#include "voice_audio_io.h"
extern "C" {
#include "call/call_audio.h"
#include "radio/radio_audio.h"
#include "speex_aec.h"
#include "debug_config.h"
}
#include <algorithm>
#include <array>
#include <chrono>
#include <cmath>
#include <cstring>
#include <system_error>

static int64_t voice_time_us() {
    return std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::steady_clock::now().time_since_epoch()).count();
}

VoiceAudioIo::~VoiceAudioIo() { stop(); }

bool VoiceAudioIo::start(Kind kind, uint64_t session) {
    stop();
    m_kind = kind; m_session = session;
    m_captureEvents.reset(); m_references.reset(); m_playback.reset();
    m_playPosition = 960; m_playEpoch = 1;
    m_captureDropped = m_referenceDropped = m_playbackUnderruns = 0;
    m_running = true;
    try { m_playbackThread = std::thread(&VoiceAudioIo::playbackLoop, this); }
    catch (const std::system_error& error) {
        m_running = false;
        DEBUG_ERROR(DEBUG_CATEGORY_CALL, "voice-io: RX worker start failed reason=%s", error.what()); return false;
    }
    DEBUG_INFO(DEBUG_CATEGORY_CALL, "voice-io: started session=%llu kind=%s PCM reserve<=40ms",
               (unsigned long long)session, kind == Kind::Call ? "call" : "radio");
    return true;
}

void VoiceAudioIo::stop() {
    stopCapture();
    m_running = false; m_wake.notify_all();
    if (m_playbackThread.joinable()) m_playbackThread.join();
}

bool VoiceAudioIo::startCapture(int channels, bool aecEnabled) {
    stopCapture();
    if (!m_running || channels < 1 || channels > 2 || (m_kind == Kind::Call && channels != 1)) {
        DEBUG_ERROR(DEBUG_CATEGORY_CALL, "voice-io: invalid capture channels=%d", channels); return false;
    }
    m_captureEvents.reset(); m_channels = channels; m_captureSequence = 0;
    m_aecRequested = aecEnabled; m_capturing = true;
    try { m_captureThread = std::thread(&VoiceAudioIo::captureLoop, this); }
    catch (const std::system_error& error) {
        m_capturing = false;
        DEBUG_ERROR(DEBUG_CATEGORY_CALL, "voice-io: capture worker start failed reason=%s", error.what()); return false;
    }
    return true;
}

void VoiceAudioIo::stopCapture() {
    if (m_captureThread.joinable()) {
        if (m_capturing) command(EventKind::Stop);
        m_captureThread.join();
    }
    m_capturing = false;
}

/* GUI-команда не теряется при заполнении PCM: зарезервированы слоты; отказ завершает capture. */
void VoiceAudioIo::command(EventKind kind, bool value) {
    if (!m_capturing) return;
    Event event{}; event.kind = kind; event.value = value;
    for (int attempt = 0; attempt < 100; ++attempt) {
        if (m_captureEvents.push(event, true)) { m_wake.notify_all(); return; }
        m_wake.notify_all(); std::this_thread::sleep_for(std::chrono::milliseconds(1));
    }
    DEBUG_ERROR(DEBUG_CATEGORY_CALL, "voice-io: control queue full session=%llu command=%d; stopping capture",
                (unsigned long long)m_session, (int)kind);
    m_capturing = false; m_wake.notify_all();
}
void VoiceAudioIo::setPtt(bool pressed) { command(EventKind::Ptt, pressed); }
void VoiceAudioIo::setMuted(bool muted) { command(EventKind::Mute, muted); }
void VoiceAudioIo::setAecEnabled(bool enabled) {
    if (enabled == m_aecRequested) return;
    m_aecRequested = enabled; command(EventKind::Aec, enabled);
}
void VoiceAudioIo::resetPlayback() { ++m_playEpoch; m_wake.notify_all(); }

void VoiceAudioIo::capture(const int16_t* pcm, unsigned frames, int64_t firstTimeUs, uint64_t route, bool missing) {
    if (!pcm || !m_capturing) return;
    if (missing) { m_captureSequence += frames; m_captureDropped.fetch_add(frames); return; }
    int64_t enqueued = voice_time_us();
    if (!firstTimeUs) firstTimeUs = enqueued - (int64_t)frames * 1000000 / 48000;
    unsigned offset = 0;
    while (offset < frames) {
        Event event{}; event.frames = std::min(frames - offset, 960u);
        event.time = firstTimeUs + (int64_t)offset * 1000000 / 48000;
        event.sequence = m_captureSequence; m_captureSequence += event.frames;
        event.route = route;
        event.enqueued = enqueued;
        memcpy(event.pcm, pcm + offset * m_channels, event.frames * m_channels * sizeof(int16_t));
        if (!m_captureEvents.push(event)) m_captureDropped.fetch_add(event.frames, std::memory_order_relaxed);
        offset += event.frames;
    }
    m_wake.notify_all();
}

