//! \file       ImagePGD.cs
//! \date       Sat Feb 13 13:56:06 2016
//! \brief      Image format used by subsidiaries of Amuse Craft (former Softpal).
//
// Copyright (C) 2016 by morkt
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//

using System;
using System.ComponentModel.Composition;
using System.IO;
using System.Windows.Media;
using GameRes.Utility;

namespace GameRes.Formats.Softpal
{
    [Export(typeof(ImageFormat))]
    public class Pgd11Format : ImageFormat
    {
        public override string         Tag { get { return "PGD/11_C"; } }
        public override string Description { get { return "Image format used by Softpal subsidiaries"; } }
        public override uint     Signature { get { return 0x1C4547; } } // 'GE\x1C'

        public Pgd11Format ()
        {
            Extensions = new string[] { "pgd" };
        }

        public override ImageMetaData ReadMetaData (Stream stream)
        {
            var header = new byte[0x20];
            if (header.Length != stream.Read (header, 0, header.Length))
                return null;
            if (!Binary.AsciiEqual (header, 0x1C, "11_C"))
                return null;
            return new ImageMetaData
            {
                Width   = LittleEndian.ToUInt32 (header, 0x0C),
                Height  = LittleEndian.ToUInt32 (header, 0x10),
                OffsetX = LittleEndian.ToInt32 (header, 4),
                OffsetY = LittleEndian.ToInt32 (header, 8),
                BPP     = 32,
            };
        }

        public override ImageData Read (Stream stream, ImageMetaData info)
        {
            using (var reader = new PgdReader (stream, 0x20))
            {
                var planes = reader.Unpack11();
                var pixels = new byte[planes.Length];
                int plane_size = (int)info.Width*(int)info.Height;
                int b_src = 0;
                int g_src = b_src+plane_size;
                int r_src = g_src+plane_size;
                int alpha_src = r_src+plane_size;
                int dst = 0;
                while (dst < pixels.Length)
                {
                    pixels[dst++] = planes[b_src++];
                    pixels[dst++] = planes[g_src++];
                    pixels[dst++] = planes[r_src++];
                    pixels[dst++] = planes[alpha_src++];
                }
                return ImageData.Create (info, PixelFormats.Bgra32, null, pixels);
            }
        }

        public override void Write (Stream file, ImageData image)
        {
            throw new NotImplementedException ("Pgd11Format.Write not implemented");
        }
    }

    [Export(typeof(ImageFormat))]
    public class Pgd00Format : ImageFormat
    {
        public override string         Tag { get { return "PGD/00_C"; } }
        public override string Description { get { return "Image format used by Softpal subsidiaries"; } }
        public override uint     Signature { get { return 0; } }

        public Pgd00Format ()
        {
            Extensions = new string[] { "pgd" };
        }

        public override ImageMetaData ReadMetaData (Stream stream)
        {
            var header = new byte[0x24];
            if (header.Length != stream.Read (header, 0, header.Length))
                return null;
            if (!Binary.AsciiEqual (header, 0x18, "00_C"))
                return null;
            return new ImageMetaData
            {
                Width   = LittleEndian.ToUInt32 (header, 8),
                Height  = LittleEndian.ToUInt32 (header, 12),
                OffsetX = LittleEndian.ToInt32 (header, 0),
                OffsetY = LittleEndian.ToInt32 (header, 4),
                BPP     = 32,
            };
        }

        public override ImageData Read (Stream stream, ImageMetaData info)
        {
            using (var reader = new PgdReader (stream, 0x1C))
            {
                var data = reader.Unpack00();
                using (var tga = new MemoryStream (data))
                {
                    var tga_info = Tga.ReadMetaData (tga);
                    if (null == tga_info)
                        throw new InvalidFormatException();
                    tga.Position = 0;
                    return Tga.Read (tga, tga_info);
                }
            }
        }

        public override void Write (Stream file, ImageData image)
        {
            throw new NotImplementedException ("Pgd00Format.Write not implemented");
        }
    }

