// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : Write.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Disk image plugins.
//
// --[ Description ] ----------------------------------------------------------
//
//     Writes Apple Universal Disk Image Format.
//
// --[ License ] --------------------------------------------------------------
//
//     This library is free software; you can redistribute it and/or modify
//     it under the terms of the GNU Lesser General Public License as
//     published by the Free Software Foundation; either version 2.1 of the
//     License, or (at your option) any later version.
//
//     This library 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
//     Lesser General Public License for more details.
//
//     You should have received a copy of the GNU Lesser General Public
//     License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2021 Natalia Portillo
// ****************************************************************************/

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using Aaru.Checksums;
using Aaru.CommonTypes;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Structs;
using Aaru.Helpers;
using Claunia.PropertyList;
using Schemas;

namespace Aaru.DiscImages
{
    public sealed partial class Udif
    {
        /// <inheritdoc />
        public bool Create(string path, MediaType mediaType, Dictionary<string, string> options, ulong sectors,
                           uint sectorSize)
        {
            if(sectorSize != 512)
            {
                ErrorMessage = "Unsupported sector size";

                return false;
            }

            if(!SupportedMediaTypes.Contains(mediaType))
            {
                ErrorMessage = $"Unsupported media format {mediaType}";

                return false;
            }

            _imageInfo = new ImageInfo
            {
                MediaType  = mediaType,
                SectorSize = sectorSize,
                Sectors    = sectors
            };

            try
            {
                _writingStream = new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.None);
            }
            catch(IOException e)
            {
                ErrorMessage = $"Could not create new image file, exception {e.Message}";

                return false;
            }

            _chunks           = new Dictionary<ulong, BlockChunk>();
            _currentChunk     = new BlockChunk();
            _currentSector    = 0;
            _dataForkChecksum = new Crc32Context();
            _masterChecksum   = new Crc32Context();

            IsWriting    = true;
            ErrorMessage = null;

            return true;
        }

        /// <inheritdoc />
        public bool WriteMediaTag(byte[] data, MediaTagType tag)
        {
            ErrorMessage = "Writing media tags is not supported.";

            return false;
        }

        /// <inheritdoc />
        public bool WriteSector(byte[] data, ulong sectorAddress)
        {
            if(!IsWriting)
            {
                ErrorMessage = "Tried to write on a non-writable image";

                return false;
            }

            if(data.Length != _imageInfo.SectorSize)
            {
                ErrorMessage = "Incorrect data size";

                return false;
            }

            if(sectorAddress >= _imageInfo.Sectors)
            {
                ErrorMessage = "Tried to write past image size";

                return false;
            }

            if(sectorAddress < _currentSector)
            {
                ErrorMessage = "Tried to rewind, this format rewinded on writing";

                return false;
            }

            _masterChecksum.Update(data);

            bool isEmpty = ArrayHelpers.ArrayIsNullOrEmpty(data);

            switch(_currentChunk.type)
            {
                case CHUNK_TYPE_ZERO:
                    _currentChunk.type = isEmpty ? CHUNK_TYPE_NOCOPY : CHUNK_TYPE_COPY;

                    break;
                case CHUNK_TYPE_NOCOPY when !isEmpty:
                case CHUNK_TYPE_COPY when isEmpty:
                    _chunks.Add(_currentChunk.sector, _currentChunk);

                    _currentChunk = new BlockChunk
                    {
                        type   = isEmpty ? CHUNK_TYPE_NOCOPY : CHUNK_TYPE_COPY,
                        sector = _currentSector,
                        offset = (ulong)(isEmpty ? 0 : _writingStream.Position)
                    };

                    break;
            }

            _currentChunk.sectors++;
            _currentChunk.length += (ulong)(isEmpty ? 0 : 512);
            _currentSector++;

            if(!isEmpty)
            {
                _dataForkChecksum.Update(data);
                _writingStream.Write(data, 0, data.Length);
            }

