#include "streamplayer_window.h"
#include "videoplayer_window.h"
#include "sound_manager.h"
#include "../transport/stream_bridge.h"
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QLabel>
#include <QPushButton>
#include <QSlider>
#include <QCloseEvent>
#include <QKeyEvent>
#include <QTransform>
#include <atomic>
#include <thread>
#include <mutex>
#include <deque>
#include <array>
#include <chrono>
#include <algorithm>
#include <cstring>

extern "C" {
#include "../../../lib/debug_config.h"
#include "../../../lib/opus_codec.h"
#include "../../../src/stream/stream.h"
#ifdef HAVE_FFMPEG
#include <libavcodec/avcodec.h>
#include <libswscale/swscale.h>
#endif
}

namespace {
int64_t nowUs() {
    return std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::steady_clock::now().time_since_epoch()).count();
}
std::atomic<uint64_t> nextId{0};
QString text(const char* value) { return QCoreApplication::translate("ChatGui", value); }
}

struct StreamPlayerWindow::Playback {
    struct Video { QImage image; int64_t pts; };
    struct Audio { std::array<int16_t, 960> pcm; int64_t pts; unsigned offset = 0; };
    uint64_t id = ++nextId, group = 0, source = 0, epoch = 0;
    std::atomic<bool> running{true}, audioAvailable{false};
    std::atomic<float> volume{1.0f};
    std::thread worker;
    std::mutex lock;
    std::deque<Video> videos;
    std::deque<Audio> audios;
    int64_t prefillUntil = 0, videoBase = -1, videoAt = 0, audioPts = -1, audioAt = 0;
    uint64_t shown = 0, underruns = 0;
    bool ended = false;

    int64_t clock(int64_t now) const {
        if (audioAvailable && audioPts >= 0 && now - audioAt < 200000) return audioPts + now - audioAt;
        return videoBase >= 0 ? videoBase + now - videoAt : 0;
    }
};

StreamPlayerWindow::StreamPlayerWindow(uint64_t group, uint64_t source, uint64_t epoch, const QString& name, QWidget* parent)
    : QWidget(parent), m_playback(std::make_unique<Playback>()) {
    m_playback->group = group; m_playback->source = source; m_playback->epoch = epoch;
    setWindowTitle(text("Live stream: %1").arg(name)); resize(800, 500);
    auto* layout = new QVBoxLayout(this);
    layout->addWidget(new QLabel(name, this));
    m_status = new QLabel(text("Connecting…"), this); layout->addWidget(m_status);
    m_render = new VideoRenderWidget(this); layout->addWidget(m_render, 1);
    auto* controls = new QHBoxLayout;
    auto* volume = new QSlider(Qt::Horizontal, this); volume->setRange(0, 100); volume->setValue(100);
    volume->setAccessibleName(text("Stream volume")); controls->addWidget(new QLabel(text("Volume"), this)); controls->addWidget(volume);
    auto* fullscreen = new QPushButton(text("Fullscreen"), this); controls->addWidget(fullscreen);
    auto* close = new QPushButton(text("Close player"), this); controls->addWidget(close); layout->addLayout(controls);
    connect(volume, &QSlider::valueChanged, this, [this](int value) { m_playback->volume = value / 100.0f; });
    connect(fullscreen, &QPushButton::clicked, this, [this] { if (isFullScreen()) showNormal(); else showFullScreen(); });
    connect(close, &QPushButton::clicked, this, &QWidget::close);
    connect(this, &StreamPlayerWindow::statusChanged, m_status, &QLabel::setText, Qt::QueuedConnection);
    connect(SoundManager::instance(), &SoundManager::contextAboutToReset, this, [this] {
        m_audio.close(); m_playback->audioAvailable = false;
        std::lock_guard<std::mutex> guard(m_playback->lock);
        m_playback->audios.clear(); m_playback->audioPts = -1;
        DEBUG_INFO(DEBUG_CATEGORY_STREAM, "desktop stream audio context reset id=%llu", (unsigned long long)m_playback->id);
    });
    connect(SoundManager::instance(), &SoundManager::contextRestored, this, &StreamPlayerWindow::openAudio);
    connect(SoundManager::instance(), &SoundManager::devicesChanged, this, [this] { m_audio.close(); openAudio(); });
    openAudio();
    connect(&m_timer, &QTimer::timeout, this, &StreamPlayerWindow::tick); m_timer.start(15);
    m_playback->worker = std::thread(&StreamPlayerWindow::decode, this);
}

