using System;
using System.IO;

namespace BizHawk.Emulation.DiscSystem
{
	public partial class Disc : IDisposable
	{
		public sealed class Blob_ZeroPadAdapter : IBlob
		{
			public Blob_ZeroPadAdapter(IBlob baseBlob, long padFrom, long padLen)
			{
				this.baseBlob = baseBlob;
				this.padFrom = padFrom;
				this.padLen = padLen;
			}

			public int Read(long byte_pos, byte[] buffer, int offset, int count)
			{
				//I have an ff9 disc which can demo this
				throw new NotImplementedException("Blob_ZeroPadAdapter hasnt been tested yet! please report this!");

				//something about this seems unnecessarily complex, but... i dunno.
				/*
				//figure out how much remains until the zero-padding begins
				long remain = byte_pos - padFrom;
				int todo;
				if (remain < count)
					todo = (int)remain;
				else todo = count;

				//read up until the zero-padding
				int totalRead = 0;
				int readed = baseBlob.Read(byte_pos, buffer, offset, todo);
				totalRead += readed;
				offset += todo;

				//if we didnt read enough, we certainly shouldnt try to read any more
				if (readed < todo)
					return readed;

				//if that was all we needed, then we're done
				count -= todo;
				if (count == 0)
					return totalRead;

				//if we need more, it must come from zero-padding
				remain = padLen;
				if (remain < count)
					todo = (int)remain;
				else todo = count;

				Array.Clear(buffer, offset, todo);
				totalRead += todo;

				return totalRead;
				*/
			}

			public void Dispose()
			{
				baseBlob.Dispose();
			}

			private readonly IBlob baseBlob;
			private long padFrom;
			private long padLen;
		}

	}
}