            ErrorMessage = "";

            return true;
        }

        // TODO: This can be optimized
        /// <inheritdoc />
        public bool WriteSectors(byte[] data, ulong sectorAddress, uint length)
        {
            if(!IsWriting)
            {
                ErrorMessage = "Tried to write on a non-writable image";

                return false;
            }

            if(data.Length % _imageInfo.SectorSize != 0)
            {
                ErrorMessage = "Incorrect data size";

                return false;
            }

            if(sectorAddress + length > _imageInfo.Sectors)
            {
                ErrorMessage = "Tried to write past image size";

                return false;
            }

            // Ignore empty sectors
            if(ArrayHelpers.ArrayIsNullOrEmpty(data))
            {
                if(_currentChunk.type == CHUNK_TYPE_COPY)
                {
                    _chunks.Add(_currentChunk.sector, _currentChunk);

                    _currentChunk = new BlockChunk
                    {
                        type   = CHUNK_TYPE_NOCOPY,
                        sector = _currentSector
                    };
                }

                _currentChunk.sectors += (ulong)(data.Length / _imageInfo.SectorSize);
                _currentSector        += (ulong)(data.Length / _imageInfo.SectorSize);
                _masterChecksum.Update(data);

                ErrorMessage = "";

                return true;
            }

            for(uint i = 0; i < length; i++)
            {
                byte[] tmp = new byte[_imageInfo.SectorSize];
                Array.Copy(data, i * _imageInfo.SectorSize, tmp, 0, _imageInfo.SectorSize);

                if(!WriteSector(tmp, sectorAddress + i))
                    return false;
            }

            ErrorMessage = "";

            return true;
        }

        /// <inheritdoc />
        public bool WriteSectorLong(byte[] data, ulong sectorAddress)
        {
            ErrorMessage = "Writing sectors with tags is not supported.";

            return false;
        }

        /// <inheritdoc />
        public bool WriteSectorsLong(byte[] data, ulong sectorAddress, uint length)
        {
            ErrorMessage = "Writing sectors with tags is not supported.";

            return false;
        }

        /// <inheritdoc />
        public bool Close()
        {
            if(!IsWriting)
            {
                ErrorMessage = "Image is not opened for writing";

                return false;
            }

            if(_currentChunk.type != CHUNK_TYPE_NOCOPY)
                _currentChunk.length = _currentChunk.sectors * 512;

            _chunks.Add(_currentChunk.sector, _currentChunk);

            _chunks.Add(_imageInfo.Sectors, new BlockChunk
            {
                type   = CHUNK_TYPE_END,
                sector = _imageInfo.Sectors
            });

            var bHdr = new BlockHeader
            {
                signature    = CHUNK_SIGNATURE,
                version      = 1,
                sectorCount  = _imageInfo.Sectors,
                checksumType = UDIF_CHECKSUM_TYPE_CRC32,
                checksumLen  = 32,
                checksum     = BitConverter.ToUInt32(_dataForkChecksum.Final().Reverse().ToArray(), 0),
                chunks       = (uint)_chunks.Count
            };

            var chunkMs = new MemoryStream();
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.signature), 0, 4);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.version), 0, 4);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.sectorStart), 0, 8);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.sectorCount), 0, 8);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.dataOffset), 0, 8);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.buffers), 0, 4);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.descriptor), 0, 4);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.reserved1), 0, 4);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.reserved2), 0, 4);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.reserved3), 0, 4);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.reserved4), 0, 4);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.reserved5), 0, 4);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.reserved6), 0, 4);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.checksumType), 0, 4);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.checksumLen), 0, 4);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.checksum), 0, 4);
            chunkMs.Write(new byte[124], 0, 124);
            chunkMs.Write(BigEndianBitConverter.GetBytes(bHdr.chunks), 0, 4);

            foreach(BlockChunk chunk in _chunks.Values)
            {
                chunkMs.Write(BigEndianBitConverter.GetBytes(chunk.type), 0, 4);
                chunkMs.Write(BigEndianBitConverter.GetBytes(chunk.comment), 0, 4);
                chunkMs.Write(BigEndianBitConverter.GetBytes(chunk.sector), 0, 8);
                chunkMs.Write(BigEndianBitConverter.GetBytes(chunk.sectors), 0, 8);
                chunkMs.Write(BigEndianBitConverter.GetBytes(chunk.offset), 0, 8);
                chunkMs.Write(BigEndianBitConverter.GetBytes(chunk.length), 0, 8);
            }

