//! \file       ImageCWP.cs
//! \date       Thu Jun 11 13:43:41 2015
//! \brief      Crowd engine image format.
//
// Copyright (C) 2015 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.ComponentModel.Composition;
using System.IO;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using GameRes.Utility;

namespace GameRes.Formats.Crowd
{
    [Export(typeof(ImageFormat))]
    public class CwpFormat : ImageFormat
    {
        public override string         Tag { get { return "CWP"; } }
        public override string Description { get { return "Crowd engine image format"; } }
        public override uint     Signature { get { return 0x50445743; } } // 'CWDP'

        public override ImageMetaData ReadMetaData (Stream stream)
        {
            using (var input = new ArcView.Reader (stream))
            {
                input.ReadInt32();
                uint width  = Binary.BigEndian (input.ReadUInt32());
                uint height = Binary.BigEndian (input.ReadUInt32());
                if (0 == width || 0 == height)
                    return null;
                int bpp = input.ReadByte();
                int color_type = input.ReadByte();
                switch (color_type)
                {
                case 2: bpp *= 3; break;
                case 4: bpp *= 2; break;
                case 6: bpp *= 4; break;
                case 3:
                case 0: break;
                default: return null;
                }
                return new ImageMetaData
                {
                    Width = width,
                    Height = height,
                    BPP = bpp,
                };
            }
        }

        public override ImageData Read (Stream stream, ImageMetaData info)
        {
            var header = new byte[0x15];
            using (var mem = new MemoryStream((int)(0x14 + stream.Length + 12)))
            using (var png = new BinaryWriter (mem))
            {
                png.Write (0x474E5089u); // png header
                png.Write (0x0A1A0A0Du);
                png.Write (0x0D000000u);
                png.Write (0x52444849u); // 'IHDR'
                stream.Position = 4;
                stream.Read (header, 0, header.Length);
                png.Write (header, 0, header.Length);
                png.Write (0x54414449u); // 'IDAT'
                stream.CopyTo (mem);
                header[1] = 0;
                header[2] = 0;
                header[3] = 0;
                LittleEndian.Pack (0x444E4549, header, 4);
                LittleEndian.Pack (0x826042AE, header, 8);
                png.Write (header, 1, 11);
                mem.Position = 0;
                var decoder = new PngBitmapDecoder (mem, BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
                BitmapSource frame = decoder.Frames[0];
                var pixels = new byte[info.Width*info.Height*4];
                frame.CopyPixels (pixels, (int)info.Width*4, 0);
                for (int i = 0; i < pixels.Length; i += 4)
                {
                    byte t = pixels[i];
                    pixels[i] = pixels[i+2];
                    pixels[i+2] = t;
                }
                return ImageData.Create (info, PixelFormats.Bgr32, null, pixels);
            }
        }

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