//
// Copyright 2020 Electronic Arts Inc.
//
// The Command & Conquer Map Editor and corresponding source code is free 
// software: you can redistribute it and/or modify it under the terms of 
// the GNU General Public License as published by the Free Software Foundation, 
// either version 3 of the License, or (at your option) any later version.

// The Command & Conquer Map Editor and corresponding source code is distributed 
// in the hope that it will be useful, but with permitted additional restrictions 
// under Section 7 of the GPL. See the GNU General Public License in LICENSE.TXT 
// distributed with this program. You should have received a copy of the 
// GNU General Public License along with permitted additional restrictions 
// with this program. If not, see https://github.com/electronicarts/CnC_Remastered_Collection
using Newtonsoft.Json.Linq;
using Pfim;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Runtime.InteropServices;
using TGASharpLib;

namespace MobiusEditor.Utility
{
    public class TextureManager
    {
#if false
        private class ImageData
        {
            public TGA TGA;
            public JObject Metadata;
        }
#endif

        private readonly MegafileManager megafileManager;

        private Dictionary<string, Bitmap> cachedTextures = new Dictionary<string, Bitmap>();
        private Dictionary<(string, TeamColor), (Bitmap, Rectangle)> teamColorTextures = new Dictionary<(string, TeamColor), (Bitmap, Rectangle)>();

        public TextureManager(MegafileManager megafileManager)
        {
            this.megafileManager = megafileManager;
        }

        public void Reset()
        {
            cachedTextures.Clear();
            teamColorTextures.Clear();
        }

        public (Bitmap, Rectangle) GetTexture(string filename, TeamColor teamColor)
        {
            if (teamColorTextures.TryGetValue((filename, teamColor), out (Bitmap bitmap, Rectangle opaqueBounds) result))
            {
                return result;
            }

            if (!cachedTextures.TryGetValue(filename, out result.bitmap))
            {
                if (Path.GetExtension(filename).ToLower() == ".tga")
                {
                    TGA tga = null;
                    JObject metadata = null;

                    // First attempt to find the texture in an archive
                    var name = Path.GetFileNameWithoutExtension(filename);
                    var archiveDir = Path.GetDirectoryName(filename);
                    var archivePath = archiveDir + ".ZIP";
                    using (var fileStream = megafileManager.Open(archivePath))
                    {
                        if (fileStream != null)
                        {
                            using (var archive = new ZipArchive(fileStream, ZipArchiveMode.Read))
                            {
                                foreach (var entry in archive.Entries)
                                {
                                    if (name == Path.GetFileNameWithoutExtension(entry.Name))
                                    {
                                        if ((tga == null) && (Path.GetExtension(entry.Name).ToLower() == ".tga"))
                                        {
                                            using (var stream = entry.Open())
                                            using (var memStream = new MemoryStream())
                                            {
                                                stream.CopyTo(memStream);
                                                tga = new TGA(memStream);
                                            }
                                        }
                                        else if ((metadata == null) && (Path.GetExtension(entry.Name).ToLower() == ".meta"))
                                        {
                                            using (var stream = entry.Open())
                                            using (var reader = new StreamReader(stream))
                                            {
                                                metadata = JObject.Parse(reader.ReadToEnd());
                                            }
                                        }

                                        if ((tga != null) && (metadata != null))
                                        {
                                            break;
                                        }
                                    }
                                }
                            }
                        }
                    }

                    // Next attempt to load a standalone file
                    if (tga == null)
                    {
                        using (var fileStream = megafileManager.Open(filename))
                        {
                            if (fileStream != null)
                            {
                                tga = new TGA(fileStream);
                            }
                        }
                    }

                    if (tga != null)
                    {
                        var bitmap = tga.ToBitmap(true);
                        if (metadata != null)
                        {
                            var size = new Size(metadata["size"][0].ToObject<int>(), metadata["size"][1].ToObject<int>());
                            var crop = Rectangle.FromLTRB(
                                metadata["crop"][0].ToObject<int>(),
                                metadata["crop"][1].ToObject<int>(),
                                metadata["crop"][2].ToObject<int>(),
                                metadata["crop"][3].ToObject<int>()
                            );

                            var uncroppedBitmap = new Bitmap(size.Width, size.Height, bitmap.PixelFormat);
                            using (var g = Graphics.FromImage(uncroppedBitmap))
                            {
                                g.DrawImage(bitmap, crop, new Rectangle(Point.Empty, bitmap.Size), GraphicsUnit.Pixel);
                            }
                            cachedTextures[filename] = uncroppedBitmap;
                        }
                        else
                        {
                            cachedTextures[filename] = bitmap;
                        }
                    }

