#include "rtp-ext.h"
#include "rtp-header.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>

static const struct rtp_ext_uri_t sc_rtpexts[] = {
    {RTP_HDREXT_PADDING, ""},

    // https://datatracker.ietf.org/doc/html/rfc6464
    {RTP_HDREXT_SSRC_AUDIO_LEVEL_ID, "urn:ietf:params:rtp-hdrext:ssrc-audio-level"},
    // https://datatracker.ietf.org/doc/html/rfc6465
    {RTP_HDREXT_CSRC_AUDIO_LEVEL_ID, "urn:ietf:params:rtp-hdrext:csrc-audio-level"},

    // https://datatracker.ietf.org/doc/html/draft-ietf-avtext-framemarking-13
    //{RTP_HDREXT_FRAME_MARKING_ID,				"http://tools.ietf.org/html/draft-ietf-avtext-framemarking-07"},
    {RTP_HDREXT_FRAME_MARKING_ID, "urn:ietf:params:rtp-hdrext:framemarking"},

    // https://datatracker.ietf.org/doc/html/rfc8843#section-16.2
    {RTP_HDREXT_SDES_MID_ID, "urn:ietf:params:rtp-hdrext:sdes:mid"},

    // https://datatracker.ietf.org/doc/html/rfc8852#section-4
    {RTP_HDREXT_SDES_RTP_STREAM_ID, "urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id"},
    {RTP_HDREXT_SDES_REPAIRED_RTP_STREAM_ID, "urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id"},

    // https://datatracker.ietf.org/doc/html/rfc5450
    {RTP_HDREXT_TOFFSET_ID, "urn:ietf:params:rtp-hdrext:toffset"},

    // https://www.arib.or.jp/english/html/overview/doc/STD-T63V12_00/5_Appendix/Rel13/26/26114-d30.pdf
    {RTP_HDREXT_VIDEO_ORIENTATION_ID, "urn:3gpp:video-orientation"},

    // // https://webrtc.googlesource.com/src/+/refs/heads/main/docs/native-code/rtp-hdrext/abs-send-time
    {RTP_HDREXT_ABSOLUTE_SEND_TIME_ID, "http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time"},

    // https://webrtc.googlesource.com/src/+/refs/heads/main/docs/native-code/rtp-hdrext/abs-capture-time/
    {RTP_HDREXT_ABSOLUTE_CAPTURE_TIME_ID, "http://www.webrtc.org/experiments/rtp-hdrext/abs-capture-time"},

    // https://webrtc.googlesource.com/src/+/refs/heads/main/docs/native-code/rtp-hdrext/transport-wide-cc-02/
    {RTP_HDREXT_TRANSPORT_WIDE_CC_ID_01, "http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01"},
    {RTP_HDREXT_TRANSPORT_WIDE_CC_ID, "http://www.webrtc.org/experiments/rtp-hdrext/transport-wide-cc-02"},

    // https://webrtc.googlesource.com/src/+/refs/heads/main/docs/native-code/rtp-hdrext/video-timing
    {RTP_HDREXT_VIDEO_TIMING_ID, "http://www.webrtc.org/experiments/rtp-hdrext/video-timing"},

    // https://webrtc.googlesource.com/src/+/refs/heads/main/docs/native-code/rtp-hdrext/playout-delay
    {RTP_HDREXT_PLAYOUT_DELAY_ID, "http://www.webrtc.org/experiments/rtp-hdrext/playout-delay"},

    {RTP_HDREXT_ONE_BYTE_RESERVED, ""},

    // https://webrtc.googlesource.com/src/+/refs/heads/main/docs/native-code/rtp-hdrext/color-space
    {RTP_HDREXT_COLOR_SPACE_ID, "http://www.webrtc.org/experiments/rtp-hdrext/color-space"},

    // https://webrtc.googlesource.com/src/+/refs/heads/main/docs/native-code/rtp-hdrext/video-content-type
    {RTP_HDREXT_VIDEO_CONTENT_TYPE_ID, "http://www.webrtc.org/experiments/rtp-hdrext/video-content-type"},

