using NLog;
using SFML.Graphics;
using SkiaSharp;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Spine.SpineWrappers
{
    /// <summary>
    /// 实现不同版本的 TextureLoader
    /// </summary>
    public class TextureLoader :
        SpineRuntime21.TextureLoader,
        SpineRuntime34.TextureLoader,
        SpineRuntime35.TextureLoader,
        SpineRuntime36.TextureLoader,
        SpineRuntime37.TextureLoader,
        SpineRuntime38.TextureLoader,
        SpineRuntime40.TextureLoader,
        SpineRuntime41.TextureLoader,
        SpineRuntime42.TextureLoader
    {
        private static readonly Logger _logger = LogManager.GetCurrentClassLogger();

        /// <summary>
        /// 默认的全局纹理加载器
        /// </summary>
        public static TextureLoader DefaultLoader { get; } = new();

        /// <summary>
        /// 在读取纹理时强制进行通道预乘操作
        /// </summary>
        public bool ForcePremul { get; set; }

        /// <summary>
        /// 强制使用 Nearest
        /// </summary>
        public bool ForceNearest { get; set; }

        /// <summary>
        /// 强制启用 Mipmap
        /// </summary>
        public bool ForceMipmap { get; set; }

        private Texture ReadTexture(string path)
        {
            if (!File.Exists(path))
            {
                _logger.Error($"Texture file not found, {path}");
                throw new FileNotFoundException("Texture file not found", path);
            }

            using var codec = SKCodec.Create(path, out var result);
            if (codec is null || result != SKCodecResult.Success)
            {
                _logger.Error($"Failed to create codec '{path}', {result}");
                throw new InvalidOperationException($"Failed to create codec '{path}', {result}");
            }

            var width = codec.Info.Width;
            var height = codec.Info.Height;

            // 判断是否需要强制预乘
            var alphaType = ForcePremul ? SKAlphaType.Premul : SKAlphaType.Unpremul;
            var info = new SKImageInfo(width, height, SKColorType.Rgba8888, alphaType);

            result = codec.GetPixels(info, out var pixels);
            if (result != SKCodecResult.Success)
            {
                _logger.Error($"Failed to decode image '{path}', {result}");
                throw new InvalidOperationException($"Failed to decode image '{path}', {result}");
            }

            Texture tex = new((uint)width, (uint)height);
            tex.Update(pixels);
            return tex;
        }

        public virtual void Load(SpineRuntime21.AtlasPage page, string path)
        {
            var texture = ReadTexture(path);

            if (page.magFilter == SpineRuntime21.TextureFilter.Linear)
            {
                texture.Smooth = true;
            }
            if (page.uWrap == SpineRuntime21.TextureWrap.Repeat && page.vWrap == SpineRuntime21.TextureWrap.Repeat)
            {
                texture.Repeated = true;
            }
            switch (page.minFilter)
            {
                case SpineRuntime21.TextureFilter.Linear:
                    texture.Smooth = true;
                    break;
                case SpineRuntime21.TextureFilter.MipMap:
                case SpineRuntime21.TextureFilter.MipMapNearestNearest:
                    texture.GenerateMipmap();
                    break;
                case SpineRuntime21.TextureFilter.MipMapLinearNearest:
                case SpineRuntime21.TextureFilter.MipMapNearestLinear:
                case SpineRuntime21.TextureFilter.MipMapLinearLinear:
                    texture.Smooth = true;
                    texture.GenerateMipmap();
                    break;
            }

            if (ForceNearest) texture.Smooth = false;
            if (ForceMipmap) texture.GenerateMipmap();

            page.rendererObject = texture;
        }

        public virtual void Load(SpineRuntime34.AtlasPage page, string path)
        {
            var texture = ReadTexture(path);

            if (page.magFilter == SpineRuntime34.TextureFilter.Linear)
            {
                texture.Smooth = true;
            }
            if (page.uWrap == SpineRuntime34.TextureWrap.Repeat && page.vWrap == SpineRuntime34.TextureWrap.Repeat)
            {
                texture.Repeated = true;
            }
            switch (page.minFilter)
            {
                case SpineRuntime34.TextureFilter.Linear:
                    texture.Smooth = true;
                    break;
                case SpineRuntime34.TextureFilter.MipMap:
                case SpineRuntime34.TextureFilter.MipMapNearestNearest:
                    texture.GenerateMipmap();
                    break;
                case SpineRuntime34.TextureFilter.MipMapLinearNearest:
                case SpineRuntime34.TextureFilter.MipMapNearestLinear:
                case SpineRuntime34.TextureFilter.MipMapLinearLinear:
                    texture.Smooth = true;
                    texture.GenerateMipmap();
                    break;
            }