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

/* Output принадлежит GUI и закрывается до shutdown общего miniaudio-контекста. */
void StreamPlayerWindow::openAudio() {
    if (!m_playback->running || m_audio.initialized()) return;
    ma_context* context = SoundManager::instance()->context();
    if (!context) { DEBUG_WARN(DEBUG_CATEGORY_STREAM, "desktop stream audio unavailable: no context"); return; }
    auto config = ma_device_config_init(ma_device_type_playback);
    config.sampleRate = 48000; config.playback.channels = 1; config.playback.format = ma_format_s16;
    ma_device_id device;
    if (SoundManager::deviceId(SoundManager::instance()->playbackDevice(), &device)) config.playback.pDeviceID = &device;
    bool initialized = m_audio.init(context, config, "stream", m_playback->id, [this](const void*, void* output, unsigned frames) {
        auto* pcm = static_cast<int16_t*>(output); std::fill(pcm, pcm + frames, 0);
        auto& p = *m_playback; std::lock_guard<std::mutex> guard(p.lock);
        int64_t now = nowUs();
        if (!p.prefillUntil || now < p.prefillUntil) return;
        unsigned written = 0; float volume = p.volume.load(); int64_t firstPts = -1;
        while (written < frames && !p.audios.empty()) {
            auto& packet = p.audios.front();
            if (firstPts < 0) firstPts = packet.pts + packet.offset * 1000000LL / 48000 - written * 1000000LL / 48000;
            unsigned count = std::min(frames - written, 960 - packet.offset);
            for (unsigned i = 0; i < count; i++) pcm[written + i] = static_cast<int16_t>(packet.pcm[packet.offset + i] * volume);
            written += count; packet.offset += count;
            if (packet.offset == 960) p.audios.pop_front();
        }
        if (firstPts >= 0) { p.audioPts = firstPts; p.audioAt = m_audio.callbackTimeUs(); }
        else if (p.audioPts >= 0) {
            p.audioPts += m_audio.callbackTimeUs() - p.audioAt; p.audioAt = m_audio.callbackTimeUs();
        }
        if (written < frames && p.audioPts >= 0 && !p.ended) p.underruns++;
    });
    if (!initialized || !m_audio.start()) {
        DEBUG_ERROR(DEBUG_CATEGORY_STREAM, "desktop stream audio device failed id=%llu", (unsigned long long)m_playback->id);
        m_audio.close(); m_playback->audioAvailable = false; return;
    }
    m_playback->audioAvailable = true;
    DEBUG_INFO(DEBUG_CATEGORY_STREAM, "desktop stream audio output ready id=%llu", (unsigned long long)m_playback->id);
}

/* GUI забирает последний готовый кадр по аппаратным часам, не накапливая Qt-сигналы с QImage. */
void StreamPlayerWindow::tick() {
    auto& p = *m_playback;
    if (m_audio.needsRecovery()) { m_audio.close(); p.audioAvailable = false; openAudio(); }
    QImage image; bool finished = false;
    {
        std::lock_guard<std::mutex> guard(p.lock);
        int64_t now = nowUs(), clock = p.clock(now);
        if (now >= p.prefillUntil) while (!p.videos.empty() && p.videos.front().pts <= clock) {
            image = std::move(p.videos.front().image); p.videos.pop_front();
        }
        finished = p.ended && p.videos.empty() && (p.audios.empty() || !p.audioAvailable);
    }
    if (!image.isNull()) {
        m_render->setFrame(image);
        if (!p.shown++) {
            m_status->setText(text("Live"));
            DEBUG_INFO(DEBUG_CATEGORY_STREAM, "desktop first frame id=%llu %dx%d", (unsigned long long)p.id, image.width(), image.height());
        }
        emit framePresented();
    }
    if (finished) { m_status->setText(text("Stream ended")); m_audio.close(); m_timer.stop(); }
}

/* Закрытие может происходить до выполнения open actor; session_id отменяет именно эту попытку. */
void StreamPlayerWindow::stop() {
    if (!m_playback->running.exchange(false) && !m_playback->worker.joinable()) return;
    m_timer.stop(); gui_stream_stop(m_playback->id);
    if (m_playback->worker.joinable()) m_playback->worker.join();
    m_audio.close(); m_playback->audioAvailable = false;
    DEBUG_INFO(DEBUG_CATEGORY_STREAM, "desktop stream player stopped id=%llu shown=%llu underruns=%llu",
               (unsigned long long)m_playback->id, (unsigned long long)m_playback->shown, (unsigned long long)m_playback->underruns);
}

void StreamPlayerWindow::closeEvent(QCloseEvent* event) { stop(); QWidget::closeEvent(event); }
void StreamPlayerWindow::keyPressEvent(QKeyEvent* event) {
    if (event->key() == Qt::Key_Escape) { if (isFullScreen()) showNormal(); else close(); }
    else QWidget::keyPressEvent(event);
}

