using System;
using System.Collections.Generic;
using System.Reflection;
using System.Xml;
using System.Xml.Serialization;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using MonoGame.Extended.Tiled.Serialization;

namespace MonoGame.Extended.Tiled
{
    public class TMXLoader
    {
        private readonly string _fileName;

        public delegate Texture2D TextureLoader(string source);
        public delegate XmlReader XmlLoader(string source);
        
        private TextureLoader _textureLoader;
        private XmlLoader _xmlLoader;

        private TMXLoader(string path, TextureLoader textureLoader, XmlLoader xmlLoader)
        {
            _fileName = path;

            _textureLoader = textureLoader;
            _xmlLoader = xmlLoader;

            Console.WriteLine($"TMX Loader: {path}");
        }

        private TiledMapObjectLayer ConvertTiledMapObjectLayer(TiledMap tiledMap
            , TiledMapObjectLayerContent lc)
        {
            List<TiledMapObject> objects = new List<TiledMapObject>();

            for (int i = 0; i < lc.Objects.Count; i++)
            {
                TiledMapObjectContent c = lc.Objects[i];

                if (c.Ellipse != null)
                {
                    // Not supported
                }
                else if (c.Polygon != null)
                {
                    // TODO
                    // List<Point2> points = new List<Point2>();
                    // var ob = new TiledMapPolygonObject(c.Identifier, c.Name, null, new Size2(c.Width, c.Height), new Vector2(c.X, c.Y), c.Rotation,  1.0f, c.Visible, c.Type );
                    // objects.Add(ob);
                }
                else if (c.Polyline != null)
                {
                    // TODO
                }
                else
                {
                    TiledMapTileset tileSet = tiledMap.GetTilesetByTileGlobalIdentifier((int) c.GlobalIdentifier);
                    if (tileSet != null)
                    {
                        var fgi = tiledMap.GetTilesetFirstGlobalIdentifier(tileSet);
                        int localIdentifier = (int) (c.GlobalIdentifier - fgi);
                        TiledMapTilesetTile tile = null;

                        foreach (var t in tileSet.Tiles)
                        {
                            if (t.LocalTileIdentifier == localIdentifier)
                            {
                                tile = t;
                                break;
                            }
                        }

                        // Copy properties

                        var tmo = new TiledMapTileObject(c.Identifier, c.Name, tileSet, tile,
                            new Vector2(c.Width, c.Height), new Vector2(c.X, c.Y), c.Rotation
                            , 1.0f, c.Visible, c.Type);

                        foreach (var prop in c.Properties)
                        {
                            tmo.Properties.Add(prop.Name, prop.Value);
                        }

                        objects.Add(tmo);
                    }
                    else
                    {
                        Console.WriteLine($"Warning: no tileset for object gid {c.GlobalIdentifier}");
                    }
                }
            }

            TiledMapObjectLayer layer = new TiledMapObjectLayer(lc.Name, objects.ToArray(),
                ColorHelper.FromHex(lc.Color),
                (TiledMapObjectDrawOrder) lc.DrawOrder,
                new Vector2(lc.OffsetX, lc.OffsetY), lc.Opacity, lc.Visible);

            return layer;
        }

        private TiledMapTileLayer ConvertTiledMapTileLayer(TiledMap tiledMap, TiledMapTileLayerContent lc)
        {
            TiledMapTileLayer layer = new TiledMapTileLayer(lc.Name, lc.Width, lc.Height, tiledMap.TileWidth,
                tiledMap.TileHeight, null, lc.Opacity, lc.Visible);

            // Copy properties

            foreach (var prop in lc.Properties)
            {
                layer.Properties.Add(prop.Name, prop.Value);
            }

            // Copy tiles

            if (lc.Data.Encoding == "csv")
            {
                string[] tileIds = lc.Data.Value.Split(",");

                int offs = 0;
                for (ushort y = 0; y < layer.Height; y++)
                {
                    for (ushort x = 0; x < layer.Width; x++)
                    {
                        layer.Tiles[offs] = new TiledMapTile(uint.Parse(tileIds[offs]), x, y);
                        offs++;
                    }
                }
            }

            return layer;
        }

        private TiledMapTileset ConvertTiledMapTileset(TiledMapTilesetContent tsc)
        {
            var texture = _textureLoader(tsc.Image.Source);
            
            var ts = new TiledMapTileset(texture, tsc.TileWidth, tsc.TileHeight, tsc.TileCount, tsc.Spacing, tsc.Margin,
                tsc.Columns);
            foreach (var t in tsc.Tiles)
            {
                // TODO: Objects?

