#include "rtp-payload-helper.h"
#include "rtp-param.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

void *rtp_payload_helper_create(struct rtp_payload_t *handler, void *cbparam)
{
    struct rtp_payload_helper_t *helper;
    helper = (struct rtp_payload_helper_t *)calloc(1, sizeof(*helper));
    if (!helper)
        return NULL;

    memcpy(&helper->handler, handler, sizeof(helper->handler));
    helper->maxsize = RTP_PAYLOAD_MAX_SIZE;
    helper->cbparam = cbparam;
    helper->__flags = -1;
    return helper;
}

void rtp_payload_helper_destroy(void *p)
{
    struct rtp_payload_helper_t *helper;
    helper = (struct rtp_payload_helper_t *)p;

    if (helper->ptr)
        free(helper->ptr);
#if defined(_DEBUG) || defined(DEBUG)
    memset(helper, 0xCC, sizeof(*helper));
#endif
    free(helper);
}

int rtp_payload_check(struct rtp_payload_helper_t *helper, const struct rtp_packet_t *pkt)
{
    int lost; // next frame lost packet flags

    // first packet only
    if (-1 == helper->__flags) {
        // TODO: first packet lost ???
        helper->__flags = 0;
        helper->seq = (uint16_t)(pkt->rtp.seq - 1); // disable packet lost
        helper->timestamp = pkt->rtp.timestamp + 1; // flag for new frame
    }

    lost = 0;
    // check sequence number
    if ((uint16_t)pkt->rtp.seq != (uint16_t)(helper->seq + 1)) {
        lost = 1;
        // helper->size = 0;
        helper->lost = 1;
        // helper->flags |= RTP_PAYLOAD_FLAG_PACKET_LOST;
        // helper->timestamp = pkt->rtp.timestamp;
    }
    helper->seq = (uint16_t)pkt->rtp.seq;

    // check timestamp
    if (pkt->rtp.timestamp != helper->timestamp) {
        rtp_payload_onframe(helper);

        // lost:
        // 0 - packet lost before timestamp change
        // 1 - packet lost on timestamp changed, can't known losted packet is at old packet tail or new packet start, so
        // two packets mark as packet lost
        if (0 != lost)
            helper->lost = lost;
    }

    helper->timestamp = pkt->rtp.timestamp;

    return 0;
}

int rtp_payload_write(struct rtp_payload_helper_t *helper, const struct rtp_packet_t *pkt)
{
    int size;
    size = helper->size + pkt->payloadlen;
    if (size > helper->maxsize || size < 0)
        return -EINVAL;

    if (size > helper->capacity) {
        void *ptr;

        size += size / 4 > 16000 ? size / 4 : 16000;
        ptr = realloc(helper->ptr, size);
        if (!ptr) {
            // helper->flags |= RTP_PAYLOAD_FLAG_PACKET_LOST;
            helper->lost = 1;
            // helper->size = 0;
            return -ENOMEM;
        }

        helper->ptr = (uint8_t *)ptr;
        helper->capacity = size;
    }

    assert(helper->capacity >= helper->size + pkt->payloadlen);
    memcpy(helper->ptr + helper->size, pkt->payload, pkt->payloadlen);
    helper->size += pkt->payloadlen;
    return 0;
}

int rtp_payload_onframe(struct rtp_payload_helper_t *helper)
{
    int r;
    r = 0;

    if (helper->size > 0
#if !defined(RTP_ENABLE_COURRUPT_PACKET)
        && 0 == helper->lost
#endif
    ) {
        // previous packet done
        r = helper->handler.packet(helper->cbparam, helper->ptr, helper->size, helper->timestamp,
                                   helper->__flags | (helper->lost ? RTP_PAYLOAD_FLAG_PACKET_CORRUPT : 0));

        // RTP_PAYLOAD_FLAG_PACKET_LOST: miss
        helper->__flags &= ~RTP_PAYLOAD_FLAG_PACKET_LOST; // clear packet lost flag
    }

    // set packet lost flag on next frame
    if (helper->lost)
        helper->__flags |= RTP_PAYLOAD_FLAG_PACKET_LOST;

    // new frame start
    helper->lost = 0;
    helper->size = 0;
    return r;
}