#if false
                    // Attempt to load parent directory as archive
                    var archiveDir = Path.GetDirectoryName(filename);
                    var archivePath = archiveDir + ".ZIP";
                    using (var fileStream = megafileManager.Open(archivePath))
                    {
                        if (fileStream != null)
                        {
                            using (var archive = new ZipArchive(fileStream, ZipArchiveMode.Read))
                            {
                                var images = new Dictionary<string, ImageData>();

                                foreach (var entry in archive.Entries)
                                {
                                    var name = Path.GetFileNameWithoutExtension(entry.Name);
                                    if (!images.TryGetValue(name, out ImageData imageData))
                                    {
                                        imageData = images[name] = new ImageData { TGA = null, Metadata = null };
                                    }

                                    if ((imageData.TGA == null) && (Path.GetExtension(entry.Name).ToLower() == ".tga"))
                                    {
                                        using (var stream = entry.Open())
                                        using (var memStream = new MemoryStream())
                                        {
                                            stream.CopyTo(memStream);
                                            imageData.TGA = new TGA(memStream);
                                        }
                                    }
                                    else if ((imageData.Metadata == null) && (Path.GetExtension(entry.Name).ToLower() == ".meta"))
                                    {
                                        using (var stream = entry.Open())
                                        using (var reader = new StreamReader(stream))
                                        {
                                            imageData.Metadata = JObject.Parse(reader.ReadToEnd());
                                        }
                                    }

                                    if ((imageData.TGA != null) && (imageData.Metadata != null))
                                    {
                                        var bitmap = imageData.TGA.ToBitmap(true);
                                        var size = new Size(imageData.Metadata["size"][0].ToObject<int>(), imageData.Metadata["size"][1].ToObject<int>());
                                        var crop = Rectangle.FromLTRB(
                                            imageData.Metadata["crop"][0].ToObject<int>(),
                                            imageData.Metadata["crop"][1].ToObject<int>(),
                                            imageData.Metadata["crop"][2].ToObject<int>(),
                                            imageData.Metadata["crop"][3].ToObject<int>()
                                        );

                                        var uncroppedBitmap = new Bitmap(size.Width, size.Height, bitmap.PixelFormat);
                                        using (var g = Graphics.FromImage(uncroppedBitmap))
                                        {
                                            g.DrawImage(bitmap, crop, new Rectangle(Point.Empty, bitmap.Size), GraphicsUnit.Pixel);
                                        }
                                        cachedTextures[Path.Combine(archiveDir, name) + ".tga"] = uncroppedBitmap;

                                        images.Remove(name);
                                    }
                                }

                                foreach (var item in images.Where(x => x.Value.TGA != null))
                                {
                                    cachedTextures[Path.Combine(archiveDir, item.Key) + ".tga"] = item.Value.TGA.ToBitmap(true);
                                }
                            }
                        }
                    }
#endif
                }

                if (!cachedTextures.TryGetValue(filename, out result.bitmap))
                {
                    // Try loading as a DDS
                    var ddsFilename = Path.ChangeExtension(filename, ".DDS");
                    using (var fileStream = megafileManager.Open(ddsFilename))
                    {
                        if (fileStream != null)
                        {
                            var bytes = new byte[fileStream.Length];
                            fileStream.Read(bytes, 0, bytes.Length);

                            using (var image = Dds.Create(bytes, new PfimConfig()))
                            {
                                PixelFormat format;
                                switch (image.Format)
                                {
                                    case Pfim.ImageFormat.Rgb24:
                                        format = PixelFormat.Format24bppRgb;
                                        break;

                                    case Pfim.ImageFormat.Rgba32:
                                        format = PixelFormat.Format32bppArgb;
                                        break;

                                    case Pfim.ImageFormat.R5g5b5:
                                        format = PixelFormat.Format16bppRgb555;
                                        break;

                                    case Pfim.ImageFormat.R5g6b5:
                                        format = PixelFormat.Format16bppRgb565;
                                        break;

                                    case Pfim.ImageFormat.R5g5b5a1:
                                        format = PixelFormat.Format16bppArgb1555;
                                        break;

                                    case Pfim.ImageFormat.Rgb8:
                                        format = PixelFormat.Format8bppIndexed;
                                        break;

                                    default:
                                        format = PixelFormat.DontCare;
                                        break;
                                }