void VoiceAudioIo::reference(const float* pcm, unsigned frames, int64_t firstTimeUs) {
    if (!m_capturing) return;
    if (!firstTimeUs) firstTimeUs = voice_time_us();
    for (unsigned offset = 0; offset < frames;) {
        Event event{}; event.frames = std::min(frames - offset, 960u);
        event.time = firstTimeUs + (int64_t)offset * 1000000 / 48000;
        event.sequence = m_playEpoch.load();
        for (unsigned i = 0; i < event.frames * 2; ++i) {
            float sample = pcm[offset * 2 + i];
            event.pcm[i] = (int16_t)std::clamp(sample * 32768.0f, -32768.0f, 32767.0f);
        }
        if (!m_references.push(event)) m_referenceDropped.fetch_add(event.frames, std::memory_order_relaxed);
        offset += event.frames;
    }
    m_wake.notify_all();
}

/* Выход всегда обслуживается независимо от capture/VAD. Уже потреблённый PCM становится референсом у владельца микшера. */
void VoiceAudioIo::mix(float* stereo, unsigned frames) {
    uint64_t epoch = m_playEpoch.load();
    for (unsigned i = 0; i < frames; ++i) {
        if (m_playCurrent.epoch != epoch) m_playPosition = 960;
        if (m_playPosition == 960) {
            bool available = false;
            for (int attempt = 0; attempt < 12 && m_playback.pop(m_playCurrent); ++attempt) {
                if (m_playCurrent.epoch == epoch) { available = true; m_playPosition = 0; break; }
            }
            if (!available) { m_playbackUnderruns.fetch_add(frames - i, std::memory_order_relaxed); break; }
        }
        stereo[2*i] += m_playCurrent.pcm[2*m_playPosition] / 32768.0f;
        stereo[2*i+1] += m_playCurrent.pcm[2*m_playPosition+1] / 32768.0f;
        ++m_playPosition;
    }
    m_wake.notify_all();
}

void VoiceAudioIo::playbackLoop() {
    uint64_t epoch = m_playEpoch.load();
    while (m_running) {
        uint64_t requested = m_playEpoch.load();
        if (requested != epoch) {
            if (m_kind == Kind::Call) call_audio_reset_io(m_session, 1);
            else radio_audio_reset_playback(m_session);
            epoch = requested;
        }
        if (m_playback.size() < 2) {
            Playback block{}; block.epoch = epoch;
            if (m_kind == Kind::Call) {
                int16_t mono[960]{};
                int count = std::clamp(call_audio_pull_pcm(m_session, mono, 960), 0, 960);
                for (int i = 0; i < count; ++i) block.pcm[2*i] = block.pcm[2*i+1] = mono[i];
            } else radio_audio_pull_pcm(m_session, block.pcm, 1920);
            if (!m_playback.push(block)) DEBUG_WARN(DEBUG_CATEGORY_CALL, "voice-io: playback queue contention");
        } else {
            std::unique_lock lock(m_waitMutex);
            m_wake.wait_for(lock, std::chrono::milliseconds(5));
        }
    }
}

