/*
    Copyright (C) 2013 by Maxim Biro <nurupo.contributions@gmail.com>
    Copyright © 2014-2015 by The qTox Project Contributors

    This file is part of qTox, a Qt-based graphical interface for Tox.

    This program 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.

    qTox 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 qTox.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "coreav.h"
#include "core.h"
#include "src/audio/audio.h"
#include "src/model/friend.h"
#include "src/model/group.h"
#include "src/persistence/settings.h"
#include "src/video/corevideosource.h"
#include "src/video/videoframe.h"
#include <QCoreApplication>
#include <QDebug>
#include <QThread>
#include <QTimer>
#include <QtConcurrent/QtConcurrentRun>
#include <cassert>

/**
 * @fn void CoreAV::avInvite(uint32_t friendId, bool video)
 * @brief Sent when a friend calls us.
 * @param friendId Id of friend in call list.
 * @param video False if chat is audio only, true audio and video.
 *
 * @fn void CoreAV::avStart(uint32_t friendId, bool video)
 * @brief Sent when a call we initiated has started.
 * @param friendId Id of friend in call list.
 * @param video False if chat is audio only, true audio and video.
 *
 * @fn void CoreAV::avEnd(uint32_t friendId)
 * @brief Sent when a call was ended by the peer.
 * @param friendId Id of friend in call list.
 *
 * @var CoreAV::VIDEO_DEFAULT_BITRATE
 * @brief Picked at random by fair dice roll.
 */

/**
 * @var std::atomic_flag CoreAV::threadSwitchLock
 * @brief This flag is to be acquired before switching in a blocking way between the UI and CoreAV
 * thread.
 *
 * The CoreAV thread must have priority for the flag, other threads should back off or release it
 * quickly.
 * CoreAV needs to interface with three threads, the toxcore/Core thread that fires non-payload
 * toxav callbacks, the toxav/CoreAV thread that fires AV payload callbacks and manages
 * most of CoreAV's members, and the UI thread, which calls our [start/answer/cancel]Call functions
 * and which we call via signals.
 * When the UI calls us, we switch from the UI thread to the CoreAV thread to do the processing,
 * when toxcore fires a non-payload av callback, we do the processing in the CoreAV thread and then
 * switch to the UI thread to send it a signal. Both switches block both threads, so this would
 * deadlock.
 */

/**
 * @brief Maps friend IDs to ToxFriendCall.
 * @note Need to use STL container here, because Qt containers need a copy constructor.
 */
std::map<uint32_t, ToxFriendCall> CoreAV::calls;

/**
 * @brief Maps group IDs to ToxGroupCalls.
 * @note Need to use STL container here, because Qt containers need a copy constructor.
 */
std::map<int, ToxGroupCall> CoreAV::groupCalls;

CoreAV::CoreAV(Tox* tox)
    : coreavThread{new QThread}
    , iterateTimer{new QTimer{this}}
    , threadSwitchLock{false}
{
    coreavThread->setObjectName("qTox CoreAV");
    moveToThread(coreavThread.get());

    iterateTimer->setSingleShot(true);
    connect(iterateTimer.get(), &QTimer::timeout, this, &CoreAV::process);

    toxav = toxav_new(tox, nullptr);

    toxav_callback_call(toxav, CoreAV::callCallback, this);
    toxav_callback_call_state(toxav, CoreAV::stateCallback, this);
    toxav_callback_bit_rate_status(toxav, CoreAV::bitrateCallback, this);
    toxav_callback_audio_receive_frame(toxav, CoreAV::audioFrameCallback, this);
    toxav_callback_video_receive_frame(toxav, CoreAV::videoFrameCallback, this);

    coreavThread->start();
}

CoreAV::~CoreAV()
{
    for (const auto& call : calls) {
        cancelCall(call.first);
    }
    killTimerFromThread();
    toxav_kill(toxav);
    coreavThread->exit(0);
    while (coreavThread->isRunning()) {
        qApp->processEvents();
        coreavThread->wait(100);
    }
}

const ToxAV* CoreAV::getToxAv() const
{
    return toxav;
}

/**
 * @brief Starts the CoreAV main loop that calls toxav's main loop
 */
void CoreAV::start()
{
    // Timers can only be touched from their own thread
    if (QThread::currentThread() != coreavThread.get())
        return (void)QMetaObject::invokeMethod(this, "start", Qt::BlockingQueuedConnection);
    iterateTimer->start();
}

