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

public partial class Tile
{
	public Dictionary<string, MeshInstance3D> tileMeshes;
	public string collapsedMesh;
	Random rand = new Random();
	public Vector3 Position;
	public Vector2I GridPosition;
	public Node3D DecorationNode;

	public void SetMeshes(Dictionary<string, MeshInstance3D> tileMeshes)
	{
		this.tileMeshes = new Dictionary<string, MeshInstance3D>(tileMeshes);
	}

	public string Collapse(string tile)
	{
		if (collapsedMesh != null) return "";
		if (tileMeshes.Keys.Count <= 0) return "ERR";
		collapsedMesh = (tile.Length > 0) ? tile : ChooseWeighted();
		tileMeshes.Clear();
		return collapsedMesh;
	}

	private string ChooseWeighted()
	{
		float totalWeight = 0f;

		foreach (string tile in tileMeshes.Keys)
		{
			totalWeight += WFC.weights[tile];
		}

		float r = (float)(rand.NextDouble() * totalWeight);

		float cumulative = 0f;

		foreach (string tile in tileMeshes.Keys)
		{
			cumulative += WFC.weights[tile];

			if (r <= cumulative)
				return tile;
		}

		return "junction";
	}

	public int Propagate(HashSet<string> possibleKeys)
	{
		int amountRemoved = 0;
		if (collapsedMesh != null) return 0;
		foreach (string key in tileMeshes.Keys.ToList())
		{
			if (!possibleKeys.Contains(key))
			{
				tileMeshes.Remove(key);
				amountRemoved++;
			}
		}
		if (tileMeshes.Count == 0) return int.MaxValue;
		return amountRemoved;
	}

	public void Reset(Dictionary<string, MeshInstance3D> tileMeshes)
	{
		collapsedMesh = null;
		SetMeshes(tileMeshes);
	}
}