    // https://webrtc.googlesource.com/src/+/refs/heads/main/docs/native-code/rtp-hdrext/inband-cn/
    {RTP_HDREXT_INBAND_CN_ID, "http://www.webrtc.org/experiments/rtp-hdrext/inband-cn"},

    // https://webrtc.googlesource.com/src/+/refs/heads/main/docs/native-code/rtp-hdrext/video-frame-tracking-id/
    {RTP_HDREXT_VIDEO_FRAME_TRACKING_ID, "http://www.webrtc.org/experiments/rtp-hdrext/video-frame-tracking-id"},

    // https://webrtc.googlesource.com/src/+/refs/heads/main/docs/native-code/rtp-hdrext/video-layers-allocation00/
    {RTP_HDREXT_VIDEO_LAYERS_ALLOCATION_ID, "http://www.webrtc.org/experiments/rtp-hdrext/video-layers-allocation00"},

    //{RTP_HDREXT_GENERIC_FRAME_DESCRIPTOR_00,
    //"http://www.webrtc.org/experiments/rtp-hdrext/generic-frame-descriptor-00"},
    //{RTP_HDREXT_GENERIC_FRAME_DESCRIPTOR_02,
    //"http://www.webrtc.org/experiments/rtp-hdrext/generic-frame-descriptor-02"},

    //{RTP_HDREXT_ENCRYPT,						"urn:ietf:params:rtp-hdrext:encrypt"},

    {0, NULL},
};

const struct rtp_ext_uri_t *rtp_ext_list()
{
    return sc_rtpexts;
}

const struct rtp_ext_uri_t *rtp_ext_find_uri(const char *uri)
{
    int i;
    for (i = 0; i < sizeof(sc_rtpexts) / sizeof(sc_rtpexts[0]); i++) {
        if (0 == strcmp(sc_rtpexts[i].uri, uri))
            return &sc_rtpexts[i];
    }
    return NULL;
}

static int rtp_ext_read_one_byte(const uint8_t *data, int bytes, struct rtp_ext_data_t exts[256])
{
    int off;
    uint8_t id;
    uint8_t len;

    for (off = 0; off < bytes; off += len + 1) {
        id = data[off] >> 4;
        len = (data[off] & 0x0f) + 1;

        if (bytes > 0xFFFF || off + len > bytes || (RTP_HDREXT_PADDING == id && 1 != len))
            return -1; // invalid

        if (RTP_HDREXT_PADDING == data[off])
            continue;
        else if (id == RTP_HDREXT_ONE_BYTE_RESERVED)
            break; // one-byte header extension reserver id

        exts[id].id = id;
        exts[id].len = len;
        exts[id].off = off + 1; // data only
    }

    return 0;
}

static int rtp_ext_write_one_byte(const uint8_t *extension, const struct rtp_ext_data_t *exts, int count, uint8_t *data,
                                  int bytes)
{
    int i, off;
    for (i = off = 0; i < count && off < bytes; off += exts[i++].len) {
        if (RTP_HDREXT_PADDING == exts[i].id) {
            assert(exts[i].len == 0);
            continue;
        }

        // 15: one-byte header extension reserver id
        if (exts[i].id >= RTP_HDREXT_ONE_BYTE_RESERVED || exts[i].len < 1 || exts[i].len > 16 ||
            (int)exts[i].len + off >= bytes) {
            assert(0);
            return -EINVAL;
        }

        data[off] = ((uint8_t)exts[i].id << 4) | ((uint8_t)exts[i].len - 1);
        memcpy(data + off + 1, extension + exts[i].off, exts[i].len);
    }

    if (i < count || ((off % 4 != 0) && (off + 3) / 4 * 4 >= bytes))
        return -E2BIG;

    while (off % 4 != 0)
        data[off++] = RTP_HDREXT_PADDING;
    return off;
}

static int rtp_ext_read_two_byte(const uint8_t *data, int bytes, struct rtp_ext_data_t exts[256])
{
    int off;
    uint8_t id;
    uint8_t len;

