using System;
using System.IO;
using System.Text;
using FileSystemIDandChk;

namespace FileSystemIDandChk.Plugins
{
	class BFS : Plugin
	{
		private const UInt32 BFS_MAGIC = 0x1BADFACE;

		public BFS(PluginBase Core)
        {
            base.Name = "UNIX Boot filesystem";
			base.PluginUUID = new Guid("1E6E0DA6-F7E4-494C-80C6-CB5929E96155");
        }
		
		public override bool Identify(FileStream stream, long offset)
		{
			UInt32 magic;

			BinaryReader br = new BinaryReader(stream);
			br.BaseStream.Seek(offset, SeekOrigin.Begin);

			magic = br.ReadUInt32();
			if(magic == BFS_MAGIC)
				return true;
			else
				return false;
		}
		
		public override void GetInformation (FileStream stream, long offset, out string information)
		{
			information = "";
			
			StringBuilder sb = new StringBuilder();
			BinaryReader br = new BinaryReader(stream);

			BFSSuperBlock bfs_sb = new BFSSuperBlock();

			br.BaseStream.Seek(offset, SeekOrigin.Begin);
			bfs_sb.s_magic = br.ReadUInt32();
			bfs_sb.s_start = br.ReadUInt32();
			bfs_sb.s_end = br.ReadUInt32();
			bfs_sb.s_from = br.ReadUInt32();
			bfs_sb.s_to = br.ReadUInt32();
			bfs_sb.s_bfrom = br.ReadInt32();
			bfs_sb.s_bto = br.ReadInt32();
			bfs_sb.s_fsname = StringHandlers.CToString(br.ReadBytes(6));
			bfs_sb.s_volume = StringHandlers.CToString(br.ReadBytes(6));

			if(MainClass.isDebug)
			{
				Console.WriteLine("(BFS) bfs_sb.s_magic: 0x{0:X8}", bfs_sb.s_magic);
				Console.WriteLine("(BFS) bfs_sb.s_start: 0x{0:X8}", bfs_sb.s_start);
				Console.WriteLine("(BFS) bfs_sb.s_end: 0x{0:X8}", bfs_sb.s_end);
				Console.WriteLine("(BFS) bfs_sb.s_from: 0x{0:X8}", bfs_sb.s_from);
				Console.WriteLine("(BFS) bfs_sb.s_to: 0x{0:X8}", bfs_sb.s_to);
				Console.WriteLine("(BFS) bfs_sb.s_bfrom: 0x{0:X8}", bfs_sb.s_bfrom);
				Console.WriteLine("(BFS) bfs_sb.s_bto: 0x{0:X8}", bfs_sb.s_bto);
				Console.WriteLine("(BFS) bfs_sb.s_fsname: 0x{0}", bfs_sb.s_fsname);
				Console.WriteLine("(BFS) bfs_sb.s_volume: 0x{0}", bfs_sb.s_volume);
			}

			sb.AppendLine("UNIX Boot filesystem");
			sb.AppendFormat("Volume goes from byte {0} to byte {1}, for {2} bytes", bfs_sb.s_start, bfs_sb.s_end, bfs_sb.s_end-bfs_sb.s_start).AppendLine();
			sb.AppendFormat("Filesystem name: {0}", bfs_sb.s_fsname).AppendLine();
			sb.AppendFormat("Volume name: {0}", bfs_sb.s_volume).AppendLine();

			information = sb.ToString();
		}

		private struct BFSSuperBlock
		{
			public UInt32 s_magic;  // 0x00, 0x1BADFACE
			public UInt32 s_start;  // 0x04, start in bytes of volume
			public UInt32 s_end;    // 0x08, end in bytes of volume
			public UInt32 s_from;   // 0x0C, unknown :p
			public UInt32 s_to;     // 0x10, unknown :p
			public Int32  s_bfrom;  // 0x14, unknown :p
			public Int32  s_bto;    // 0x18, unknown :p
			public string s_fsname; // 0x1C, 6 bytes, filesystem name
			public string s_volume; // 0x22, 6 bytes, volume name
		}
	}
}