#include "utils_frame_queue.h"
#include "../base/logger.h"
#include <algorithm>
#include <deque>
#include <shared_mutex>

namespace av {
namespace utils {

using namespace av;

FrameQueue::FrameQueue(const FrameQueueConfig& config)
    : config_(config) {
    Logger::instance().debugf("FrameQueue created with max size: {}", config_.maxSize);
}

FrameQueue::~FrameQueue() {
    shutdown_ = true;
    notEmpty_.notify_all();
    notFull_.notify_all();
    clear();
    Logger::instance().debug("FrameQueue destroyed");
}

ErrorCode FrameQueue::enqueue(std::unique_ptr<FrameQueueItem> item) {
    if (!item) {
        return ErrorCode::INVALID_PARAMS;
    }
    
    if (shutdown_) {
        return ErrorCode::INVALID_STATE;
    }
    
    std::unique_lock<std::mutex> lock(queueMutex_);
    
    // 检查是否需要丢帧
    if (shouldDropFrame(*item)) {
        if (dropCallback_) {
            dropCallback_(*item, "Smart frame drop");
        }
        
        std::lock_guard<std::mutex> statsLock(statsMutex_);
        stats_.totalDropped++;
        
        Logger::instance().debug("Frame dropped by smart drop policy");
        return ErrorCode::SUCCESS;
    }
    
    // 等待队列有空间
    if (blocking_ && queue_.size() >= config_.maxSize) {
        if (config_.dropOnFull) {
            if (config_.dropOldest) {
                dropOldestFrame();
            } else {
                if (dropCallback_) {
                    dropCallback_(*item, "Queue full - drop newest");
                }
                
                std::lock_guard<std::mutex> statsLock(statsMutex_);
                stats_.totalDropped++;
                
                Logger::instance().debug("Frame dropped - queue full");
                return ErrorCode::SUCCESS;
            }
        } else {
            // 等待队列有空间
            if (!notFull_.wait_for(lock, std::chrono::milliseconds(config_.timeoutMs),
                                  [this] { return queue_.size() < config_.maxSize || shutdown_; })) {
                Logger::instance().warning("Enqueue timeout");
                return ErrorCode::TIMEOUT;
            }
            
            if (shutdown_) {
                return ErrorCode::INVALID_STATE;
            }
        }
    }
    
    // 添加到队列
    queue_.push_back(std::move(item));
    
    // 更新统计信息
    if (config_.enableStats) {
        updateStats(*queue_.back(), true);
    }
    
    // 通知等待的消费者
    notEmpty_.notify_one();
    
    // 回调
    if (enqueueCallback_) {
        enqueueCallback_(*queue_.back());
    }
    
    return ErrorCode::SUCCESS;
}

// 预览方法实现
const FrameQueueItem* FrameQueue::peek() const {
    std::lock_guard<std::mutex> lock(queueMutex_);
    if (queue_.empty()) {
        return nullptr;
    }
    return queue_.front().get();
}

const FrameQueueItem* FrameQueue::peek(int index) const {
    std::lock_guard<std::mutex> lock(queueMutex_);
    if (index < 0 || static_cast<size_t>(index) >= queue_.size()) {
        return nullptr;
    }
    
    // 使用deque的随机访问能力
    return queue_[index].get();
}

AVFrame* FrameQueue::peekFrame() const {
    const FrameQueueItem* item = peek();
    return item ? item->frame : nullptr;
}

std::unique_ptr<FrameQueueItem> FrameQueue::dequeue() {
    return dequeue(config_.timeoutMs);
}

std::unique_ptr<FrameQueueItem> FrameQueue::dequeue(int timeoutMs) {
    std::unique_lock<std::mutex> lock(queueMutex_);
    
    // 等待队列有数据
    if (blocking_ && queue_.empty()) {
        if (!notEmpty_.wait_for(lock, std::chrono::milliseconds(timeoutMs),
                               [this] { return !queue_.empty() || shutdown_; })) {
            return nullptr; // 超时
        }
        
        if (shutdown_ || queue_.empty()) {
            return nullptr;
        }
    }
    
    if (queue_.empty()) {
        return nullptr;
    }
    
    // 取出队列头部元素
    auto item = std::move(queue_.front());
    queue_.pop_front();
    
    // 更新统计信息
    if (config_.enableStats) {
        updateStats(*item, false);
    }
    
    // 通知等待的生产者
    notFull_.notify_one();
    
    // 回调
    if (dequeueCallback_) {
        dequeueCallback_(*item);
    }
    
    return item;
}

ErrorCode FrameQueue::enqueue(AVFrame* frame, int streamIndex) {
    if (!frame) {
        return ErrorCode::INVALID_PARAMS;
    }
    
    auto item = std::make_unique<FrameQueueItem>(frame, streamIndex);
    return enqueue(std::move(item));
}

AVFrame* FrameQueue::dequeueFrame() {
    auto item = dequeue();
    if (item) {
        AVFrame* frame = item->frame;
        item->frame = nullptr; // 转移所有权
        return frame;
    }
    return nullptr;
}