/* Референс хранится как PCM + время, а не как фиксированный двухкадровый FIFO независимых часов. */
void VoiceAudioIo::captureLoop() {
    std::array<Event, 96> history{};
    size_t historyHead = 0, historyCount = 0;
    uint64_t referenceEpoch = m_playEpoch.load(), referenceDrops = m_referenceDropped.load();
    speex_aec_t* aec = nullptr;
    auto configureAec = [&](bool enabled) {
        speex_aec_destroy(aec); aec = nullptr;
        if (enabled) aec = speex_aec_create_mc(48000, 960, 14400, 1, m_channels, 2);
        if (enabled && !aec) DEBUG_ERROR(DEBUG_CATEGORY_AEC, "voice-io: AEC unavailable session=%llu", (unsigned long long)m_session);
        DEBUG_INFO(DEBUG_CATEGORY_AEC, "voice-io: capture AEC=%d mic=%d render=2 session=%llu",
                   aec != nullptr, m_channels, (unsigned long long)m_session);
    };
    configureAec(m_aecRequested);
    struct Marker { unsigned position; EventKind kind; bool value; };
    std::array<Marker, 64> markers{};
    size_t markerCount = 0;
    int16_t raw[1920]{}, cleaned[1920]{}, referencePcm[1920]{};
    uint8_t muteMask[960]{};
    unsigned filled = 0;
    int64_t frameTime = 0, lastReport = voice_time_us();
    uint64_t expectedSequence = 0, missingReference = 0, reportedReferenceDrops = referenceDrops, captureRoute = 0;
    int64_t expectedCaptureTime = 0;
    bool referenceAvailable = false;
    bool muted = false;
    auto applyMarker = [&](EventKind kind, bool value) {
        if (kind == EventKind::Mute) muted = value;
        else if (kind == EventKind::Ptt && m_kind == Kind::Radio) {
            if (value) radio_audio_talk_begin(m_session); else radio_audio_talk_end(m_session);
        }
    };
    auto consumeReference = [&]() {
        uint64_t epoch = m_playEpoch.load(), drops = m_referenceDropped.load();
        if (epoch != referenceEpoch || drops != referenceDrops) {
            DEBUG_DEBUG(DEBUG_CATEGORY_AEC, "voice-io: reference reset epoch=%llu->%llu dropped=%llu",
                       (unsigned long long)referenceEpoch, (unsigned long long)epoch, (unsigned long long)(drops - referenceDrops));
            historyHead = historyCount = 0;
            if (aec) speex_aec_reset(aec);
            referenceEpoch = epoch; referenceDrops = drops;
        }
        Event event{};
        for (unsigned drained = 0; drained < 32 && m_references.pop(event); ++drained) {
            if (event.sequence != referenceEpoch) continue;
            if (historyCount && event.time <= history[(historyHead + historyCount - 1) % history.size()].time) {
                DEBUG_WARN(DEBUG_CATEGORY_AEC, "voice-io: non-monotonic render clock, resetting AEC");
                historyHead = historyCount = 0;
                if (aec) speex_aec_reset(aec);
            }
            if (historyCount == history.size()) { historyHead = (historyHead + 1) % history.size(); --historyCount; }
            history[(historyHead + historyCount++) % history.size()] = event;
        }
    };
    auto alignReference = [&]() {
        if (!historyCount) return false;
        size_t index = 0;
        for (unsigned i = 0; i < 960; ++i) {
            double time = frameTime + (double)i * 1000000.0 / 48000.0;
            while (index + 1 < historyCount && history[(historyHead + index + 1) % history.size()].time <= time) ++index;
            auto& block = history[(historyHead + index) % history.size()];
            double interval = 1000000.0 / 48000.0;
            if (index + 1 < historyCount) {
                auto& next = history[(historyHead + index + 1) % history.size()];
                double measured = (double)(next.time - block.time) / block.frames;
                if (measured > interval * 0.95 && measured < interval * 1.05) interval = measured;
            }
            double position = (time - block.time) / interval;
            if (position < 0 || position >= block.frames) return false;
            unsigned sample = (unsigned)position;
            double fraction = position - sample;
            for (unsigned channel = 0; channel < 2; ++channel) {
                int first = block.pcm[2*sample+channel];
                int second = sample + 1 < block.frames ? block.pcm[2*(sample+1)+channel] : first;
                referencePcm[2*i+channel] = (int16_t)(first + (second - first) * fraction);
            }
        }
        return true;
    };
    auto deliver = [&](unsigned frames) {
        unsigned begin = 0;
        for (size_t mark = 0; mark <= markerCount; ++mark) {
            unsigned end = mark < markerCount ? markers[mark].position : frames;
            if (m_kind == Kind::Call) memset(muteMask + begin, muted, end - begin);
            else if (end > begin) radio_audio_feed_pcm(m_session, cleaned + begin * m_channels, (end - begin) * m_channels);
            if (mark < markerCount) applyMarker(markers[mark].kind, markers[mark].value);
            begin = end;
        }
