/*
 * SIP Communicator, the OpenSource Java VoIP and Instant Messaging client.
 *
 * Distributable under LGPL license.
 * See terms of license at gnu.org.
 */
package net.java.sip.communicator.impl.protocol.irc;

import java.util.*;

import net.java.sip.communicator.service.protocol.*;
import net.java.sip.communicator.service.protocol.event.*;
import net.java.sip.communicator.util.*;

/**
 * An IRC implementation of the ProtocolProviderService.
 *
 * @author Loic Kempf
 * @author Stephane Remy
 */
public class ProtocolProviderServiceIrcImpl
    implements ProtocolProviderService
{
    private static final Logger logger
        = Logger.getLogger(ProtocolProviderServiceIrcImpl.class);
    
    /**
     * The irc server.
     */
    private IrcStack ircStack;
    
    /**
     * The id of the account that this protocol provider represents.
     */
    private AccountID accountID = null;

    /**
     * We use this to lock access to initialization.
     */
    private Object initializationLock = new Object();

    /**
     * The hashtable with the operation sets that we support locally.
     */
    private Hashtable supportedOperationSets = new Hashtable();

    /**
     * A list of listeners interested in changes in our registration state.
     */
    private Vector registrationStateListeners = new Vector();

    /**
     * Indicates whether or not the provider is initialized and ready for use.
     */
    private boolean isInitialized = false;
    
    /**
     * The icon corresponding to the irc protocol.
     */
    private ProtocolIconIrcImpl ircIcon = new ProtocolIconIrcImpl();

    /**
     * The default constructor for the IRC protocol provider.
     */
    public ProtocolProviderServiceIrcImpl()
    {
        logger.trace("Creating a irc provider.");
    }
    
    /**
     * Keeps our current registration state.
     */
    private RegistrationState currentRegistrationState
        = RegistrationState.UNREGISTERED;

    /**
     * Initializes the service implementation, and puts it in a sate where it
     * could operate with other services. It is strongly recommended that
     * properties in this Map be mapped to property names as specified by
     * <tt>AccountProperties</tt>.
     *
     * @param userID the user id of the IRC account we're currently
     * initializing
     * @param accountID the identifier of the account that this protocol
     * provider represents.
     *
     * @see net.java.sip.communicator.service.protocol.AccountID
     */
    protected void initialize(String userID, AccountID accountID)
    {
        synchronized(initializationLock)
        {
            this.accountID = accountID;

            //Initialize the multi user chat support
            OperationSetMultiUserChatIrcImpl multiUserChat
                = new OperationSetMultiUserChatIrcImpl(this);
            
            supportedOperationSets.put(
                OperationSetMultiUserChat.class.getName(), multiUserChat);

            this.ircStack = new IrcStack(   this,
                                            getAccountID().getUserID(),
                                            getAccountID().getUserID(),
                                            "SIP Communicator 1.0",
                                            "");

            isInitialized = true;
        }
    }

    /**
     * Registers the specified listener with this provider so that it would
     * receive notifications on changes of its state or other properties such
     * as its local address and display name.
     *
     * @param listener the listener to register.
     */
    public void addRegistrationStateChangeListener(
        RegistrationStateChangeListener listener)
    {
        synchronized(registrationStateListeners)
        {
            if (!registrationStateListeners.contains(listener))
                registrationStateListeners.add(listener);
        }

    }

    /**
     * Removes the specified registration listener so that it won't receive
     * further notifications when our registration state changes.
     *
     * @param listener the listener to remove.
     */
    public void removeRegistrationStateChangeListener(
        RegistrationStateChangeListener listener)
    {
        synchronized(registrationStateListeners)
        {
            registrationStateListeners.remove(listener);
        }
    }