            if (ForceNearest) texture.Smooth = false;
            if (ForceMipmap) texture.GenerateMipmap();

            page.rendererObject = texture;
        }

        public virtual void Load(SpineRuntime35.AtlasPage page, string path)
        {
            var texture = ReadTexture(path);

            if (page.magFilter == SpineRuntime35.TextureFilter.Linear)
            {
                texture.Smooth = true;
            }
            if (page.uWrap == SpineRuntime35.TextureWrap.Repeat && page.vWrap == SpineRuntime35.TextureWrap.Repeat)
            {
                texture.Repeated = true;
            }
            switch (page.minFilter)
            {
                case SpineRuntime35.TextureFilter.Linear:
                    texture.Smooth = true;
                    break;
                case SpineRuntime35.TextureFilter.MipMap:
                case SpineRuntime35.TextureFilter.MipMapNearestNearest:
                    texture.GenerateMipmap();
                    break;
                case SpineRuntime35.TextureFilter.MipMapLinearNearest:
                case SpineRuntime35.TextureFilter.MipMapNearestLinear:
                case SpineRuntime35.TextureFilter.MipMapLinearLinear:
                    texture.Smooth = true;
                    texture.GenerateMipmap();
                    break;
            }

            if (ForceNearest) texture.Smooth = false;
            if (ForceMipmap) texture.GenerateMipmap();

            page.rendererObject = texture;
        }

        public virtual void Load(SpineRuntime36.AtlasPage page, string path)
        {
            var texture = ReadTexture(path);

            if (page.magFilter == SpineRuntime36.TextureFilter.Linear)
            {
                texture.Smooth = true;
            }
            if (page.uWrap == SpineRuntime36.TextureWrap.Repeat && page.vWrap == SpineRuntime36.TextureWrap.Repeat)
            {
                texture.Repeated = true;
            }
            switch (page.minFilter)
            {
                case SpineRuntime36.TextureFilter.Linear:
                    texture.Smooth = true;
                    break;
                case SpineRuntime36.TextureFilter.MipMap:
                case SpineRuntime36.TextureFilter.MipMapNearestNearest:
                    texture.GenerateMipmap();
                    break;
                case SpineRuntime36.TextureFilter.MipMapLinearNearest:
                case SpineRuntime36.TextureFilter.MipMapNearestLinear:
                case SpineRuntime36.TextureFilter.MipMapLinearLinear:
                    texture.Smooth = true;
                    texture.GenerateMipmap();
                    break;
            }

            if (ForceNearest) texture.Smooth = false;
            if (ForceMipmap) texture.GenerateMipmap();

            page.rendererObject = texture;
        }

        public virtual void Load(SpineRuntime37.AtlasPage page, string path)
        {
            var texture = ReadTexture(path);

            if (page.magFilter == SpineRuntime37.TextureFilter.Linear)
            {
                texture.Smooth = true;
            }
            if (page.uWrap == SpineRuntime37.TextureWrap.Repeat && page.vWrap == SpineRuntime37.TextureWrap.Repeat)
            {
                texture.Repeated = true;
            }
            switch (page.minFilter)
            {
                case SpineRuntime37.TextureFilter.Linear:
                    texture.Smooth = true;
                    break;
                case SpineRuntime37.TextureFilter.MipMap:
                case SpineRuntime37.TextureFilter.MipMapNearestNearest:
                    texture.GenerateMipmap();
                    break;
                case SpineRuntime37.TextureFilter.MipMapLinearNearest:
                case SpineRuntime37.TextureFilter.MipMapNearestLinear:
                case SpineRuntime37.TextureFilter.MipMapLinearLinear:
                    texture.Smooth = true;
                    texture.GenerateMipmap();
                    break;
            }

            if (ForceNearest) texture.Smooth = false;
            if (ForceMipmap) texture.GenerateMipmap();

            page.rendererObject = texture;
        }

        public virtual void Load(SpineRuntime38.AtlasPage page, string path)
        {
            var texture = ReadTexture(path);

            if (page.magFilter == SpineRuntime38.TextureFilter.Linear)
            {
                texture.Smooth = true;
            }
            if (page.uWrap == SpineRuntime38.TextureWrap.Repeat && page.vWrap == SpineRuntime38.TextureWrap.Repeat)
            {
                texture.Repeated = true;
            }
            switch (page.minFilter)
            {
                case SpineRuntime38.TextureFilter.Linear:
                    texture.Smooth = true;
                    break;
                case SpineRuntime38.TextureFilter.MipMap:
                case SpineRuntime38.TextureFilter.MipMapNearestNearest:
                    texture.GenerateMipmap();
                    break;
                case SpineRuntime38.TextureFilter.MipMapLinearNearest:
                case SpineRuntime38.TextureFilter.MipMapNearestLinear:
                case SpineRuntime38.TextureFilter.MipMapLinearLinear:
                    texture.Smooth = true;
                    texture.GenerateMipmap();
                    break;
            }

            if (ForceNearest) texture.Smooth = false;
            if (ForceMipmap) texture.GenerateMipmap();

            page.rendererObject = texture;

