/**  toxav.c
 *
 *   Copyright (C) 2013 Tox project All Rights Reserved.
 *
 *   This file is part of Tox.
 *
 *   Tox is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   Tox is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with Tox. If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* HAVE_CONFIG_H */

#define TOX_DEFINED
typedef struct Messenger Tox;

#define _GNU_SOURCE /* implicit declaration warning */

#include "codec.h"
#include "msi.h"
#include "group.h"

#include "../toxcore/logger.h"
#include "../toxcore/util.h"

#include <assert.h>
#include <stdlib.h>
#include <string.h>

/* Assume 24 fps*/
#define MAX_ENCODE_TIME_US ((1000 / 24) * 1000)

/* true if invalid call index */
#define CALL_INVALID_INDEX(idx, max) (idx < 0 || idx >= max)

const ToxAvCSettings av_DefaultSettings = {
    av_TypeAudio,

    500,
    1280,
    720,

    32000,
    20,
    48000,
    1
};

static const uint32_t jbuf_capacity = 6;
static const uint8_t audio_index = 0, video_index = 1;

typedef struct _ToxAvCall {
    pthread_mutex_t mutex[1];
    pthread_mutex_t mutex_encoding_audio[1];
    pthread_mutex_t mutex_encoding_video[1];
    pthread_mutex_t mutex_do[1];
    RTPSession *crtps[2]; /** Audio is first and video is second */
    CSSession *cs;
    _Bool active;
} ToxAvCall;

struct _ToxAv {
    Messenger *messenger;
    MSISession *msi_session; /** Main msi session */
    ToxAvCall *calls; /** Per-call params */
    uint32_t max_calls;

    PAIR(ToxAvAudioCallback, void *) acb;
    PAIR(ToxAvVideoCallback, void *) vcb;

    /* Decode time measure */
    int32_t dectmsscount; /** Measure count */
    int32_t dectmsstotal; /** Last cycle total */
    int32_t avgdectms; /** Average decoding time in ms */
};

static const MSICSettings *msicsettings_cast (const ToxAvCSettings *from)
{
    assert(sizeof(MSICSettings) == sizeof(ToxAvCSettings));
    return (const MSICSettings *) from;
}

static const ToxAvCSettings *toxavcsettings_cast (const MSICSettings *from)
{
    assert(sizeof(MSICSettings) == sizeof(ToxAvCSettings));
    return (const ToxAvCSettings *) from;

}

ToxAv *toxav_new( Tox *messenger, int32_t max_calls)
{
    ToxAv *av = calloc ( sizeof(ToxAv), 1);

    if (av == NULL) {
        LOGGER_WARNING("Allocation failed!");
        return NULL;
    }

    av->messenger = (Messenger *)messenger;
    av->msi_session = msi_new(av->messenger, max_calls);
    av->msi_session->agent_handler = av;
    av->calls = calloc(sizeof(ToxAvCall), max_calls);
    av->max_calls = max_calls;

    unsigned int i;

    for (i = 0; i < max_calls; ++i) {
        if (create_recursive_mutex(av->calls[i].mutex) != 0 ) {
            LOGGER_WARNING("Failed to init call(%u) mutex!", i);
            msi_kill(av->msi_session);

            free(av->calls);
            free(av);
            return NULL;
        }
    }

    return av;
}

void toxav_kill ( ToxAv *av )
{
    uint32_t i;

    for (i = 0; i < av->max_calls; i ++) {
        if ( av->calls[i].crtps[audio_index] )
            rtp_kill(av->calls[i].crtps[audio_index], av->msi_session->messenger_handle);


        if ( av->calls[i].crtps[video_index] )
            rtp_kill(av->calls[i].crtps[video_index], av->msi_session->messenger_handle);

        if ( av->calls[i].cs )
            cs_kill(av->calls[i].cs);

        pthread_mutex_destroy(av->calls[i].mutex);
    }

    msi_kill(av->msi_session);