/**
 * @brief Stops the main loop
 */
void CoreAV::stop()
{
    // Timers can only be touched from their own thread
    if (QThread::currentThread() != coreavThread.get())
        return (void)QMetaObject::invokeMethod(this, "stop", Qt::BlockingQueuedConnection);
    iterateTimer->stop();
}

/**
 * @brief Calls itself blocking queued on the coreav thread
 */
void CoreAV::killTimerFromThread()
{
    // Timers can only be touched from their own thread
    if (QThread::currentThread() != coreavThread.get())
        return (void)QMetaObject::invokeMethod(this, "killTimerFromThread",
                                               Qt::BlockingQueuedConnection);
    iterateTimer.release();
}

void CoreAV::process()
{
    toxav_iterate(toxav);
    iterateTimer->start(toxav_iteration_interval(toxav));
}

/**
 * @brief Check, if any calls are currently active.
 * @return true if any calls are currently active, false otherwise
 * @note A call about to start is not yet active.
 */
bool CoreAV::anyActiveCalls() const
{
    return !calls.empty();
}

/**
 * @brief Checks the call status for a Tox friend.
 * @param f the friend to check
 * @return true, if call is started for the friend, false otherwise
 */
bool CoreAV::isCallStarted(const Friend* f) const
{
    return f && (calls.find(f->getId()) != calls.end());
}

/**
 * @brief Checks the call status for a Tox group.
 * @param g the group to check
 * @return true, if call is started for the group, false otherwise
 */
bool CoreAV::isCallStarted(const Group* g) const
{
    return g && (groupCalls.find(g->getId()) != groupCalls.end());
}

/**
 * @brief Checks the call status for a Tox friend.
 * @param f the friend to check
 * @return true, if call is active for the friend, false otherwise
 */
bool CoreAV::isCallActive(const Friend* f) const
{
    return isCallStarted(f) && calls[f->getId()].isActive();
}

/**
 * @brief Checks the call status for a Tox group.
 * @param g the group to check
 * @return true, if the call is active for the group, false otherwise
 */
bool CoreAV::isCallActive(const Group* g) const
{
    return isCallStarted(g) && groupCalls[g->getId()].isActive();
}

bool CoreAV::isCallVideoEnabled(const Friend* f) const
{
    return isCallStarted(f) && calls[f->getId()].getVideoEnabled();
}

bool CoreAV::answerCall(uint32_t friendNum, bool video)
{
    if (QThread::currentThread() != coreavThread.get()) {
        if (threadSwitchLock.test_and_set(std::memory_order_acquire)) {
            qDebug() << "CoreAV::answerCall: Backed off of thread-switch lock";
            return false;
        }

        bool ret;
        QMetaObject::invokeMethod(this, "answerCall", Qt::BlockingQueuedConnection,
                                  Q_RETURN_ARG(bool, ret), Q_ARG(uint32_t, friendNum),
                                  Q_ARG(bool, video));

        threadSwitchLock.clear(std::memory_order_release);
        return ret;
    }

    qDebug() << QString("answering call %1").arg(friendNum);
    assert(calls.find(friendNum) != calls.end());
    TOXAV_ERR_ANSWER err;

