package com.bytezone.diskbrowser.applefile;

import com.bytezone.diskbrowser.HexFormatter;

// only used by Prodos text files - note the fixed block size of 512 - bad!
public class TextBuffer
{
	public final byte[] buffer;
	public final int reclen;
	public final int firstRecNo;

	public TextBuffer (byte[] tempBuffer, int reclen, int firstBlock)
	{
		this.reclen = reclen;

		// calculate recNo of first full record
		int firstByte = firstBlock * 512; // logical byte #
		int rem = firstByte % reclen;
		firstRecNo = firstByte / reclen + (rem > 0 ? 1 : 0);
		int offset = (rem > 0) ? reclen - rem : 0;

		int availableBytes = tempBuffer.length - offset;
		int totalRecords = (availableBytes - 1) / reclen + 1;

		// should check whether the two buffers are identical, and maybe skip this
		// step
		buffer = new byte[totalRecords * reclen];
		int copyBytes = Math.min (availableBytes, buffer.length);
		System.arraycopy (tempBuffer, offset, buffer, 0, copyBytes);
	}

	@Override
	public String toString ()
	{
		StringBuilder text = new StringBuilder ();

		text.append ("Record length : " + reclen + "\n");
		text.append ("First record  : " + firstRecNo + "\n\n");
		text.append (HexFormatter.format (buffer, 0, buffer.length) + "\n");

		return text.toString ();
	}
}