    /**
     * Creates a <tt>RegistrationStateChangeEvent</tt> corresponding to the
     * specified old and new states and notifies all currently registered
     * listeners.
     *
     * @param oldState the state that the provider had before the change
     * occurred
     * @param newState the state that the provider is currently in.
     * @param reasonCode a value corresponding to one of the REASON_XXX fields
     * of the RegistrationStateChangeEvent class, indicating the reason for
     * this state transition.
     * @param reason a String further explaining the reason code or null if
     * no such explanation is necessary.
     */
    protected void fireRegistrationStateChanged(RegistrationState oldState, 
                                                RegistrationState newState,
                                                int               reasonCode,
                                                String            reason)
    {
        RegistrationStateChangeEvent event =
            new RegistrationStateChangeEvent(   this,
                                                oldState,
                                                newState,
                                                reasonCode,
                                                reason);

        logger.debug("Dispatching " + event + " to "
                     + registrationStateListeners.size()+ " listeners.");

        Iterator listeners = null;
        synchronized (registrationStateListeners)
        {
            listeners = new ArrayList(registrationStateListeners).iterator();
        }

        while (listeners.hasNext())
        {
            RegistrationStateChangeListener listener
                = (RegistrationStateChangeListener) listeners.next();

            listener.registrationStateChanged(event);
        }

        logger.trace("Done.");
    }


    /**
     * Returns the AccountID that uniquely identifies the account represented
     * by this instance of the ProtocolProviderService.
     *
     * @return the id of the account represented by this provider.
     */
    public AccountID getAccountID()
    {
        return accountID;
    }

    /**
     * Returns the operation set corresponding to the specified class or null
     * if this operation set is not supported by the provider implementation.
     *
     * @param opsetClass the <tt>Class</tt> of the operation set that we're
     *   looking for.
     * @return returns an OperationSet of the specified <tt>Class</tt> if
     *   the underlying implementation supports it or null otherwise.
     */
    public OperationSet getOperationSet(Class opsetClass)
    {
        return (OperationSet) getSupportedOperationSets()
                    .get(opsetClass.getName());
    }

    /**
     * Returns the short name of the protocol that the implementation of this
     * provider is based upon (like SIP, Jabber, ICQ/AIM, or others for
     * example).
     *
     * @return a String containing the short name of the protocol this
     *   service is implementing (most often that would be a name in
     *   ProtocolNames).
     */
    public String getProtocolName()
    {
        return ProtocolNames.IRC;
    }

    /**
     * Returns the state of the registration of this protocol provider with
     * the corresponding registration service.
     *
     * @return ProviderRegistrationState
     */
    public RegistrationState getRegistrationState()
    {
        return currentRegistrationState;
    }

    /**
     * Returns an array containing all operation sets supported by the
     * current implementation.
     *
     * @return a java.util.Map containing instance of all supported
     *   operation sets mapped against their class names (e.g.
     *   OperationSetPresence.class.getName()) .
     */
    public Map getSupportedOperationSets()
    {
        //Copy the map so that the caller is not able to modify it.
        return (Map) supportedOperationSets.clone();
    }

    /**
     * Indicates whether or not this provider is registered
     *
     * @return true if the provider is currently registered and false
     *   otherwise.
     */
    public boolean isRegistered()
    {
        return currentRegistrationState
            .equals(RegistrationState.REGISTERED);
    }

    /**
     * Starts the registration process.
     *
     * @param authority the security authority that will be used for
     *   resolving any security challenges that may be returned during the
     *   registration or at any moment while wer're registered.
     * @throws OperationFailedException with the corresponding code it the
     *   registration fails for some reason (e.g. a networking error or an
     *   implementation problem).
     */
    public void register(SecurityAuthority authority)
        throws OperationFailedException
    {
        Map accountProperties = getAccountID().getAccountProperties();
        
        String serverAddress = (String) accountProperties
            .get(ProtocolProviderFactory.SERVER_ADDRESS);
        
        String serverPort = (String) accountProperties
            .get(ProtocolProviderFactory.SERVER_PORT);
        
        if(serverPort == null || serverPort.equals(""))
        {
            serverPort = "6667";
        }
        