    const uint32_t videoBitrate = video ? VIDEO_DEFAULT_BITRATE : 0;
    if (toxav_answer(toxav, friendNum, Settings::getInstance().getAudioBitrate(), videoBitrate, &err)) {
        calls[friendNum].setActive(true);
        return true;
    } else {
        qWarning() << "Failed to answer call with error" << err;
        toxav_call_control(toxav, friendNum, TOXAV_CALL_CONTROL_CANCEL, nullptr);
        calls.erase(friendNum);
        return false;
    }
}

bool CoreAV::startCall(uint32_t friendNum, bool video)
{
    if (QThread::currentThread() != coreavThread.get()) {
        if (threadSwitchLock.test_and_set(std::memory_order_acquire)) {
            qDebug() << "CoreAV::startCall: Backed off of thread-switch lock";
            return false;
        }

        bool ret;
        QMetaObject::invokeMethod(this, "startCall", Qt::BlockingQueuedConnection,
                                  Q_RETURN_ARG(bool, ret), Q_ARG(uint32_t, friendNum),
                                  Q_ARG(bool, video));

        threadSwitchLock.clear(std::memory_order_release);
        return ret;
    }

    qDebug() << QString("Starting call with %1").arg(friendNum);
    if (calls.find(friendNum) != calls.end()) {
        qWarning() << QString("Can't start call with %1, we're already in this call!").arg(friendNum);
        return false;
    }

    uint32_t videoBitrate = video ? VIDEO_DEFAULT_BITRATE : 0;
    if (!toxav_call(toxav, friendNum, Settings::getInstance().getAudioBitrate(), videoBitrate, nullptr))
        return false;

    calls.insert(std::make_pair(friendNum, ToxFriendCall(friendNum, video, *this)));
    calls[friendNum].startTimeout(friendNum);
    return true;
}

bool CoreAV::cancelCall(uint32_t friendNum)
{
    if (QThread::currentThread() != coreavThread.get()) {
        if (threadSwitchLock.test_and_set(std::memory_order_acquire)) {
            qDebug() << "CoreAV::cancelCall: Backed off of thread-switch lock";
            return false;
        }

        bool ret;
        QMetaObject::invokeMethod(this, "cancelCall", Qt::BlockingQueuedConnection,
                                  Q_RETURN_ARG(bool, ret), Q_ARG(uint32_t, friendNum));

        threadSwitchLock.clear(std::memory_order_release);
        return ret;
    }

    qDebug() << QString("Cancelling call with %1").arg(friendNum);
    if (!toxav_call_control(toxav, friendNum, TOXAV_CALL_CONTROL_CANCEL, nullptr)) {
        qWarning() << QString("Failed to cancel call with %1").arg(friendNum);
        return false;
    }

    calls.erase(friendNum);
    emit avEnd(friendNum);
    return true;
}

void CoreAV::timeoutCall(uint32_t friendNum)
{
    // Non-blocking switch to the CoreAV thread, we really don't want to be coming
    // blocking-queued from the UI thread while we emit blocking-queued to it
    if (QThread::currentThread() != coreavThread.get()) {
        QMetaObject::invokeMethod(this, "timeoutCall", Qt::QueuedConnection,
                                  Q_ARG(uint32_t, friendNum));
        return;
    }

    if (!cancelCall(friendNum)) {
        qWarning() << QString("Failed to timeout call with %1").arg(friendNum);
        return;
    }
    qDebug() << "Call with friend" << friendNum << "timed out";
}

/**
 * @brief Send audio frame to a friend
 * @param callId Id of friend in call list.
 * @param pcm An array of audio samples (Pulse-code modulation).
 * @param samples Number of samples in this frame.
 * @param chans Number of audio channels.
 * @param rate Audio sampling rate used in this frame.
 * @return False only on error, but not if there's nothing to send.
 */
bool CoreAV::sendCallAudio(uint32_t callId, const int16_t* pcm, size_t samples, uint8_t chans,
                           uint32_t rate)
{
    if (calls.find(callId) == calls.end()) {
        return false;
    }

    ToxFriendCall& call = calls[callId];

    if (call.getMuteMic() || !call.isActive()
        || !(call.getState() & TOXAV_FRIEND_CALL_STATE_ACCEPTING_A)) {
        return true;
    }

