//! \file       ImageGPS.cs
//! \date       Sat Feb 20 14:13:10 2016
//! \brief      ADVEngine compressed bitmap.
//
// 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.Collections.Generic;
using System.ComponentModel.Composition;
using System.IO;
using GameRes.Compression;
using GameRes.Utility;

namespace GameRes.Formats.Abel
{
    internal class GpsMetaData : ImageMetaData
    {
        public byte Compression;
        public  int PackedSize;
        public  int UnpackedSize;
    }

    [Export(typeof(ImageFormat))]
    public class GpsFormat : BmpFormat
    {
        public override string         Tag { get { return "GPS"; } }
        public override string Description { get { return "ADVEngine compressed bitmap"; } }
        public override uint     Signature { get { return 0x535047; } } // 'GPS'
        public override bool      CanWrite { get { return false; } }

        public GpsFormat ()
        {
            Extensions = new string[] { "gps", "cmp" };
        }

        public override ImageMetaData ReadMetaData (Stream stream)
        {
            var header = new byte[0x29];
            if (header.Length != stream.Read (header, 0, header.Length))
                return null;
            var gps = new GpsMetaData
            {
                Width   = LittleEndian.ToUInt32 (header, 0x19),
                Height  = LittleEndian.ToUInt32 (header, 0x1D),
                Compression = header[0x10],
                UnpackedSize = LittleEndian.ToInt32 (header, 0x11),
                PackedSize = LittleEndian.ToInt32 (header, 0x15),
            };
            // read BMP header
            using (var input = OpenGpsStream (stream, gps.Compression, 0x54))
            {
                var bmp_info = base.ReadMetaData (input);
                if (null == bmp_info)
                    return null;
                gps.BPP = bmp_info.BPP;
                return gps;
            }
        }

        public override ImageData Read (Stream stream, ImageMetaData info)
        {
            var gps = (GpsMetaData)info;
            stream.Position = 0x29;
            using (var input = OpenGpsStream (stream, gps.Compression, gps.UnpackedSize))
                return base.Read (input, info);
        }

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

        Stream OpenGpsStream (Stream input, byte compression, int unpacked_size)
        {
            if (0 == compression)
                return new StreamRegion (input, 0x29, true);
            else if (1 == compression)
                return OpenRLEStream (input, unpacked_size);
            else if (2 == compression)
                return new LzssStream (input, LzssMode.Decompress, true);
            else if (3 == compression)
            {
                using (var lzss = new LzssStream (input, LzssMode.Decompress, true))
                    return OpenRLEStream (lzss, unpacked_size);
            }
            else
                throw new InvalidFormatException();
        }

        Stream OpenRLEStream (Stream input, int output_size)
        {
            var output = new byte[output_size];
            UnpackRLE (input, output);
            return new MemoryStream (output);
        }

        void UnpackRLE (Stream input, byte[] output)
        {
            int dst = 0;
            while (dst < output.Length)
            {
                int count = Math.Min (3, output.Length-dst);
                count = input.Read (output, dst, count);
                if (count < 3)
                    break;
                count = input.ReadByte();
                if (-1 == count)
                    break;
                dst += 3;
                if (count > 1)
                {
                    count = Math.Min ((count-1) * 3, output.Length-dst);
                    Binary.CopyOverlapped (output, dst-3, dst, count);
                    dst += count;
                }
            }
        }
    }
}