    [Export(typeof(ImageFormat))]
    public class PgdTgaFormat : TgaFormat
    {
        public override string         Tag { get { return "PGD/TGA"; } }
        public override string Description { get { return "Image format used by Softpal subsidiaries"; } }
        public override uint     Signature { get { return 0; } }

        public PgdTgaFormat ()
        {
            Extensions = new string[] { "pgd" };
        }

        public override ImageMetaData ReadMetaData (Stream stream)
        {
            var header = new byte[0x2A];
            if (header.Length != stream.Read (header, 0, header.Length))
                return null;
            int x = LittleEndian.ToInt32 (header, 0);
            int y = LittleEndian.ToInt32 (header, 4);
            if (Math.Abs (x) > 0x2000 || Math.Abs (y) > 0x2000)
                return null;
            uint width  = LittleEndian.ToUInt32 (header, 8);
            uint height = LittleEndian.ToUInt32 (header, 12);
            if (0 == width || 0 == height
                || width != LittleEndian.ToUInt16 (header, 0x24)
                || height != LittleEndian.ToUInt16 (header, 0x26))
                return null;
            stream.Position = 0x18;
            var tga_info = base.ReadMetaData (stream);
            if (null == tga_info)
                return null;
            tga_info.OffsetX = x;
            tga_info.OffsetY = y;
            return tga_info;
        }

        public override ImageData Read (Stream stream, ImageMetaData info)
        {
            using (var tga = new StreamRegion (stream, 0x18, true))
                return base.Read (tga, info);
        }

        public override void Write (Stream file, ImageData image)
        {
            throw new NotImplementedException ("PgdTgaFormat.Write not implemented");
        }
    }

    internal class PgdGeMetaData : ImageMetaData
    {
        public int  Method;
    }

    [Export(typeof(ImageFormat))]
    public class PgdGeFormat : ImageFormat
    {
        public override string         Tag { get { return "PGD/GE"; } }
        public override string Description { get { return "Image format used by Softpal subsidiaries"; } }
        public override uint     Signature { get { return 0x204547; } } // 'GE '

        public PgdGeFormat ()
        {
            Extensions = new string[] { "pgd" };
        }

        public override ImageMetaData ReadMetaData (Stream stream)
        {
            var header = new byte[0x20];
            if (header.Length != stream.Read (header, 0, header.Length))
                return null;
            return new PgdGeMetaData
            {
                Width   = LittleEndian.ToUInt32 (header, 0x0C),
                Height  = LittleEndian.ToUInt32 (header, 0x10),
                OffsetX = LittleEndian.ToInt32 (header, 4),
                OffsetY = LittleEndian.ToInt32 (header, 8),
                BPP     = 32,
                Method  = LittleEndian.ToUInt16 (header, 0x1C),
            };
        }

        public override ImageData Read (Stream stream, ImageMetaData info)
        {
            using (var reader = new PgdReader (stream, (PgdGeMetaData)info))
            {
                var pixels = reader.UnpackGE();
                return ImageData.Create (info, reader.Format, null, pixels);
            }
        }

        public override void Write (Stream file, ImageData image)
        {
            throw new NotImplementedException ("PgdGeFormat.Write not implemented");
        }
    }

    internal class PgdIncMetaData : ImageMetaData
    {
        public string   BaseName;
    }

    [Export(typeof(ImageFormat))]
    public class Pgd3Format : ImageFormat
    {
        public override string         Tag { get { return "PGD3"; } }
        public override string Description { get { return "Softpal incremental image format"; } }
        public override uint     Signature { get { return 0x33444750; } } // 'PGD3'

        public Pgd3Format ()
        {
            Extensions = new string[] { "pgd" };
            Signatures = new uint[] { 0x33444750, 0x32444750 }; // 'PGD3', 'PGD2'
        }

        public override ImageMetaData ReadMetaData (Stream stream)
        {
            var header = new byte[0x30];
            if (header.Length != stream.Read (header, 0, header.Length))
                return null;
            string base_name = Binary.GetCString (header, 0xE, 0x22);
            if (string.IsNullOrEmpty (base_name))
                return null;
            return new PgdIncMetaData
            {
                OffsetX = LittleEndian.ToUInt16 (header, 4),
                OffsetY = LittleEndian.ToUInt16 (header, 6),
                Width   = LittleEndian.ToUInt16 (header, 8),
                Height  = LittleEndian.ToUInt16 (header, 0xA),
                BPP     = LittleEndian.ToUInt16 (header, 0xC),
                BaseName = base_name,
            };
        }

        static readonly Lazy<ImageFormat> PalFormat = new Lazy<ImageFormat> (() => FindByTag ("PGD/GE"));

