using Godot;
using System;
using System.Collections.Generic;
using System.Linq;
using static GameData;

public partial class World : Node3D
{
	public Dictionary<string, MeshInstance3D> tileMeshes;
	public Dictionary<string, MeshInstance3D> decorationMeshes;
	public Dictionary<string, List<Placeholder>> tilePlaceholders;
	PackedScene layerPrefab = ResourceLoader.LoadLayerPrefab();
	private Dictionary<string, MultiMeshInstance3D> multiMeshes = new();
	private Dictionary<string, Mesh> meshLibrary = new();
	Layer[] map;
	Layer layerNode;
	// Called when the node enters the scene tree for the first time.
	public override void _Ready()
	{
		WFC.FillAdjacencies();
		tileMeshes = ResourceLoader.LoadTiles();
		decorationMeshes = ResourceLoader.LoadDecorations();
		tilePlaceholders = new Dictionary<string, List<Placeholder>>();
		foreach (var kvp in tileMeshes)
		{
			tilePlaceholders.Add(kvp.Key, new List<Placeholder>());
			foreach (MeshInstance3D child in kvp.Value.GetChildren())
			{
				tilePlaceholders[kvp.Key].Add(new Placeholder(child.Name, child.Transform.Origin));
			}
			var temp = kvp.Value;
			meshLibrary[kvp.Key] = temp.Mesh;
			temp.QueueFree();
		}
		foreach (var kvp in meshLibrary)
		{
			var mm = new MultiMesh();
			mm.Mesh = kvp.Value;
			mm.TransformFormat = MultiMesh.TransformFormatEnum.Transform3D;

			var instance = new MultiMeshInstance3D();
			instance.Multimesh = mm;

			AddChild(instance);
			multiMeshes[kvp.Key] = instance;
		}
		map = new Layer[ruinSize];
		GenerateWorld();
		GD.Print("World generated");
		BuildMeshesForLayer(0);
	}

	// Called every frame. 'delta' is the elapsed time since the previous frame.
	public override void _Process(double delta)
	{
		if (Input.IsActionJustPressed("layer_up") && currentLayer > 0) currentLayer--;
		if (Input.IsActionJustPressed("layer_down") && currentLayer < ruinSize - 1) currentLayer++;
		if (currentLayer != visibleLayer)
		{
			BuildMeshesForLayer(currentLayer);
			visibleLayer = currentLayer;
		}
	}

	private void GenerateWorld()
	{
		DateTime now = DateTime.Now;
		for (int layer = 0; layer < ruinSize; layer++)
		{
			layerNode = layerPrefab.Instantiate<Layer>();
			AddChild(layerNode);
			layerNode.SetupLayer(layerSize, layer, tileMeshes);
			map[layer] = layerNode;
		}
		GD.Print("Time for map generation: " + (DateTime.Now - now).Seconds);
	}

	private void BuildMeshesForLayer(int layerIndex)
	{
		foreach (MultiMeshInstance3D mm in multiMeshes.Values)
		{
			mm.Multimesh.InstanceCount = 0;
		}

		Layer layer = map[layerIndex];

		Dictionary<string, List<Transform3D>> batches = new();

		for (int x = 0; x < layerSize; x++)
		{
			for (int y = 0; y < layerSize; y++)
			{
				Tile tile = layer.tiles[x, y];
				string key = tile.collapsedMesh;

				if (!batches.ContainsKey(key))
					batches[key] = new List<Transform3D>();

				batches[key].Add(new Transform3D(
					Basis.Identity,
					tile.Position
				));
			}
		}

		foreach (var kvp in batches)
		{
			MultiMesh mm = multiMeshes[kvp.Key].Multimesh;
			List<Placeholder> placeholders = tilePlaceholders[kvp.Key];
			List<Transform3D> list = kvp.Value;

			mm.InstanceCount = list.Count;

			for (int i = 0; i < list.Count; i++)
			{
				mm.SetInstanceTransform(i, list[i]);
				if (placeholders.Count > 0)
				{
					Node3D decoration;

					Mesh mesh = decorationMeshes.Values.ToList()[0].Mesh;
					for(int j = 0; j < placeholders.Count; j++)
					{
						foreach (MeshInstance3D meshes in decorationMeshes.Values)
						{
							if (meshes.Name.ToString().ToLower() == placeholders[j].name.ToLower())
							{
								mesh = meshes.Mesh;
								break;
							}
						}
						decoration = new MeshInstance3D();
						(decoration as MeshInstance3D).Mesh = mesh;
						if (placeholders[j].name.ToLower() == "light")
						{
							GD.Print("Adding OmniLight");
							decoration.AddChild(new OmniLight3D()
							{
								OmniAttenuation = 2f,
								LightColor = new Color("#eae7ad"),
								ShadowEnabled = true,
								LightEnergy = 5f,
								LightIndirectEnergy = 1.5f,
								Position = new Vector3(0.5f, 0, 0)
							});
						}
						decoration.Transform = list[i];
						decoration.Position += placeholders[j].pos;
						decoration.Name = placeholders[j].name + j;
						decoration.Rotate(Vector3.Up, Mathf.DegToRad(-90));
						layer.AddChild(decoration);
					}
				}
			}
		}
	}
}