    free(av->calls);
    free(av);
}

uint32_t toxav_do_interval(ToxAv *av)
{
    int i = 0;
    uint32_t rc = 200 + av->avgdectms; /* Return 200 if no call is active */

    for (; i < av->max_calls; i ++) {
        pthread_mutex_lock(av->calls[i].mutex);

        if (av->calls[i].active) {
            /* This should work. Video payload will always come in greater intervals */
            rc = MIN(av->calls[i].cs->audio_decoder_frame_duration, rc);
        }

        pthread_mutex_unlock(av->calls[i].mutex);
    }

    return rc < av->avgdectms ? 0 : rc - av->avgdectms;
}

void toxav_do(ToxAv *av)
{
    msi_do(av->msi_session);

    uint64_t start = current_time_monotonic();

    uint32_t i = 0;

    for (; i < av->max_calls; i ++) {
        pthread_mutex_lock(av->calls[i].mutex);

        if (av->calls[i].active) {
            pthread_mutex_lock(av->calls[i].mutex_do);
            pthread_mutex_unlock(av->calls[i].mutex);
            cs_do(av->calls[i].cs);
            pthread_mutex_unlock(av->calls[i].mutex_do);
        } else {
            pthread_mutex_unlock(av->calls[i].mutex);
        }
    }

    uint64_t end = current_time_monotonic();

    /* TODO maybe use variable for sizes */
    av->dectmsstotal += end - start;

    if (++av->dectmsscount == 3) {
        av->avgdectms = av->dectmsstotal / 3 + 2 /* NOTE Magic Offset */;
        av->dectmsscount = 0;
        av->dectmsstotal = 0;
    }
}

void toxav_register_callstate_callback ( ToxAv *av, ToxAVCallback cb, ToxAvCallbackID id, void *userdata )
{
    msi_register_callback(av->msi_session, (MSICallbackType)cb, (MSICallbackID) id, userdata);
}

void toxav_register_audio_callback(ToxAv *av, ToxAvAudioCallback cb, void *userdata)
{
    av->acb.first = cb;
    av->acb.second = userdata;
}

void toxav_register_video_callback(ToxAv *av, ToxAvVideoCallback cb, void *userdata)
{
    av->vcb.first = cb;
    av->vcb.second = userdata;
}

int toxav_call (ToxAv *av,
                int32_t *call_index,
                int user,
                const ToxAvCSettings *csettings,
                int ringing_seconds )
{
    return msi_invite(av->msi_session, call_index, msicsettings_cast(csettings), ringing_seconds * 1000, user);
}

int toxav_hangup ( ToxAv *av, int32_t call_index )
{
    return msi_hangup(av->msi_session, call_index);
}

int toxav_answer ( ToxAv *av, int32_t call_index, const ToxAvCSettings *csettings )
{
    return msi_answer(av->msi_session, call_index, msicsettings_cast(csettings));
}

int toxav_reject ( ToxAv *av, int32_t call_index, const char *reason )
{
    return msi_reject(av->msi_session, call_index, reason);
}

int toxav_cancel ( ToxAv *av, int32_t call_index, int peer_id, const char *reason )
{
    return msi_cancel(av->msi_session, call_index, peer_id, reason);
}

int toxav_change_settings(ToxAv *av, int32_t call_index, const ToxAvCSettings *csettings)
{
    return msi_change_csettings(av->msi_session, call_index, msicsettings_cast(csettings));
}

int toxav_stop_call ( ToxAv *av, int32_t call_index )
{
    return msi_stopcall(av->msi_session, call_index);
}

int toxav_prepare_transmission ( ToxAv *av, int32_t call_index, int support_video )
{
    if ( !av->msi_session || CALL_INVALID_INDEX(call_index, av->msi_session->max_calls) ||
            !av->msi_session->calls[call_index] || !av->msi_session->calls[call_index]->csettings_peer) {
        LOGGER_ERROR("Error while starting RTP session: invalid call!\n");
        return av_ErrorNoCall;
    }