/* Worker владеет codec contexts. GAP/pressure сбрасывает refs и часы до следующего ключевого кадра. */
void StreamPlayerWindow::decode() {
    auto& p = *m_playback;
#ifndef HAVE_FFMPEG
    DEBUG_ERROR(DEBUG_CATEGORY_STREAM, "desktop live decoder unavailable: FFmpeg disabled");
    emit statusChanged(text("Live video playback requires FFmpeg"));
#else
    AVCodecContext* decoder = nullptr; AVFrame* frame = av_frame_alloc(); AVPacket* packet = av_packet_alloc();
    SwsContext* converter = nullptr;
    opus_codec_decoder_t* opus = nullptr;
    bool waitKey = true, opened = false;
    int64_t deadline = nowUs() + 10000000, reportAt = nowUs(), expectedAudio = -1;
    uint64_t decoded = 0, discarded = 0;
    auto reset = [&] {
        avcodec_free_context(&decoder);
        opus_codec_decoder_destroy(opus); opus = nullptr; expectedAudio = -1; waitKey = true;
        std::lock_guard<std::mutex> guard(p.lock);
        p.videos.clear(); p.audios.clear(); p.prefillUntil = 0; p.videoBase = p.audioPts = -1;
        emit statusChanged(text("Waiting for a key frame…"));
    };
    auto fail = [&](const QString& reason) {
        DEBUG_ERROR(DEBUG_CATEGORY_STREAM, "desktop viewer failed id=%llu: %s", (unsigned long long)p.id, qPrintable(reason));
        emit statusChanged(reason);
    };
    if (!frame || !packet) fail(text("Stream decoder allocation failed"));
    else if (!gui_stream_open(p.id, p.group, p.source, p.epoch)) fail(text("Could not connect to the stream"));
    else while (p.running) {
        StreamRecord record;
        if (!gui_stream_pull(p.id, record)) {
            if (!gui_stream_ready()) { fail(text("Chat service is stopped")); break; }
            if ((!opened || waitKey) && nowUs() > deadline) { fail(text("Stream connection timed out")); break; }
            std::this_thread::sleep_for(std::chrono::milliseconds(5)); continue;
        }
        if (record.kind == StreamRecordKind::Opened) { opened = true; continue; }
        if (record.kind == StreamRecordKind::Gap) { reset(); deadline = nowUs() + 10000000; continue; }
        if (record.kind == StreamRecordKind::Closed) {
            const char* reason = record.reason == STREAM_CLOSE_SOURCE_CHANGED ? "The stream restarted. Select a source again."
                : record.reason == STREAM_CLOSE_MEMBER ? "The source is no longer a channel member"
                : record.reason == STREAM_CLOSE_SERVICE ? "Chat service is stopped"
                : record.reason == STREAM_CLOSE_GROUP ? "The channel is closed" : "Could not continue the stream";
            fail(text(reason)); break;
        }
        if (record.kind == StreamRecordKind::End) { std::lock_guard<std::mutex> guard(p.lock); p.ended = true; break; }
        if (record.pts > INT64_MAX) { fail(text("Invalid stream timestamp")); break; }
        if (record.kind == StreamRecordKind::Audio) {
            if (!p.audioAvailable) continue;
            if (!opus) opus = opus_codec_decoder_create(48000, 1);
            if (!opus) { fail(text("Stream audio decoder failed")); break; }
            if (expectedAudio >= 0 && (static_cast<int64_t>(record.pts) < expectedAudio - 10000
                || static_cast<int64_t>(record.pts) > expectedAudio + 100000)) {
                DEBUG_WARN(DEBUG_CATEGORY_STREAM, "desktop audio discontinuity id=%llu expected=%lld pts=%llu",
                           (unsigned long long)p.id, (long long)expectedAudio, (unsigned long long)record.pts);
                reset(); deadline = nowUs() + 10000000; continue;
            }
            int missing = expectedAudio < 0 ? 0 : static_cast<int>((static_cast<int64_t>(record.pts) - expectedAudio + 10000) / 20000);
            bool failed = false, pressure = false;
            for (int i = 0; i <= missing; i++) {
                Playback::Audio audio{}; audio.pts = i == missing ? static_cast<int64_t>(record.pts) : expectedAudio + i * 20000;
                int count = opus_codec_decode(opus, i == missing ? reinterpret_cast<const uint8_t*>(record.data.constData()) : nullptr,
                                             i == missing ? record.data.size() : 0, audio.pcm.data(), 960);
                if (count != 960) { fail(text("Stream audio decoder failed")); failed = true; break; }
                std::lock_guard<std::mutex> guard(p.lock);
                if (!p.prefillUntil) p.prefillUntil = nowUs() + 150000;
                if (p.audios.size() >= 25) { pressure = true; break; }
                p.audios.push_back(std::move(audio));
