/**
 * liburtc
 * Copyright 2020 Chris Hiszpanski
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#ifndef _URTC_SDP_H
#define _URTC_SDP_H

#ifdef __cplusplus
extern "C" {
#endif

#include <stdbool.h>
#include <stdint.h>


// Maximum size of SDP string (in bytes)
#define SDP_MAX_SIZE					2048

#define SDP_MAX_USERNAME_SIZE			32
#define SDP_MAX_SESSION_ID_SIZE			32
#define SDP_MAX_SESSION_VERSION_SIZE	32
#define SDP_MAX_SESSION_NAME_SIZE		32

#define SDP_MAX_BUNDLE_IDS				5
#define SDP_MAX_BUNDLE_ID_SIZE			32
#define SDP_MAX_RTP_PAYLOAD_TYPES		32


typedef enum sdp_mode {
	SDP_MODE_SEND_AND_RECEIVE = 0,
	SDP_MODE_RECEIVE_ONLY,
	SDP_MODE_SEND_ONLY
} sdp_mode_t;

typedef enum sdp_media {
	SDP_MEDIA_TYPE_NULL = 0,
	SDP_MEDIA_TYPE_AUDIO,
	SDP_MEDIA_TYPE_VIDEO,
	SDP_MEDIA_TYPE_TEXT,
	SDP_MEDIA_TYPE_APPLICATION,
	SDP_MEDIA_TYPE_MESSAGE
} sdp_media_type_t;

// Codecs recognized by SDP parser
typedef enum sdp_codec {
	SDP_CODEC_NULL = 0,
	SDP_CODEC_H264,
	SDP_CODEC_VP9
} sdp_codec_t;

// Dynamic payload type
typedef struct sdp_rtpmap {
	unsigned int      type;             // Dynamic RTP payload type (e.g. 96)
	enum sdp_codec    codec;            // H264, VP9, etc.
	unsigned int      clock;            // Typically 90kHz for video
	unsigned int      flags;
} sdp_rtpmap_t;

typedef struct sdp {
	// protocol version
	uint8_t version;

	// originator and session identifier
	char username[SDP_MAX_USERNAME_SIZE+1];
	char session_id[SDP_MAX_SESSION_ID_SIZE+1];
	char session_version[SDP_MAX_SESSION_VERSION_SIZE+1];

	// session name
	char session_name[SDP_MAX_SESSION_NAME_SIZE+1];

	// time description (mandatory)
	uint64_t start_time;
	uint64_t stop_time;

	// session attributes
	
	// bundle media identification tags
	char mid[SDP_MAX_BUNDLE_IDS][SDP_MAX_BUNDLE_ID_SIZE+1];
	
	// ice
	char ufrag[4*256];					// ice-ufrag (256 unicode chars max.)
	char pwd[4*256];					// ice-pwd (256 unicode chars max.)
	struct {
		bool trickle;
	} ice_options;

	// video media
	struct {
		uint16_t port;
		struct sdp_rtpmap params[SDP_MAX_RTP_PAYLOAD_TYPES];
		int count;
	} video;

	sdp_mode_t mode;					// send, receive, and send-and-receive

	bool rtcp_mux;						// is rtcp multiplexed on same socket
	bool rtcp_rsize;

	union {
		uint8_t sha256[32];				// certificate fingerprint
	} fingerprint;

} sdp_t;


/**
 * Parse SDP string into structure
 *
 * \param dst[out] SDP structure
 * \param src[in] NULL-terminated SDP string
 *
 * \return 0 on success, negative on error.
 */
int sdp_parse(struct sdp *dst, const char *src);

/**
 * Serialize SDP structure into string
 *
 * \param dst[out] NULL-terminated SDP string
 * \param len[in] Capacity of dst
 * \param src[in] SDP structure
 *
 * \return 0 on success, negative on error.
 */
int sdp_serialize(char *dst, size_t len, const struct sdp *src);

#ifdef __cplusplus
}
#endif

#endif /* _URTC_SDP_H */