            byte[] plist = Encoding.UTF8.GetBytes(new NSDictionary
            {
                {
                    "resource-fork", new NSDictionary
                    {
                        {
                            "blkx", new NSArray
                            {
                                new NSDictionary
                                {
                                    {
                                        "Attributes", "0x0050"
                                    },
                                    {
                                        "CFName", "whole disk (Aaru : 0)"
                                    },
                                    {
                                        "Data", chunkMs.ToArray()
                                    },
                                    {
                                        "ID", "0"
                                    },
                                    {
                                        "Name", "whole disk (Aaru : 0)"
                                    }
                                }
                            }
                        }
                    }
                }
            }.ToXmlPropertyList());

            _footer = new Footer
            {
                signature       = UDIF_SIGNATURE,
                version         = 4,
                headerSize      = 512,
                flags           = 1,
                dataForkLen     = (ulong)_writingStream.Length,
                segmentNumber   = 1,
                segmentCount    = 1,
                segmentId       = Guid.NewGuid(),
                dataForkChkType = UDIF_CHECKSUM_TYPE_CRC32,
                dataForkChkLen  = 32,
                dataForkChk     = BitConverter.ToUInt32(_dataForkChecksum.Final().Reverse().ToArray(), 0),
                plistOff        = (ulong)_writingStream.Length,
                plistLen        = (ulong)plist.Length,

                // TODO: Find how is this calculated
                /*masterChkType   = 2,
                masterChkLen    = 32,
                masterChk       = BitConverter.ToUInt32(masterChecksum.Final().Reverse().ToArray(), 0),*/
                imageVariant = 2,
                sectorCount  = _imageInfo.Sectors
            };

            _writingStream.Seek(0, SeekOrigin.End);
            _writingStream.Write(plist, 0, plist.Length);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.signature), 0, 4);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.version), 0, 4);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.headerSize), 0, 4);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.flags), 0, 4);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.runningDataForkOff), 0, 8);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.dataForkOff), 0, 8);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.dataForkLen), 0, 8);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.rsrcForkOff), 0, 8);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.rsrcForkLen), 0, 8);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.segmentNumber), 0, 4);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.segmentCount), 0, 4);
            _writingStream.Write(_footer.segmentId.ToByteArray(), 0, 16);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.dataForkChkType), 0, 4);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.dataForkChkLen), 0, 4);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.dataForkChk), 0, 4);
            _writingStream.Write(new byte[124], 0, 124);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.plistOff), 0, 8);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.plistLen), 0, 8);
            _writingStream.Write(new byte[120], 0, 120);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.masterChkType), 0, 4);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.masterChkLen), 0, 4);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.masterChk), 0, 4);
            _writingStream.Write(new byte[124], 0, 124);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.imageVariant), 0, 4);
            _writingStream.Write(BigEndianBitConverter.GetBytes(_footer.sectorCount), 0, 8);
            _writingStream.Write(new byte[12], 0, 12);

            _writingStream.Flush();
            _writingStream.Close();

            IsWriting    = false;
            ErrorMessage = "";

            return true;
        }

        // TODO: Comments
        /// <inheritdoc />
        public bool SetMetadata(ImageInfo metadata) => true;

        /// <inheritdoc />
        public bool SetGeometry(uint cylinders, uint heads, uint sectorsPerTrack) => true;

        /// <inheritdoc />
        public bool WriteSectorTag(byte[] data, ulong sectorAddress, SectorTagType tag)
        {
            ErrorMessage = "Writing sectors with tags is not supported.";

            return false;
        }

        /// <inheritdoc />
        public bool WriteSectorsTag(byte[] data, ulong sectorAddress, uint length, SectorTagType tag)
        {
            ErrorMessage = "Writing sectors with tags is not supported.";

            return false;
        }

        /// <inheritdoc />
        public bool SetDumpHardware(List<DumpHardwareType> dumpHardware) => false;

        /// <inheritdoc />
        public bool SetCicmMetadata(CICMMetadataType metadata) => false;
    }
}