            }
            if (failed) break;
            if (pressure) {
                DEBUG_WARN(DEBUG_CATEGORY_STREAM, "desktop decoded audio pressure id=%llu; wait KEY", (unsigned long long)p.id);
                reset(); deadline = nowUs() + 10000000;
            } else expectedAudio = static_cast<int64_t>(record.pts) + 20000;
            continue;
        }
        if (waitKey && !(record.flags & STREAM_MEDIA_KEY)) continue;
        if (!decoder) {
            const AVCodec* codec = avcodec_find_decoder(AV_CODEC_ID_H264);
            decoder = codec ? avcodec_alloc_context3(codec) : nullptr;
            if (!decoder || avcodec_open2(decoder, codec, nullptr) < 0) { fail(text("Stream video decoder failed")); break; }
            decoder->pkt_timebase = AVRational{1, 1000000};
            waitKey = false;
            DEBUG_INFO(DEBUG_CATEGORY_STREAM, "desktop H264 decoder started id=%llu", (unsigned long long)p.id);
        }
        av_packet_unref(packet);
        if (av_new_packet(packet, record.data.size()) < 0) { fail(text("Stream decoder allocation failed")); break; }
        std::memcpy(packet->data, record.data.constData(), static_cast<size_t>(record.data.size()));
        packet->pts = packet->dts = static_cast<int64_t>(record.pts);
        int sent = avcodec_send_packet(decoder, packet);
        if (sent < 0) {
            DEBUG_WARN(DEBUG_CATEGORY_STREAM, "desktop H264 packet rejected result=%d id=%llu", sent, (unsigned long long)p.id);
            reset(); deadline = nowUs() + 10000000; continue;
        }
        int received;
        while ((received = avcodec_receive_frame(decoder, frame)) == 0) {
            decoded++;
            if (frame->width <= 0 || frame->height <= 0 || frame->width > 4096 || frame->height > 4096) {
                fail(text("Invalid stream video dimensions")); p.running = false; break;
            }
            int64_t pts = frame->best_effort_timestamp == AV_NOPTS_VALUE ? static_cast<int64_t>(record.pts) : frame->best_effort_timestamp;
            {
                std::lock_guard<std::mutex> guard(p.lock);
                if (!p.prefillUntil) p.prefillUntil = nowUs() + 150000;
                if (p.videoBase < 0) { p.videoBase = pts; p.videoAt = p.prefillUntil; }
                if (pts < p.clock(nowUs()) - 100000) { discarded++; continue; }
            }
            converter = sws_getCachedContext(converter, frame->width, frame->height, static_cast<AVPixelFormat>(frame->format),
                frame->width, frame->height, AV_PIX_FMT_RGB24, SWS_BILINEAR, nullptr, nullptr, nullptr);
            QImage image(frame->width, frame->height, QImage::Format_RGB888);
            if (!converter || image.isNull()) { fail(text("Stream decoder allocation failed")); p.running = false; break; }
            uint8_t* destination[] = {image.bits(), nullptr, nullptr, nullptr}; int strides[] = {image.bytesPerLine(), 0, 0, 0};
            if (sws_scale(converter, frame->data, frame->linesize, 0, frame->height, destination, strides) != frame->height) {
                fail(text("Stream video conversion failed")); p.running = false; break;
            }
            if (record.format.rotation) image = image.transformed(QTransform().rotate(record.format.rotation));
            std::lock_guard<std::mutex> guard(p.lock);
            if (p.videos.size() == 6) { p.videos.pop_front(); discarded++; }
            p.videos.push_back({std::move(image), pts});
        }
        if (received != AVERROR(EAGAIN) && received != AVERROR_EOF && p.running) {
            DEBUG_WARN(DEBUG_CATEGORY_STREAM, "desktop H264 decode rejected result=%d id=%llu", received, (unsigned long long)p.id);
            reset(); deadline = nowUs() + 10000000;
        }
        if (nowUs() - reportAt >= 1000000) {
            reportAt = nowUs(); std::lock_guard<std::mutex> guard(p.lock);
            DEBUG_DEBUG(DEBUG_CATEGORY_STREAM, "desktop viewer id=%llu decoded=%llu discarded=%llu videoQ=%zu audioQ=%zu underruns=%llu",
                       (unsigned long long)p.id, (unsigned long long)decoded, (unsigned long long)discarded,
                       p.videos.size(), p.audios.size(), (unsigned long long)p.underruns);
        }
    }
    avcodec_free_context(&decoder); av_frame_free(&frame); av_packet_free(&packet);
    if (converter) sws_freeContext(converter);
    opus_codec_decoder_destroy(opus);
#endif
    gui_stream_stop(p.id);
    DEBUG_INFO(DEBUG_CATEGORY_STREAM, "desktop decoder released id=%llu", (unsigned long long)p.id);
}