// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : Super.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Apple Lisa filesystem plugin.
//
// --[ Description ] ----------------------------------------------------------
//
//     Handles mounting and umounting the Apple Lisa filesystem.
//
// --[ 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 © 2011-2017 Natalia Portillo
// ****************************************************************************/

using System;
using System.Collections.Generic;
using DiscImageChef.Console;
using DiscImageChef.ImagePlugins;
using DiscImageChef.Decoders;

namespace DiscImageChef.Filesystems.LisaFS
{
    public partial class LisaFS : Filesystem
    {
        /// <summary>
        /// Mounts an Apple Lisa filesystem
        /// </summary>
        public override Errno Mount()
        {
            return Mount(false);
        }

        /// <summary>
        /// Mounts an Apple Lisa filesystem
        /// </summary>
        public override Errno Mount(bool debug)
        {
            try
            {
                // Lisa OS is unable to work on disks without tags.
                // This code is designed like that.
                // However with some effort the code may be modified to ignore them.
                if(device.ImageInfo.readableSectorTags == null ||
                   !device.ImageInfo.readableSectorTags.Contains(SectorTagType.AppleSectorTag))
                {
                    DicConsole.DebugWriteLine("LisaFS plugin", "Underlying device does not support Lisa tags");
                    return Errno.InOutError;
                }

                // LisaOS is big-endian
                BigEndianBitConverter.IsLittleEndian = BitConverter.IsLittleEndian;

                // Minimal LisaOS disk is 3.5" single sided double density, 800 sectors
                if(device.GetSectors() < 800)
                {
                    DicConsole.DebugWriteLine("LisaFS plugin", "Device is too small");
                    return Errno.InOutError;
                }

                // MDDF cannot be at end of device, of course
                volumePrefix = device.ImageInfo.sectors;

                // LisaOS searches sectors until tag tells MDDF resides there, so we'll search 100 sectors
                for(ulong i = 0; i < 100; i++)
                {
                    LisaTag.PriamTag searchTag;
                    DecodeTag(device.ReadSectorTag(i, SectorTagType.AppleSectorTag), out searchTag);

                    DicConsole.DebugWriteLine("LisaFS plugin", "Sector {0}, file ID 0x{1:X4}", i, searchTag.fileID);

                    if(volumePrefix == device.ImageInfo.sectors && searchTag.fileID == FILEID_LOADER_SIGNED)
                        volumePrefix = i - 1;

                    if(searchTag.fileID == FILEID_MDDF)
                    {
                        devTagSize = device.ReadSectorTag(i, SectorTagType.AppleSectorTag).Length;

                        byte[] sector = device.ReadSector(i);
                        mddf = new MDDF();
                        byte[] pString = new byte[33];
                        uint lisa_time;