            // 似乎是不需要设置的, 因为存在某些 png 和 atlas 大小不同的情况, 一般是有一些缩放, 如果设置了反而渲染异常
            // page.width = (int)texture.Size.X;
            // page.height = (int)texture.Size.Y;
        }

        public virtual void Load(SpineRuntime40.AtlasPage page, string path)
        {
            var texture = ReadTexture(path);

            if (page.magFilter == SpineRuntime40.TextureFilter.Linear)
            {
                texture.Smooth = true;
            }
            if (page.uWrap == SpineRuntime40.TextureWrap.Repeat && page.vWrap == SpineRuntime40.TextureWrap.Repeat)
            {
                texture.Repeated = true;
            }
            switch (page.minFilter)
            {
                case SpineRuntime40.TextureFilter.Linear:
                    texture.Smooth = true;
                    break;
                case SpineRuntime40.TextureFilter.MipMap:
                case SpineRuntime40.TextureFilter.MipMapNearestNearest:
                    texture.GenerateMipmap();
                    break;
                case SpineRuntime40.TextureFilter.MipMapLinearNearest:
                case SpineRuntime40.TextureFilter.MipMapNearestLinear:
                case SpineRuntime40.TextureFilter.MipMapLinearLinear:
                    texture.Smooth = true;
                    texture.GenerateMipmap();
                    break;
            }

            if (ForceNearest) texture.Smooth = false;
            if (ForceMipmap) texture.GenerateMipmap();

            page.rendererObject = texture;
        }

        public virtual void Load(SpineRuntime41.AtlasPage page, string path)
        {
            var texture = ReadTexture(path);

            if (page.magFilter == SpineRuntime41.TextureFilter.Linear)
            {
                texture.Smooth = true;
            }
            if (page.uWrap == SpineRuntime41.TextureWrap.Repeat && page.vWrap == SpineRuntime41.TextureWrap.Repeat)
            {
                texture.Repeated = true;
            }
            switch (page.minFilter)
            {
                case SpineRuntime41.TextureFilter.Linear:
                    texture.Smooth = true;
                    break;
                case SpineRuntime41.TextureFilter.MipMap:
                case SpineRuntime41.TextureFilter.MipMapNearestNearest:
                    texture.GenerateMipmap();
                    break;
                case SpineRuntime41.TextureFilter.MipMapLinearNearest:
                case SpineRuntime41.TextureFilter.MipMapNearestLinear:
                case SpineRuntime41.TextureFilter.MipMapLinearLinear:
                    texture.Smooth = true;
                    texture.GenerateMipmap();
                    break;
            }

            if (ForceNearest) texture.Smooth = false;
            if (ForceMipmap) texture.GenerateMipmap();

            page.rendererObject = texture;
        }

        public virtual void Load(SpineRuntime42.AtlasPage page, string path)
        {
            var texture = ReadTexture(path);

            if (page.magFilter == SpineRuntime42.TextureFilter.Linear)
            {
                texture.Smooth = true;
            }
            if (page.uWrap == SpineRuntime42.TextureWrap.Repeat && page.vWrap == SpineRuntime42.TextureWrap.Repeat)
            {
                texture.Repeated = true;
            }
            switch (page.minFilter)
            {
                case SpineRuntime42.TextureFilter.Linear:
                    texture.Smooth = true;
                    break;
                case SpineRuntime42.TextureFilter.MipMap:
                case SpineRuntime42.TextureFilter.MipMapNearestNearest:
                    texture.GenerateMipmap();
                    break;
                case SpineRuntime42.TextureFilter.MipMapLinearNearest:
                case SpineRuntime42.TextureFilter.MipMapNearestLinear:
                case SpineRuntime42.TextureFilter.MipMapLinearLinear:
                    texture.Smooth = true;
                    texture.GenerateMipmap();
                    break;
            }

            if (ForceNearest) texture.Smooth = false;
            if (ForceMipmap) texture.GenerateMipmap();

            page.rendererObject = texture;
        }

        public virtual void Unload(object texture)
        {
            ((Texture)texture).Dispose();
        }
    }
}