/*
 *  cotp.h
 *
 *  Copyright 2013-2018 Michael Zillgith
 *
 *  This file is part of libIEC61850.
 *
 *  libIEC61850 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.
 *
 *  libIEC61850 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 libIEC61850.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  See COPYING file for the complete license text.
 */

#ifndef COTP_H_
#define COTP_H_

#include "libiec61850_platform_includes.h"
#include "byte_buffer.h"
#include "buffer_chain.h"
#include "hal_socket.h"
#include "iso_connection_parameters.h"
#include "tls_socket.h"

typedef struct {
    TSelector tSelSrc;
    TSelector tSelDst;
    uint8_t tpduSize;
} CotpOptions;

typedef struct {
    int state;
    int remoteRef;
    int localRef;
    int protocolClass;

    HandleSet handleSet;
    Socket socket;
#if (CONFIG_MMS_SUPPORT_TLS == 1)
    TLSSocket tlsSocket;
#endif

    CotpOptions options;
    bool isLastDataUnit;
    ByteBuffer* payload;
    ByteBuffer* writeBuffer;  /* buffer to store TPKT packet to send */
    ByteBuffer* readBuffer;   /* buffer to store received TPKT packet */
    uint16_t packetSize;      /* size of the packet currently received */

    uint8_t* socketExtensionBuffer; /* buffer to store data when TCP socket is not accepting all data */
    int socketExtensionBufferSize; /* maximum number of bytes to store in the extension buffer */
    int socketExtensionBufferFill; /* number of bytes in the extension buffer (bytes to write) */
} CotpConnection;

typedef enum {
    COTP_OK,
    COTP_ERROR,
    COTP_CONNECT_INDICATION,
    COTP_DATA_INDICATION,
    COTP_DISCONNECT_INDICATION,
    COTP_MORE_FRAGMENTS_FOLLOW
} CotpIndication;

typedef enum {
    TPKT_PACKET_COMPLETE = 0,
    TPKT_WAITING = 1,
    TPKT_ERROR = 2
} TpktState;

LIB61850_INTERNAL int /* in byte */
CotpConnection_getTpduSize(CotpConnection* self);

LIB61850_INTERNAL void
CotpConnection_setTpduSize(CotpConnection* self, int tpduSize /* in byte */);

LIB61850_INTERNAL void
CotpConnection_init(CotpConnection* self, Socket socket,
        ByteBuffer* payloadBuffer, ByteBuffer* readBuffer, ByteBuffer* writeBuffer,
        uint8_t* socketExtensionBuffer, int socketExtensionBufferSize);

LIB61850_INTERNAL CotpIndication
CotpConnection_parseIncomingMessage(CotpConnection* self);

LIB61850_INTERNAL void
CotpConnection_resetPayload(CotpConnection* self);

LIB61850_INTERNAL TpktState
CotpConnection_readToTpktBuffer(CotpConnection* self);

LIB61850_INTERNAL CotpIndication
CotpConnection_sendConnectionRequestMessage(CotpConnection* self, IsoConnectionParameters isoParameters);

LIB61850_INTERNAL CotpIndication
CotpConnection_sendConnectionResponseMessage(CotpConnection* self);

LIB61850_INTERNAL CotpIndication
CotpConnection_sendDataMessage(CotpConnection* self, BufferChain payload);

LIB61850_INTERNAL ByteBuffer*
CotpConnection_getPayload(CotpConnection* self);

LIB61850_INTERNAL int
CotpConnection_getRemoteRef(CotpConnection* self);

LIB61850_INTERNAL int
CotpConnection_getLocalRef(CotpConnection* self);

LIB61850_INTERNAL void
CotpConnection_flushBuffer(CotpConnection* self);

#endif /* COTP_H_ */