                        mddf.fsversion = BigEndianBitConverter.ToUInt16(sector, 0x00);
                        mddf.volid = BigEndianBitConverter.ToUInt64(sector, 0x02);
                        mddf.volnum = BigEndianBitConverter.ToUInt16(sector, 0x0A);
                        Array.Copy(sector, 0x0C, pString, 0, 33);
                        mddf.volname = StringHandlers.PascalToString(pString, CurrentEncoding);
                        mddf.unknown1 = sector[0x2D];
                        Array.Copy(sector, 0x2E, pString, 0, 33);
                        // Prevent garbage
                        if(pString[0] <= 32)
                            mddf.password = StringHandlers.PascalToString(pString, CurrentEncoding);
                        else
                            mddf.password = "";
                        mddf.unknown2 = sector[0x4F];
                        mddf.machine_id = BigEndianBitConverter.ToUInt32(sector, 0x50);
                        mddf.master_copy_id = BigEndianBitConverter.ToUInt32(sector, 0x54);
                        lisa_time = BigEndianBitConverter.ToUInt32(sector, 0x58);
                        mddf.dtvc = DateHandlers.LisaToDateTime(lisa_time);
                        lisa_time = BigEndianBitConverter.ToUInt32(sector, 0x5C);
                        mddf.dtcc = DateHandlers.LisaToDateTime(lisa_time);
                        lisa_time = BigEndianBitConverter.ToUInt32(sector, 0x60);
                        mddf.dtvb = DateHandlers.LisaToDateTime(lisa_time);
                        lisa_time = BigEndianBitConverter.ToUInt32(sector, 0x64);
                        mddf.dtvs = DateHandlers.LisaToDateTime(lisa_time);
                        mddf.unknown3 = BigEndianBitConverter.ToUInt32(sector, 0x68);
                        mddf.mddf_block = BigEndianBitConverter.ToUInt32(sector, 0x6C);
                        mddf.volsize_minus_one = BigEndianBitConverter.ToUInt32(sector, 0x70);
                        mddf.volsize_minus_mddf_minus_one = BigEndianBitConverter.ToUInt32(sector, 0x74);
                        mddf.vol_size = BigEndianBitConverter.ToUInt32(sector, 0x78);
                        mddf.blocksize = BigEndianBitConverter.ToUInt16(sector, 0x7C);
                        mddf.datasize = BigEndianBitConverter.ToUInt16(sector, 0x7E);
                        mddf.unknown4 = BigEndianBitConverter.ToUInt16(sector, 0x80);
                        mddf.unknown5 = BigEndianBitConverter.ToUInt32(sector, 0x82);
                        mddf.unknown6 = BigEndianBitConverter.ToUInt32(sector, 0x86);
                        mddf.clustersize = BigEndianBitConverter.ToUInt16(sector, 0x8A);
                        mddf.fs_size = BigEndianBitConverter.ToUInt32(sector, 0x8C);
                        mddf.unknown7 = BigEndianBitConverter.ToUInt32(sector, 0x90);
                        mddf.srec_ptr = BigEndianBitConverter.ToUInt32(sector, 0x94);
                        mddf.unknown9 = BigEndianBitConverter.ToUInt16(sector, 0x98);
                        mddf.srec_len = BigEndianBitConverter.ToUInt16(sector, 0x9A);
                        mddf.unknown10 = BigEndianBitConverter.ToUInt32(sector, 0x9C);
                        mddf.unknown11 = BigEndianBitConverter.ToUInt32(sector, 0xA0);
                        mddf.unknown12 = BigEndianBitConverter.ToUInt32(sector, 0xA4);
                        mddf.unknown13 = BigEndianBitConverter.ToUInt32(sector, 0xA8);
                        mddf.unknown14 = BigEndianBitConverter.ToUInt32(sector, 0xAC);
                        mddf.filecount = BigEndianBitConverter.ToUInt16(sector, 0xB0);
                        mddf.unknown15 = BigEndianBitConverter.ToUInt32(sector, 0xB2);
                        mddf.unknown16 = BigEndianBitConverter.ToUInt32(sector, 0xB6);
                        mddf.freecount = BigEndianBitConverter.ToUInt32(sector, 0xBA);
                        mddf.unknown17 = BigEndianBitConverter.ToUInt16(sector, 0xBE);
                        mddf.unknown18 = BigEndianBitConverter.ToUInt32(sector, 0xC0);
                        mddf.overmount_stamp = BigEndianBitConverter.ToUInt64(sector, 0xC4);
                        mddf.serialization = BigEndianBitConverter.ToUInt32(sector, 0xCC);
                        mddf.unknown19 = BigEndianBitConverter.ToUInt32(sector, 0xD0);
                        mddf.unknown_timestamp = BigEndianBitConverter.ToUInt32(sector, 0xD4);
                        mddf.unknown20 = BigEndianBitConverter.ToUInt32(sector, 0xD8);
                        mddf.unknown21 = BigEndianBitConverter.ToUInt32(sector, 0xDC);
                        mddf.unknown22 = BigEndianBitConverter.ToUInt32(sector, 0xE0);
                        mddf.unknown23 = BigEndianBitConverter.ToUInt32(sector, 0xE4);
                        mddf.unknown24 = BigEndianBitConverter.ToUInt32(sector, 0xE8);
                        mddf.unknown25 = BigEndianBitConverter.ToUInt32(sector, 0xEC);
                        mddf.unknown26 = BigEndianBitConverter.ToUInt32(sector, 0xF0);
                        mddf.unknown27 = BigEndianBitConverter.ToUInt32(sector, 0xF4);
                        mddf.unknown28 = BigEndianBitConverter.ToUInt32(sector, 0xF8);
                        mddf.unknown29 = BigEndianBitConverter.ToUInt32(sector, 0xFC);
                        mddf.unknown30 = BigEndianBitConverter.ToUInt32(sector, 0x100);
                        mddf.unknown31 = BigEndianBitConverter.ToUInt32(sector, 0x104);
                        mddf.unknown32 = BigEndianBitConverter.ToUInt32(sector, 0x108);
                        mddf.unknown33 = BigEndianBitConverter.ToUInt32(sector, 0x10C);
                        mddf.unknown34 = BigEndianBitConverter.ToUInt32(sector, 0x110);
                        mddf.unknown35 = BigEndianBitConverter.ToUInt32(sector, 0x114);
                        mddf.backup_volid = BigEndianBitConverter.ToUInt64(sector, 0x118);
                        mddf.label_size = BigEndianBitConverter.ToUInt16(sector, 0x120);
                        mddf.fs_overhead = BigEndianBitConverter.ToUInt16(sector, 0x122);
                        mddf.result_scavenge = BigEndianBitConverter.ToUInt16(sector, 0x124);
                        mddf.boot_code = BigEndianBitConverter.ToUInt16(sector, 0x126);
                        mddf.boot_environ = BigEndianBitConverter.ToUInt16(sector, 0x6C);
                        mddf.unknown36 = BigEndianBitConverter.ToUInt32(sector, 0x12A);
                        mddf.unknown37 = BigEndianBitConverter.ToUInt32(sector, 0x12E);
                        mddf.unknown38 = BigEndianBitConverter.ToUInt32(sector, 0x132);
                        mddf.vol_sequence = BigEndianBitConverter.ToUInt16(sector, 0x136);
                        mddf.vol_left_mounted = sector[0x138];