                TiledMapTilesetTile tile;

                if (t.Frames.Count == 0)
                {
                    tile = new TiledMapTilesetTile(t.LocalIdentifier, t.Type, null);
                }
                else
                {
                    // Animation frames

                    TiledMapTilesetTileAnimationFrame[] frames = new TiledMapTilesetTileAnimationFrame[t.Frames.Count];

                    for (int i = 0; i < t.Frames.Count; i++)
                    {
                        var frameContent = t.Frames[i];

                        BindingFlags bindingFlags = BindingFlags.NonPublic | BindingFlags.Instance;
                        object[] parameters = {ts, frameContent.TileIdentifier, frameContent.Duration};

                        object instantiatedType =
                            Activator.CreateInstance(typeof(TiledMapTilesetTileAnimationFrame),
                                bindingFlags,
                                null, parameters, null);

                        frames[i] = (TiledMapTilesetTileAnimationFrame) instantiatedType;
                    }

                    tile = new TiledMapTilesetAnimatedTile(t.LocalIdentifier, frames, t.Type, null);
                }

                // Copy properties

                foreach (var prop in t.Properties)
                {
                    tile.Properties[prop.Name] = prop.Value;
                }

                ts.Tiles.Add(tile);
            }

            foreach (var prop in tsc.Properties)
            {
                ts.Properties[prop.Name] = prop.Value;
            }

            return ts;
        }

        private TiledMap ConvertTiledMap()
        {
            var xmlSerializer = new XmlSerializer(typeof(TiledMapContent));
            var xmlReader = _xmlLoader(_fileName);
            
            TiledMapContent tiledMapContent = (TiledMapContent) xmlSerializer.Deserialize(xmlReader);

            TiledMap tiledMap = new TiledMap(tiledMapContent.Name, tiledMapContent.Width, tiledMapContent.Height,
                tiledMapContent.TileWidth, tiledMapContent.TileHeight,
                (TiledMapTileDrawOrder) tiledMapContent.RenderOrder,
                TiledMapOrientation.Orthogonal, ColorHelper.FromHex(tiledMapContent.BackgroundColor));

            foreach (var prop in tiledMapContent.Properties)
            {
                tiledMap.Properties[prop.Name] = prop.Value;
            }

            foreach (var tileSetContent in tiledMapContent.Tilesets)
            {
                TiledMapTilesetContent content = tileSetContent;

                if (tileSetContent.Source != null)
                {
                    // load content from file
                    content =
                        (TiledMapTilesetContent) new XmlSerializer(typeof(TiledMapTilesetContent)).Deserialize(
                            _xmlLoader(tileSetContent.Source));
                }

                TiledMapTileset tileSet = ConvertTiledMapTileset(content);
                tiledMap.AddTileset(tileSet, tileSetContent.FirstGlobalIdentifier);
            }

            foreach (var layerContent in tiledMapContent.Layers)
            {
                switch (layerContent.Type)
                {
                    case TiledMapLayerType.TileLayer:
                        TiledMapTileLayer layer =
                            ConvertTiledMapTileLayer(tiledMap, (TiledMapTileLayerContent) layerContent);
                        tiledMap.AddLayer(layer);
                        break;
                    case TiledMapLayerType.ObjectLayer:
                        var objectLayer =
                            ConvertTiledMapObjectLayer(tiledMap, (TiledMapObjectLayerContent) layerContent);
                        tiledMap.AddLayer(objectLayer);
                        break;
                }
            }

            return tiledMap;
        }
        
        public static TiledMap LoadTiledMap(string path, TextureLoader textureLoader, XmlLoader xmlLoader)
        {
            var loader = new TMXLoader(path, textureLoader, xmlLoader);
            return loader.ConvertTiledMap();
        }
    }
}