/*
 * Created on Oct 12, 2005
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
package fr.lifl.stc.stan.tools;

import java.io.IOException;
import org.apache.bcel.classfile.ClassParser;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.ConstantPool;
import org.apache.bcel.classfile.Constant;
import org.apache.bcel.classfile.ConstantMethodref;
import org.apache.bcel.classfile.ConstantInterfaceMethodref;
import org.apache.bcel.classfile.ConstantCP;
import org.apache.bcel.classfile.ConstantNameAndType;


/**
 * @author dorina
 *
 * Analyzes the constant pool of the classes passed as command line arguments, and outputs statistics 
 * on the number of methods
 */
public class ConstantPoolAnalyser {
	
	JavaClass[] classes;
	
	ConstantPoolAnalyser(JavaClass classes[]){
		this.classes = classes;
	}
	
	void analyse() {
		JavaClass currentClass;
		int n =0;
		int total = 0;
		int noMethods = 0;
		for(int i = 0; i < classes.length; i++) {
			currentClass = classes[i];
			System.out.println("\n Analysing class "+currentClass.getClassName());
			n = analyseConstantPool(currentClass.getConstantPool());
			total += n;
			noMethods += currentClass.getMethods().length;
			System.out.println("--class methods = "+currentClass.getMethods().length+"  \n--external methods = "+ n);
		}
		System.out.println("\n no classes = "+classes.length+"  no methods = "+noMethods+"    external methods = "+total);
	}
	
	int analyseConstantPool(ConstantPool cp) {
		Constant[] cst = cp.getConstantPool();
		int noMeth = 0;
		for(int i = 0; i < cst.length; i++) {
			if(cst[i] instanceof ConstantMethodref || cst[i] instanceof ConstantInterfaceMethodref){
				ConstantCP c = (ConstantCP)cst[i];
				
				System.out.println(c.toString());
				ConstantNameAndType n = (ConstantNameAndType)cp.getConstant(c.getNameAndTypeIndex());
				System.out.println(n.getName(cp));
				noMeth++;
			}
			/*		
			 else if (cst[i] instanceof ConstantInterfaceMethodref) {
			 ConstantCP c = (ConstantCP)cst[i];
			 System.out.println("ConstantInterfaceMethodref "+c.toString());
			 }
			 */
			/*
			 if(cst[i] instanceof ConstantNameAndType) {
			 ConstantNameAndType c = (ConstantNameAndType)cst[i]; 
			 System.out.println(c+"  "+c.getName(cp));
			 }
			 */
		}
		
		return noMeth;
		
	}
	
	
	public static void main(String[] args) {
		
		JavaClass classes[];
		System.out.println("PROGRAM ARGUMENTS: "+args.length);
		int i=0;
		
		ConstantPoolAnalyser cpanalyser;
		
		try
		{
			classes = new JavaClass[args.length];
			for (i = 0; i < args.length; i++)
				classes[i] = (new ClassParser(args[i])).parse();
			
			cpanalyser = new ConstantPoolAnalyser(classes);
			cpanalyser.analyse();
		}
		
		catch (IOException e)
		{
			e.printStackTrace();
			System.err.println("E: File " + args[i]
			                                     + " does not exist or you don't have permission on it.");
		}
		catch (OutOfMemoryError er)
		{
			System.err.println("EXCEPTION:: "+er);
			er.printStackTrace();
		}    
	}
}