    // TOXAV_ERR_SEND_FRAME_SYNC means toxav failed to lock, retry 5 times in this case
    TOXAV_ERR_SEND_FRAME err;
    int retries = 0;
    do {
        if (!toxav_audio_send_frame(toxav, callId, pcm, samples, chans, rate, &err)) {
            if (err == TOXAV_ERR_SEND_FRAME_SYNC) {
                ++retries;
                QThread::usleep(500);
            } else {
                qDebug() << "toxav_audio_send_frame error: " << err;
            }
        }
    } while (err == TOXAV_ERR_SEND_FRAME_SYNC && retries < 5);
    if (err == TOXAV_ERR_SEND_FRAME_SYNC) {
        qDebug() << "toxav_audio_send_frame error: Lock busy, dropping frame";
    }

    return true;
}

void CoreAV::sendCallVideo(uint32_t callId, std::shared_ptr<VideoFrame> vframe)
{
    // We might be running in the FFmpeg thread and holding the CameraSource lock
    // So be careful not to deadlock with anything while toxav locks in toxav_video_send_frame
    if (calls.find(callId) == calls.end()) {
        return;
    }

    ToxFriendCall& call = calls[callId];

    if (!call.getVideoEnabled() || !call.isActive()
        || !(call.getState() & TOXAV_FRIEND_CALL_STATE_ACCEPTING_V)) {
        return;
    }

    if (call.getNullVideoBitrate()) {
        qDebug() << "Restarting video stream to friend" << callId;
#if TOX_VERSION_IS_API_COMPATIBLE(0, 2, 0)
        toxav_video_set_bit_rate(toxav, callId, VIDEO_DEFAULT_BITRATE, nullptr);
#else
        toxav_bit_rate_set(toxav, callId, -1, VIDEO_DEFAULT_BITRATE, nullptr);
#endif
        call.setNullVideoBitrate(false);
    }

    ToxYUVFrame frame = vframe->toToxYUVFrame();

    if (!frame) {
        return;
    }

    // TOXAV_ERR_SEND_FRAME_SYNC means toxav failed to lock, retry 5 times in this case
    // We don't want to be dropping iframes because of some lock held by toxav_iterate
    TOXAV_ERR_SEND_FRAME err;
    int retries = 0;
    do {
        if (!toxav_video_send_frame(toxav, callId, frame.width, frame.height, frame.y, frame.u,
                                    frame.v, &err)) {
            if (err == TOXAV_ERR_SEND_FRAME_SYNC) {
                ++retries;
                QThread::usleep(500);
            } else {
                qDebug() << "toxav_video_send_frame error: " << err;
            }
        }
    } while (err == TOXAV_ERR_SEND_FRAME_SYNC && retries < 5);
    if (err == TOXAV_ERR_SEND_FRAME_SYNC) {
        qDebug() << "toxav_video_send_frame error: Lock busy, dropping frame";
    }
}

/**
 * @brief Toggles the mute state of the call's input (microphone).
 * @param f The friend assigned to the call
 */
void CoreAV::toggleMuteCallInput(const Friend* f)
{
    if (f && (calls.find(f->getId()) != calls.end())) {
        ToxCall& call = calls[f->getId()];
        call.setMuteMic(!call.getMuteMic());
    }
}

/**
 * @brief Toggles the mute state of the call's output (speaker).
 * @param f The friend assigned to the call
 */
void CoreAV::toggleMuteCallOutput(const Friend* f)
{
    if (f && (calls.find(f->getId()) != calls.end())) {
        ToxCall& call = calls[f->getId()];
        call.setMuteVol(!call.getMuteVol());
    }
}

