using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.Json;
using Microsoft.Xna.Framework.Graphics;

namespace FreedomFighter;

/// <summary>
/// Port of TOmegaMap, loading the JSON files converted from the .omap format.
/// Only Layer1 pattern indices and triggers are used by the game.
/// </summary>
public class GameMap
{
    public int WidthCount;
    public int HeightCount;
    public int TileWidth = 32;
    public int TileHeight = 32;
    public int[][] Layer1 = [];             // [x][y] -> tileset pattern index, -1 = empty
    public string?[,] TriggerActions = new string?[0, 0];
    public OmegaImage? Tileset;

    readonly GraphicsDevice _gd;
    readonly string _contentDir;
    readonly Dictionary<string, OmegaImage> _tilesetCache = new();

    public GameMap(GraphicsDevice gd, string contentDir)
    {
        _gd = gd;
        _contentDir = contentDir;
    }

    record TriggerJson(int x, int y, string name, string action);
    record MapJson(int widthCount, int heightCount, string oil, int tileWidth, int tileHeight,
        int[][] layer1, TriggerJson[] triggers);

    public void LoadMap(string mapName)
    {
        string path = Path.Combine(_contentDir, "maps", Path.GetFileNameWithoutExtension(mapName) + ".json");
        var m = JsonSerializer.Deserialize<MapJson>(File.ReadAllText(path))!;

        WidthCount = m.widthCount;
        HeightCount = m.heightCount;
        TileWidth = m.tileWidth;
        TileHeight = m.tileHeight;
        Layer1 = m.layer1;

        TriggerActions = new string?[WidthCount, HeightCount];
        foreach (var t in m.triggers)
            TriggerActions[t.x, t.y] = t.action;

        string tilesetFile = Path.GetFileNameWithoutExtension(m.oil).ToLowerInvariant() + "_00.png";
        if (!_tilesetCache.TryGetValue(tilesetFile, out var tileset))
        {
            tileset = OmegaImage.Load(_gd, Path.Combine(_contentDir, "tilesets", tilesetFile), TileWidth, TileHeight, m.oil);
            _tilesetCache[tilesetFile] = tileset;
        }
        Tileset = tileset;
    }
}