplier:0.##})");
                        }
                    } catch (Exception e) {
                        PrintWarning($"[{ruleKey}] Failed to update '{id}': {e.Message}");
                    }
                }
            }

            try {
                ConsoleSystem.Run(ConsoleSystem.Option.Server, "spawn.delete_populations");
                ConsoleSystem.Run(ConsoleSystem.Option.Server, "spawn.fill_populations");
            } catch (Exception e) {
                PrintWarning($"Failed to refill populations: {e.Message}");
            }

            Puts($"PlantBiomeTuner: matched {matched} populations; applied changes to {changed}.");
        }

        int BuildBiomeMask(IEnumerable<string> names) {
            if (names == null) return 0;
            int mask = 0;
            foreach (var n in names) {
                if (string.IsNullOrWhiteSpace(n)) continue;
                try {
                    var value = (TerrainMeta.BiomeType)Enum.Parse(typeof(TerrainMeta.BiomeType), n.Trim(), true);
                    mask |= (int)value; // combine provided flags; no manual shifts
                } catch {
                    PrintWarning($"Unknown biome '{n}'. Ensure names match TerrainMeta.BiomeType.");
                }
            }
            return mask;
        }

        string GetPopulationIdentity(SpawnPopulation population) {
            try {
                var res = population.Resource;
                if (res != null) {
                    var prefab = res.prefab;
                    if (prefab != null) {
                        var path = prefab.resourcePath;
                        if (!string.IsNullOrEmpty(path)) return path;
                    }
                }
            } catch {
                // ignore
            }
            return population.name ?? population.GetType().Name;
        }

        bool TrySetBiomeMask(SpawnPopulation population, int biomeMask) {
            bool changed = false;

            var field = population.GetType().GetField("BiomePreference") ??
                population.GetType().GetField("TopologyPreference");
            if (field != null && field.FieldType == typeof(int)) {
                int current = (int) field.GetValue(population);
                if (current != biomeMask) {
                    field.SetValue(population, biomeMask);
                    changed = true;
                }
                return changed;
            }

            var prop = population.GetType().GetProperty("BiomePreference");
            if (prop != null && prop.PropertyType == typeof(int) && prop.CanWrite) {
                int current = (int) (prop.GetValue(population) ?? 0);
                if (current != biomeMask) {
                    prop.SetValue(population, biomeMask, null);
                    changed = true;
                }
                return changed;
            }

            return false;
        }

        bool TrySetDensity(SpawnPopulation population, float multiplier) {
            if (Mathf.Approximately(multiplier, 1f)) return false;

            bool changed = false;

            var densityField = population.GetType().GetField("Density");
            if (densityField != null && densityField.FieldType == typeof(float)) {
                float d = (float)densityField.GetValue(population);
                float nd = Mathf.Max(0f, d * multiplier);
                if (!Mathf.Approximately(d, nd)) {
                    densityField.SetValue(population, nd);
                    changed = true;
                }
            }

            var sptField = population.GetType().GetField("SpawnPerTick");
            if (sptField != null && sptField.FieldType == typeof(float)) {
                float v = (float)sptField.GetValue(population);
                float nv = Mathf.Max(0f, v * multiplier);
                if (!Mathf.Approximately(v, nv)) {
                    sptField.SetValue(population, nv);
                    changed = true;
                }
            }

            var clusterField = population.GetType().GetField("ClusterDensities");
            if (clusterField != null && typeof(float[]).IsAssignableFrom(clusterField.FieldType)) {
                var arr = (float[])clusterField.GetValue(population);
                if (arr != null && arr.Length > 0) {
                    for (int i = 0; i < arr.Length; i++) arr[i] = Mathf.Max(0f, arr[i] * multiplier);
                    changed = true;
                }
            }

            return changed;
        }
    }
}