    ToxAvCall *call = &av->calls[call_index];

    pthread_mutex_lock(call->mutex);

    if (call->active) {
        pthread_mutex_unlock(call->mutex);
        LOGGER_ERROR("Error while starting RTP session: call already active!\n");
        return av_ErrorAlreadyInCallWithPeer;
    }

    if (pthread_mutex_init(call->mutex_encoding_audio, NULL) != 0
            || pthread_mutex_init(call->mutex_encoding_video, NULL) != 0 || pthread_mutex_init(call->mutex_do, NULL) != 0) {
        pthread_mutex_unlock(call->mutex);
        LOGGER_ERROR("Error while starting RTP session: mutex initializing failed!\n");
        return av_ErrorUnknown;
    }

    const ToxAvCSettings *c_peer = toxavcsettings_cast
                                   (&av->msi_session->calls[call_index]->csettings_peer[0]);
    const ToxAvCSettings *c_self = toxavcsettings_cast
                                   (&av->msi_session->calls[call_index]->csettings_local);

    LOGGER_DEBUG(
        "Type: %u(s) %u(p)\n"
        "Video bitrate: %u(s) %u(p)\n"
        "Video height: %u(s) %u(p)\n"
        "Video width: %u(s) %u(p)\n"
        "Audio bitrate: %u(s) %u(p)\n"
        "Audio framedur: %u(s) %u(p)\n"
        "Audio sample rate: %u(s) %u(p)\n"
        "Audio channels: %u(s) %u(p)\n",
        c_self->call_type,              c_peer->call_type,
        c_self->video_bitrate,          c_peer->video_bitrate,
        c_self->max_video_height,       c_peer->max_video_height,
        c_self->max_video_width,        c_peer->max_video_width,
        c_self->audio_bitrate,          c_peer->audio_bitrate,
        c_self->audio_frame_duration,   c_peer->audio_frame_duration,
        c_self->audio_sample_rate,      c_peer->audio_sample_rate,
        c_self->audio_channels,         c_peer->audio_channels );

    if ( !(call->cs = cs_new(c_self, c_peer, jbuf_capacity, support_video)) ) {
        LOGGER_ERROR("Error while starting Codec State!\n");
        pthread_mutex_unlock(call->mutex);
        return av_ErrorInitializingCodecs;
    }

    call->cs->agent = av;
    call->cs->call_idx = call_index;

    call->cs->acb.first = av->acb.first;
    call->cs->acb.second = av->acb.second;

    call->cs->vcb.first = av->vcb.first;
    call->cs->vcb.second = av->vcb.second;


    call->crtps[audio_index] =
        rtp_new(msi_TypeAudio, av->messenger, av->msi_session->calls[call_index]->peers[0]);

    if ( !call->crtps[audio_index] ) {
        LOGGER_ERROR("Error while starting audio RTP session!\n");
        goto error;
    }

    call->crtps[audio_index]->cs = call->cs;

    if ( support_video ) {
        call->crtps[video_index] =
            rtp_new(msi_TypeVideo, av->messenger, av->msi_session->calls[call_index]->peers[0]);

        if ( !call->crtps[video_index] ) {
            LOGGER_ERROR("Error while starting video RTP session!\n");
            goto error;
        }

        call->crtps[video_index]->cs = call->cs;
    }

    call->active = 1;
    pthread_mutex_unlock(call->mutex);
    return av_ErrorNone;
error:
    rtp_kill(call->crtps[audio_index], av->messenger);
    call->crtps[audio_index] = NULL;
    rtp_kill(call->crtps[video_index], av->messenger);
    call->crtps[video_index] = NULL;
    cs_kill(call->cs);
    call->cs = NULL;
    call->active = 0;
    pthread_mutex_destroy(call->mutex_encoding_audio);
    pthread_mutex_destroy(call->mutex_encoding_video);
    pthread_mutex_destroy(call->mutex_do);

    pthread_mutex_unlock(call->mutex);
    return av_ErrorCreatingRtpSessions;
}

int toxav_kill_transmission ( ToxAv *av, int32_t call_index )
{
    if (CALL_INVALID_INDEX(call_index, av->msi_session->max_calls)) {
        LOGGER_WARNING("Invalid call index: %d", call_index);
        return av_ErrorNoCall;
    }

