/*
 * Created on Oct 13, 2005
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
package org.apache.bcel.classfile;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

import org.apache.bcel.SignatureConstants;


/**
 * @author dorina
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
public class LinkAttribute extends Attribute {

	/**
	 * 
	 */
	private static final long serialVersionUID = -6979030289206998650L;
	byte []links;
	

	public LinkAttribute(byte constant_attr, int name_index, int length, byte[] links, ConstantPool cp) {
		super(constant_attr, name_index, length, cp);
		this.links = links;
	}

	
	public LinkAttribute(byte constant_attr, int name_index, int length, DataInputStream str, ConstantPool cp)
	throws IOException {
		this(constant_attr, name_index, length, (byte [])null, cp);

		if( length > 0) {
			links = new byte[length];
        
			for(int i = 0; i < length; i++) {
				links[i] = str.readByte();
			}
		}
	}
	
	/* (non-Javadoc)
	 * @see org.apache.bcel.classfile.Node#accept(org.apache.bcel.classfile.Visitor)
	 */
	public void accept(Visitor v) {
		// TODO Auto-generated method stub

	}

	/* (non-Javadoc)
	 * @see org.apache.bcel.classfile.Attribute#copy(org.apache.bcel.classfile.ConstantPool)
	 */
	public Attribute copy(ConstantPool constant_pool) {
		LinkAttribute copy = (LinkAttribute)clone();
		System.arraycopy(links,0,copy.links,0,links.length);
		return copy;
	}

	
	public final void dump(DataOutputStream file) throws IOException {
		super.dump(file);
		// FIXME: sort the output ?
		for(int i = 0; i < links.length; i++) {
				file.writeByte(links[i]);
				//file.writeByte(i%2);
		    
		}
	}

	public String toString() {
		return toString("LinkAttribute");
	}
	
	public String toString(String name) {
		return LinkAttribute.print(name, this.links);
	}

    public int getLinkCount()
    {
        int index = 0;
		byte codification = links[index++];
		boolean isNewSign = (codification & SignatureConstants.ACC_NEW_SIGNATURE) != 0; 
		
        index += SignatureConstants.LABEL_BYTECODE_SIZE;
		
		//number of links
		int length = 0;
		
		if((codification & SignatureConstants.CODIF_4B) != 0)
        {
            length = SignatureConstants.readInt(links, index, 1);
		}
		else {
			System.err.println(" Unsupported codification ! ");
			return -1;
		}

        return length;

    }
    
    public int[] getLink(int ind)
    {
		int index = 0;
		byte codification = links[index++];
		boolean isNewSign = (codification & SignatureConstants.ACC_NEW_SIGNATURE) != 0; 
		
        index += SignatureConstants.LABEL_BYTECODE_SIZE;
		
		if((codification & SignatureConstants.CODIF_4B) != 0)
            index += 1;
		else {
			System.err.println(" Unsupported codification ! ");
			return null;
		}

        // Skip to wanted link
        index += ind * 2;

        int line = 0;
        int column = 0;
			
        column = links[index] & 0xF;
        line = (links[index] >> 4) & 0xF;
        index += 1;
        byte value = links[index];
        
        return new int[]{column, line, (value < 0? value+128: value)};
        //return new int[]{column, line, (value < 0? value+256: value)};
            
    }
    
	public static String print(String name, byte[] links) {
		StringBuffer buf = new StringBuffer(name+"(");
	    
		int index = 0;
		byte codification = links[index++];
		boolean isNewSign = (codification & SignatureConstants.ACC_NEW_SIGNATURE) != 0; 
		buf.append("codification = "+codification+", ");
		
		//int dim = 
			SignatureConstants.readInt(links, index, SignatureConstants.LABEL_BYTECODE_SIZE);
		index += SignatureConstants.LABEL_BYTECODE_SIZE;
		
		//number of links
		int length = 0;
		
		
		if((codification & SignatureConstants.CODIF_4B) != 0) {
				length = SignatureConstants.readInt(links, index, 1);
				index += 1;
		}
		else if((codification & SignatureConstants.CODIF_8B) !=0){
				length = SignatureConstants.readInt(links, index, 2);
				index += 2;
		}
		else {
			System.err.println(" codification error! ");
			return null;
		}
		
		if(isNewSign)
			buf.append("no of links = "+length+", ");
		else
			buf.append("no of links to add = "+length+", ");
		for(int i=0; i < length; i++) {
			buf.append("[ ");

			int line = 0;
			int column = 0;
			
			
			if((codification & SignatureConstants.CODIF_4B) != 0){
				column = links[index] & 0xF;
				line = (links[index] >> 4) & 0xF;					
				index += 1;
			}
			else if((codification & SignatureConstants.CODIF_8B) != 0){
				line = SignatureConstants.readInt(links, index, 1);
				index += 1;
				column = SignatureConstants.readInt(links, index, 1);
				index += 1;
				break;
			}
			
			byte value = links[index++];
			buf.append(line+" ,"+column+" ,"+value+" ]");
        
			if(i < length - 1)
				buf.append(", ");
		}
		buf.append(')');
		
		if(!isNewSign){

			if((codification & SignatureConstants.CODIF_4B) != 0){
				length = SignatureConstants.readInt(links, index, 1);
				index += 1;
			}
			else if((codification & SignatureConstants.CODIF_8B) != 0){
					length = SignatureConstants.readInt(links, index, 2);
					index += 2;
			}
			else {
				System.err.println(" codification error! ");
				return null;
			}
	
			buf.append("no of links to delete= "+length+", ");
				
			for(int i=0; i < length; i++) {
				buf.append("[ ");
	
				int line = 0;
				int column = 0;
				
				
				if((codification & SignatureConstants.CODIF_4B) != 0){
					column = links[index] & 0xF;
					line = (links[index] >> 4) & 0xF;					
					index += 1;
				}
				else if((codification & SignatureConstants.CODIF_8B) != 0){
					line = SignatureConstants.readInt(links, index, 1);
					index += 1;
					column = SignatureConstants.readInt(links, index, 1);
					index += 1;
					break;
				}
				
				byte value = links[index++];
				buf.append(line+" ,"+column+" ,"+value+" ]");
	        
				if(i < length - 1)
					buf.append(", ");
			}
			buf.append(')');
		
		}


 	
		return buf.toString(); 
	}
	
	/**
	 * 
	 * @param links
	 * @return
	 */
	public static int getLength(byte[] links) {
	    
		int index = 0;
		byte codification = links[index++];
			
		//int dim = 
			SignatureConstants.readInt(links, index, SignatureConstants.LABEL_BYTECODE_SIZE);
		index += SignatureConstants.LABEL_BYTECODE_SIZE;
		
		int length = 0;
		int totalSize = 1;
		
		switch(codification) {
			case SignatureConstants.CODIF_4B:
				length = SignatureConstants.readInt(links, index, 1);
				totalSize += 1;
				totalSize += (length * 2);
				break;
			case  SignatureConstants.CODIF_8B:
				length = SignatureConstants.readInt(links, index, 2);
				totalSize += 2;
				totalSize += (length * 3);
				break;
			default:
				System.err.println(" codification error! ");
				return 0;
		}
	return totalSize;
	}
}