package de.lmu.ifi.dbs.elki.gui.configurator;

/*
 This file is part of ELKI:
 Environment for Developing KDD-Applications Supported by Index-Structures

 Copyright (C) 2015
 Ludwig-Maximilians-Universität München
 Lehr- und Forschungseinheit für Datenbanksysteme
 ELKI Development Team

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU Affero General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Affero General Public License for more details.

 You should have received a copy of the GNU Affero General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

import java.awt.BorderLayout;
import java.awt.GridBagConstraints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFileChooser;
import javax.swing.JPanel;
import javax.swing.JTextField;

import de.lmu.ifi.dbs.elki.gui.icons.StockIcon;
import de.lmu.ifi.dbs.elki.logging.LoggingUtil;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.FileParameter;

/**
 * Provide a configuration panel to choose a file with a file selector button.
 * 
 * @author Erich Schubert
 * 
 * @apiviz.uses FileParameter
 */
public class FileParameterConfigurator extends AbstractSingleParameterConfigurator<FileParameter> implements ActionListener {
  /**
   * The panel to store the components
   */
  final JPanel panel;

  /**
   * Text field to store the name
   */
  final JTextField textfield;

  /**
   * The button to open the file selector
   */
  final JButton button;

  /**
   * Constructor.
   * 
   * @param fp File parameter
   * @param parent Component to attach to.
   */
  public FileParameterConfigurator(FileParameter fp, JComponent parent) {
    super(fp, parent);
    // create components
    textfield = new JTextField();
    textfield.setToolTipText(param.getShortDescription());
    textfield.addActionListener(this);
    button = new JButton(StockIcon.getStockIcon(StockIcon.DOCUMENT_OPEN));
    button.setToolTipText(param.getShortDescription());
    button.addActionListener(this);
    // fill with value
    File f = null;
    if (fp.isDefined()) {
      f = fp.getValue();
    }
    if (f != null) {
      String fn = f.getPath();
      textfield.setText(fn);
    } else {
      textfield.setText("");
    }

    // make a panel
    GridBagConstraints constraints = new GridBagConstraints();
    constraints.fill = GridBagConstraints.HORIZONTAL;
    constraints.weightx = 1.0;
    panel = new JPanel(new BorderLayout());
    panel.add(textfield, BorderLayout.CENTER);
    panel.add(button, BorderLayout.EAST);

    parent.add(panel, constraints);
    finishGridRow();
  }

  /**
   * Button callback to show the file selector
   */
  @Override
  public void actionPerformed(ActionEvent e) {
    // Use a new JFileChooser. Inconsistent behaviour otherwise!
    final JFileChooser fc = new JFileChooser(new File("."));
    if (param.isDefined()) {
      fc.setSelectedFile(param.getValue());
    }

    if (e.getSource() == button) {
      int returnVal = fc.showOpenDialog(button);

      if (returnVal == JFileChooser.APPROVE_OPTION) {
        textfield.setText(fc.getSelectedFile().getPath());
        fireValueChanged();
      } else {
        // Do nothing on cancel.
      }
    } else if (e.getSource() == textfield) {
      fireValueChanged();
    } else {
      LoggingUtil.warning("actionPerformed triggered by unknown source: " + e.getSource());
    }
  }

  @Override
  public String getUserInput() {
    return textfield.getText();
  }
}