/*
 *  JFLAP - Formal Languages and Automata Package
 * 
 * 
 *  Susan H. Rodger
 *  Computer Science Department
 *  Duke University
 *  August 27, 2009

 *  Copyright (c) 2002-2009
 *  All rights reserved.

 *  JFLAP is open source software. Please see the LICENSE for terms.
 *
 */




package gui.action;

import java.awt.event.ActionEvent;

import javax.swing.JOptionPane;

import java.util.*;
import gui.deterministic.AddTrapStatePane;
import gui.environment.AutomatonEnvironment;
import gui.environment.Environment;
import gui.environment.Universe;
import gui.environment.tag.CriticalTag;
import gui.minimize.MinimizePane;
import automata.Automaton;
import automata.AutomatonChecker;
import automata.State;
import automata.Transition;
import automata.fsa.FiniteStateAutomaton;
import automata.fsa.Minimizer;

/**
 * Add a trap state to existing DFA or NFA
 * @author Kyung Min (Jason) Lee
 *
 */
public class AddTrapStateToDFAAction extends FSAAction{
	

	/** The automaton. */
	private Automaton automaton;

	/** The environment. */
	private AutomatonEnvironment environment;

	
	/**
	 * Instantiates a new <CODE>MinimizeTreeAction</CODE>.
	 * 
	 * @param automaton
	 *            the automaton that the tree will be shown for
	 * @param environment
	 *            the environment object that we shall add our simulator pane to
	 */
	public AddTrapStateToDFAAction(AutomatonEnvironment environment) 
	{
		super("Add Trap State to DFA", null);
		this.environment = environment;
		this.automaton=environment.getAutomaton();

	}

	
	/**
	 * Puts the DFA form in another window.
	 * 
	 * @param e
	 *            the action event
	 */
	public void actionPerformed(ActionEvent e) {
		if (automaton.getInitialState() == null) {
			JOptionPane.showMessageDialog(Universe
					.frameForEnvironment(environment),
					"The automaton should have " + "an initial state.");
			return;
		}
		AutomatonChecker ac = new AutomatonChecker();
		if (ac.isNFA(automaton)) {
			JOptionPane.showMessageDialog(Universe
					.frameForEnvironment(environment), "This isn't a DFA!");
			return;
		}
		boolean isComplete=checkIfDFAisComplete();
		if (isComplete)
		{
			JOptionPane.showMessageDialog(Universe
					.frameForEnvironment(environment), "DFA is complete. No need for the Trap State");
			
			return;
		}
		AddTrapStatePane trapPane = new AddTrapStatePane(environment);
		environment.add(trapPane, "Adding Trap State", new CriticalTag() {
		});
		environment.setActive(trapPane);
	}
	
	/**
	 * Check if DFA already has trap state and complete
	 * @return True if DFA already has a trap state and complete
	 */
	private boolean checkIfDFAisComplete()
	{
		Transition[] t=automaton.getTransitions();
		State[] s=automaton.getStates();
		TreeSet <String> reads=new TreeSet<String>();
		for (int i=0; i<t.length; i++)
		{
			reads.add(t[i].getDescription());
		}
		int count=0;
		for (int i=0; i<s.length; i++)
		{
			Transition[] tt=automaton.getTransitionsFromState(s[i]);
			if (tt.length<reads.size())
				count++;
		}
		if (count==0)
			return true;
		return false;
	}
}