//! \file       ImageIAR.cs
//! \date       Fri Oct 23 15:17:52 2015
//! \brief      Intermediate image format representing IAR archives entries.
//
// 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 GameRes.Utility;
using System;
using System.ComponentModel.Composition;
using System.IO;
using System.Windows.Media;
using System.Windows.Media.Imaging;

namespace GameRes.Formats.Sas5
{
    internal class IarMetaData : ImageMetaData
    {
        public int  Stride;
        public int  PaletteSize;
        public int  ImageSize;
    }

    // This is an artificial format, used by GARbro internally. structure:
    // 0x0000 'IAR\x00'
    // 0x0004 'SAS5'
    // 0x0008 Width
    // 0x000C Height
    // 0x0010 OffsetX
    // 0x0014 OffsetY
    // 0x0018 BPP
    // 0x001C Stride
    // 0x0020 PaletteSize
    // 0x0024 ImageSize
    // 0x0028 Palette [if PaletteSize > 0]
    // ...... Image data

    [Export(typeof(ImageFormat))]
    public class IarFormat : ImageFormat
    {
        public override string         Tag { get { return "IAR/IMAGE"; } }
        public override string Description { get { return "SAS5 engine compressed image format"; } }
        public override uint     Signature { get { return 0x00524149; } } // 'IAR'

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

        public override ImageMetaData ReadMetaData (Stream stream)
        {
            var header = new byte[0x28];
            if (header.Length != stream.Read (header, 0, header.Length))
                return null;
            if (!Binary.AsciiEqual (header, 4, "SAS5"))
                return null;
            return new IarMetaData
            {
                Width   = LittleEndian.ToUInt32 (header, 0x08),
                Height  = LittleEndian.ToUInt32 (header, 0x0C),
                OffsetX = -LittleEndian.ToInt32 (header, 0x10),
                OffsetY = -LittleEndian.ToInt32 (header, 0x14),
                BPP     = LittleEndian.ToInt32 (header, 0x18),
                Stride  = LittleEndian.ToInt32 (header, 0x1C),
                PaletteSize = LittleEndian.ToInt32 (header, 0x20),
                ImageSize = LittleEndian.ToInt32 (header, 0x24),
            };
        }

        public override ImageData Read (Stream stream, ImageMetaData info)
        {
            var meta = info as IarMetaData;
            if (null == meta)
                throw new ArgumentException ("IarFormat.Read should be supplied with IarMetaData", "info");

            PixelFormat format;
            if (32 == meta.BPP)
                format = PixelFormats.Bgra32;
            else if (24 == meta.BPP)
                format = PixelFormats.Bgr24;
            else if (0 == meta.PaletteSize)
                format = PixelFormats.Gray8;
            else
                format = PixelFormats.Indexed8;

            stream.Position = 0x28;
            BitmapPalette palette = null;
            if (meta.PaletteSize > 0)
                palette = ReadPalette (stream, meta.PaletteSize);
            var pixels = new byte[meta.ImageSize];
            stream.Read (pixels, 0, pixels.Length);
            return ImageData.Create (info, format, palette, pixels, meta.Stride);
        }

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

        static BitmapPalette ReadPalette (Stream input, int palette_size)
        {
            var palette_data = new byte[palette_size];
            if (palette_data.Length != input.Read (palette_data, 0, palette_data.Length))
                throw new EndOfStreamException();
            palette_size = Math.Min (0x400, palette_size);
            int color_size = palette_size / 0x100;
            var palette = new Color[0x100];
            for (int i = 0; i < palette.Length; ++i)
            {
                int c = i * color_size;
                palette[i] = Color.FromRgb (palette_data[c+2], palette_data[c+1], palette_data[c]);
            }
            return new BitmapPalette (palette);
        }
    }
}
