//@INFO: Compatibility for Id colliding mods
//@DESC: Rewrite item ids to fake ones so that broken mods still show up
//@VER: 1
//@AFTER: unzip

using System;
using System.IO;
using System.Reflection;
using UnityEngine;
using Patchwork;
using System.Linq;
using System.Collections.Generic;
using MessagePack;
using static ChaListDefine;


public class FakeID : ScriptEvents
{
	const int FAKE_BASE = -100;
	public override void Start()
	{
		InitListInfo();
	}

	// ids to never rewrite as those are treated specially by the game
	public static bool exempt(CategoryNo cat, int id)
	{
		if (cat < 0)
			return true;
		if (id == -1)
			return true;
		if (id != 0 && id != 1)
			return false;
		//unfortunately some mods do this. for id 1/2. what now?
		if ((cat >= CategoryNo.co_top && cat <= CategoryNo.co_shoes))
			return true;
		if (cat >= CategoryNo.cpo_sailor_a && cat <= CategoryNo.cpo_sailor_c)
			return true;
		if (cat >= CategoryNo.cpo_jacket_a && cat <= CategoryNo.cpo_jacket_c)
			return true;
		return false;
	}

	// (re)load the listinfos
	public static IdMap idMap;
	public void InitListInfo()
	{
		idMap = new IdMap();
		if (Manager.Character.Instance != null)
		{
			Manager.Character.Instance.chaListCtrl = new ChaListControl();
			Manager.Character.Instance.chaListCtrl.LoadListInfoAll();
		}
	}

	override public void OnSetListInfo(ListInfoBase lib)
	{
		lib.Id = idMap.NewFake(lib.Category, lib.Id, lib.Clone());
	}

	public class IdMap
	{
		public int counter = FAKE_BASE;
		// map a real <cat,id> pair to list of fake ids
		public Dictionary<KeyValuePair<int, int>, List<int>> real2fake = new Dictionary<KeyValuePair<int, int>, List<int>>();
		// map one fake id to real <cat,id,dist> (all contained in infobase)
		public Dictionary<int, ListInfoBase> fake2real = new Dictionary<int, ListInfoBase>();
		public int NewFake(int cat, int realid, ListInfoBase data)
		{
			if (exempt((CategoryNo)cat, realid))
				return realid;
			var realpair = new KeyValuePair<int, int>(cat, realid);
			List<int> fakeids;
			if (!real2fake.TryGetValue(realpair, out fakeids))
				fakeids = real2fake[realpair] = new List<int>();
			// already added?
			foreach (var item in fakeids)
				if (fake2real[item].Distribution2 == data.Distribution2)
					return item;
			// otherwise make a new fake
			int fakeid = --counter;
			fakeids.Add(fakeid);
			fake2real[fakeid] = data;
			return fakeid;
		}
	}

	[MessagePackObject(true)]
	public class GuidMap
	{
		[MessagePackObject(true)]
		public class Item
		{
			public string guid;
			public int cat;
			public int id;
			public string prop;
		}
		public Dictionary<string, Item> items = new Dictionary<string, Item>();

		// translate real to fake, taking into account guid hints.
		// if no hint is present, first fake is used
		public int GetFake(string prop, int cat, int id)
		{
			Item item;
			List<int> candidates;
			if (exempt((CategoryNo)cat, id) || id < 0)
				return id;
			var realpair = new KeyValuePair<int, int>(cat, id);
			if (items.TryGetValue(prop, out item))
			{
				if (idMap.real2fake.TryGetValue(realpair, out candidates))
				{
					var match = candidates.FirstOrDefault((x) => idMap.fake2real[x].Distribution2 == item.guid);
					if (match != 0)
						return match;
				}
			}
			// nothing found via our guid mappings, so default to a first fake we encounter
			if (idMap.real2fake.TryGetValue(realpair, out candidates))
				return candidates.FirstOrDefault();

			print($"Failed to translate real to fake prop={prop} cat={cat} id={id}");

			return id;// int.MaxValue;
		}

		// translate fake id to a real one. at the same time, record guid usage.
		public int GetReal(string prop, int cat, int id)
		{
			ListInfoBase lib;
			if (exempt((CategoryNo)cat, id) || id >= FAKE_BASE)
				return id;
			if (!idMap.fake2real.TryGetValue(id, out lib) || lib.Category != cat)
			{
				print($"Failed to translate fake to real prop={prop} cat({cat}), id={id}");
				return id;
			}
			if (lib.Distribution2.IsNullOrEmpty())
			{ // if no guid now, nuke the mapping
				items.Remove(prop);
			}
			else
			{
				items[prop] = new Item()
				{
					guid = lib.Distribution2,
					cat = cat,
					id = lib.Id,
					prop = prop
				};
			}
			return lib.Id;
		}
	}

	public GuidMap map;
	public bool tofake;
	public int rewrite(string prefix, int cat, int id, string name) => tofake ? map.GetFake(prefix, cat, id) : map.GetReal(prefix, cat, id);


	// traverse object and rewrite ids
	public void traverse(string prefix, object root, int currIdx = 0)
	{
		if (root == null) return;
		var t = root.GetType();

		if (t.IsArray)
		{
			var arr = root as Array;
			int idx = 0;
			if (arr != null && !t.GetElementType().IsBasic())
				foreach (var sub in arr)
					traverse($"{prefix}[{idx}]", sub, idx++);
			return;
		}

		foreach (var mem in t.GetVars(!tofake))
		{
			var mt = mem.GetVarType();
			if (mt == null) continue;
			var name = mem.GetName();

			if (name == "pattern" || name == "id" || name.EndsWith("Id"))
			{
				CatHint hint = null;
				if (!mem.GetAttr(ref hint))
					continue;
				hint.Reset();
				var cat = hint.Get(root, mem, currIdx);
				var val = mem.GetValue(root);
				var arr = val as Array;
				if (mt == typeof(int))
					mem.SetValue(root, rewrite(prefix + "." + name, cat, (int)val, name));
				else if (arr != null && mt.GetElementType() == typeof(int))
					for (int i = 0; i < arr.Length; i++)
						arr.SetValue(rewrite($"{prefix}.{name}[{i}]", hint.Next(), (int)arr.GetValue(i), name), i);
			}
			else if (name == "parts" || name == "pupil" || mt.CachedGetMethod("SaveBytes") != null || mt.HasAttr<MessagePackObjectAttribute>())
				traverse(prefix + "." + name, mem.GetValue(root));
		}
	}

	public override void OnCardLoad(ChaFile f, BlockHeader bh, bool nopng, bool nostatus)
	{
		map = f.dict.Get<GuidMap>("guidmap");
		tofake = true;
		traverse("coordinate",f.coordinate);
		traverse("custom",f.custom);
	}

	// rewrite our fake ids to the actual real ones again
	public override void OnCardSave(ChaFile f, BinaryWriter w, List<object> blocks, bool nopng)
	{
		if (f.dict == null)
			Debug.Log("dict is null");
		map = f.dict.Get<GuidMap>("guidmap");
		if (map == null)
			Debug.Log("map is null");
		map.items.Clear(); // guid mappings will be be-regenerated
		tofake = false;
		foreach (var b in blocks)
		{
			if ((b is Array) && b.GetType().GetElementType() == typeof(ChaFileCoordinate))
				traverse("coordinate", b);
			else if (b is ChaFileCustom)
				traverse("custom", b);
		}
	}
}