package calculator;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class CalcController2 {

	private CalcModel model;
	private CalcView2 view;

	/**
	 * Create a controller with no view and no model.
	 */
	public CalcController2() {

	}

	/**
	 * Returns the view of this controller.
	 * 
	 * @return the view of this controller.
	 */
	public CalcView2 getView() {
		return this.view;
	}

	/**
	 * Returns the model of this controller.
	 * 
	 * @return the model of this controller.
	 */
	public CalcModel getModel() {
		return this.model;
	}

	/**
	 * Sets the model of this controller to the given model.
	 * 
	 * @param model
	 *            the new model of this controller.
	 * @pre. model != null
	 */
	public void setModel(CalcModel model) {
		this.model = model;
	}

	/**
	 * Sets the view of this controller to the given view.
	 * 
	 * @param view
	 *            the new view of this controller.
	 * @pre. view != null
	 */
	public void setView(CalcView2 view) {
		this.view = view;

		this.view.addSumListener(new SumListener());
		this.view.addSubtractListener(new SubtractListener());
		this.view.addMultiplyListener(new MultiplyListener());
		this.view.addDivideListener(new DivideListener());
		this.view.addClearListener(new ClearListener());
	}

	/**
	 * Abstract base class for classes that listen for arithmetic events (sum,
	 * subtract, multiply, divide.
	 */
	private abstract class ArithmeticListener implements ActionListener {
		private int getUserValue() {
			int userValue = 0;
			try {
				userValue = Integer.parseInt(getView().getUserValue());
			} catch (NumberFormatException ex) {
			}
			return userValue;
		}

		private void setCalculatedValue() {
			getView().setCalcValue("" + getModel().getCalcValue());
		}

		protected abstract void doOperation(int userValue);

		@Override
		public void actionPerformed(ActionEvent action) {
			int userValue = this.getUserValue();
			doOperation(userValue);
			this.setCalculatedValue();
		}
	}

	private class SumListener extends ArithmeticListener {
		@Override
		protected void doOperation(int userValue) {
				getModel().sum(userValue);
		}
	}

	private class SubtractListener extends ArithmeticListener {
		@Override
		protected void doOperation(int userValue) {
			getModel().subtract(userValue);
		}
	}

	private class MultiplyListener extends ArithmeticListener {
		@Override
		protected void doOperation(int userValue) {
			getModel().multiply(userValue);
		}
	}

	private class DivideListener extends ArithmeticListener {
		@Override
		protected void doOperation(int userValue) {
			if (userValue != 0) {
				getModel().divide(userValue);
			}
		}
	}

	private class ClearListener extends ArithmeticListener {
		@Override
		protected void doOperation(int userValue) {
			getModel().clear();
		}
	}

}