//! \file       ImageWIP.cs
//! \date       Fri Oct 31 14:52:49 2014
//! \brief      Will image format implementation.
//
// Copyright (C) 2014 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.IO;
using System.Text;
using System.Diagnostics;
using System.ComponentModel.Composition;
using System.Windows.Media;
using System.Windows.Media.Imaging;

namespace GameRes.Formats.Will
{
    internal class WipMetaData : ImageMetaData
    {
        public int  FrameCount;
        public uint FrameSize;
    }

    [Export(typeof(ImageFormat))]
    public class WipFormat : ImageFormat
    {
        public override string         Tag { get { return "WIP"; } }
        public override string Description { get { return "Will Co. image format"; } }
        public override uint     Signature { get { return 0x46504957u; } } // 'WIPF'

        public WipFormat ()
        {
            Extensions = new string[] { "wip", "msk", "mos" };
        }

        public override ImageMetaData ReadMetaData (Stream stream)
        {
            using (var file = new BinaryReader (stream, Encoding.ASCII, true))
            {
                if (Signature != file.ReadUInt32())
                    return null;
                int frames = file.ReadUInt16();
                int bpp    = file.ReadUInt16();
                uint width = file.ReadUInt32();
                uint height = file.ReadUInt32();
                int x = file.ReadInt32();
                int y = file.ReadInt32();
                file.ReadUInt32(); // 0
                uint frame_size = file.ReadUInt32();
                if (24 != bpp && 8 != bpp)
                {
                    Trace.WriteLine ("unsupported bpp", "WipFormat");
                    return null;
                }
                if (frames > 1)
                    Trace.WriteLine ("Extra frames ignored", "WipFormat");
                return new WipMetaData
                {
                    Width   = width,
                    Height  = height,
                    OffsetX = x,
                    OffsetY = y,
                    BPP     = bpp,
                    FrameCount  = frames,
                    FrameSize   = frame_size,
                };
            }
        }

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

        public override ImageData Read (Stream file, ImageMetaData info)
        {
            var meta = info as WipMetaData;
            if (null == meta)
                throw new ArgumentException ("WipFormat.Read should be supplied with WipMetaData", "info");
            file.Position = 8 + 24 * meta.FrameCount;
            Color[] palette = null;
            if (8 == meta.BPP)
            {
                var palette_data = new byte[0x400];
                if (palette_data.Length != file.Read (palette_data, 0, palette_data.Length))
                    throw new InvalidFormatException();
                palette = new Color[0x100];
                for (int i = 0; i < 0x100; ++i)
                {
                    palette[i] = Color.FromRgb (palette_data[i*4], palette_data[i*4+1], palette_data[i*4+2]);
                }
            }
            using (var reader = new Reader (file, meta))
            {
                reader.Unpack();
                if (24 == meta.BPP)
                {
                    byte[] raw = reader.Data;
                    int size = (int)meta.Width * (int)meta.Height;
                    byte[] pixels = new byte[size*3];
                    for (int i = 0; i < size; ++i)
                    {
                        pixels[i*3]   = raw[i];
                        pixels[i*3+1] = raw[i+size];
                        pixels[i*3+2] = raw[i+size*2];
                    }
                    return ImageData.Create (meta, PixelFormats.Bgr24, null, pixels, (int)meta.Width*3);
                }
                else if (8 == meta.BPP)
                {
                    byte[] pixels = reader.Data;
                    var bmp_palette = new BitmapPalette (palette);
                    return ImageData.Create (meta, PixelFormats.Indexed8, bmp_palette, pixels, (int)meta.Width);
                }
                else
                    throw new InvalidFormatException();
            }
        }

        internal class Reader : IDisposable
        {
            private BinaryReader    m_input;
            private uint            m_length;
            private byte[]          m_data;

            public byte[] Data { get { return m_data; } }

            public Reader (Stream file, WipMetaData info)
            {
                m_length = info.FrameSize;
//                int stride = (int)info.Width*((info.BPP+7)/8);
                int stride = (int)info.Width*4;
                m_data = new byte[stride * (int)info.Height];
                m_input = new BinaryReader (file, Encoding.ASCII, true);
            }

            private byte[] m_window = new byte[0x1000];

            public void Unpack ()
            {
                int current = 0;
                int window_index = 1;
                int control = 0;
                byte input = 0;
                for (uint length = m_length; length > 0; )
                {
                    control >>= 1;
                    if (0 == (control & 0x100))
                    {
                        input = m_input.ReadByte();
                        --length;
                        control = input | 0xff00;
                    }
                    if (0 != (control & 1))
                    {
                        if (length < 1)
                            throw new InvalidFormatException();
                        input = m_input.ReadByte();
                        --length;
                        m_data[current++] = input;
                        m_window[window_index++] = input;
                        window_index &= 0xfff;
                    }
                    else
                    {
                        if (length < 2)
                            throw new InvalidFormatException();
                        int di = m_input.ReadByte();
                        input = m_input.ReadByte();
                        length -= 2;
                        int offset = ((di << 8) | input) >> 4;
                        int count = (input & 0xf) + 2;
                        for (int i = 0; i < count; ++i)
                        {
                            int src = (i + offset) & 0xfff;
                            input = m_window[src];
                            m_data[current++] = input;
                            m_window[window_index++] = input;
                            window_index &= 0xfff;
                        }
                    }
                }
            }

            #region IDisposable Members
            bool disposed = false;

            public void Dispose ()
            {
                Dispose (true);
                GC.SuppressFinalize (this);
            }

            protected virtual void Dispose (bool disposing)
            {
                if (!disposed)
                {
                    if (disposing)
                        m_input.Dispose();
                    m_input = null;
                    m_data = null;
                    disposed = true;
                }
            }
            #endregion
        }
    }
}
