/*
 * Connection.h
 *
 * Copyright (C) 2008 Matthias Schiffer <matthias@gamezock.de>
 *
 * 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 3 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 program. If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef MAD_NET_CONNECTION_H_
#define MAD_NET_CONNECTION_H_

#include "Packet.h"

#include <queue>
#include <string>
#include <gnutls/gnutls.h>
#include <sigc++/signal.h>
#include <poll.h>

namespace Mad {
namespace Net {

class IPAddress;
class Packet;

class Connection {
  private:
    struct Transmission {
      unsigned long length;
      unsigned long transmitted;

      uint8_t *data;

      sigc::slot<void,const void*,unsigned long> notify;
    };

    enum State {
      DISCONNECTED, HANDSHAKE, CONNECTION_HEADER, PACKET_HEADER, PACKET_DATA, DISCONNECT, BYE
    } state;

    Transmission transR;
    std::queue<Transmission> transS;

    Packet::Data header;

    sigc::signal<void,Connection*,const Packet&> signal;

    void doHandshake();

    void packetHeaderReceiveHandler(const void *data, unsigned long length);
    void packetDataReceiveHandler(const void *data, unsigned long length);

    void doReceive();
    void doSend();

    void doBye();

    void doDisconnect();

    bool receiveComplete() const {
      return (transR.length == transR.transmitted);
    }

    void bye();

    void updateEvents() const;

    // Prevent shallow copy
    Connection(const Connection &o);
    Connection& operator=(const Connection &o);

  protected:
    struct ConnectionHeader {
      uint8_t m;
      uint8_t a;
      uint8_t d;
      uint8_t type;

      uint8_t versionMajor;
      uint8_t versionMinor;
      uint8_t protVerMin;
      uint8_t protVerMax;
    };

    int sock;
    gnutls_session_t session;
    gnutls_certificate_credentials_t x509_cred;

    IPAddress *peer;
    bool authenticated, identified;

    void handshake();

    virtual void connectionHeader() = 0;

    bool rawReceive(unsigned long length, const sigc::slot<void,const void*,unsigned long> &notify);
    bool rawSend(const uint8_t *data, unsigned long length);

    bool enterReceiveLoop();

  public:
    Connection() : state(DISCONNECTED), peer(0), authenticated(false), identified(false) {
      transR.length = transR.transmitted = 0;
      transR.data = 0;

      gnutls_certificate_allocate_credentials(&x509_cred);
    }

    virtual ~Connection();

    bool isConnected() const {return (state != DISCONNECTED);}
    bool isConnecting() const {
      return (state == HANDSHAKE || state == CONNECTION_HEADER);
    }

    bool isDisconnecting() const {
      return (state == DISCONNECT || state == BYE);
    }

    bool isAuthenticated() const {return authenticated;}
    void setAuthenticated() {authenticated = true;}

    bool isIdentified() const {return identified;}
    void setIdentified() {identified = true;}

    const gnutls_datum_t* getCertificate() {
      return gnutls_certificate_get_ours(session);
    }

    const gnutls_datum_t* getPeerCertificate() {
      unsigned int n;
      return gnutls_certificate_get_peers(session, &n);
    }

    const IPAddress* getPeer() {return peer;}
    int getSocket() const {return sock;}

    void disconnect();

    bool send(const Packet &packet);

    void sendReceive(short events);

    bool sendQueueEmpty() const {return transS.empty();}

    sigc::signal<void,Connection*,const Packet&> signalReceive() const {return signal;}

    static void init() {
      gnutls_global_init();
    }

    static void deinit() {
      gnutls_global_deinit();
    }
};

}
}

#endif /*MAD_NET_CONNECTION_H_*/