package com.nilhcem.fakesmtp.gui;
   
   import java.awt.Component;
   import java.io.File;
   import java.util.Observable;
   import java.util.Observer;
   import javax.swing.JFileChooser;
   import com.nilhcem.fakesmtp.core.Configuration;
   import com.nilhcem.fakesmtp.core.I18n;
  import com.nilhcem.fakesmtp.gui.info.SaveMsgField;
  import com.nilhcem.fakesmtp.model.UIModel;
  
  /**
   * Provides a graphical directory chooser dialog.
   * <p>
   * The directory chooser is used to select the folder where emails will be saved in.<br>
   * It can be launched from the menu bar, or from the main panel.
   * </p>
   *
   * @author Nilhcem
   * @since 1.0
   */
  public final class DirChooser extends Observable implements Observer {
  
  	private final JFileChooser dirChooser = new JFileChooser();
  	private Component parent = null;
  
  	/**
  	 * Creates a {@code JFileChooser} component and sets it to be for directories only.
  	 *
  	 * @param parent the component from where the chooser will be launched <i>(should be the main panel of the application)</i>.
  	 */
  	public DirChooser(Component parent) {
  		this.parent = parent;
  		dirChooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
  		dirChooser.setDialogTitle(String.format(I18n.INSTANCE.get("dirchooser.title"),
  			Configuration.INSTANCE.get("application.name")));
  		dirChooser.setApproveButtonText(I18n.INSTANCE.get("dirchooser.approve.btn"));
  	}
  
  	/**
  	 * Opens the folder selection.
  	 * <p>
  	 * This method will be called by an {@code Observable} element:
       * </p>
  	 * <ul>
  	 *   <li>The {@link MenuBar};</li>
  	 *   <li>Or the {@link SaveMsgField}.</li>
  	 * </ul>
  	 *
  	 * @param o the observable element which will notify this class.
  	 * @param arg optional parameters (not used).
  	 */
  	@Override
  	public void update(Observable o, Object arg) {
  		if (o instanceof MenuBar || o instanceof SaveMsgField) {
  			openFolderSelection();
  		}
  	}
  
  	/**
  	 * Opens the folder selection dialog and notify observers once the directory is selected.
  	 * <p>
  	 * The only observer notified is the {@link SaveMsgField}.
  	 * </p>
  	 */
  	private void openFolderSelection() {
  		File filePath = new File(Configuration.INSTANCE.get("emails.default.dir"));
  		dirChooser.setCurrentDirectory(filePath);
  
  		int result = dirChooser.showOpenDialog(parent);
  
  		if (result == JFileChooser.APPROVE_OPTION) {
  			File selectedDir = dirChooser.getSelectedFile();
  			if (selectedDir != null) {
  				UIModel.INSTANCE.setSavePath(selectedDir.getAbsolutePath());
  				setChanged();
  				notifyObservers();
  			}
  		}
  	}
  }