package com.nilhcem.fakesmtp.gui;
   
   import com.nilhcem.fakesmtp.core.ArgsHandler;
   import com.nilhcem.fakesmtp.core.I18n;
   import com.nilhcem.fakesmtp.gui.info.ClearAllButton;
   import com.nilhcem.fakesmtp.gui.info.NbReceivedLabel;
   import com.nilhcem.fakesmtp.gui.info.PortTextField;
   import com.nilhcem.fakesmtp.gui.info.SaveMsgField;
   import com.nilhcem.fakesmtp.gui.info.StartServerButton;
  import com.nilhcem.fakesmtp.gui.tab.LastMailPane;
  import com.nilhcem.fakesmtp.gui.tab.LogsPane;
  import com.nilhcem.fakesmtp.gui.tab.MailsListPane;
  import com.nilhcem.fakesmtp.server.MailSaver;
  import com.nilhcem.fakesmtp.server.SMTPServerHandler;
  import net.miginfocom.swing.MigLayout;
  
  import javax.swing.JLabel;
  import javax.swing.JPanel;
  import javax.swing.JTabbedPane;
  import java.util.Observable;
  
  /**
   * Provides the main panel of the application, which will contain all the components.
   *
   * @author Nilhcem
   * @since 1.0
   */
  public final class MainPanel {
  	// I18n
  	private final I18n i18n = I18n.INSTANCE;
  
  	// Panel and layout
  	private final MigLayout layout = new MigLayout(
  		"", // Layout constraints
  		"[] 10 [] [] [grow,fill]", // Column constraints
  		"[] [] 5 [] 5 [grow,fill] []"); // Row constraints
  	private final JPanel mainPanel = new JPanel(layout);
  
  	// Directory chooser
  	private final DirChooser dirChooser = new DirChooser(mainPanel);
  
  	// Port
  	private final JLabel portLabel = new JLabel(i18n.get("mainpanel.listening.port"));
  	private final PortTextField portText = new PortTextField();
  	private final StartServerButton startServerBtn = new StartServerButton();
  
  	// Messages received
  	private final JLabel receivedLabel = new JLabel(i18n.get("mainpanel.messages.received"));
  	private final NbReceivedLabel nbReceivedLabel = new NbReceivedLabel();
  
  	// Save incoming messages to
  	private final JLabel saveMessages = new JLabel(i18n.get("mainpanel.save.messages"));
  	private final SaveMsgField saveMsgTextField = new SaveMsgField();
  
  	// Tab pane
  	private final JTabbedPane tabbedPane = new JTabbedPane();
  	private final LogsPane logsPane = new LogsPane();
  	private final MailsListPane mailsListPane = new MailsListPane();
  	private final LastMailPane lastMailPane = new LastMailPane();
  
  	// Clear all
  	private final ClearAllButton clearAll = new ClearAllButton();
  
  	/**
  	 * Creates the main panel.
  	 * <p>
  	 * To create the main panel, the method will first have to handle components interactions by
  	 * adding observers to observable elements, then the method will build the GUI by placing all the
  	 * components in the main panel.
  	 * </p>
  	 *
  	 * @param menu the menu bar which will notify the directory file chooser.
  	 */
  	public MainPanel(Observable menu) {
  		assignLabelsToFields();
  		addObservers(menu);
  		buildGUI();
  		checkArgs();
  	}
  
  	/**
  	 * Returns the JPanel object.
  	 *
  	 * @return the JPanel object.
  	 */
  	public JPanel get() {
  		return mainPanel;
  	}
  
  	/**
  	 * Handles components interactions by adding observers to observable elements.
  	 * <p>
  	 * The interactions are the following:
  	 * <ul>
  	 *   <li>Open the directory chooser when clicking on the menu/the save message field;</li>
  	 *   <li>Enable/Disable the port field when the server starts;</li>
  	 *   <li>Set the new directory, once a folder is selected;<li>
  	 *   <li>Notify components when a message is received;</li>
  	 *   <li>Notify components when the user wants to clear them all.</li>
 	 * </ul>
 	 * </p>
 	 *
 	 * @param menu the menu bar which will notify the directory file chooser.
 	 */
 	private void addObservers(Observable menu) {
 		// When we want to select a directory
 		menu.addObserver(dirChooser);
 		saveMsgTextField.addObserver(dirChooser);
 