        //Verify whether a password has already been stored for this account
        String serverPassword = IrcActivator.
            getProtocolProviderFactory().loadPassword(getAccountID());

        boolean autoNickChange = true;
        
        boolean passwordRequired = true;
        
        if(accountProperties
            .get(ProtocolProviderFactory.AUTO_CHANGE_USER_NAME) != null)
        {
            autoNickChange = new Boolean((String)accountProperties
                .get(ProtocolProviderFactory.AUTO_CHANGE_USER_NAME))
                    .booleanValue();
        }
        
        if(accountProperties
            .get(ProtocolProviderFactory.PASSWORD_REQUIRED) != null)
        {
            passwordRequired = new Boolean((String)accountProperties
                .get(ProtocolProviderFactory.PASSWORD_REQUIRED))
                    .booleanValue();
        }
            
        //if we don't - retrieve it from the user through the security authority
        if (serverPassword == null && passwordRequired)
        {
            //create a default credentials object
            UserCredentials credentials = new UserCredentials();
            credentials.setUserName(getAccountID().getUserID());

            //request a password from the user
            credentials
                = authority.obtainCredentials(ProtocolNames.IRC, credentials);

            //extract the password the user passed us.
            char[] pass = credentials.getPassword();

            // the user didn't provide us a password (canceled the operation)
            if (pass == null)
            {
                fireRegistrationStateChanged(
                    getRegistrationState(),
                    RegistrationState.UNREGISTERED,
                    RegistrationStateChangeEvent.REASON_USER_REQUEST, "");
                return;
            }
            serverPassword = new String(pass);

            //if the user indicated that the password should be saved, we'll ask
            //the proto provider factory to store it for us.
            if (credentials.isPasswordPersistent())
            {
                IrcActivator.getProtocolProviderFactory()
                    .storePassword(getAccountID(), serverPassword);
            }
        }

        this.ircStack.connect(  serverAddress,
                                Integer.parseInt(serverPort),
                                serverPassword,
                                autoNickChange);
    }

    /**
     * Makes the service implementation close all open sockets and release
     * any resources that it might have taken and prepare for
     * shutdown/garbage collection.
     */
    public void shutdown()
    {
        if(!isInitialized)
        {
            return;
        }
        logger.trace("Killing the Irc Protocol Provider.");

        if(isRegistered())
        {
            try
            {
                //do the un-registration
                synchronized(this.initializationLock)
                {
                    unregister();
                    this.ircStack.dispose();
                    ircStack = null;
                }
            }
            catch (OperationFailedException ex)
            {
                //we're shutting down so we need to silence the exception here
                logger.error(
                    "Failed to properly unregister before shutting down. "
                    + getAccountID()
                    , ex);
            }
        }

        isInitialized = false;
    }

    /**
     * Ends the registration of this protocol provider with the current
     * registration service.
     *
     * @throws OperationFailedException with the corresponding code it the
     *   registration fails for some reason (e.g. a networking error or an
     *   implementation problem).
     */
    public void unregister()
        throws OperationFailedException
    {
        RegistrationState oldState = currentRegistrationState;
        currentRegistrationState = RegistrationState.UNREGISTERED;
        
        if (ircStack.isConnected())
            ircStack.disconnect();
        
        fireRegistrationStateChanged(
            oldState
            , currentRegistrationState
            , RegistrationStateChangeEvent.REASON_USER_REQUEST
            , null);
    }

    /**
     * Returns the icon for this protocol.
     * 
     * @return the icon for this protocol
     */
    public ProtocolIcon getProtocolIcon()
    {
        return ircIcon;
    }

    /**
     * Returns the IRC stack implementation.
     * 
     * @return the IRC stack implementation.
     */
    public IrcStack getIrcStack()
    {
        return ircStack;
    }

    /**
     * Returns the current registration state of this protocol provider.
     * 
     * @return the current registration state of this protocol provider
     */
    protected RegistrationState getCurrentRegistrationState()
    {
        return currentRegistrationState;
    }

    /**
     * Sets the current registration state of this protocol provider.
     * 
     * @param currentRegistrationState the new registration state to set
     */
    protected void setCurrentRegistrationState(
        RegistrationState currentRegistrationState)
    {
        this.currentRegistrationState = currentRegistrationState;
    }
}