/*
 * sxemanager.h - Whiteboard manager
 * Copyright (C) 2006  Joonas Govenius
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#ifndef SXDEMANAGER_H
#define SXDEMANAGER_H

#include "QTimer"

#include "sxesession.h"

namespace XMPP {
    class Client;
    class Jid;
    class Message;
}

using namespace XMPP;

/*! \brief The manager for SXE sessions and negotiations.
 *  This class listens to incoming messages and picks up any that contain an
 *  SxdE element. If the element belongs to an already established session,
 *  the element is passed to the session. If the element is a negotiation element,
 *  the manager handles it. Accepting invitations is determined based on callback
 *  functions provided to the class.
 *
 *  The manager also provides a possibillity for the local client to start
 *  a new session negotiation with the desired contact.
 *
 *  One instance per PsiAccount should be created.
 *
 *  \sa SxeSession
 */
class SxeManager : public QObject
{
    Q_OBJECT

    /*! \brief A simple struct used to keep track of the detected SXE sessions.*/
    struct DetectedSession {
        QString session;
        Jid jid;
        QTime time;
    };

    /*! \brief A simple class to keep track of the state of a session negotiation process.*/
    class SxeNegotiation{
    public:
        enum Role {Participant, Joiner};
        enum State {NotStarted, InvitationSent, ConnectionRequested, InvitationAccepted, DocumentBegan, /*DocumentEnded,*/ HistoryOffered, HistoryAccepted, Finished, Aborted};

        /*! \brief Describes our role in the negotiation.*/
        Role role;
        /*! \brief Describes the current state of the negotiation.*/
        State state;
        /*! \brief The identifier for the session.*/
        QString sessionId;
        /*! \brief The JID that will be used for delivering the sxe messages once session is established.*/
        Jid target;
        /*! \brief The JID where negotiation messages are sent.*/
        Jid peer;
        /*! \brief The user's own JID used in the session.*/
        Jid ownJid;
        /*! \brief Set if the target is a groupchat.*/
        bool groupChat;
        /*! \brief The document to be sent as the initial document during the negotiation.
         *      This is only relevant when Role == Participant.
         */
        QDomDocument initialDoc;
        /*! \brief A list of features proposed for the session.*/
        QList<QString> features;
        /*! \brief The session created for this negotiation.*/
        QPointer<SxeSession> session;
    };
    
public:
    /*! \brief Constructor.
     *  Creates a new manager for the specified Client and PsiAccount
     */
    SxeManager(XMPP::Client* client, PsiAccount* pa);
    /*! \brief Return a list of pointers to sessions to the specified contact.
     *  If no such session exits, returns 0.
     */
    QList< QPointer<SxeSession> > findSession(const Jid &target);
    /*! \brief Return a pointer to the specified session.
     *  If such session doesn't exits, returns 0.
     */
    QPointer<SxeSession> findSession(const QString &session);
    /*! \brief Add a callback for invitations.*/
    void addInvitationCallback(bool (*callback)(const Jid &peer, const QList<QString> &features));
    /*! \brief Starts a new session negotiation to the specified contact with given list of features.*/
    void startNewSession(const Jid &target, const Jid &ownJid, bool groupChat, const QDomDocument &initialDoc, QList<QString> features = QList<QString>());
    /*! \brief Join an existing session.*/
    void joinSession(const Jid &target, const Jid &ownJid, bool groupChat, const QString &session);
    /*! \brief Checks that \a jid supports SXE and \a features. */
    bool checkSupport(const Jid &jid, const QList<QString> &features);

signals:
    /*! \brief Emitted when \a session has been established.*/
    void sessionNegotiated(SxeSession* session);
    /*! \brief Emitted when \a an invitation to \a jid was declined and joining an alternative session \a session was suggested.*/
    void alternativeSession(const Jid &jid, const QString &session);

