// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : MMC.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Core.
//
// --[ Description ] ----------------------------------------------------------
//
//     Detects media types in MultiMediaCommand devices
//
// --[ License ] --------------------------------------------------------------
//
//     This program is free software: you can redistribute it and/or modify
//     it under the terms of the GNU General Public License as
//     published by the Free Software Foundation, either version 3 of the
//     License, or (at your option) any later version.
//
//     This program is distributed in the hope that it will be useful,
//     but WITHOUT ANY WARRANTY; without even the implied warranty of
//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//     GNU General Public License for more details.
//
//     You should have received a copy of the GNU General Public License
//     along with this program.  If not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2019 Natalia Portillo
// ****************************************************************************/

using System;
using System.Linq;

namespace DiscImageChef.Core.Media.Detection
{
    public static class MMC
    {
        /// <summary>This is some kind of header. Every 10 bytes there's an audio byte.</summary>
        static readonly byte[] VideoNowColorFrameMarker =
        {
            0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3,
            0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81,
            0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7,
            0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3,
            0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00,
            0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3,
            0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81,
            0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7,
            0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3,
            0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00,
            0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3,
            0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81,
            0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7, 0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x81, 0xE3, 0xE3, 0xC7,
            0xC7, 0x81, 0x81, 0xE3, 0xC7, 0x00, 0x00, 0x00, 0x02, 0x01, 0x04, 0x02, 0x06, 0x03, 0xFF, 0x00, 0x08, 0x04,
            0x0A, 0x05, 0x0C, 0x06, 0x0E, 0x07, 0xFF, 0x00, 0x11, 0x08, 0x13, 0x09, 0x15, 0x0A, 0x17, 0x0B, 0xFF, 0x00,
            0x19, 0x0C, 0x1B, 0x0D, 0x1D, 0x0E, 0x1F, 0x0F, 0xFF, 0x00, 0x00, 0x28, 0x02, 0x29, 0x04, 0x2A, 0x06, 0x2B,
            0xFF, 0x00, 0x08, 0x2C, 0x0A, 0x2D, 0x0C, 0x2E, 0x0E, 0x2F, 0xFF, 0x00, 0x11, 0x30, 0x13, 0x31, 0x15, 0x32,
            0x17, 0x33, 0xFF, 0x00, 0x19, 0x34, 0x1B, 0x35, 0x1D, 0x36, 0x1F, 0x37, 0xFF, 0x00, 0x00, 0x38, 0x02, 0x39,
            0x04, 0x3A, 0x06, 0x3B, 0xFF, 0x00, 0x08, 0x3C, 0x0A, 0x3D, 0x0C, 0x3E, 0x0E, 0x3F, 0xFF, 0x00, 0x11, 0x40,
            0x13, 0x41, 0x15, 0x42, 0x17, 0x43, 0xFF, 0x00, 0x19, 0x44, 0x1B, 0x45, 0x1D, 0x46, 0x1F, 0x47, 0xFF, 0x00,
            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
            0xFF, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
            0xFF, 0xFF, 0xFF, 0x00
        };

        /// <summary>Checks if the media corresponds to CD-i.</summary>
        /// <param name="sector0">Contents of LBA 0, with all headers.</param>
        /// <param name="sector16">Contents of LBA 0, with all headers.</param>
        /// <returns><c>true</c> if it corresponds to a CD-i, <c>false</c>otherwise.</returns>
        public static bool IsCdi(byte[] sector0, byte[] sector16)
        {
            if(sector0?.Length  != 2352 ||
               sector16?.Length != 2352)
                return false;

            byte[] syncMark =
            {
                0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00
            };

            byte[] cdiMark =
            {
                0x01, 0x43, 0x44, 0x2D
            };

            byte[] testMark = new byte[12];
            Array.Copy(sector0, 0, testMark, 0, 12);

            bool hiddenData = syncMark.SequenceEqual(testMark) &&
                              (sector0[0xF] == 0 || sector0[0xF] == 1 || sector0[0xF] == 2);

            if(!hiddenData ||
               sector0[0xF] != 2)
                return false;

            testMark = new byte[4];
            Array.Copy(sector16, 24, testMark, 0, 4);

            return cdiMark.SequenceEqual(testMark);
        }

        public static bool IsVideoNowColor(byte[] videoFrame)
        {
            if(videoFrame is null ||
               videoFrame.Length < VideoNowColorFrameMarker.Length)
                return false;

            byte[] buffer = new byte[VideoNowColorFrameMarker.Length];

            for(int framePosition = 0; framePosition + buffer.Length < videoFrame.Length; framePosition++)
            {
                Array.Copy(videoFrame, framePosition, buffer, 0, buffer.Length);

                for(int ab = 9; ab < buffer.Length; ab += 10)
                    buffer[ab] = 0;

                if(!VideoNowColorFrameMarker.SequenceEqual(buffer))
                    continue;

                return true;
            }

            return false;
        }

        public static int GetVideoNowColorOffset(byte[] data)
        {
            byte[] buffer = new byte[VideoNowColorFrameMarker.Length];

            for(int framePosition = 0; framePosition + buffer.Length < data.Length; framePosition++)
            {
                Array.Copy(data, framePosition, buffer, 0, buffer.Length);

                for(int ab = 9; ab < buffer.Length; ab += 10)
                    buffer[ab] = 0;

                if(!VideoNowColorFrameMarker.SequenceEqual(buffer))
                    continue;

                return 18032 - framePosition;
            }

            return 0;
        }
    }
}