                        // Check that the MDDF is correct
                        if(mddf.mddf_block != i - volumePrefix ||
                            mddf.vol_size > device.GetSectors() ||
                            mddf.vol_size - 1 != mddf.volsize_minus_one ||
                            mddf.vol_size - i - 1 != mddf.volsize_minus_mddf_minus_one - volumePrefix ||
                            mddf.datasize > mddf.blocksize ||
                            mddf.blocksize < device.GetSectorSize() ||
                            mddf.datasize != device.GetSectorSize())
                        {
                            DicConsole.DebugWriteLine("LisaFS plugin", "Incorrect MDDF found");
                            return Errno.InvalidArgument;
                        }

                        // Check MDDF version
                        switch(mddf.fsversion)
                        {
                            case LisaFSv1:
                                DicConsole.DebugWriteLine("LisaFS plugin", "Mounting LisaFS v1");
                                break;
                            case LisaFSv2:
                                DicConsole.DebugWriteLine("LisaFS plugin", "Mounting LisaFS v2");
                                break;
                            case LisaFSv3:
                                DicConsole.DebugWriteLine("LisaFS plugin", "Mounting LisaFS v3");
                                break;
                            default:
                                DicConsole.ErrorWriteLine("Cannot mount LisaFS version {0}", mddf.fsversion.ToString());
                                return Errno.NotSupported;
                        }

                        // Initialize caches
                        extentCache = new Dictionary<short, ExtentFile>();
                        systemFileCache = new Dictionary<short, byte[]>();
                        fileCache = new Dictionary<short, byte[]>();
                        //catalogCache = new Dictionary<short, List<CatalogEntry>>();
                        fileSizeCache = new Dictionary<short, int>();

                        Errno error;

                        mounted = true;
                        this.debug = debug;

                        if(debug)
                        {
                            printedExtents = new List<short>();
                        }

                        // Read the S-Records file
                        error = ReadSRecords();
                        if(error != Errno.NoError)
                        {
                            DicConsole.ErrorWriteLine("Error {0} reading S-Records file.", error);
                            return error;
                        }

                        directoryDTCCache = new Dictionary<short, DateTime>();
                        directoryDTCCache.Add(DIRID_ROOT, mddf.dtcc);

                        // Read the Catalog File
                        error = ReadCatalog();

                        if(error != Errno.NoError)
                        {
                            DicConsole.DebugWriteLine("LisaFS plugin", "Cannot read Catalog File, error {0}", error.ToString());
                            mounted = false;
                            return error;
                        }

                        // If debug, cache system files
                        if(debug)
                        {
                            byte[] temp;

                            error = ReadSystemFile(FILEID_BOOT_SIGNED, out temp);
                            if(error != Errno.NoError)
                            {
                                DicConsole.DebugWriteLine("LisaFS plugin", "Unable to read boot blocks");
                                mounted = false;
                                return error;
                            }

