using System;

namespace Cosmos.HAL.BlockDevice
{
	public class Partition : BlockDevice
	{
		private readonly BlockDevice mHost;
		private readonly UInt64 mStartingSector;

		public Partition(BlockDevice aHost, UInt64 aStartingSector, UInt64 aSectorCount)
		{
			mHost = aHost;
			mStartingSector = aStartingSector;
			mBlockCount = aSectorCount;
			mBlockSize = aHost.BlockSize;
		}

		public override void ReadBlock(UInt64 aBlockNo, UInt64 aBlockCount, ref byte[] aData)
		{
            CheckDataSize(aData, aBlockCount);
            UInt64 xHostBlockNo = mStartingSector + aBlockNo;
			CheckBlockNo(xHostBlockNo, aBlockCount);
			mHost.ReadBlock(xHostBlockNo, aBlockCount, ref aData);
		}

		public override void WriteBlock(UInt64 aBlockNo, UInt64 aBlockCount,ref  byte[] aData)
		{
            CheckDataSize(aData, aBlockCount);
            UInt64 xHostBlockNo = mStartingSector + aBlockNo;
			CheckBlockNo(xHostBlockNo, aBlockCount);
			mHost.WriteBlock(xHostBlockNo, aBlockCount, ref aData);
		}

	    public override string ToString()
	    {
	        return "Partition";
	    }
	}
}