        if (m_kind == Kind::Call && frames == 960) call_audio_feed_prepared_pcm(m_session, cleaned, muteMask);
        filled = 0; markerCount = 0;
    };
    bool stopping = false;
    while (m_capturing && !stopping) {
        consumeReference();
        Event event{};
        if (!m_captureEvents.pop(event)) {
            std::unique_lock lock(m_waitMutex); m_wake.wait_for(lock, std::chrono::milliseconds(5)); continue;
        }
        if (event.kind == EventKind::Stop) { stopping = true; break; }
        if (event.kind == EventKind::Aec) { configureAec(event.value); continue; }
        if (event.kind != EventKind::Pcm) {
            if (!filled) applyMarker(event.kind, event.value);
            else if (markerCount < markers.size()) markers[markerCount++] = {filled, event.kind, event.value};
            else { DEBUG_ERROR(DEBUG_CATEGORY_CALL, "voice-io: too many controls within one capture frame"); stopping = true; }
            continue;
        }
        if (voice_time_us() - event.enqueued > 100000) {
            m_captureDropped.fetch_add(event.frames); continue;
        }
        bool clockJump = expectedCaptureTime && std::abs(event.time - expectedCaptureTime) > 20000;
        if (event.sequence != expectedSequence || (captureRoute && event.route != captureRoute) || clockJump) {
            DEBUG_WARN(DEBUG_CATEGORY_CALL, "voice-io: capture discontinuity expected=%llu actual=%llu pending=%u route=%016llx->%016llx",
                       (unsigned long long)expectedSequence, (unsigned long long)event.sequence, filled,
                       (unsigned long long)captureRoute, (unsigned long long)event.route);
            if (clockJump) DEBUG_WARN(DEBUG_CATEGORY_AEC, "voice-io: capture clock jump=%lldus", (long long)(event.time - expectedCaptureTime));
            for (size_t i = 0; i < markerCount; ++i) applyMarker(markers[i].kind, markers[i].value);
            filled = 0; markerCount = 0;
            if (aec) speex_aec_reset(aec);
            if (m_kind == Kind::Radio) radio_audio_capture_discontinuity(m_session);
        }
        expectedSequence = event.sequence + event.frames;
        captureRoute = event.route;
        expectedCaptureTime = event.time + (int64_t)event.frames * 1000000 / 48000;
        for (unsigned offset = 0; offset < event.frames;) {
            if (!filled) frameTime = event.time + (int64_t)offset * 1000000 / 48000;
            unsigned take = std::min(960 - filled, event.frames - offset);
            memcpy(raw + filled * m_channels, event.pcm + offset * m_channels, take * m_channels * sizeof(int16_t));
            filled += take; offset += take;
            if (filled != 960) continue;
            memcpy(cleaned, raw, 960 * m_channels * sizeof(int16_t));
            consumeReference();
            bool available = aec && alignReference();
            if (available) {
                speex_aec_feed_playback(aec, referencePcm, 1920);
                speex_aec_process_capture(aec, raw, 960 * m_channels, cleaned);
            } else if (aec) {
                ++missingReference;
                if (referenceAvailable) speex_aec_reset(aec);
            }
            referenceAvailable = available;
            deliver(960);
        }
        int64_t now = voice_time_us();
        if (now - lastReport >= 1000000) {
            uint64_t captureDrops = m_captureDropped.exchange(0), refDrops = m_referenceDropped.load();
            uint64_t underruns = m_playbackUnderruns.exchange(0);
            if (captureDrops || refDrops != reportedReferenceDrops || missingReference || underruns)
                DEBUG_WARN(DEBUG_CATEGORY_AEC, "voice-io: session=%llu capture_drop=%llu reference_drop=%llu missing_ref=%llu output_missing=%llu",
                           (unsigned long long)m_session, (unsigned long long)captureDrops, (unsigned long long)refDrops,
                           (unsigned long long)missingReference, (unsigned long long)underruns);
            else DEBUG_DEBUG(DEBUG_CATEGORY_AEC, "voice-io: session=%llu aligned history=%zu capture_queue=%zu",
                             (unsigned long long)m_session, historyCount, m_captureEvents.size());
            missingReference = 0; reportedReferenceDrops = refDrops; lastReport = now;
        }
    }
    if (filled) {
        DEBUG_WARN(DEBUG_CATEGORY_CALL, "voice-io: capture tail=%u frames bypasses AEC; call tail discarded, radio tail preserved", filled);
        memcpy(cleaned, raw, filled * m_channels * sizeof(int16_t));
        deliver(filled);
    }
    uint64_t lostCapture = m_captureDropped.exchange(0), lostReference = m_referenceDropped.load() - reportedReferenceDrops;
    if (lostCapture || lostReference || missingReference)
        DEBUG_WARN(DEBUG_CATEGORY_AEC, "voice-io: capture stopped lost_capture=%llu lost_reference=%llu missing_reference=%llu",
                   (unsigned long long)lostCapture, (unsigned long long)lostReference, (unsigned long long)missingReference);

    speex_aec_destroy(aec);
    m_capturing = false;
}