// RFC3551 RTP Profile for Audio and Video Conferences with Minimal Control

#include "rtp-packet.h"
#include "rtp-payload-internal.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>

struct rtp_packer_t {
    struct rtp_payload_t handler;
    void *cbparam;

    struct rtp_packet_t pkt;
    int size;
};

static void *rtp_pack_create(int size, uint8_t pt, uint16_t seq, uint32_t ssrc, struct rtp_payload_t *handler,
                             void *param)
{
    struct rtp_packer_t *packer;
    packer = (struct rtp_packer_t *)calloc(1, sizeof(*packer));
    if (!packer)
        return NULL;

    memcpy(&packer->handler, handler, sizeof(packer->handler));
    packer->cbparam = param;
    packer->size = size;

    packer->pkt.rtp.v = RTP_VERSION;
    packer->pkt.rtp.pt = pt;
    packer->pkt.rtp.seq = seq;
    packer->pkt.rtp.ssrc = ssrc;
    return packer;
}

void rtp_pack_destroy(void *p)
{
    struct rtp_packer_t *packer;
    packer = (struct rtp_packer_t *)p;
#if defined(_DEBUG) || defined(DEBUG)
    memset(packer, 0xCC, sizeof(*packer));
#endif
    free(packer);
}

void rtp_pack_get_info(void *p, uint16_t *seq, uint32_t *timestamp)
{
    struct rtp_packer_t *packer;
    packer = (struct rtp_packer_t *)p;
    *seq = (uint16_t)packer->pkt.rtp.seq;
    *timestamp = packer->pkt.rtp.timestamp;
}

int rtp_pack_input(void *p, const void *data, int bytes, uint32_t timestamp)
{
    int r, n;
    uint8_t *rtp;
    const uint8_t *ptr;
    struct rtp_packer_t *packer;

    r = 0;
    packer = (struct rtp_packer_t *)p;
    assert(packer->pkt.rtp.timestamp != timestamp || !packer->pkt.payload /*first packet*/);
    packer->pkt.rtp.timestamp = timestamp; // (uint32_t)time * packer->frequency / 1000; // ms -> 8KHZ
    packer->pkt.rtp.m = 0;                 // marker bit alway 0

    for (ptr = (const uint8_t *)data; 0 == r && bytes > 0; ++packer->pkt.rtp.seq) {
        packer->pkt.payload = ptr;
        packer->pkt.payloadlen = (bytes + RTP_FIXED_HEADER) <= packer->size ? bytes : (packer->size - RTP_FIXED_HEADER);
        ptr += packer->pkt.payloadlen;
        bytes -= packer->pkt.payloadlen;

        n = RTP_FIXED_HEADER + packer->pkt.payloadlen;
        rtp = (uint8_t *)packer->handler.alloc(packer->cbparam, n);
        if (!rtp)
            return -ENOMEM;

        n = rtp_packet_serialize(&packer->pkt, rtp, n);
        if (n != RTP_FIXED_HEADER + packer->pkt.payloadlen) {
            assert(0);
            return -1;
        }

        r = packer->handler.packet(packer->cbparam, rtp, n, packer->pkt.rtp.timestamp, 0);
        packer->handler.free(packer->cbparam, rtp);

        // packer->pkt.rtp.timestamp += packer->pkt.payloadlen * packer->frequency / 1000;
    }

    return r;
}

struct rtp_payload_encode_t *rtp_common_encode()
{
    static struct rtp_payload_encode_t packer = {
        rtp_pack_create,
        rtp_pack_destroy,
        rtp_pack_get_info,
        rtp_pack_input,
    };

    return &packer;
}