/// <summary>
/// Inspects data in the stream to determine if it appears to be a LUIGI ROM.
/// </summary>
/// <param name="stream">The stream containing the data to inspect.</param>
/// <returns><c>RomFormat.Luigi</c> if the data at the beginning of <paramref name="stream"/> is a valid
/// LUIGI file header, otherwise <c>RomFormat.None</c>.</returns>
internal static RomFormat CheckFormat(System.IO.Stream stream)
{
var position = 0L;
var format = RomFormat.None;
try
{
position = stream.Position;
if (LuigiFileHeader.Inflate(stream) != null)
{
format = RomFormat.Luigi;
}
}
catch (System.Exception)
{
}
finally
{
if (stream != null)
{
stream.Seek(position, System.IO.SeekOrigin.Begin);
}
}
return(format);
}
/// <summary>
/// Locates the first data block of the requested type in the ROM.
/// </summary>
/// <typeparam name="T">The type of LUIGI block to locate.</typeparam>
/// <returns>The data block, or <c>null</c> if no block of the requested type is in the ROM.</returns>
internal T LocateDataBlock <T>() where T : LuigiDataBlock
{
var dataBlock = default(T);
if (StreamUtilities.FileExists(RomPath))
{
using (var file = StreamUtilities.OpenFileStream(RomPath))
{
if (file != null)
{
if (file.Length > 0)
{
var desiredBlockType = LuigiDataBlock.GetBlockType <T>();
var luigiHeader = LuigiFileHeader.Inflate(file);
var bytesRead = luigiHeader.DeserializeByteCount;
// Start looking for desired block immediately after header.
var block = LuigiDataBlock.Inflate(file);
bytesRead += block.DeserializeByteCount;
if (StopIfScrambleKeyBlockFound(desiredBlockType, block.Type))
{
// Stop looking. If we hit the scramble key, there's nothing more to be looked at.
bytesRead = (int)file.Length;
}
while ((bytesRead < file.Length) && (block.Type != desiredBlockType) && (block.Type != LuigiDataBlockType.EndOfFile))
{
block = LuigiDataBlock.Inflate(file);
bytesRead += block.DeserializeByteCount;
if (StopIfScrambleKeyBlockFound(desiredBlockType, block.Type))
{
break;
}
}
if (block.Type == desiredBlockType)
{
dataBlock = block as T;
}
}
}
}
}
return(dataBlock);
}