/**
 * @brief Called from Tox API when group call receives audio data.
 *
 * @param[in] tox          the Tox object
 * @param[in] group        the group number
 * @param[in] peer         the peer number
 * @param[in] data         the audio data to playback
 * @param[in] samples      the audio samples
 * @param[in] channels     the audio channels
 * @param[in] sample_rate  the audio sample rate
 * @param[in] core         the qTox Core class
 */
void CoreAV::groupCallCallback(void* tox, int group, int peer, const int16_t* data,
                               unsigned samples, uint8_t channels, unsigned sample_rate, void* core)
{
    Q_UNUSED(tox);

    Core* c = static_cast<Core*>(core);
    CoreAV* cav = c->getAv();

    if (cav->groupCalls.find(group) == cav->groupCalls.end()) {
        return;
    }

    ToxGroupCall& call = cav->groupCalls[group];

    emit c->groupPeerAudioPlaying(group, peer);

    if (call.getMuteVol() || !call.isActive()) {
        return;
    }

    Audio& audio = Audio::getInstance();
    if (!call.getPeers()[peer]) {
        // FIXME: 0 is a valid sourceId, we shouldn't necessarily re-subscribe just because we have 0
        audio.subscribeOutput(call.getPeers()[peer]);
    }

    audio.playAudioBuffer(call.getPeers()[peer], data, samples, channels, sample_rate);
}

/**
 * @brief Called from core to make sure the source for that peer is invalidated when they leave.
 * @param group Group Index
 * @param peer Peer Index
 */
void CoreAV::invalidateGroupCallPeerSource(int group, int peer)
{
    Audio& audio = Audio::getInstance();
    audio.unsubscribeOutput(groupCalls[group].getPeers()[peer]);
    groupCalls[group].getPeers()[peer] = 0;
}

/**
 * @brief Get a call's video source.
 * @param friendNum Id of friend in call list.
 * @return Video surface to show
 */
VideoSource* CoreAV::getVideoSourceFromCall(int friendNum)
{
    if (calls.find(friendNum) == calls.end()) {
        qWarning() << "CoreAV::getVideoSourceFromCall: No such call, did it die before we finished "
                      "answering?";
        return nullptr;
    }

    return calls[friendNum].getVideoSource();
}

/**
 * @brief Starts a call in an existing AV groupchat.
 * @note Call from the GUI thread.
 * @param groupId Id of group to join
 */
void CoreAV::joinGroupCall(int groupId)
{
    qDebug() << QString("Joining group call %1").arg(groupId);

    groupCalls[groupId] = ToxGroupCall{groupId, *this};
    groupCalls[groupId].setActive(true);
}

/**
 * @brief Will not leave the group, just stop the call.
 * @note Call from the GUI thread.
 * @param groupId Id of group to leave
 */
void CoreAV::leaveGroupCall(int groupId)
{
    qDebug() << QString("Leaving group call %1").arg(groupId);

    groupCalls.erase(groupId);
}

bool CoreAV::sendGroupCallAudio(int groupId, const int16_t* pcm, size_t samples, uint8_t chans,
                                uint32_t rate)
{
    if (groupCalls.find(groupId) == groupCalls.end()) {
        return false;
    }

    ToxGroupCall& call = groupCalls[groupId];

    if (!call.isActive() || call.getMuteMic()) {
        return true;
    }

    if (toxav_group_send_audio(toxav_get_tox(toxav), groupId, pcm, samples, chans, rate) != 0)
        qDebug() << "toxav_group_send_audio error";

    return true;
}

/**
 * @brief Mutes or unmutes the group call's input (microphone).
 * @param g The group
 * @param mute True to mute, false to unmute
 */
void CoreAV::muteCallInput(const Group* g, bool mute)
{
    if (g && (groupCalls.find(g->getId()) != groupCalls.end())) {
        groupCalls[g->getId()].setMuteMic(mute);
    }
}

/**
 * @brief Mutes or unmutes the group call's output (speaker).
 * @param g The group
 * @param mute True to mute, false to unmute
 */
void CoreAV::muteCallOutput(const Group* g, bool mute)
{
    if (g && (groupCalls.find(g->getId()) != groupCalls.end())) {
        groupCalls[g->getId()].setMuteVol(mute);
    }
}

