package com.nilhcem.fakesmtp.gui.tab;
   
   import com.nilhcem.fakesmtp.core.ArgsHandler;
   import com.nilhcem.fakesmtp.core.Configuration;
   import com.nilhcem.fakesmtp.core.I18n;
   import com.nilhcem.fakesmtp.gui.info.ClearAllButton;
   import com.nilhcem.fakesmtp.model.EmailModel;
   import com.nilhcem.fakesmtp.model.UIModel;
   import com.nilhcem.fakesmtp.server.MailSaver;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.mail.internet.MimeUtility;
  import javax.swing.JOptionPane;
  import javax.swing.JScrollPane;
  import javax.swing.JTable;
  import javax.swing.table.DefaultTableModel;
  import java.awt.Desktop;
  import java.awt.Rectangle;
  import java.awt.event.ComponentAdapter;
  import java.awt.event.ComponentEvent;
  import java.awt.event.MouseEvent;
  import java.awt.event.MouseListener;
  import java.io.File;
  import java.io.IOException;
  import java.io.UnsupportedEncodingException;
  import java.text.SimpleDateFormat;
  import java.util.Observable;
  import java.util.Observer;
  
  /**
   * Scrolled table where will be displayed every received email (one line for each email).
   * <p>
   * The user can double-click on any row to see the selected email.
   * </p>
   *
   * @author Nilhcem
   * @since 1.0
   */
  public final class MailsListPane implements Observer {
  
  	private int nbElements = 0;
  	private Desktop desktop = null;
  	private static final Logger LOGGER = LoggerFactory.getLogger(MailsListPane.class);
  	private final I18n i18n = I18n.INSTANCE;
  	private final JScrollPane mailsListPane = new JScrollPane();
  	private final SimpleDateFormat dateFormat = new SimpleDateFormat("hh:mm:ss a");
  	private final int[] widths = new int[] {85, 140, 140}; // widths of columns in tab
  
  	/**
  	 * Table with non-editable cells.
  	 */
  	private final JTable table = new JTable() {
  		private static final long serialVersionUID = 6332956458868628779L;
  
  		@Override
  		public boolean isCellEditable(int row, int column) {
  			return false;
  		}
  	};
  
  	/**
  	 * Table model with non-editable cells.
  	 */
  	private final DefaultTableModel model = new DefaultTableModel() {
  		private static final long serialVersionUID = -6716294637919469299L;
  
  		public boolean isCellEditable(int rowIndex, int mColIndex) {
  			return false;
  		}
  	};
  
  	/**
  	 * Creates the table and sets its cells as non editable.
  	 * <p>
  	 * Adds some mouse events on the table, to display emails, when a user clicks on
  	 * a specific row.<br>
  	 * If the email can't be found, an error message will be displayed.<br>
  	 * The table will reset the size of its column every time the size of the table changed
  	 * (for example when the user maximizes the window).
  	 * </p>
  	 */
  	public MailsListPane() {
  		// Init desktop (Java 6 Desktop API)
  		if (Desktop.isDesktopSupported()) {
  			desktop = Desktop.getDesktop();
  		}
  
  		if (!ArgsHandler.INSTANCE.memoryModeEnabled()) {
  			table.addMouseListener(new MouseListener() {
  				@Override
  				public void mouseReleased(MouseEvent e) {
  				}
  
  				@Override
  				public void mousePressed(MouseEvent e) {
  				}
  
  				@Override
 				public void mouseExited(MouseEvent e) {
 				}
 
 				@Override
 				public void mouseEntered(MouseEvent e) {
 				}
 
 				@Override
 				public void mouseClicked(MouseEvent e) {
 
 					String emlViewer = ArgsHandler.INSTANCE.getEmlViewer();
 
 					if (e.getClickCount() == 2 && (emlViewer != null || desktop != null)) {
 						File file = null;
 						JTable target = (JTable) e.getSource();
 						String fileName = UIModel.INSTANCE.getListMailsMap().get(target.getSelectedRow());
 						if (fileName == null) {
 							LOGGER.error("Can't find any associated email for row #{}", target.getSelectedRow());
 						} else {
 							file = new File(fileName);
 						}
 
 						if (file != null && file.exists()) {
 							try {
 								if (emlViewer != null) {
 									Runtime.getRuntime().exec(emlViewer + " " + file.getAbsolutePath());
 								} else {
 									desktop.open(file);
 								}
 							} catch (IOException ioe) {
 								LOGGER.error("", ioe);
 								displayError(String.format(i18n.get("mailslist.err.open"), file.getAbsolutePath()));
 							}
 						} else {
 							displayError(String.format(i18n.get("mailslist.err.find"), file.getAbsolutePath()));
 						}
 					}
 				}
 			});
         }
 
