// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : Info.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Apple Macintosh File System plugin.
//
// --[ Description ] ----------------------------------------------------------
//
//     Identifies the Apple Macintosh File System and shows information.
//
// --[ 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.Text;
using Aaru.CommonTypes;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Interfaces;
using Aaru.Helpers;
using Claunia.Encoding;
using Schemas;
using Encoding = System.Text.Encoding;

namespace Aaru.Filesystems
{
    // Information from Inside Macintosh Volume II
    public sealed partial class AppleMFS
    {
        /// <inheritdoc />
        public bool Identify(IMediaImage imagePlugin, Partition partition)
        {
            if(2 + partition.Start >= partition.End)
                return false;

            ErrorNumber errno = imagePlugin.ReadSector(2 + partition.Start, out byte[] mdbSector);

            if(errno != ErrorNumber.NoError)
                return false;

            ushort drSigWord = BigEndianBitConverter.ToUInt16(mdbSector, 0x000);

            return drSigWord == MFS_MAGIC;
        }

        /// <inheritdoc />
        public void GetInformation(IMediaImage imagePlugin, Partition partition, out string information,
                                   Encoding encoding)
        {
            Encoding    = encoding ?? new MacRoman();
            information = "";

            var sb = new StringBuilder();

            var mdb = new MasterDirectoryBlock();

            ErrorNumber errno = imagePlugin.ReadSector(2 + partition.Start, out byte[] mdbSector);

            if(errno != ErrorNumber.NoError)
                return;

            errno = imagePlugin.ReadSector(0 + partition.Start, out byte[] bbSector);

            if(errno != ErrorNumber.NoError)
                return;

            mdb.drSigWord = BigEndianBitConverter.ToUInt16(mdbSector, 0x000);

            if(mdb.drSigWord != MFS_MAGIC)
                return;

            mdb.drCrDate   = BigEndianBitConverter.ToUInt32(mdbSector, 0x002);
            mdb.drLsBkUp   = BigEndianBitConverter.ToUInt32(mdbSector, 0x006);
            mdb.drAtrb     = (AppleCommon.VolumeAttributes)BigEndianBitConverter.ToUInt16(mdbSector, 0x00A);
            mdb.drNmFls    = BigEndianBitConverter.ToUInt16(mdbSector, 0x00C);
            mdb.drDirSt    = BigEndianBitConverter.ToUInt16(mdbSector, 0x00E);
            mdb.drBlLen    = BigEndianBitConverter.ToUInt16(mdbSector, 0x010);
            mdb.drNmAlBlks = BigEndianBitConverter.ToUInt16(mdbSector, 0x012);
            mdb.drAlBlkSiz = BigEndianBitConverter.ToUInt32(mdbSector, 0x014);
            mdb.drClpSiz   = BigEndianBitConverter.ToUInt32(mdbSector, 0x018);
            mdb.drAlBlSt   = BigEndianBitConverter.ToUInt16(mdbSector, 0x01C);
            mdb.drNxtFNum  = BigEndianBitConverter.ToUInt32(mdbSector, 0x01E);
            mdb.drFreeBks  = BigEndianBitConverter.ToUInt16(mdbSector, 0x022);
            mdb.drVNSiz    = mdbSector[0x024];
            byte[] variableSize = new byte[mdb.drVNSiz + 1];
            Array.Copy(mdbSector, 0x024, variableSize, 0, mdb.drVNSiz + 1);
            mdb.drVN = StringHandlers.PascalToString(variableSize, Encoding);

            sb.AppendLine("Apple Macintosh File System");
            sb.AppendLine();
            sb.AppendLine("Master Directory Block:");
            sb.AppendFormat("Creation date: {0}", DateHandlers.MacToDateTime(mdb.drCrDate)).AppendLine();
            sb.AppendFormat("Last backup date: {0}", DateHandlers.MacToDateTime(mdb.drLsBkUp)).AppendLine();