/**
 * @brief Returns the group calls input (microphone) state.
 * @param groupId The group id to check
 * @return true when muted, false otherwise
 */
bool CoreAV::isGroupCallInputMuted(const Group* g) const
{
    if (!g) {
        return false;
    }

    const uint32_t groupId = g->getId();
    return (groupCalls.find(groupId) != groupCalls.end()) && groupCalls[groupId].getMuteMic();
}

/**
 * @brief Returns the group calls output (speaker) state.
 * @param groupId The group id to check
 * @return true when muted, false otherwise
 */
bool CoreAV::isGroupCallOutputMuted(const Group* g) const
{
    if (!g) {
        return false;
    }

    const uint32_t groupId = g->getId();
    return (groupCalls.find(groupId) != groupCalls.end()) && groupCalls[groupId].getMuteVol();
}

/**
 * @brief Check, that group has audio or video stream
 * @param groupId Id of group to check
 * @return True for AV groups, false for text-only groups
 */
bool CoreAV::isGroupAvEnabled(int groupId) const
{
    Tox* tox = Core::getInstance()->tox;
    TOX_ERR_CONFERENCE_GET_TYPE error;
    TOX_CONFERENCE_TYPE type = tox_conference_get_type(tox, groupId, &error);
    switch (error) {
    case TOX_ERR_CONFERENCE_GET_TYPE_OK:
        break;
    case TOX_ERR_CONFERENCE_GET_TYPE_CONFERENCE_NOT_FOUND:
        qCritical() << "Conference not found";
        break;
    default:
        break;
    }

    return type == TOX_CONFERENCE_TYPE_AV;
}

/**
 * @brief Returns the calls input (microphone) mute state.
 * @param f The friend to check
 * @return true when muted, false otherwise
 */
bool CoreAV::isCallInputMuted(const Friend* f) const
{
    if (!f) {
        return false;
    }
    const uint32_t friendId = f->getId();
    return (calls.find(friendId) != calls.end()) && calls[friendId].getMuteMic();
}

/**
 * @brief Returns the calls output (speaker) mute state.
 * @param friendId The friend to check
 * @return true when muted, false otherwise
 */
bool CoreAV::isCallOutputMuted(const Friend* f) const
{
    if (!f) {
        return false;
    }
    const uint32_t friendId = f->getId();
    return (calls.find(friendId) != calls.end()) && calls[f->getId()].getMuteVol();
}

/**
 * @brief Forces to regenerate each call's audio sources.
 */
void CoreAV::invalidateCallSources()
{
    for (auto& kv : groupCalls) {
        kv.second.getPeers().clear();
    }

    for (auto& kv : calls) {
        // TODO: this is wrong, "0" is a valid source id
        kv.second.setAlSource(0);
    }
}

/**
 * @brief Signal to all peers that we're not sending video anymore.
 * @note The next frame sent cancels this.
 */
void CoreAV::sendNoVideo()
{
    // We don't change the audio bitrate, but we signal that we're not sending video anymore
    qDebug() << "CoreAV: Signaling end of video sending";
    for (auto& kv : calls) {
        ToxFriendCall& call = kv.second;
#if TOX_VERSION_IS_API_COMPATIBLE(0, 2, 0)
        toxav_video_set_bit_rate(toxav, kv.first, 0, nullptr);
#else
        toxav_bit_rate_set(toxav, kv.first, -1, 0, nullptr);
#endif
        call.setNullVideoBitrate(true);
    }
}

void CoreAV::callCallback(ToxAV* toxav, uint32_t friendNum, bool audio, bool video, void* vSelf)
{
    CoreAV* self = static_cast<CoreAV*>(vSelf);

