package javax.mail;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Vector;
import java.util.concurrent.Executor;
import javax.mail.event.ConnectionEvent;
import javax.mail.event.ConnectionListener;
import javax.mail.event.MailEvent;

public abstract class Service {
  protected Session session;
  
  protected URLName url = null;
  
  protected boolean debug = false;
  
  private boolean connected = false;
  
  private final Vector connectionListeners = new Vector();
  
  private final EventQueue q;
  
  protected Service(Session session, URLName urlname) {
    this.session = session;
    this.debug = session.getDebug();
    this.url = urlname;
    String protocol = null;
    String host = null;
    int port = -1;
    String user = null;
    String password = null;
    String file = null;
    if (this.url != null) {
      protocol = this.url.getProtocol();
      host = this.url.getHost();
      port = this.url.getPort();
      user = this.url.getUsername();
      password = this.url.getPassword();
      file = this.url.getFile();
    } 
    if (protocol != null) {
      if (host == null)
        host = session.getProperty("mail." + protocol + ".host"); 
      if (user == null)
        user = session.getProperty("mail." + protocol + ".user"); 
    } 
    if (host == null)
      host = session.getProperty("mail.host"); 
    if (user == null)
      user = session.getProperty("mail.user"); 
    if (user == null)
      try {
        user = System.getProperty("user.name");
      } catch (SecurityException e) {} 
    this.url = new URLName(protocol, host, port, file, user, password);
    String scope = session.getProperties().getProperty("mail.event.scope", "folder");
    Executor executor = (Executor)
      session.getProperties().get("mail.event.executor");
    if (scope.equalsIgnoreCase("application")) {
      this.q = EventQueue.getApplicationEventQueue(executor);
    } else if (scope.equalsIgnoreCase("session")) {
      this.q = session.getEventQueue();
    } else {
      this.q = new EventQueue(executor);
    } 
  }
  
  public void connect() throws MessagingException {
    connect(null, null, null);
  }
  
  public void connect(String host, String user, String password) throws MessagingException {
    connect(host, -1, user, password);
  }
  
  public void connect(String user, String password) throws MessagingException {
    connect(null, user, password);
  }
  
  public synchronized void connect(String host, int port, String user, String password) throws MessagingException {
    if (isConnected())
      throw new IllegalStateException("already connected"); 
    boolean connected = false;
    boolean save = false;
    String protocol = null;
    String file = null;
    if (this.url != null) {
      protocol = this.url.getProtocol();
      if (host == null)
        host = this.url.getHost(); 
      if (port == -1)
        port = this.url.getPort(); 
      if (user == null) {
        user = this.url.getUsername();
        if (password == null)
          password = this.url.getPassword(); 
      } else if (password == null && user.equals(this.url.getUsername())) {
        password = this.url.getPassword();
      } 
      file = this.url.getFile();
    } 
    if (protocol != null) {
      if (host == null)
        host = this.session.getProperty("mail." + protocol + ".host"); 
      if (user == null)
        user = this.session.getProperty("mail." + protocol + ".user"); 
    } 
    if (host == null)
      host = this.session.getProperty("mail.host"); 
    if (user == null)
      user = this.session.getProperty("mail.user"); 
    if (user == null)
      try {
        user = System.getProperty("user.name");
      } catch (SecurityException e) {} 
    if (password == null && this.url != null) {
      setURLName(new URLName(protocol, host, port, file, user, null));
      PasswordAuthentication pw = this.session.getPasswordAuthentication(getURLName());
      if (pw != null) {
        if (user == null) {
          user = pw.getUserName();
          password = pw.getPassword();
        } else if (user.equals(pw.getUserName())) {
          password = pw.getPassword();
        } 
      } else {
        save = true;
      } 
    } 
    AuthenticationFailedException authEx = null;
    try {
      connected = protocolConnect(host, port, user, password);
    } catch (AuthenticationFailedException ex) {
      authEx = ex;
    } 
    if (!connected) {
      InetAddress addr;
      try {
        addr = InetAddress.getByName(host);
      } catch (UnknownHostException e) {
        addr = null;
      } 
      PasswordAuthentication pw = this.session.requestPasswordAuthentication(addr, port, protocol, null, user);
      if (pw != null) {
        user = pw.getUserName();
        password = pw.getPassword();
        connected = protocolConnect(host, port, user, password);
      } 
    } 
    if (!connected) {
      if (authEx != null)
        throw authEx; 
      if (user == null)
        throw new AuthenticationFailedException("failed to connect, no user name specified?"); 
      if (password == null)
        throw new AuthenticationFailedException("failed to connect, no password specified?"); 
      throw new AuthenticationFailedException("failed to connect");
    } 
    setURLName(new URLName(protocol, host, port, file, user, password));
    if (save)
      this.session.setPasswordAuthentication(getURLName(), new PasswordAuthentication(user, password)); 
    setConnected(true);
    notifyConnectionListeners(1);
  }
  
  protected boolean protocolConnect(String host, int port, String user, String password) throws MessagingException {
    return false;
  }
  
  public synchronized boolean isConnected() {
    return this.connected;
  }
  
  protected synchronized void setConnected(boolean connected) {
    this.connected = connected;
  }
  
  public synchronized void close() throws MessagingException {
    setConnected(false);
    notifyConnectionListeners(3);
  }
  
  public synchronized URLName getURLName() {
    if (this.url != null && (this.url.getPassword() != null || this.url.getFile() != null))
      return new URLName(this.url.getProtocol(), this.url.getHost(), 
          this.url.getPort(), null, 
          this.url.getUsername(), null); 
    return this.url;
  }
  
  protected synchronized void setURLName(URLName url) {
    this.url = url;
  }
  
  public void addConnectionListener(ConnectionListener l) {
    this.connectionListeners.addElement(l);
  }
  
  public void removeConnectionListener(ConnectionListener l) {
    this.connectionListeners.removeElement(l);
  }
  
  protected void notifyConnectionListeners(int type) {
    if (this.connectionListeners.size() > 0) {
      ConnectionEvent e = new ConnectionEvent(this, type);
      queueEvent(e, this.connectionListeners);
    } 
    if (type == 3)
      this.q.terminateQueue(); 
  }
  
  public String toString() {
    URLName url = getURLName();
    if (url != null)
      return url.toString(); 
    return super.toString();
  }
  
  protected void queueEvent(MailEvent event, Vector vector) {
    Vector v = (Vector)vector.clone();
    this.q.enqueue(event, v);
  }
  
  protected void finalize() throws Throwable {
    super.finalize();
    this.q.terminateQueue();
  }
  
  Session getSession() {
    return this.session;
  }
  
  EventQueue getEventQueue() {
    return this.q;
  }
}