    for (off = 0; off < bytes; off += len) {
        id = data[off++];
        if (RTP_HDREXT_PADDING == id) {
            len = 0;
            continue;
        }

        if (off >= bytes)
            return -EINVAL;

        len = data[off++];
        if (off + len > bytes)
            return -EINVAL;
        ; // invalid

        exts[id].id = id;
        exts[id].len = len;
        exts[id].off = off; // data only
    }

    return 0;
}

static int rtp_ext_write_two_byte(const uint8_t *extension, const struct rtp_ext_data_t *exts, int count, uint8_t *data,
                                  int bytes)
{
    int i, off;
    for (i = off = 0; i < count && off < bytes; off += exts[i++].len) {
        if (RTP_HDREXT_PADDING == exts[i].id) {
            assert(exts[i].len == 0);
            continue;
        }

        if ((int)exts[i].len + off + 2 >= bytes) {
            assert(0);
            return -EINVAL;
        }

        data[off++] = (uint8_t)exts[i].id;
        data[off++] = (uint8_t)exts[i].len;
        memcpy(data + off, extension + exts[i].off, exts[i].len);
    }

    if (i < count || ((off % 4 != 0) && (off + 3) / 4 * 4 >= bytes))
        return -E2BIG;

    while (off % 4 != 0)
        data[off++] = RTP_HDREXT_PADDING;
    return off;
}

int rtp_ext_read(uint16_t profile, const uint8_t *data, int bytes, struct rtp_ext_data_t exts[256])
{
    // caller to do
    // memset(exts, 0, sizeof(exts));

    if (RTP_HDREXT_PROFILE_ONE_BYTE == profile)
        return rtp_ext_read_one_byte(data, bytes, exts);
    else if (RTP_HDREXT_PROFILE_TWO_BYTE == (profile & RTP_HDREXT_PROFILE_TWO_BYTE_FILTER))
        return rtp_ext_read_two_byte(data, bytes, exts);

    return 0; // ignore
}

int rtp_ext_write(uint16_t profile, const uint8_t *extension, const struct rtp_ext_data_t *exts, int count,
                  uint8_t *data, int bytes)
{
    int i;
    if (0 == profile) {
        profile = RTP_HDREXT_PROFILE_ONE_BYTE;
        for (i = 0; i < count; i++) {
            // 15: one-byte header extension reserver id
            if (exts[i].len >= 16 || RTP_HDREXT_ONE_BYTE_RESERVED == exts[i].id)
                profile = RTP_HDREXT_PROFILE_TWO_BYTE;
        }
    }

    if (RTP_HDREXT_PROFILE_ONE_BYTE == profile)
        return rtp_ext_write_one_byte(extension, exts, count, data, bytes);
    else if (RTP_HDREXT_PROFILE_TWO_BYTE == (profile & RTP_HDREXT_PROFILE_TWO_BYTE_FILTER))
        return rtp_ext_write_two_byte(extension, exts, count, data, bytes);

    return -1; // ignore
}

#if defined(DEBUG) || defined(_DEBUG)
static void rtp_ext_read_onebyte_test(void)
{
    const uint8_t data[] = {0x22, 0xca, 0x4e, 0x36, 0x31, 0x00, 0x01, 0x40, 0x30, 0x10, 0xb2, 0x00};
    struct rtp_ext_data_t exts[256];
    int i;
    memset(exts, 0, sizeof(exts));
    assert(0 == rtp_ext_read(RTP_HDREXT_PROFILE_ONE_BYTE, data, sizeof(data), exts));
    assert(exts[2].len == 3 && exts[3].len == 2 && exts[4].len == 1 && exts[1].len == 1);
    for (i = 0; i < sizeof(exts) / sizeof(exts[0]); i++) {
        if (i == 1 || i == 2 || i == 3 || i == 4)
            continue;
        assert(exts[i].id == 0 && exts[i].len == 0);
    }
}

static void rtp_ext_read_twobyte_test(void) {}

void rtp_ext_read_test(void)
{
    rtp_ext_read_onebyte_test();
    rtp_ext_read_twobyte_test();
}
#endif