    // Run this slow callback asynchronously on the AV thread to avoid deadlocks with what our
    // caller (toxcore) holds
    // Also run the code to switch to the CoreAV thread in yet another thread, in case CoreAV
    // has threadSwitchLock and wants a toxcore lock that our call stack is holding...
    if (QThread::currentThread() != self->coreavThread.get()) {
        QtConcurrent::run([=]() {
            // We assume the original caller doesn't come from the CoreAV thread here
            while (self->threadSwitchLock.test_and_set(std::memory_order_acquire))
                QThread::yieldCurrentThread(); // Shouldn't spin for long, we have priority

            QMetaObject::invokeMethod(self, "callCallback", Qt::QueuedConnection,
                                      Q_ARG(ToxAV*, toxav), Q_ARG(uint32_t, friendNum),
                                      Q_ARG(bool, audio), Q_ARG(bool, video), Q_ARG(void*, vSelf));
        });
        return;
    }

    if (self->calls.find(friendNum) != self->calls.end()) {
        /// Hanging up from a callback is supposed to be UB,
        /// but since currently the toxav callbacks are fired from the toxcore thread,
        /// we'll always reach this point through a non-blocking queud connection, so not in the
        /// callback.
        qWarning() << QString("Rejecting call invite from %1, we're already in that call!").arg(friendNum);
        toxav_call_control(toxav, friendNum, TOXAV_CALL_CONTROL_CANCEL, nullptr);
        return;
    }
    qDebug() << QString("Received call invite from %1").arg(friendNum);
    self->calls[friendNum] = ToxFriendCall{friendNum, video, *self};

    // We don't get a state callback when answering, so fill the state ourselves in advance
    int state = 0;
    if (audio)
        state |= TOXAV_FRIEND_CALL_STATE_SENDING_A | TOXAV_FRIEND_CALL_STATE_ACCEPTING_A;
    if (video)
        state |= TOXAV_FRIEND_CALL_STATE_SENDING_V | TOXAV_FRIEND_CALL_STATE_ACCEPTING_V;
    calls[friendNum].setState(static_cast<TOXAV_FRIEND_CALL_STATE>(state));

    emit reinterpret_cast<CoreAV*>(self)->avInvite(friendNum, video);
    self->threadSwitchLock.clear(std::memory_order_release);
}

void CoreAV::stateCallback(ToxAV* toxav, uint32_t friendNum, uint32_t state, void* vSelf)
{
    CoreAV* self = static_cast<CoreAV*>(vSelf);

    // Run this slow callback asynchronously on the AV thread to avoid deadlocks with what our
    // caller (toxcore) holds
    // Also run the code to switch to the CoreAV thread in yet another thread, in case CoreAV
    // has threadSwitchLock and wants a toxcore lock that our call stack is holding...
    if (QThread::currentThread() != self->coreavThread.get()) {
        QtConcurrent::run([=]() {
            // We assume the original caller doesn't come from the CoreAV thread here
            while (self->threadSwitchLock.test_and_set(std::memory_order_acquire))
                QThread::yieldCurrentThread(); // Shouldn't spin for long, we have priority

            QMetaObject::invokeMethod(self, "stateCallback", Qt::QueuedConnection,
                                      Q_ARG(ToxAV*, toxav), Q_ARG(uint32_t, friendNum),
                                      Q_ARG(uint32_t, state), Q_ARG(void*, vSelf));
        });
        return;
    }

    if (self->calls.find(friendNum) == self->calls.end()) {
        qWarning() << QString("stateCallback called, but call %1 is already dead").arg(friendNum);
        self->threadSwitchLock.clear(std::memory_order_release);
        return;
    }

