/**
 * WebRTC implementation for tiny devices
 *
 * Copyright (c) 2022 Chris Hiszpanski. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 */

#ifndef TINYRTC_H
#define TINYRTC_H

#define TRTC_MAX_ICE_CANDIDATE_SIZE                     256
#define TRTC_MAX_ICE_SERVER_CREDENTIAL_SIZE             128
#define TRTC_MAX_ICE_SERVERS                            2
#define TRTC_MAX_ICE_SERVER_URL_SIZE                    128
#define TRTC_MAX_ICE_SERVER_URLS                        3
#define TRTC_MAX_ICE_SERVER_USERNAME_SIZE               128
#define TRTC_MAX_ICE_CANDIDATE_USERNAME_FRAGMENT_SIZE   8
#define TRTC_MAX_ICE_CANDIDATE_SDP_MID_SIZE             32
#define TRTC_MAX_PEER_CONNECTIONS                       5
#define TRTC_MAX_SDP_SIZE                               4096
#define TRTC_MAX_ICE_UFRAG_SIZE                         5
#define TRTC_MAX_ICE_PWD_SIZE                           32


///  PRIVATE TYPE DEFINITIONS  ///////////////////////////////////////////////

struct trtc_peerconn_t;


///  PUBLIC TYPE DEFINITIONS  ////////////////////////////////////////////////

struct trtc_ice_server_t {
    char credential[TRTC_MAX_ICE_SERVER_CREDENTIAL_SIZE];
    char urls[3][TRTC_MAX_ICE_SERVER_URL_SIZE];
    char username[TRTC_MAX_ICE_SERVER_USERNAME_SIZE];
};

struct trtc_config_t {
    struct trtc_ice_server_t ice_servers[TRTC_MAX_ICE_SERVERS];
};

struct trtc_ice_candidate_t {
    char candidate[TRTC_MAX_ICE_CANDIDATE_SIZE];
    int  sdp_mline_index;
    char sdp_mid[TRTC_MAX_ICE_CANDIDATE_SDP_MID_SIZE];
    char username_fragment[TRTC_MAX_ICE_CANDIDATE_USERNAME_FRAGMENT_SIZE];
};


///  CALLBACKS  //////////////////////////////////////////////////////////////

typedef void (trtc_on_ice_candidate_t)(const struct trtc_ice_candidate_t c, void *arg);


///  RTC PEER CONNECTION API  ////////////////////////////////////////////////

/**
 * Initialize library. Must call once before calling other functions.
 */
void trtc_init();

/**
 * Create new peer connection
 *
 * \param cfg[in] Configuration.
 *
 * \return Peer connection. NULL if all peer connections are already in use.
 */
struct trtc_peerconn_t* trtc_peer_connection(struct trtc_config_t cfg);
void trtc_peer_connection_destroy(struct trtc_peerconn_t* pc);

/**
 * Adds remote ICE candidate to local ICE agent
 *
 * \param pc[in] Peer connection.
 * \param c[in] ICE candidate from remote peer.
 *
 * \return 0 on success. -1 on error.
 */
int trtc_add_ice_candidate(
    struct trtc_peerconn_t *pc, const struct trtc_ice_candidate_t c);

int trtc_add_track(struct trtc_peerconn_t *pc);

/**
 * Create SDP answer in response to a received SDP offer.
 *
 * \param pc[in] Peer connection.
 *
 * \return SDP answer. NULL on error.
 */
const char * trtc_create_answer(struct trtc_peerconn_t *pc);

/**
 * Sets callback to call for each discovered local ICE candidate
 *
 * \param pc[in] Peer connection.
 * \param cb[in] Callback function.
 * \param arg[in] User-specified argument to pass to callback function.
 *
 * \return 0 on success. -1 on error.
 */
int trtc_set_on_ice_candidate(
    struct trtc_peerconn_t* pc, trtc_on_ice_candidate_t* cb, void* arg);

int trtc_set_local_description(struct trtc_peerconn_t *pc, const char *sdp);
int trtc_set_remote_description(struct trtc_peerconn_t *pc, const char *sdp);

#endif

/* vim: set et ts=4 sw=4 : */