// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : Write.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Disk image plugins.
//
// --[ Description ] ----------------------------------------------------------
//
//     Writes Parallels disk images.
//
// --[ 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 Aaru.CommonTypes;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Structs;
using Aaru.Helpers;
using Schemas;

namespace Aaru.DiscImages
{
    public sealed partial class Parallels
    {
        // TODO: Support extended
        /// <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;
            }

            if(sectors * sectorSize / DEFAULT_CLUSTER_SIZE > uint.MaxValue)
            {
                ErrorMessage = "Too many sectors for selected cluster size";

                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;
            }

            uint batEntries = (uint)(sectors * sectorSize / DEFAULT_CLUSTER_SIZE);

            if(sectors * sectorSize % DEFAULT_CLUSTER_SIZE > 0)
                batEntries++;

            uint headerSectors = (uint)Marshal.SizeOf<Header>() + (batEntries * 4);

            if((uint)Marshal.SizeOf<Header>() + (batEntries % 4) > 0)
                headerSectors++;

            _pHdr = new Header
            {
                magic        = _magic,
                version      = PARALLELS_VERSION,
                sectors      = sectors,
                in_use       = PARALLELS_CLOSED,
                bat_entries  = batEntries,
                data_off     = headerSectors,
                cluster_size = DEFAULT_CLUSTER_SIZE / 512
            };

            _bat                    = new uint[batEntries];
            _currentWritingPosition = headerSectors * 512;

            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 != 512)
            {
                ErrorMessage = "Incorrect data size";

                return false;
            }

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

                return false;
            }

            // Ignore empty sectors
            if(ArrayHelpers.ArrayIsNullOrEmpty(data))
                return true;

            ulong index  = sectorAddress / _pHdr.cluster_size;
            ulong secOff = sectorAddress % _pHdr.cluster_size;

            uint batOff = _bat[index];

            if(batOff == 0)
            {
                batOff                  =  (uint)(_currentWritingPosition / 512);
                _bat[index]             =  batOff;
                _currentWritingPosition += _pHdr.cluster_size * 512L;
            }

            ulong imageOff = batOff * 512UL;

            _writingStream.Seek((long)imageOff, SeekOrigin.Begin);
            _writingStream.Seek((long)secOff * 512, SeekOrigin.Current);
            _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 % 512 != 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))
                return true;

            for(uint i = 0; i < length; i++)
            {
                byte[] tmp = new byte[512];
                Array.Copy(data, i * 512, tmp, 0, 512);

                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(_pHdr.cylinders == 0)
            {
                _pHdr.cylinders            = (uint)(_imageInfo.Sectors / 16 / 63);
                _pHdr.heads                = 16;
                _imageInfo.SectorsPerTrack = 63;

                while(_pHdr.cylinders == 0)
                {
                    _pHdr.heads--;

                    if(_pHdr.heads == 0)
                    {
                        _imageInfo.SectorsPerTrack--;
                        _pHdr.heads = 16;
                    }

                    _pHdr.cylinders = (uint)(_imageInfo.Sectors / _pHdr.heads / _imageInfo.SectorsPerTrack);

                    if(_pHdr.cylinders            == 0 &&
                       _pHdr.heads                == 0 &&
                       _imageInfo.SectorsPerTrack == 0)
                        break;
                }
            }

            byte[] hdr    = new byte[Marshal.SizeOf<Header>()];
            IntPtr hdrPtr = System.Runtime.InteropServices.Marshal.AllocHGlobal(Marshal.SizeOf<Header>());
            System.Runtime.InteropServices.Marshal.StructureToPtr(_pHdr, hdrPtr, true);
            System.Runtime.InteropServices.Marshal.Copy(hdrPtr, hdr, 0, hdr.Length);
            System.Runtime.InteropServices.Marshal.FreeHGlobal(hdrPtr);

            _writingStream.Seek(0, SeekOrigin.Begin);
            _writingStream.Write(hdr, 0, hdr.Length);

            for(long i = 0; i < _bat.LongLength; i++)
                _writingStream.Write(BitConverter.GetBytes(_bat[i]), 0, 4);

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

            IsWriting    = false;
            ErrorMessage = "";

            return true;
        }

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

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

            return 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;
    }
}