// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : SFS.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : SmartFileSystem plugin.
//
// --[ Description ] ----------------------------------------------------------
//
//     Identifies the SmartFileSystem 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 © 2011-2017 Natalia Portillo
// ****************************************************************************/

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Text;
using DiscImageChef.CommonTypes;

namespace DiscImageChef.Filesystems
{
    public class SFS : Filesystem
    {
        public SFS()
        {
            Name = "SmartFileSystem";
            PluginUUID = new Guid("26550C19-3671-4A2D-BC2F-F20CEB7F48DC");
            CurrentEncoding = Encoding.GetEncoding("iso-8859-1");
        }

        public SFS(ImagePlugins.ImagePlugin imagePlugin, Partition partition, Encoding encoding)
        {
            Name = "SmartFileSystem";
            PluginUUID = new Guid("26550C19-3671-4A2D-BC2F-F20CEB7F48DC");
            if(encoding == null)
                CurrentEncoding = Encoding.GetEncoding("iso-8859-1");
            else
                CurrentEncoding = encoding;
        }

        [Flags]
        enum SFSFlags : byte
        {
            RecyledFolder = 64,
            CaseSensitive = 128
        }

        [StructLayout(LayoutKind.Sequential, Pack = 1)]
        struct RootBlock
        {
            public uint blockId;
            public uint blockChecksum;
            public uint blockSelfPointer;
            public ushort version;
            public ushort sequence;
            public uint datecreated;
            public SFSFlags bits;
            public byte padding1;
            public ushort padding2;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
            public uint[] reserved1;
            public ulong firstbyte;
            public ulong lastbyte;
            public uint totalblocks;
            public uint blocksize;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
            public uint[] reserved2;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
            public uint[] reserved3;
            public uint bitmapbase;
            public uint adminspacecontainer;
            public uint rootobjectcontainer;
            public uint extentbnoderoot;
            public uint objectnoderoot;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
            public uint[] reserved4;
        }

        /// <summary>Identifier for SFS v1</summary>
        const uint SFS_MAGIC = 0x53465300;
        /// <summary>Identifier for SFS v2</summary>
        const uint SFS2_MAGIC = 0x53465302;

        public override bool Identify(ImagePlugins.ImagePlugin imagePlugin, Partition partition)
        {
            if(partition.Start >= partition.End)
                return false;

            BigEndianBitConverter.IsLittleEndian = BitConverter.IsLittleEndian;

            byte[] sector = imagePlugin.ReadSector(partition.Start);

            uint magic = BigEndianBitConverter.ToUInt32(sector, 0x00);

            return magic == SFS_MAGIC || magic == SFS2_MAGIC;
        }

        public override void GetInformation(ImagePlugins.ImagePlugin imagePlugin, Partition partition, out string information)
        {
            byte[] RootBlockSector = imagePlugin.ReadSector(partition.Start);
            RootBlock rootBlock = new RootBlock();
            rootBlock = BigEndianMarshal.ByteArrayToStructureBigEndian<RootBlock>(RootBlockSector);

            StringBuilder sbInformation = new StringBuilder();

            sbInformation.AppendLine("SmartFileSystem");

            sbInformation.AppendFormat("Volume version {0}", rootBlock.version).AppendLine();
            sbInformation.AppendFormat("Volume starts on device byte {0} and ends on byte {1}", rootBlock.firstbyte, rootBlock.lastbyte).AppendLine();
            sbInformation.AppendFormat("Volume has {0} blocks of {1} bytes each", rootBlock.totalblocks, rootBlock.blocksize).AppendLine();
            sbInformation.AppendFormat("Volume created on {0}", DateHandlers.UNIXUnsignedToDateTime(rootBlock.datecreated).AddYears(8)).AppendLine();
            sbInformation.AppendFormat("Bitmap starts in block {0}", rootBlock.bitmapbase).AppendLine();
            sbInformation.AppendFormat("Admin space container starts in block {0}", rootBlock.adminspacecontainer).AppendLine();
            sbInformation.AppendFormat("Root object container starts in block {0}", rootBlock.rootobjectcontainer).AppendLine();
            sbInformation.AppendFormat("Root node of the extent B-tree resides in block {0}", rootBlock.extentbnoderoot).AppendLine();
            sbInformation.AppendFormat("Root node of the object B-tree resides in block {0}", rootBlock.objectnoderoot).AppendLine();
            if(rootBlock.bits.HasFlag(SFSFlags.CaseSensitive))
                sbInformation.AppendLine("Volume is case sensitive");
            if(rootBlock.bits.HasFlag(SFSFlags.RecyledFolder))
                sbInformation.AppendLine("Volume moves deleted files to a recycled folder");
            information = sbInformation.ToString();

            xmlFSType = new Schemas.FileSystemType
            {
                CreationDate = DateHandlers.UNIXUnsignedToDateTime(rootBlock.datecreated).AddYears(8),
                CreationDateSpecified = true,
                Clusters = rootBlock.totalblocks,
                ClusterSize = (int)rootBlock.blocksize,
                Type = "SmartFileSystem"
            };
        }

        public override Errno Mount()
        {
            return Errno.NotImplemented;
        }

        public override Errno Mount(bool debug)
        {
            return Errno.NotImplemented;
        }

        public override Errno Unmount()
        {
            return Errno.NotImplemented;
        }

        public override Errno MapBlock(string path, long fileBlock, ref long deviceBlock)
        {
            return Errno.NotImplemented;
        }

        public override Errno GetAttributes(string path, ref FileAttributes attributes)
        {
            return Errno.NotImplemented;
        }

        public override Errno ListXAttr(string path, ref List<string> xattrs)
        {
            return Errno.NotImplemented;
        }

        public override Errno GetXattr(string path, string xattr, ref byte[] buf)
        {
            return Errno.NotImplemented;
        }

        public override Errno Read(string path, long offset, long size, ref byte[] buf)
        {
            return Errno.NotImplemented;
        }

        public override Errno ReadDir(string path, ref List<string> contents)
        {
            return Errno.NotImplemented;
        }

        public override Errno StatFs(ref FileSystemInfo stat)
        {
            return Errno.NotImplemented;
        }

        public override Errno Stat(string path, ref FileEntryInfo stat)
        {
            return Errno.NotImplemented;
        }

        public override Errno ReadLink(string path, ref string dest)
        {
            return Errno.NotImplemented;
        }
    }
}