    ToxFriendCall& call = self->calls[friendNum];

    if (state & TOXAV_FRIEND_CALL_STATE_ERROR) {
        qWarning() << "Call with friend" << friendNum << "died of unnatural causes!";
        calls.erase(friendNum);
        emit self->avEnd(friendNum, true);
    } else if (state & TOXAV_FRIEND_CALL_STATE_FINISHED) {
        qDebug() << "Call with friend" << friendNum << "finished quietly";
        calls.erase(friendNum);
        emit self->avEnd(friendNum);
    } else {
        // If our state was null, we started the call and were still ringing
        if (!call.getState() && state) {
            call.stopTimeout();
            call.setActive(true);
            emit self->avStart(friendNum, call.getVideoEnabled());
        } else if ((call.getState() & TOXAV_FRIEND_CALL_STATE_SENDING_V)
                   && !(state & TOXAV_FRIEND_CALL_STATE_SENDING_V)) {
            qDebug() << "Friend" << friendNum << "stopped sending video";
            if (call.getVideoSource()) {
                call.getVideoSource()->stopSource();
            }
        } else if (!(call.getState() & TOXAV_FRIEND_CALL_STATE_SENDING_V)
                   && (state & TOXAV_FRIEND_CALL_STATE_SENDING_V)) {
            // Workaround toxav sometimes firing callbacks for "send last frame" -> "stop sending
            // video"
            // out of orders (even though they were sent in order by the other end).
            // We simply stop the videoSource from emitting anything while the other end says it's
            // not sending
            if (call.getVideoSource()) {
                call.getVideoSource()->restartSource();
            }
        }

        call.setState(static_cast<TOXAV_FRIEND_CALL_STATE>(state));
    }
    self->threadSwitchLock.clear(std::memory_order_release);
}

void CoreAV::bitrateCallback(ToxAV* toxav, uint32_t friendNum, uint32_t arate, uint32_t vrate,
                             void* vSelf)
{
    CoreAV* self = static_cast<CoreAV*>(vSelf);

    // Run this slow path callback asynchronously on the AV thread to avoid deadlocks
    if (QThread::currentThread() != self->coreavThread.get()) {
        return (void)QMetaObject::invokeMethod(self, "bitrateCallback", Qt::QueuedConnection,
                                               Q_ARG(ToxAV*, toxav), Q_ARG(uint32_t, friendNum),
                                               Q_ARG(uint32_t, arate), Q_ARG(uint32_t, vrate),
                                               Q_ARG(void*, vSelf));
    }

    qDebug() << "Recommended bitrate with" << friendNum << " is now " << arate << "/" << vrate
             << ", ignoring it";
}

void CoreAV::audioFrameCallback(ToxAV*, uint32_t friendNum, const int16_t* pcm, size_t sampleCount,
                                uint8_t channels, uint32_t samplingRate, void* vSelf)
{
    CoreAV* self = static_cast<CoreAV*>(vSelf);
    if (self->calls.find(friendNum) == self->calls.end()) {
        return;
    }

    ToxFriendCall& call = self->calls[friendNum];

    if (call.getMuteVol()) {
        return;
    }

    Audio& audio = Audio::getInstance();
    if (!call.getAlSource()) {
        quint32 sourceId;
        audio.subscribeOutput(sourceId);
        call.setAlSource(sourceId);
    }

    audio.playAudioBuffer(call.getAlSource(), pcm, sampleCount, channels, samplingRate);
}

void CoreAV::videoFrameCallback(ToxAV*, uint32_t friendNum, uint16_t w, uint16_t h,
                                const uint8_t* y, const uint8_t* u, const uint8_t* v,
                                int32_t ystride, int32_t ustride, int32_t vstride, void*)
{
    if (calls.find(friendNum) == calls.end()) {
        return;
    }

    CoreVideoSource* videoSource = calls[friendNum].getVideoSource();
    if (!videoSource) {
        return;
    }

    vpx_image frame;
    frame.d_h = h;
    frame.d_w = w;
    frame.planes[0] = const_cast<uint8_t*>(y);
    frame.planes[1] = const_cast<uint8_t*>(u);
    frame.planes[2] = const_cast<uint8_t*>(v);
    frame.stride[0] = ystride;
    frame.stride[1] = ustride;
    frame.stride[2] = vstride;

    videoSource->pushFrame(&frame);
}