    ToxAvCall *call = &av->calls[call_index];

    pthread_mutex_lock(call->mutex);

    if (!call->active) {
        pthread_mutex_unlock(call->mutex);
        LOGGER_WARNING("Action on inactive call: %d", call_index);
        return av_ErrorInvalidState;
    }

    call->active = 0;

    pthread_mutex_lock(call->mutex_encoding_audio);
    pthread_mutex_unlock(call->mutex_encoding_audio);
    pthread_mutex_lock(call->mutex_encoding_video);
    pthread_mutex_unlock(call->mutex_encoding_video);
    pthread_mutex_lock(call->mutex_do);
    pthread_mutex_unlock(call->mutex_do);

    rtp_kill(call->crtps[audio_index], av->messenger);
    call->crtps[audio_index] = NULL;
    rtp_kill(call->crtps[video_index], av->messenger);
    call->crtps[video_index] = NULL;
    cs_kill(call->cs);
    call->cs = NULL;

    pthread_mutex_destroy(call->mutex_encoding_audio);
    pthread_mutex_destroy(call->mutex_encoding_video);
    pthread_mutex_destroy(call->mutex_do);

    pthread_mutex_unlock(call->mutex);

    return av_ErrorNone;
}

static int toxav_send_rtp_payload(ToxAv *av,
                                  ToxAvCall *call,
                                  ToxAvCallType type,
                                  const uint8_t *payload,
                                  unsigned int length)
{
    if (call->crtps[type - av_TypeAudio]) {

        /* Audio */
        if (type == av_TypeAudio)
            return rtp_send_msg(call->crtps[audio_index], av->messenger, payload, length);

        /* Video */
        int parts = cs_split_video_payload(call->cs, payload, length);

        if (parts < 0) return parts;

        uint16_t part_size;
        const uint8_t *iter;

        int i;

        for (i = 0; i < parts; i++) {
            iter = cs_get_split_video_frame(call->cs, &part_size);

            if (rtp_send_msg(call->crtps[video_index], av->messenger, iter, part_size) < 0)
                return av_ErrorSendingPayload;
        }

        return av_ErrorNone;

    } else return av_ErrorNoRtpSession;
}

int toxav_prepare_video_frame ( ToxAv *av, int32_t call_index, uint8_t *dest, int dest_max, vpx_image_t *input)
{
    if (CALL_INVALID_INDEX(call_index, av->msi_session->max_calls)) {
        LOGGER_WARNING("Invalid call index: %d", call_index);
        return av_ErrorNoCall;
    }


    ToxAvCall *call = &av->calls[call_index];
    pthread_mutex_lock(call->mutex);

    if (!call->active) {
        pthread_mutex_unlock(call->mutex);
        LOGGER_WARNING("Action on inactive call: %d", call_index);
        return av_ErrorInvalidState;
    }

    if (!(call->cs->capabilities & cs_VideoEncoding)) {
        pthread_mutex_unlock(call->mutex);
        LOGGER_WARNING("Call doesn't support encoding video: %d", call_index);
        return av_ErrorInvalidState;
    }

    if (cs_set_video_encoder_resolution(call->cs, input->w, input->h) < 0) {
        pthread_mutex_unlock(call->mutex);
        return av_ErrorSettingVideoResolution;
    }

    pthread_mutex_lock(call->mutex_encoding_video);
    pthread_mutex_unlock(call->mutex);

    int rc = vpx_codec_encode(&call->cs->v_encoder, input, call->cs->frame_counter, 1, 0, MAX_ENCODE_TIME_US);

    if ( rc != VPX_CODEC_OK) {
        LOGGER_ERROR("Could not encode video frame: %s\n", vpx_codec_err_to_string(rc));
        pthread_mutex_unlock(call->mutex_encoding_video);
        return av_ErrorEncodingVideo;
    }