            if(mdb.drAtrb.HasFlag(AppleCommon.VolumeAttributes.HardwareLock))
                sb.AppendLine("Volume is locked by hardware.");

            sb.AppendLine(mdb.drAtrb.HasFlag(AppleCommon.VolumeAttributes.Unmounted) ? "Volume was unmonted."
                              : "Volume is mounted.");

            if(mdb.drAtrb.HasFlag(AppleCommon.VolumeAttributes.SparedBadBlocks))
                sb.AppendLine("Volume has spared bad blocks.");

            if(mdb.drAtrb.HasFlag(AppleCommon.VolumeAttributes.DoesNotNeedCache))
                sb.AppendLine("Volume does not need cache.");

            if(mdb.drAtrb.HasFlag(AppleCommon.VolumeAttributes.BootInconsistent))
                sb.AppendLine("Boot volume is inconsistent.");

            if(mdb.drAtrb.HasFlag(AppleCommon.VolumeAttributes.ReusedIds))
                sb.AppendLine("There are reused CNIDs.");

            if(mdb.drAtrb.HasFlag(AppleCommon.VolumeAttributes.Inconsistent))
                sb.AppendLine("Volume is seriously inconsistent.");

            if(mdb.drAtrb.HasFlag(AppleCommon.VolumeAttributes.SoftwareLock))
                sb.AppendLine("Volume is locked by software.");

            sb.AppendFormat("{0} files on volume", mdb.drNmFls).AppendLine();
            sb.AppendFormat("First directory sector: {0}", mdb.drDirSt).AppendLine();
            sb.AppendFormat("{0} sectors in directory.", mdb.drBlLen).AppendLine();
            sb.AppendFormat("{0} volume allocation blocks.", mdb.drNmAlBlks + 1).AppendLine();
            sb.AppendFormat("Size of allocation blocks: {0} bytes", mdb.drAlBlkSiz).AppendLine();
            sb.AppendFormat("{0} bytes to allocate.", mdb.drClpSiz).AppendLine();
            sb.AppendFormat("First allocation block (#2) starts in sector {0}.", mdb.drAlBlSt).AppendLine();
            sb.AppendFormat("Next unused file number: {0}", mdb.drNxtFNum).AppendLine();
            sb.AppendFormat("{0} unused allocation blocks.", mdb.drFreeBks).AppendLine();
            sb.AppendFormat("Volume name: {0}", mdb.drVN).AppendLine();

            string bootBlockInfo = AppleCommon.GetBootBlockInformation(bbSector, Encoding);

            if(bootBlockInfo != null)
            {
                sb.AppendLine("Volume is bootable.");
                sb.AppendLine();
                sb.AppendLine(bootBlockInfo);
            }
            else
                sb.AppendLine("Volume is not bootable.");

            information = sb.ToString();

            XmlFsType = new FileSystemType();

            if(mdb.drLsBkUp > 0)
            {
                XmlFsType.BackupDate          = DateHandlers.MacToDateTime(mdb.drLsBkUp);
                XmlFsType.BackupDateSpecified = true;
            }

            XmlFsType.Bootable    = bootBlockInfo != null;
            XmlFsType.Clusters    = mdb.drNmAlBlks;
            XmlFsType.ClusterSize = mdb.drAlBlkSiz;

            if(mdb.drCrDate > 0)
            {
                XmlFsType.CreationDate          = DateHandlers.MacToDateTime(mdb.drCrDate);
                XmlFsType.CreationDateSpecified = true;
            }

            XmlFsType.Files                 = mdb.drNmFls;
            XmlFsType.FilesSpecified        = true;
            XmlFsType.FreeClusters          = mdb.drFreeBks;
            XmlFsType.FreeClustersSpecified = true;
            XmlFsType.Type                  = "MFS";
            XmlFsType.VolumeName            = mdb.drVN;
        }
    }
}