                            error = ReadSystemFile(FILEID_LOADER_SIGNED, out temp);
                            if(error != Errno.NoError)
                            {
                                DicConsole.DebugWriteLine("LisaFS plugin", "Unable to read boot loader");
                                mounted = false;
                                return error;
                            }

                            error = ReadSystemFile((short)FILEID_MDDF, out temp);
                            if(error != Errno.NoError)
                            {
                                DicConsole.DebugWriteLine("LisaFS plugin", "Unable to read MDDF");
                                mounted = false;
                                return error;
                            }

                            error = ReadSystemFile((short)FILEID_BITMAP, out temp);
                            if(error != Errno.NoError)
                            {
                                DicConsole.DebugWriteLine("LisaFS plugin", "Unable to read volume bitmap");
                                mounted = false;
                                return error;
                            }

                            error = ReadSystemFile((short)FILEID_SRECORD, out temp);
                            if(error != Errno.NoError)
                            {
                                DicConsole.DebugWriteLine("LisaFS plugin", "Unable to read S-Records file");
                                mounted = false;
                                return error;
                            }
                        }

                        // Create XML metadata for mounted filesystem
                        xmlFSType = new Schemas.FileSystemType();
                        if(DateTime.Compare(mddf.dtvb, DateHandlers.LisaToDateTime(0)) > 0)
                        {
                            xmlFSType.BackupDate = mddf.dtvb;
                            xmlFSType.BackupDateSpecified = true;
                        }
                        xmlFSType.Clusters = mddf.vol_size;
                        xmlFSType.ClusterSize = mddf.clustersize * mddf.datasize;
                        if(DateTime.Compare(mddf.dtvc, DateHandlers.LisaToDateTime(0)) > 0)
                        {
                            xmlFSType.CreationDate = mddf.dtvc;
                            xmlFSType.CreationDateSpecified = true;
                        }
                        xmlFSType.Dirty = mddf.vol_left_mounted != 0;
                        xmlFSType.Files = mddf.filecount;
                        xmlFSType.FilesSpecified = true;
                        xmlFSType.FreeClusters = mddf.freecount;
                        xmlFSType.FreeClustersSpecified = true;
                        xmlFSType.Type = "LisaFS";
                        xmlFSType.VolumeName = mddf.volname;
                        xmlFSType.VolumeSerial = string.Format("{0:X16}", mddf.volid);

                        return Errno.NoError;
                    }
                }

                DicConsole.DebugWriteLine("LisaFS plugin", "Not a Lisa filesystem");
                return Errno.NotSupported;
            }
            catch(Exception ex)
            {
                DicConsole.ErrorWriteLine("Exception {0}, {1}, {2}", ex.Message, ex.InnerException, ex.StackTrace);
                return Errno.InOutError;
            }
        }

        /// <summary>
        /// Umounts this Lisa filesystem
        /// </summary>
        public override Errno Unmount()
        {
            mounted = false;
            extentCache = null;
            systemFileCache = null;
            fileCache = null;
            catalogCache = null;
            fileSizeCache = null;
            printedExtents = null;
            mddf = new MDDF();
            volumePrefix = 0;
            devTagSize = 0;
            srecords = null;

            return Errno.NoError;
        }

        /// <summary>
        /// Gets information about the mounted volume.
        /// </summary>
        /// <param name="stat">Information about the mounted volume.</param>
        public override Errno StatFs(ref FileSystemInfo stat)
        {
            if(!mounted)
                return Errno.AccessDenied;

            stat = new FileSystemInfo();
            stat.Blocks = mddf.vol_size;
            stat.FilenameLength = (ushort)E_NAME;
            stat.Files = mddf.filecount;
            stat.FreeBlocks = mddf.freecount;
            stat.FreeFiles = FILEID_MAX - stat.Files;
            stat.Id.Serial64 = mddf.volid;
            stat.Id.IsLong = true;
            stat.PluginId = PluginUUID;
            switch(mddf.fsversion)
            {
                case LisaFSv1:
                    stat.Type = "LisaFS v1";
                    break;
                case LisaFSv2:
                    stat.Type = "LisaFS v2";
                    break;
                case LisaFSv3:
                    stat.Type = "LisaFS v3";
                    break;
            }

            return Errno.NoError;
        }
    }
}