    ++call->cs->frame_counter;

    vpx_codec_iter_t iter = NULL;
    const vpx_codec_cx_pkt_t *pkt;
    int copied = 0;

    while ( (pkt = vpx_codec_get_cx_data(&call->cs->v_encoder, &iter)) ) {
        if (pkt->kind == VPX_CODEC_CX_FRAME_PKT) {
            if ( copied + pkt->data.frame.sz > dest_max ) {
                pthread_mutex_unlock(call->mutex_encoding_video);
                return av_ErrorPacketTooLarge;
            }

            memcpy(dest + copied, pkt->data.frame.buf, pkt->data.frame.sz);
            copied += pkt->data.frame.sz;
        }
    }

    pthread_mutex_unlock(call->mutex_encoding_video);
    return copied;
}

int toxav_send_video ( ToxAv *av, int32_t call_index, const uint8_t *frame, unsigned int frame_size)
{

    if (CALL_INVALID_INDEX(call_index, av->msi_session->max_calls)) {
        LOGGER_WARNING("Invalid call index: %d", call_index);
        return av_ErrorNoCall;
    }

    ToxAvCall *call = &av->calls[call_index];
    pthread_mutex_lock(call->mutex);


    if (!call->active) {
        pthread_mutex_unlock(call->mutex);
        LOGGER_WARNING("Action on inactive call: %d", call_index);
        return av_ErrorInvalidState;
    }

    int rc = toxav_send_rtp_payload(av, call, av_TypeVideo, frame, frame_size);
    pthread_mutex_unlock(call->mutex);

    return rc;
}

int toxav_prepare_audio_frame ( ToxAv *av,
                                int32_t call_index,
                                uint8_t *dest,
                                int dest_max,
                                const int16_t *frame,
                                int frame_size)
{
    if (CALL_INVALID_INDEX(call_index, av->msi_session->max_calls)) {
        LOGGER_WARNING("Action on nonexisting call: %d", call_index);
        return av_ErrorNoCall;
    }

    ToxAvCall *call = &av->calls[call_index];
    pthread_mutex_lock(call->mutex);

    if (!call->active) {
        pthread_mutex_unlock(call->mutex);
        LOGGER_WARNING("Action on inactive call: %d", call_index);
        return av_ErrorInvalidState;
    }

    pthread_mutex_lock(call->mutex_encoding_audio);
    pthread_mutex_unlock(call->mutex);
    int32_t rc = opus_encode(call->cs->audio_encoder, frame, frame_size, dest, dest_max);
    pthread_mutex_unlock(call->mutex_encoding_audio);

    if (rc < 0) {
        LOGGER_ERROR("Failed to encode payload: %s\n", opus_strerror(rc));
        return av_ErrorEncodingAudio;
    }

    return rc;
}

int toxav_send_audio ( ToxAv *av, int32_t call_index, const uint8_t *data, unsigned int size)
{
    if (CALL_INVALID_INDEX(call_index, av->msi_session->max_calls)) {
        LOGGER_WARNING("Action on nonexisting call: %d", call_index);
        return av_ErrorNoCall;
    }

    ToxAvCall *call = &av->calls[call_index];
    pthread_mutex_lock(call->mutex);


    if (!call->active) {
        pthread_mutex_unlock(call->mutex);
        LOGGER_WARNING("Action on inactive call: %d", call_index);
        return av_ErrorInvalidState;
    }

    int rc = toxav_send_rtp_payload(av, call, av_TypeAudio, data, size);
    pthread_mutex_unlock(call->mutex);
    return rc;
}

int toxav_get_peer_csettings ( ToxAv *av, int32_t call_index, int peer, ToxAvCSettings *dest )
{
    if ( peer < 0 || CALL_INVALID_INDEX(call_index, av->msi_session->max_calls) ||
            !av->msi_session->calls[call_index] || av->msi_session->calls[call_index]->peer_count <= peer )
        return av_ErrorNoCall;

