/*
 * Copyright (c) 2007 innoSysTec (R) GmbH, Germany. All rights reserved.
 * Original author: Edmund Wagner
 * Creation date: 22.05.2007
 *
 * Source: $HeadURL$
 * Last changed: $LastChangedDate$
 *
 *
 * the unrar licence applies to all junrar source and binary distributions
 * you are not allowed to use this source to re-create the RAR compression algorithm
 *
 * Here some html entities which can be used for escaping javadoc tags:
 * "&":  "&" or "&"
 * "<":  "&#060;" or "&lt;"
 * ">":  "&#062;" or "&gt;"
 * "@":  "&#064;"
 */
package de.innosystec.unrar.rarfile;

import de.innosystec.unrar.io.Raw;


/**
 * Base class of all rar headers
 *
 * @author $LastChangedBy$
 * @version $LastChangedRevision$
 */
public class BaseBlock{

	public static final short BaseBlockSize = 7;

	//TODO move somewhere else

	public static final short MHD_VOLUME = 0x0001;
	public static final short MHD_COMMENT = 0x0002;
	public static final short MHD_LOCK = 0x0004;
	public static final short MHD_SOLID = 0x0008;
	public static final short MHD_PACK_COMMENT = 0x0010;
	public static final short MHD_NEWNUMBERING = 0x0010;
	public static final short MHD_AV = 0x0020;
	public static final short MHD_PROTECT = 0x0040;
	public static final short MHD_PASSWORD = 0x0080;
	public static final short MHD_FIRSTVOLUME = 0x0100;
	public static final short MHD_ENCRYPTVER = 0x0200;


	public static final short LHD_SPLIT_BEFORE =  0x0001;
	public static final short LHD_SPLIT_AFTER  =  0x0002;
	public static final short LHD_PASSWORD     =  0x0004;
	public static final short LHD_COMMENT      =  0x0008;
	public static final short LHD_SOLID        =  0x0010;

	public static final short LHD_WINDOWMASK   =  0x00e0;
	public static final short LHD_WINDOW64     =  0x0000;
	public static final short LHD_WINDOW128    =  0x0020;
	public static final short LHD_WINDOW256    =  0x0040;
	public static final short LHD_WINDOW512    =  0x0060;
	public static final short LHD_WINDOW1024   =  0x0080;
	public static final short LHD_WINDOW2048   =  0x00a0;
	public static final short LHD_WINDOW4096   =  0x00c0;
	public static final short LHD_DIRECTORY    =  0x00e0;

	public static final short LHD_LARGE        =  0x0100;
	public static final short LHD_UNICODE      =  0x0200;
	public static final short LHD_SALT         =  0x0400;
	public static final short LHD_VERSION      =  0x0800;
	public static final short LHD_EXTTIME      =  0x1000;
	public static final short LHD_EXTFLAGS     =  0x2000;

	public static final short SKIP_IF_UNKNOWN  =  0x4000;
	public static final short LONG_BLOCK 	   = -0x8000;

	public static final short EARC_NEXT_VOLUME =  0x0001;
	public static final short EARC_DATACRC     =  0x0002;
	public static final short EARC_REVSPACE    =  0x0004;
	public static final short EARC_VOLNUMBER   =  0x0008;


	protected long positionInFile;

	protected short headCRC = 0;
	protected byte headerType = 0;
	protected short flags = 0;
	protected short headerSize = 0 ;

	/**
	 *
	 */
	public BaseBlock(){

	}

	public BaseBlock(BaseBlock bb){
		this.flags = bb.getFlags();
    	this.headCRC = bb.getHeadCRC();
    	this.headerType = bb.getHeaderType().getHeaderByte();
    	this.headerSize = bb.getHeaderSize();
    	this.positionInFile = bb.getPositionInFile();
	}
	public BaseBlock(byte[] baseBlockHeader){

		int pos = 0;
		this.headCRC = Raw.readShortLittleEndian(baseBlockHeader, pos);
		pos+=2;
		this.headerType |= baseBlockHeader[pos]&0xff;
		pos++;
		this.flags = Raw.readShortLittleEndian(baseBlockHeader, pos);
		pos+=2;
		this.headerSize = Raw.readShortLittleEndian(baseBlockHeader, pos);
	}


	public boolean hasArchiveDataCRC(){
		return (this.flags & EARC_DATACRC)!=0;
	}

	public boolean hasVolumeNumber(){
		return (this.flags & EARC_VOLNUMBER)!=0;
	}

	public boolean hasEncryptVersion(){
		return (flags & MHD_ENCRYPTVER)!=0;
	}

	/**
	 * @return is it a sub block
	 */
	public boolean isSubBlock()
	{
		 if (UnrarHeadertype.SubHeader.equals(headerType)){
			 return(true);
		 }
		 if (UnrarHeadertype.NewSubHeader.equals(headerType) && (flags & LHD_SOLID)!=0)
		 {
			 return(true);
		 }
		 return(false);

	}

	public long getPositionInFile() {
		return positionInFile;
	}

	public short getFlags() {
		return flags;
	}

	public short getHeadCRC() {
		return headCRC;
	}

	public short getHeaderSize() {
		return headerSize;
	}

	public UnrarHeadertype getHeaderType() {
		return UnrarHeadertype.findType(headerType);
	}

	public void setPositionInFile(long positionInFile) {
		this.positionInFile = positionInFile;
	}

	public String toString(){
		StringBuilder str  =new StringBuilder();
		str.append("HeaderType: " + getHeaderType());
		str.append("\nHeadCRC: "+Integer.toHexString(getHeadCRC()));
		str.append("\nFlags: "+Integer.toHexString(getFlags()));
		str.append("\nHeaderSize: "+getHeaderSize());
		str.append("\nPosition in file: "+getPositionInFile());
		return str.toString();
	}
}