        public override ImageData Read (Stream stream, ImageMetaData info)
        {
            var meta = (PgdIncMetaData)info;
            string dir_name = VFS.GetDirectoryName (meta.FileName);
            string name = VFS.CombinePath (dir_name, meta.BaseName);
            PgdGeMetaData base_info;
            byte[] image, overlay;
            PixelFormat format;
            using (var base_file = VFS.OpenSeekableStream (name))
            {
                base_info = PalFormat.Value.ReadMetaData (base_file) as PgdGeMetaData;
                if (null == base_info)
                    throw new InvalidFormatException ("Invalid baseline image format");
                if (meta.OffsetX + meta.Width > base_info.Width ||
                    meta.OffsetY + meta.Height > base_info.Height)
                    throw new InvalidFormatException ("Incompatible baseline image dimensions");
                base_info.FileName = name;
                using (var reader = new PgdReader (base_file, base_info))
                {
                    image = reader.UnpackGE();
                    format = reader.Format;
                }
            }
            using (var reader = new PgdReader (stream, meta))
                overlay = reader.UnpackOverlay();

            int overlay_bpp = meta.BPP / 8;
            int base_bpp = format.BitsPerPixel / 8;
            int dst = (meta.OffsetY * (int)base_info.Width + meta.OffsetX) * base_bpp;
            int gap = (int)(base_info.Width - meta.Width) * base_bpp;
            int src = 0;
            bool apply_alpha = overlay_bpp == 4 && base_bpp == 4;
            for (uint y = 0; y < meta.Height; ++y)
            {
                for (uint x = 0; x < meta.Width; ++x)
                {
                    image[dst  ] ^= overlay[src  ];
                    image[dst+1] ^= overlay[src+1];
                    image[dst+2] ^= overlay[src+2];
                    if (apply_alpha)
                        image[dst+3] ^= overlay[src+3];
                    dst += base_bpp;
                    src += overlay_bpp;
                }
                dst += gap;
            }
            base_info.FileName = meta.FileName;
            return ImageData.Create (base_info, format, null, image);
        }

        public override void Write (Stream file, ImageData image)
        {
            throw new NotImplementedException ("Pgd3Format.Write not implemented");
        }
    }

    internal sealed class PgdReader : IDisposable
    {
        BinaryReader        m_input;
        byte[]              m_output;
        int                 m_width;
        int                 m_height;
        int                 m_bpp;
        int                 m_method;

        public PixelFormat Format { get; private set; }

        public PgdReader (Stream input, int position)
        {
            input.Position = position;
            m_input = new ArcView.Reader (input);
            int unpacked_size = m_input.ReadInt32();
            m_input.ReadInt32(); // packed_size
            m_output = new byte[unpacked_size];
        }

        public PgdReader (Stream input, PgdGeMetaData info) : this (input, 0x20)
        {
            m_width = (int)info.Width;
            m_height = (int)info.Height;
            m_method = info.Method;
        }

        public PgdReader (Stream input, PgdIncMetaData info) : this (input, 0x30)
        {
            m_width = (int)info.Width;
            m_height = (int)info.Height;
            m_bpp = info.BPP;
        }

        public byte[] UnpackGE ()
        {
            UnpackGePre();
            switch (m_method)
            {
            case 1: return PostProcess1 (m_output);
            case 2: return PostProcess2 (m_output);
            case 3: return PostProcess3 (m_output);
            default: throw new NotSupportedException ("Not supported PGD compression");
            }
        }

        public byte[] UnpackOverlay ()
        {
            UnpackGePre();
            return PostProcessPal (m_output, 0, m_bpp / 8);
        }

        public byte[] Unpack00 ()
        {
            return Unpack (3000);
        }

        public byte[] Unpack11 ()
        {
            return Unpack (0xFFC);
        }

        byte[] Unpack (int look_behind)
        {
            int dst = 0;
            int ctl = 2;
            while (dst < m_output.Length)
            {
                ctl >>= 1;
                if (1 == ctl)
                {
                    ctl = m_input.ReadByte() | 0x100;
                }
                int count;
                if (0 != (ctl & 1))
                {
                    int src = m_input.ReadUInt16();
                    count = m_input.ReadByte();
                    if (dst > look_behind)
                        src += dst - look_behind;
                    Binary.CopyOverlapped (m_output, src, dst, count);
                }
                else
                {
                    count = m_input.ReadByte();
                    m_input.Read (m_output, dst, count);
                }
                dst += count;
            }
            return m_output;
        }

        byte[] UnpackGePre ()
        {
            int dst = 0;
            int ctl = 2;
            while (dst < m_output.Length)
            {
                ctl >>= 1;
                if (1 == ctl)
                    ctl = m_input.ReadByte() | 0x100;
                int count;
                if (0 != (ctl & 1))
                {
                    int offset = m_input.ReadUInt16();
                    count = offset & 7;
                    if (0 == (offset & 8))
                    {
                        count = count << 8 | m_input.ReadByte();
                    }
                    count += 4;
                    offset >>= 4;
                    Binary.CopyOverlapped (m_output, dst - offset, dst, count);
                }
                else
                {
                    count = m_input.ReadByte();
                    m_input.Read (m_output, dst, count);
                }
                dst += count;
            }
            return m_output;
        }