    *dest = *toxavcsettings_cast(&av->msi_session->calls[call_index]->csettings_peer[peer]);
    return av_ErrorNone;
}

int toxav_get_peer_id ( ToxAv *av, int32_t call_index, int peer )
{
    if ( peer < 0 || CALL_INVALID_INDEX(call_index, av->msi_session->max_calls) || !av->msi_session->calls[call_index]
            || av->msi_session->calls[call_index]->peer_count <= peer )
        return av_ErrorNoCall;

    return av->msi_session->calls[call_index]->peers[peer];
}

ToxAvCallState toxav_get_call_state(ToxAv *av, int32_t call_index)
{
    if ( CALL_INVALID_INDEX(call_index, av->msi_session->max_calls) || !av->msi_session->calls[call_index] )
        return av_CallNonExistent;

    return av->msi_session->calls[call_index]->state;

}

int toxav_capability_supported ( ToxAv *av, int32_t call_index, ToxAvCapabilities capability )
{
    return av->calls[call_index].cs ? av->calls[call_index].cs->capabilities & (CSCapabilities) capability : 0;
    /* 0 is error here */
}

Tox *toxav_get_tox(ToxAv *av)
{
    return (Tox *)av->messenger;
}

int toxav_get_active_count(ToxAv *av)
{
    if (!av) return -1;

    int rc = 0, i = 0;

    for (; i < av->max_calls; i++) {
        pthread_mutex_lock(av->calls[i].mutex);

        if (av->calls[i].active) rc++;

        pthread_mutex_unlock(av->calls[i].mutex);
    }

    return rc;
}

/* Create a new toxav group.
 *
 * return group number on success.
 * return -1 on failure.
 *
 * Audio data callback format:
 *   audio_callback(Tox *tox, int groupnumber, int peernumber, const int16_t *pcm, unsigned int samples, uint8_t channels, unsigned int sample_rate, void *userdata)
 *
 * Note that total size of pcm in bytes is equal to (samples * channels * sizeof(int16_t)).
 */
int toxav_add_av_groupchat(Tox *tox, void (*audio_callback)(Messenger *, int, int, const int16_t *, unsigned int,
                           uint8_t, unsigned int, void *), void *userdata)
{
    Messenger *m = tox;
    return add_av_groupchat(m->group_chat_object, audio_callback, userdata);
}

/* Join a AV group (you need to have been invited first.)
 *
 * returns group number on success
 * returns -1 on failure.
 *
 * Audio data callback format (same as the one for toxav_add_av_groupchat()):
 *   audio_callback(Tox *tox, int groupnumber, int peernumber, const int16_t *pcm, unsigned int samples, uint8_t channels, unsigned int sample_rate, void *userdata)
 *
 * Note that total size of pcm in bytes is equal to (samples * channels * sizeof(int16_t)).
 */
int toxav_join_av_groupchat(Tox *tox, int32_t friendnumber, const uint8_t *data, uint16_t length,
                            void (*audio_callback)(Messenger *, int, int, const int16_t *, unsigned int, uint8_t, unsigned int, void *),
                            void *userdata)
{
    Messenger *m = tox;
    return join_av_groupchat(m->group_chat_object, friendnumber, data, length, audio_callback, userdata);
}

/* Send audio to the group chat.
 *
 * return 0 on success.
 * return -1 on failure.
 *
 * Note that total size of pcm in bytes is equal to (samples * channels * sizeof(int16_t)).
 *
 * Valid number of samples are ((sample rate) * (audio length (Valid ones are: 2.5, 5, 10, 20, 40 or 60 ms)) / 1000)
 * Valid number of channels are 1 or 2.
 * Valid sample rates are 8000, 12000, 16000, 24000, or 48000.
 *
 * Recommended values are: samples = 960, channels = 1, sample_rate = 48000
 */
int toxav_group_send_audio(Tox *tox, int groupnumber, const int16_t *pcm, unsigned int samples, uint8_t channels,
                           unsigned int sample_rate)
{
    Messenger *m = tox;
    return group_send_audio(m->group_chat_object, groupnumber, pcm, samples, channels, sample_rate);
}