/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.mahout.ga.watchmaker.travellingsalesman;

import com.google.common.collect.Lists;

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Collection;
import java.util.TreeSet;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JPanel;

/**
 * Component for selecting which cities are to be visited by the travelling salesman.
 * 
 * <br>
 * The original code is from <b>the Watchmaker project</b> (https://watchmaker.dev.java.net/).
 */
final class ItineraryPanel extends JPanel {
  
  private final Collection<JCheckBox> checkBoxes;
  private final JButton selectAllButton;
  private final JButton clearButton;
  
  ItineraryPanel(Collection<String> cities) {
    super(new BorderLayout());
    
    Container checkBoxPanel = new JPanel(new GridLayout(0, 1));
    checkBoxes = Lists.newArrayListWithCapacity(cities.size());
    for (String city : cities) {
      JCheckBox checkBox = new JCheckBox(city, false);
      checkBoxes.add(checkBox);
      checkBoxPanel.add(checkBox);
    }
    add(checkBoxPanel, BorderLayout.CENTER);
    
    Container buttonPanel = new JPanel(new GridLayout(2, 1));
    selectAllButton = new JButton("Select All");
    buttonPanel.add(selectAllButton);
    clearButton = new JButton("Clear Selection");
    buttonPanel.add(clearButton);
    ActionListener buttonListener = new ActionListener() {
      
      @Override
      public void actionPerformed(ActionEvent actionEvent) {
        boolean select = actionEvent.getSource() == selectAllButton;
        for (JCheckBox checkBox : checkBoxes) {
          checkBox.setSelected(select);
        }
      }
    };
    selectAllButton.addActionListener(buttonListener);
    clearButton.addActionListener(buttonListener);
    add(buttonPanel, BorderLayout.SOUTH);
    
    setBorder(BorderFactory.createTitledBorder("Itinerary"));
  }
  
  /**
   * Returns the cities that have been selected as part of the itinerary.
   */
  public Collection<String> getSelectedCities() {
    Collection<String> cities = new TreeSet<String>();
    for (JCheckBox checkBox : checkBoxes) {
      if (checkBox.isSelected()) {
        cities.add(checkBox.getText());
      }
    }
    return cities;
  }
  
  @Override
  public void setEnabled(boolean b) {
    for (JCheckBox checkBox : checkBoxes) {
      checkBox.setEnabled(b);
    }
    selectAllButton.setEnabled(b);
    clearButton.setEnabled(b);
    super.setEnabled(b);
  }
}