 		// When we click on "start server" button
 		startServerBtn.addObserver(portText);
 
 		// When we press "Enter" on the PortTextField
 		portText.addObserver(startServerBtn);
 
 		// Once we chose a directory
 		dirChooser.addObserver(saveMsgTextField);
 
 		// When a message is received
 		MailSaver mailSaver = SMTPServerHandler.INSTANCE.getMailSaver();
 		mailSaver.addObserver(nbReceivedLabel);
 		mailSaver.addObserver(mailsListPane);
 		mailSaver.addObserver(lastMailPane);
 		mailSaver.addObserver(clearAll);
 
 		// When we click on "clear all"
 		clearAll.addObserver(nbReceivedLabel);
 		clearAll.addObserver(mailsListPane);
 		clearAll.addObserver(logsPane);
 		clearAll.addObserver(lastMailPane);
 	}
 
 	/**
 	 * Places all components in the panel.
 	 */
 	private void buildGUI() {
 		// Port / Start server
 		mainPanel.add(portLabel);
 		mainPanel.add(portText.get(), "w 60!");
 		mainPanel.add(startServerBtn.get(), "span, w 165!");
 
 		// Save messages to...
 		mainPanel.add(saveMessages);
 		mainPanel.add(saveMsgTextField.get(), "span, w 230!");
 
 		// Nb received
 		mainPanel.add(receivedLabel);
 		mainPanel.add(nbReceivedLabel.get(), "span");
 
 		// Tab pane
 		tabbedPane.add(mailsListPane.get(), i18n.get("mainpanel.tab.mailslist"));
 		tabbedPane.add(logsPane.get(), i18n.get("mainpanel.tab.smtplog"));
 		tabbedPane.add(lastMailPane.get(), i18n.get("mainpanel.tab.lastmessage"));
 		mainPanel.add(tabbedPane, "span, grow");
 
 		// Clear all
 		mainPanel.add(clearAll.get(), "span, center");
 	}
 
 	/**
 	 * Checks command line arguments and toggles components if necessary.
 	 * <p>
 	 * <ul><li>if the user has chosen a different port, then specifies it in the port text field.</li>
 	 * <li>if the user has chosen to auto-start the SMTP server, then it toggles automatically the "start server" button.</li></ul>
 	 * </p>
 	 */
 	private void checkArgs() {
 		ArgsHandler args = ArgsHandler.INSTANCE;
 
 		if (args.getPort() != null) {
 			portText.setText(args.getPort());
 		}
 
 		if (args.shouldStartServerAtLaunch()) {
 			startServerBtn.toggleButton();
 		}
 
 		if (args.memoryModeEnabled()) {
 			saveMsgTextField.get().setEnabled(false);
 		}
 	}
 
 	/**
 	 * Assigns labels to components, for accessibility purpose.
 	 */
 	private void assignLabelsToFields() {
 		portLabel.setLabelFor(portText.get());
 		saveMessages.setLabelFor(saveMsgTextField.get());
 		receivedLabel.setLabelFor(nbReceivedLabel.get());
 	}
 
 	/**
 	 * Returns reference to portText field. Used for saving last values to file
 	 *
 	 * @return reference to portText field. Used for saving last values to file
 	 */
 	public PortTextField getPortText() {
 		return portText;
 	}
 
 	/**
 	 * Returns reference to saveMsgTextField. Used for saving last values to file
      *
      * @return reference to saveMsgTextField. Used for saving last values to file
 	 */
 	public SaveMsgField getSaveMsgTextField() {
 		return saveMsgTextField;
 	}
 }