        byte[] PostProcess1 (byte[] input)
        {
            Format = PixelFormats.Bgra32;
            var output = new byte[input.Length];
            int plane_size = input.Length / 4;
            int a_src = 0;
            int r_src = plane_size;
            int g_src = 2 * plane_size;
            int b_src = 3 * plane_size;
            int dst = 0;
            for (int i = 0; i < plane_size; ++i)
            {
                output[dst++] = input[b_src+i];
                output[dst++] = input[g_src+i];
                output[dst++] = input[r_src+i];
                output[dst++] = input[a_src+i];
            }
            return output;
        }

        byte[] PostProcess2 (byte[] input)
        {
            Format = PixelFormats.Bgr24;
            int stride = m_width * 3;

            int segment_size = m_width * m_height / 4;
            int src0 = 0;
            int src1 = segment_size;
            int src2 = segment_size + src1;

            var output = new byte[stride * m_height];
            int dst = 0;

            int[] points = { 0, 1, m_width, m_width + 1 };
            for (int y = m_height / 2; y > 0; --y)
            {
                for (int x = m_width / 2; x > 0; --x)
                {
                    sbyte i0 = (sbyte)input[src0];
                    sbyte i1 = (sbyte)input[src1];
                    int b = 226 * i0;
                    int g = -43 * i0 - 89 * i1;
                    int r = 179 * i1;
                    ++src0;
                    ++src1;
                    for (int i = 0; i < points.Length; ++i)
                    {
                        int offset = points[i];
                        int base_value = input[src2+offset] << 7;
                        offset = dst + 3 * offset;
                        output[offset++] = Clamp ((base_value + b) >> 7);
                        output[offset++] = Clamp ((base_value + g) >> 7);
                        output[offset++] = Clamp ((base_value + r) >> 7);
                    }
                    src2 += 2;
                    dst += 6;
                }
                src2 += m_width;
                dst += stride;
            }
            return output;
        }

        static byte Clamp (int val)
        {
            if (val > 255)      val = 255;
            else if (val < 0)   val = 0;
            return (byte)val;
        }

        byte[] PostProcess3 (byte[] input)
        {
            int bpp = LittleEndian.ToUInt16 (input, 2);
            if (32 == bpp)
                Format = PixelFormats.Bgra32;
            else if (24 == bpp)
                Format = PixelFormats.Bgr24;
            else
                throw new InvalidFormatException();
            m_width  = LittleEndian.ToUInt16 (input, 4);
            m_height = LittleEndian.ToUInt16 (input, 6);
            return PostProcessPal (input, 8, bpp / 8);
        }

        byte[] PostProcessPal (byte[] input, int src, int pixel_size)
        {
            int stride = m_width * pixel_size;
            var output = new byte[m_height * stride];
            int ctl = src;
            src += m_height;
            int dst = 0;
            for (int row = 0; row < m_height; ++row)
            {
                byte c = input[ctl++];
                if (0 != (c & 1))
                {
                    int prev = dst;
                    Buffer.BlockCopy (input, src, output, dst, pixel_size);
                    src += pixel_size;
                    dst += pixel_size;
                    int count = stride - pixel_size;
                    while (count --> 0)
                    {
                        output[dst++] = (byte)(output[prev++] - input[src++]);
                    }
                }
                else if (0 != (c & 2))
                {
                    int prev = dst - stride;
                    int count = stride;
                    while (count --> 0)
                    {
                        output[dst++] = (byte)(output[prev++] - input[src++]);
                    }
                }
                else
                {
                    Buffer.BlockCopy (input, src, output, dst, pixel_size);
                    dst += pixel_size;
                    src += pixel_size;
                    int prev = dst - stride;
                    int count = stride - pixel_size;
                    while (count --> 0)
                    {
                        output[dst] = (byte)((output[prev++] + output[dst-pixel_size]) / 2 - input[src++]);
                        ++dst;
                    }
                }
            }
            return output;
        }

        #region IDisposable Members
        bool _disposed = false;
        public void Dispose ()
        {
            if (!_disposed)
            {
                m_input.Dispose();
                _disposed = true;
            }
        }
        #endregion
    }
}