 		// Auto scroll tab to bottom when a new element is inserted
 		table.addComponentListener(new ComponentAdapter() {
 			public void componentResized(ComponentEvent e) {
 				table.scrollRectToVisible(new Rectangle(table.getCellRect(nbElements, 0, true)));
 			}
 		});
 
 		model.addColumn(i18n.get("mailslist.col.received"));
 		model.addColumn(i18n.get("mailslist.col.from"));
 		model.addColumn(i18n.get("mailslist.col.to"));
 		model.addColumn(i18n.get("mailslist.col.subject"));
 		table.setModel(model);
 
 		mailsListPane.addComponentListener(new ComponentAdapter() {
 			public void componentResized(ComponentEvent e) {
 				// When the width of a column is changed, only the columns to the left and right of the margin change
 				table.setAutoResizeMode(JTable.AUTO_RESIZE_NEXT_COLUMN);
 
 				// Set width for each column
 				int total = 0;
 				int length = widths.length;
 				for (int i = 0; i < length; i++) {
 					table.getColumnModel().getColumn(i).setPreferredWidth(widths[i]);
 					total += widths[i];
 				}
 				table.getColumnModel().getColumn(length).setPreferredWidth(table.getWidth() - total);
 			}
 		});
 		mailsListPane.getViewport().add(table, null);
 	}
 
 	/**
 	 * Returns the JScrollPane object.
 	 *
 	 * @return the JScrollPane object.
 	 */
 	public JScrollPane get() {
 		return mailsListPane;
 	}
 
 	/**
 	 * Updates the content of the table.
 	 * <p>
 	 * This method will be called by an observable element.
      * </p>
 	 * <ul>
 	 *   <li>If the observable is a {@link MailSaver} object, a new row will be added
 	 *   to the table, and the {@link UIModel} will be updated;</li>
 	 *   <li>If the observable is a {@link ClearAllButton} object, all the cells
 	 *   of the table will be removed, and the {@link UIModel} will be updated.</li>
 	 * </ul>
 	 *
 	 * @param o the observable element which will notify this class.
 	 * @param arg optional parameters (an {@code EmailModel} object, for the case of
 	 * a {@code MailSaver} observable) containing all the information about the email.
 	 */
 	@Override
 	public void update(Observable o, Object arg) {
 		if (o instanceof MailSaver) {
 			EmailModel email = (EmailModel) arg;
 			String subject;
 			try {
 				subject = MimeUtility.decodeText(email.getSubject());
 			} catch (UnsupportedEncodingException e) {
 				LOGGER.error("", e);
 				subject = email.getSubject();
 			}
 
 			model.addRow(new Object[] {dateFormat.format(email.getReceivedDate()), email.getFrom(), email.getTo(), subject});
 			UIModel.INSTANCE.getListMailsMap().put(nbElements++, email.getFilePath());
 		} else if (o instanceof ClearAllButton) {
 			// Delete information from the map
 			UIModel.INSTANCE.getListMailsMap().clear();
 
 			// Remove elements from the list
 			try {
 				while (nbElements > 0) {
 					model.removeRow(--nbElements);
 				}
 			} catch (ArrayIndexOutOfBoundsException e) {
 				LOGGER.error("", e);
 			}
 		}
 	}
 
 	/**
 	 * Displays a message dialog containing the error specified in parameter.
 	 *
 	 * @param error a String representing an error message to display.
 	 */
 	private void displayError(String error) {
 		JOptionPane.showMessageDialog(mailsListPane.getParent(), error,
 			String.format(i18n.get("mailslist.err.title"), Configuration.INSTANCE.get("application.name")),
 			JOptionPane.ERROR_MESSAGE);
 	}
 }