import java.io.*;
import java.util.*;
import java.util.zip.*;

class Unpack2 {
					
		public static void main ( String args [] ) throws IOException {
		
		if (args.length != 1 && args.length != 2) {System.out.print("\n     Unpack v. 2.02     © CplFilth\n\n     Usage : \n     1. Unpack adbFileIn\n     For example : Unpack elements.adb\n     Outputs to the correspondingly named .txt file \n\n     2. Unpack inFileName outFilename\n     For example Unpack c:\\temp\\elements.adb e:\\elements.hex\n\n");
		System.exit(0);
										}							
		
		
		
		int ta;	
		String inputFileName = new String(args[0]);
		File inputFile = new File(inputFileName);
		String cha=".";
		String txtFileString ="";
		int index=0;
		File txtFile;
		// initialize txtFileString
		while (  cha.compareTo(inputFileName.substring(index,index+1)) != 0) {
			txtFileString = txtFileString + inputFileName.substring(index,index+1);
			index++;
			} 	
		
		txtFileString = txtFileString + ".txt";
		
		
		
		if ( args.length != 2 ) {txtFile = new File(txtFileString);} 
		else { txtFile = new File(args[1]);}
		
		// read adbFile to byte array "data"
		// considerably faster than the previous method
		
		DataInputStream read = new DataInputStream(new FileInputStream(inputFile));
		int adbLength = read.available();
		byte[] data = new byte[adbLength];
		read.readFully(data);
		int zipStart=0;
		read.close();
		// find the bytes 78 9C, which indicate start of compressed data
		
		for ( index = 0 ; index < adbLength ; index++ )
		 {
		 if ( (data[index] & 0xFF )== 0x78 && (data[index+1] & 0xFF)== 0x9C ) {zipStart = index;index = adbLength;}	
		}
		
		// create a stream into memory, which is used to depict a dummy zip file
		
		ByteArrayOutputStream zipOut = new ByteArrayOutputStream();
		
		// Insert zip header 	
		
		zipOut.write(80);zipOut.write(75);zipOut.write(3);zipOut.write(4);
		zipOut.write(20);zipOut.write(0);zipOut.write(8);zipOut.write(0);
		zipOut.write(8);zipOut.write(0);
		zipOut.write(206);zipOut.write(102);zipOut.write(119);zipOut.write(39);
		
		// write 4 bytes of zeros as the CRC
		
		zipOut.write(0);zipOut.write(0);zipOut.write(0);zipOut.write(0);
		
		// insert compressed length
		
		int compLength = adbLength - zipStart;
		zipOut.write(intToByteArray(compLength));
		
		
		// insert uncompressed size FF FF FF 00, should be enough
		zipOut.write(255);zipOut.write(255);zipOut.write(255);zipOut.write(0);
		
		// insert number of characters in txt file name
		zipOut.write(CountChars(txtFileString));zipOut.write(0);
		
		// and 2 zeros , extra field length
		zipOut.write(0);zipOut.write(0);

		// insert txt file name
	
		StringReader inString = new StringReader (txtFileString);
		int a;
		while ( (a = inString.read() ) != -1 ) 
		zipOut.write(a);
		
		// insert data
		int i;
		zipOut.write(data,zipStart+2,compLength-2);
			
		// insert local file header
		String localFileHeader1 = "PK..........f.as";
		StringReader readString = new StringReader(localFileHeader1);
		ta=0;
		while ((ta = readString.read()) != -1 ) {
		zipOut.write(ta);
		}
		
		// another CRC of 4 nulls	
		
		zipOut.write(0);zipOut.write(0);zipOut.write(0);zipOut.write(0);
		
		//insert compressed size 00 00 00 00 for now
		zipOut.write(0);zipOut.write(0);zipOut.write(0);zipOut.write(0);

		// insert uncompressed size FF FF FF 00
		zipOut.write(255);zipOut.write(255);zipOut.write(255);zipOut.write(0);
		// insert filename length
		zipOut.write(CountChars(txtFileString));zipOut.write(0);
		
		// insert extra field length 00 00
		zipOut.write(0);zipOut.write(0);
		// insert file comment length 00 00 
		zipOut.write(0);zipOut.write(0);
		// get current number of bytes, used later
		
		int start=zipOut.size();
		
		
		// insert disk number start 00 00
		zipOut.write(0);zipOut.write(0);
		// insert internal file attributes 00 00
		zipOut.write(0);zipOut.write(0);
		// insert external file attributes 20 00
		zipOut.write(32);zipOut.write(0);
		
		// insert txt file name
	
		inString = new StringReader (txtFileString);
		
		while ( (a = inString.read() ) != -1 ) 
		zipOut.write(a);
		// end of central dir sig
		String endOfCentralDir = "PK";
		int b;
		StringReader readEnd = new StringReader(endOfCentralDir);
		a=0;
		while ( (a = readEnd.read() ) != -1 ) {
		zipOut.write(a);
				}
		readEnd.close();
		zipOut.write(6);zipOut.write(5);
		
		// insert number of disk, number of disk with central dir, total number of entries on disk,
		// total number of entries in central dir 00 00 00 00 01 00 01 00
		zipOut.write(0);zipOut.write(0);zipOut.write(0);zipOut.write(0);zipOut.write(1);zipOut.write(0);
		zipOut.write(1);zipOut.write(0);
		
		// insert size of central dir
		int size;
		size = CountChars(txtFileString);
		size = size + 46;
		zipOut.write(size);zipOut.write(0);zipOut.write(0);zipOut.write(0);
		
		// offset of central dir in respect to starting disk number
		
		zipOut.write(start);
		zipOut.write(start >> 8 );
		
		// insert comment length 00 00 
		zipOut.write(0);zipOut.write(0);
		
		
		// dump stream into a byte array
		
		byte[] zipData = new byte[zipOut.size()];
		
		zipData = zipOut.toByteArray();
		
		// decompress to name.txt, method shamelessly copied from some Sun document or another

		String inFilename2;
        
   
		ByteArrayInputStream zipIn = new ByteArrayInputStream(zipData);
	        ZipInputStream in2 = new ZipInputStream(zipIn);
	
	        OutputStream out2 = new FileOutputStream(txtFile);
	
	
		    try {
				ZipEntry entry;
				byte[] buff = new byte[1024];
				int leng;
      
      				if ((entry = in2.getNextEntry()) != null) {

            				while ((leng = in2.read(buff)) > 0) {

	                			out2.write(buff, 0, leng);

        								    }

        								}
	
      

   		} catch (IOException e) {  } 
   		
   		out2.close();

        	in2.close();
        	zipIn.close();
		zipOut.close();
		
		
		
		
		
		
		}
	
	// helper method to convert an integer value into a array of bytes 4 cells in length
	
	static byte[] intToByteArray ( int value ) {
		
		byte[] arr = new byte[4];
		
		arr[0] = (byte ) (value);
		
		arr[1] = (byte ) (value >> 8 );
		
		arr[2] = (byte ) (value >> 16 );
		
		arr[3] = (byte ) (value >> 24);
		
		
		return(arr);
		
						}
	public static int CountChars(String stringin) throws IOException
{
	

	String stringhere = stringin;
	int count=0;
	int tempo;
	StringReader thisString = new StringReader(stringhere);
 
	while ( (tempo = thisString.read() ) != -1 ) {
		count++; }
		thisString.close();
return(count);
}  
	}