/*
 * Created on Nov 24, 2004
 */
package fr.lifl.stc.stan.execution.stack;

import java.util.Iterator;
import java.util.Stack;


import fr.lifl.stc.stan.execution.Interpreter;


/**
 * @author yann
 */
public class ExecutionStack {

	private Stack<MultiObject> m_stack;

	/**
	 *
	 */
	public ExecutionStack() {
		super();
		m_stack = new Stack<MultiObject>();
	}

	public void push(MultiObject o) {
		m_stack.push(o);
	}

	public MultiObject pop() {
		return m_stack.pop();
	}

	public MultiObject peek() {
		return m_stack.peek();
	}

	public MultiObject peek(int n) {
		Stack<MultiObject> tmp = new Stack<MultiObject>();
		for(int i = 0; i<n; i++)
			tmp.push(pop());
		MultiObject res = peek();
		for(int i = 0; i<n; i++)
			push(tmp.pop());

		return res;
	}

	public Object clone() {
		ExecutionStack res = new ExecutionStack();

		Iterator<MultiObject> it = m_stack.iterator();
		while(it.hasNext()) {
			res.m_stack.push((MultiObject)(it.next()).clone());
		}
		return res;
	}

	public int size() {
		return m_stack.size();
	}

	private MultiObject get(int index) {
		return m_stack.get(index);
	}

	public void clear() {
		m_stack.clear();
	}

	public boolean merge(ExecutionStack s) {
		if(size() != s.size()) {
			System.err.println("--------------------------->>>>>>>>>>>>>>>>>>>>>Error: Execution.merge(): TOS differ on same instruction. Our size = "+this.size()+"  other size = "+s.size());
			System.exit(1);
			return false;
		}

		boolean res = false;
		for(int i = 0; i<size(); i++) {
			res = res || get(i).merge(s.get(i));
		}
		return res;
	}

	public String toString() {
		String res = "";
		Iterator<MultiObject> it = m_stack.iterator();
		while(it.hasNext()) {
			res += it.next();
		}
		return res + "\n";
	}

	public boolean equals(Object o){
		ExecutionStack es = (ExecutionStack)o;
		return this.m_stack.equals(es.m_stack);
	}

	private MultiObject[] content() {
		MultiObject res[] = new MultiObject[this.size()];
		int size = this.size();

		ExecutionStack tmp = new ExecutionStack();
		for(int i = 0; i<size; i++){
			res[i] = this.pop();
			tmp.push(res[i]);
		}

		for(int i = 0; i< size; i++)
			push(tmp.pop());

		return res;
	}

	public byte[] toBytes(int codification, Interpreter intr){
		MultiObject[] input = this.content();
		return MultiObject.toBytes(input, input.length, codification, intr);
	}
}