private:
    /*! \brief Process a message that contains a negotiation element.
     *  Returns a pointer to the new session if negotiation finished.
     */
    QPointer<SxeSession> processNegotiationMessage(const Message &message);
    /*! \brief Process a negotiation element as a Participant.
        Appends the appropriate responses to \a response.
        Returns false iff the negotiation object was deleted. */
    bool processNegotiationAsParticipant(const QDomNode &negotiationElement, SxeNegotiation* negotiation, QDomNode response);
    /*! \brief Process a negotiation element as a Joiner.
        Appends the appropriate responses to \a response.
        Returns false iff the negotiation object was deleted. */
    bool processNegotiationAsJoiner(const QDomNode &negotiationElement, SxeNegotiation* negotiation, QDomNode response, const Message &message);
    /*! \brief Returns a pointer to a new session instance.*/
    QPointer<SxeSession> createSxeSession(const Jid &target, QString session, const Jid &ownJid, bool groupChat, const QList<QString> &features);
    /*! \brief Aborts the negotiation of \a session started with \a peer.*/
    void abortNegotiation(QString session, const Jid &peer, bool groupChat);
    /*! \brief Aborts the negotiation with the peer and deletes the session.*/
    void abortNegotiation(SxeNegotiation* negotiation);
    /*! \brief Records the session that the message refers to as a DetectedSession if no entry for the session exists yet.*/
    void recordDetectedSession(const Message &message);
    /*! \brief Returns a pointer to a new negotiation instance based on \a message.*/
    SxeNegotiation* createNegotiation(const Message &message);
    /*! \brief Returns a pointer to a new negotiation instance.*/
    SxeNegotiation* createNegotiation(SxeNegotiation::Role role, SxeNegotiation::State state, const QString &sessionId, const Jid &target, const Jid &ownJid, bool groupChat);
    /*! \brief Returns a pointer to an existing negotiation object of \a session with \a jid.*/
    SxeNegotiation* findNegotiation(const Jid &jid, const QString &session);
    /*! \brief Remove the negotiation object of \a session with \a jid.*/
    void removeNegotiation(SxeNegotiation* negotiation);
    

    /*! \brief A pointer to the Client to listen to.*/
    XMPP::Client* client_;
    /*! \brief A pointer to the PsiAccount to listen to.*/
    PsiAccount* pa_;
    /*! \brief A list of of established sessions.*/
    QList< QPointer<SxeSession> > sessions_;
    /*! \brief A list of negotiations in process.*/
    QMultiHash<QString, SxeNegotiation* > negotiations_;
    /*! \brief A timer used to remove unfinished negotiations after a timeout.*/
    QTimer negotiationTimer_;
    /*! \brief A list of of detected sessions.*/
    QList<DetectedSession> DetectedSessions_;
    /*! \brief A list of Jids corresponding to self.*/
    QList<QString> ownJids_;
    /*! \brief A list of callbacks used to determine whether an invitation should be accepted.*/
    QList<bool (*)(const Jid &peer, const QList<QString> &features)> invitationCallbacks_;
    /*! \brief A counter used for including a unique id in each sent sxe element.*/
    int sxeId_;
    /*! \brief A list of messages waiting to be sent out.*/
    QList<Message> queuedMessages_;

private slots:
    /*! \brief Receives incoming message and determines what to do with them.*/
    void messageReceived(const Message &message);
    /*! \brief Send given whiteboard element to receiver in a message.*/
    void sendSxe(QDomElement sxe, const Jid & receiver, bool groupChat);
    /*! \brief Removes and deletes the session.*/
    void removeSession(SxeSession* session);
    /*! \brief Removes the "detected session" record of the given session.*/
    void removeDetectedSession(SxeSession* session);
    /*! \brief Removes and deletes the possible sessions for the groupchat.*/
    void groupChatLeft(const Jid &);
    /*! \brief Keeps a record of groupchats.*/
    void groupChatJoined(const Jid &, const Jid &ownJid);
    /*! \brief Removes inactive and unfinished session negotiations.*/
    void negotiationTimeout();
};

#endif