                                var bitmap = new Bitmap(image.Width, image.Height, format);
                                var bitmapData = bitmap.LockBits(new Rectangle(0, 0, image.Width, image.Height), ImageLockMode.WriteOnly, bitmap.PixelFormat);
                                Marshal.Copy(image.Data, 0, bitmapData.Scan0, image.Stride * image.Height);
                                bitmap.UnlockBits(bitmapData);
                                cachedTextures[filename] = bitmap;
                            }
                        }
                    }
                }
            }

            if (!cachedTextures.TryGetValue(filename, out result.bitmap))
            {
                return result;
            }

            result.bitmap = new Bitmap(result.bitmap);
            result.opaqueBounds = new Rectangle(0, 0, result.bitmap.Width, result.bitmap.Height);
            if (teamColor != null)
            {
                float frac(float x) => x - (int)x;
                float lerp(float x, float y, float t) => (x * (1.0f - t)) + (y * t);
                float saturate(float x) => Math.Max(0.0f, Math.Min(1.0f, x));

                BitmapData data = null;
                try
                {
                    data = result.bitmap.LockBits(new Rectangle(0, 0, result.bitmap.Width, result.bitmap.Height), ImageLockMode.ReadWrite, result.bitmap.PixelFormat);
                    var bpp = Image.GetPixelFormatSize(data.PixelFormat) / 8;
                    var bytes = new byte[data.Stride * data.Height];
                    Marshal.Copy(data.Scan0, bytes, 0, bytes.Length);

                    result.opaqueBounds = CalculateOpaqueBounds(bytes, data.Width, data.Height, bpp, data.Stride);

                    for (int j = 0; j < bytes.Length; j += bpp)
                    {
                        var pixel = Color.FromArgb(bytes[j + 2], bytes[j + 1], bytes[j + 0]);
                        (float r, float g, float b) = (pixel.R.ToLinear(), pixel.G.ToLinear(), pixel.B.ToLinear());

                        (float x, float y, float z, float w) K = (0.0f, -1.0f / 3.0f, 2.0f / 3.0f, -1.0f);
                        (float x, float y, float z, float w) p = (g >= b) ? (g, b, K.x, K.y) : (b, g, K.w, K.z);
                        (float x, float y, float z, float w) q = (r >= p.x) ? (r, p.y, p.z, p.x) : (p.x, p.y, p.w, r);
                        (float d, float e) = (q.x - Math.Min(q.w, q.y), 1e-10f);
                        (float hue, float saturation, float value) = (Math.Abs(q.z + (q.w - q.y) / (6.0f * d + e)), d / (q.x + e), q.x);

                        var lowerHue = teamColor.LowerBounds.GetHue() / 360.0f;
                        var upperHue = teamColor.UpperBounds.GetHue() / 360.0f;
                        if ((hue >= lowerHue) && (upperHue >= hue))
                        {
                            hue = (hue / (upperHue - lowerHue)) * ((upperHue + teamColor.Fudge) - (lowerHue - teamColor.Fudge));
                            hue += teamColor.HSVShift.X;
                            saturation += teamColor.HSVShift.Y;
                            value += teamColor.HSVShift.Z;

                            (float x, float y, float z, float w) L = (1.0f, 2.0f / 3.0f, 1.0f / 3.0f, 3.0f);
                            (float x, float y, float z) m = (
                                Math.Abs(frac(hue + L.x) * 6.0f - L.w),
                                Math.Abs(frac(hue + L.y) * 6.0f - L.w),
                                Math.Abs(frac(hue + L.z) * 6.0f - L.w)
                            );

                            r = value * lerp(L.x, saturate(m.x - L.x), saturation);
                            g = value * lerp(L.x, saturate(m.y - L.x), saturation);
                            b = value * lerp(L.x, saturate(m.z - L.x), saturation);

                            (float x, float y, float z) n = (
                                Math.Min(1.0f, Math.Max(0.0f, r - teamColor.InputLevels.X) / (teamColor.InputLevels.Z - teamColor.InputLevels.X)),
                                Math.Min(1.0f, Math.Max(0.0f, g - teamColor.InputLevels.X) / (teamColor.InputLevels.Z - teamColor.InputLevels.X)),
                                Math.Min(1.0f, Math.Max(0.0f, b - teamColor.InputLevels.X) / (teamColor.InputLevels.Z - teamColor.InputLevels.X))
                            );
                            n.x = (float)Math.Pow(n.x, teamColor.InputLevels.Y);
                            n.y = (float)Math.Pow(n.y, teamColor.InputLevels.Y);
                            n.z = (float)Math.Pow(n.z, teamColor.InputLevels.Y);

