import nz.ac.waikato.modeljunit.Action;
import nz.ac.waikato.modeljunit.FsmModel;


/**
 * An EFSM for Calculator3
 * @author Erik Lindqvist
 *
 */
public class CalcFsm implements FsmModel{
	public enum State { I, N, O, E};
	private State mCurrentState;
	private int mBrackets = 0;
	private boolean bracketClosed = false;

	@Override
	public Object getState() {
		return mCurrentState;
	}

	public void reset(boolean arg0) {
		mCurrentState = State.I;
		mBrackets = 0;
		bracketClosed = false;
	}

	public int getBrackets(){
		return mBrackets;
	}

	/*
	 * Transitions from state I
	 */
	public boolean addDigitIGuard(){ return mCurrentState == State.I; }
	@Action public void addDigitI(){
		mCurrentState = State.N;
	}

	public boolean openBracketIGuard(){ return mCurrentState == State.I; }
	@Action public void openBracketI(){
		mBrackets++;
		mCurrentState = State.I;
	}

	public boolean opIGuard(){ return mCurrentState == State.I; }
	@Action public void opI(){
		mCurrentState = State.E;
	}

	public boolean closeBracketIGuard(){ return mCurrentState == State.I; }
	@Action public void closeBracketI(){
		mCurrentState = State.E;
	}


	/*
	 * Transitions from state N
	 * 
	 */
	public boolean equalNGuard(){ return mCurrentState == State.N && mBrackets == 0; }
	@Action public void equalN(){
		mCurrentState = State.I;
		bracketClosed = false;
	}

	public boolean closeBracketN1Guard(){ return mCurrentState == State.N && mBrackets > 0; }
	@Action public void closeBracketN1(){
		bracketClosed = true;
		mCurrentState = State.N;
		mBrackets--;
	}

	public boolean closeBracketN2Guard(){ return mCurrentState == State.N && mBrackets <= 0; }
	@Action public void closeBracketN2(){
		mCurrentState = State.E;
	}

	public boolean addDigitN1Guard(){ return mCurrentState == State.N && bracketClosed == false; }
	@Action public void addDigitN1(){
		mCurrentState = State.N;
	}

	public boolean addDigitN2Guard(){ return mCurrentState == State.N && bracketClosed == true; }
	@Action public void addDigitN2(){
		mCurrentState = State.E;
		bracketClosed = false;
	}

	public boolean pressOpNGuard(){ return mCurrentState == State.N; }
	@Action public void pressOpN(){
		mCurrentState = State.O;
		bracketClosed = false;
	}

	public boolean openBracketNGuard(){ return mCurrentState == State.N; }
	@Action public void openBracketN(){
		mCurrentState = State.E;
	}

	/*
	 * Transitions from state O
	 */
	public boolean pressOpOGuard(){ return mCurrentState == State.O; }
	@Action public void pressOpO(){
		mCurrentState = State.O;
	}

	public boolean addDigitOGuard(){ return mCurrentState == State.O; }
	@Action public void addDigitO(){
		mCurrentState = State.N;
	}

	public boolean closeBracketOGuard(){ return mCurrentState == State.O; }
	@Action public void closeBracketO(){
		mCurrentState = State.E;
	}

	public boolean openBracketOGuard(){ return mCurrentState == State.O; }
	@Action public void openBracketO(){
		mCurrentState = State.I;
		mBrackets++;
	}

	/*
	 * Transition from any state
	 */
	@Action public void pressReset(){
		reset(true);
	}

}