                            r = lerp(teamColor.OutputLevels.X, teamColor.OutputLevels.Y, n.x);
                            g = lerp(teamColor.OutputLevels.X, teamColor.OutputLevels.Y, n.y);
                            b = lerp(teamColor.OutputLevels.X, teamColor.OutputLevels.Y, n.z);
                        }

                        (float x, float y, float z) n2 = (
                            Math.Min(1.0f, Math.Max(0.0f, r - teamColor.OverallInputLevels.X) / (teamColor.OverallInputLevels.Z - teamColor.OverallInputLevels.X)),
                            Math.Min(1.0f, Math.Max(0.0f, g - teamColor.OverallInputLevels.X) / (teamColor.OverallInputLevels.Z - teamColor.OverallInputLevels.X)),
                            Math.Min(1.0f, Math.Max(0.0f, b - teamColor.OverallInputLevels.X) / (teamColor.OverallInputLevels.Z - teamColor.OverallInputLevels.X))
                        );
                        n2.x = (float)Math.Pow(n2.x, teamColor.OverallInputLevels.Y);
                        n2.y = (float)Math.Pow(n2.y, teamColor.OverallInputLevels.Y);
                        n2.z = (float)Math.Pow(n2.z, teamColor.OverallInputLevels.Y);

                        r = lerp(teamColor.OverallOutputLevels.X, teamColor.OverallOutputLevels.Y, n2.x);
                        g = lerp(teamColor.OverallOutputLevels.X, teamColor.OverallOutputLevels.Y, n2.y);
                        b = lerp(teamColor.OverallOutputLevels.X, teamColor.OverallOutputLevels.Y, n2.z);

                        bytes[j + 2] = (byte)(r.ToSRGB() * 255.0f);
                        bytes[j + 1] = (byte)(g.ToSRGB() * 255.0f);
                        bytes[j + 0] = (byte)(b.ToSRGB() * 255.0f);
                    }

                    Marshal.Copy(bytes, 0, data.Scan0, bytes.Length);
                }
                finally
                {
                    if (data != null)
                    {
                        result.bitmap.UnlockBits(data);
                    }
                }
            }
            else
            {
                result.opaqueBounds = CalculateOpaqueBounds(result.bitmap);
            }

            teamColorTextures[(filename, teamColor)] = result;
            return result;
        }

        private static Rectangle CalculateOpaqueBounds(byte[] data, int width, int height, int bpp, int stride)
        {
            bool isTransparentRow(int y)
            {
                var start = y * stride;
                for (var i = bpp - 1; i < stride; i += bpp)
                {
                    if (data[start + i] != 0)
                    {
                        return false;
                    }
                }
                return true;
            }

            var opaqueBounds = new Rectangle(0, 0, width, height);
            for (int y = 0; y < height; ++y)
            {
                if (!isTransparentRow(y))
                {
                    opaqueBounds.Offset(0, y);
                    break;
                }
            }
            for (int y = height; y > 0; --y)
            {
                if (!isTransparentRow(y - 1))
                {
                    opaqueBounds.Height = y - opaqueBounds.Top;
                    break;
                }
            }

            bool isTransparentColumn(int x)
            {
                var start = (x * bpp) + (bpp - 1);
                for (var y = opaqueBounds.Top; y < opaqueBounds.Bottom; ++y)
                {
                    if (data[start + (y * stride)] != 0)
                    {
                        return false;
                    }
                }
                return true;
            }

            for (int x = 0; x < width; ++x)
            {
                if (!isTransparentColumn(x))
                {
                    opaqueBounds.Offset(x, 0);
                    break;
                }
            }
            for (int x = width; x > 0; --x)
            {
                if (!isTransparentColumn(x - 1))
                {
                    opaqueBounds.Width = x - opaqueBounds.Left;
                    break;
                }
            }

            return opaqueBounds;
        }

        private static Rectangle CalculateOpaqueBounds(Bitmap bitmap)
        {
            BitmapData data = null;
            try
            {
                data = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadWrite, bitmap.PixelFormat);
                var bpp = Image.GetPixelFormatSize(data.PixelFormat) / 8;
                var bytes = new byte[data.Stride * data.Height];
                Marshal.Copy(data.Scan0, bytes, 0, bytes.Length);
                return CalculateOpaqueBounds(bytes, data.Width, data.Height, bpp, data.Stride);
            }
            finally
            {
                if (data != null)
                {
                    bitmap.UnlockBits(data);
                }
            }
        }
    }
}