AVFrame* FrameQueue::dequeueFrame(int timeoutMs) {
    auto item = dequeue(timeoutMs);
    if (item) {
        AVFrame* frame = item->frame;
        item->frame = nullptr; // 转移所有权
        return frame;
    }
    return nullptr;
}

void FrameQueue::clear() {
    std::lock_guard<std::mutex> lock(queueMutex_);
    
    while (!queue_.empty()) {
        queue_.pop_front();
    }
    
    Logger::instance().debug("Frame queue cleared");
}

void FrameQueue::flush() {
    clear();
    notEmpty_.notify_all();
    notFull_.notify_all();
}

void FrameQueue::setMaxSize(size_t maxSize) {
    std::lock_guard<std::mutex> lock(queueMutex_);
    config_.maxSize = maxSize;
    
    // 如果当前队列大小超过新的最大值，丢弃多余的帧
    while (queue_.size() > maxSize) {
        if (config_.dropOldest) {
            dropOldestFrame();
        } else {
            break; // 不丢弃，保持当前状态
        }
    }
    
    Logger::instance().debugf("Frame queue max size set to: {}", maxSize);
}

void FrameQueue::setDropPolicy(bool dropOnFull, bool dropOldest) {
    config_.dropOnFull = dropOnFull;
    config_.dropOldest = dropOldest;
    Logger::instance().debugf("Drop policy set: dropOnFull={}, dropOldest={}", dropOnFull, dropOldest);
}

size_t FrameQueue::size() const {
    std::lock_guard<std::mutex> lock(queueMutex_);
    return queue_.size();
}

bool FrameQueue::empty() const {
    std::lock_guard<std::mutex> lock(queueMutex_);
    return queue_.empty();
}

bool FrameQueue::full() const {
    std::lock_guard<std::mutex> lock(queueMutex_);
    return queue_.size() >= config_.maxSize;
}

size_t FrameQueue::capacity() const {
    return config_.maxSize;
}

FrameQueueStats FrameQueue::getStats() const {
    std::lock_guard<std::mutex> lock(statsMutex_);
    FrameQueueStats stats = stats_;
    stats.currentSize = size();
    return stats;
}

void FrameQueue::resetStats() {
    std::lock_guard<std::mutex> lock(statsMutex_);
    stats_ = FrameQueueStats();
    Logger::instance().debug("Frame queue stats reset");
}

void FrameQueue::enableFrameDrop(bool enable, double maxLatency, int dropRatio) {
    config_.enableFrameDrop = enable;
    config_.maxLatency = maxLatency;
    config_.dropRatio = dropRatio;
    
    Logger::instance().debugf("Frame drop enabled: {}, maxLatency: {}ms, dropRatio: {}", 
                 enable, maxLatency, dropRatio);
}

void FrameQueue::setFrameDropCallback(std::function<bool(const FrameQueueItem&)> callback) {
    frameDropCallback_ = callback;
}

void FrameQueue::setBlocking(bool blocking) {
    blocking_ = blocking;
    if (!blocking) {
        notEmpty_.notify_all();
        notFull_.notify_all();
    }
    Logger::instance().debugf("Frame queue blocking mode: {}", blocking);
}

void FrameQueue::wakeup() {
    notEmpty_.notify_all();
    notFull_.notify_all();
}

// 内部方法实现
bool FrameQueue::shouldDropFrame(const FrameQueueItem& item) const {
    if (!config_.enableFrameDrop) {
        return false;
    }
    
    // 自定义丢帧回调
    if (frameDropCallback_ && frameDropCallback_(item)) {
        return true;
    }
    
    // 基于延迟的丢帧
    if (shouldDropByLatency(item)) {
        return true;
    }
    
    // 基于比例的丢帧
    if (shouldDropByRatio()) {
        return true;
    }
    
    return false;
}

void FrameQueue::dropOldestFrame() {
    if (!queue_.empty()) {
        auto& oldestItem = queue_.front();
        
        if (dropCallback_) {
            dropCallback_(*oldestItem, "Drop oldest frame");
        }
        
        queue_.pop_front();
        
        std::lock_guard<std::mutex> statsLock(statsMutex_);
        stats_.totalDropped++;
        
        Logger::instance().debug("Dropped oldest frame");
    }
}

void FrameQueue::dropNewestFrame() {
    // 这个方法在enqueue时调用，不需要实际操作队列
    // 只需要更新统计信息
}

void FrameQueue::updateStats(const FrameQueueItem& item, bool isEnqueue) {
    std::lock_guard<std::mutex> lock(statsMutex_);
    
    if (isEnqueue) {
        stats_.totalEnqueued++;
        stats_.maxSize = std::max(stats_.maxSize, queue_.size());
    } else {
        stats_.totalDequeued++;
        
        // 计算等待时间
        double waitTime = calculateWaitTime(item);
        if (waitTime > 0) {
            // 更新平均等待时间
            if (stats_.totalDequeued == 1) {
                stats_.averageWaitTime = waitTime;
            } else {
                stats_.averageWaitTime = (stats_.averageWaitTime * (stats_.totalDequeued - 1) + waitTime) / stats_.totalDequeued;
            }
            
            stats_.maxWaitTime = std::max(stats_.maxWaitTime, waitTime);
        }
    }
    
    stats_.currentSize = queue_.size();
    stats_.lastUpdateTime = std::chrono::steady_clock::now();
}

double FrameQueue::calculateWaitTime(const FrameQueueItem& item) const {
    auto now = std::chrono::steady_clock::now();
    auto duration = std::chrono::duration_cast<std::chrono::microseconds>(now - item.enqueueTime);
    return duration.count() / 1000.0; // 转换为毫秒
}

bool FrameQueue::shouldDropByLatency(const FrameQueueItem& item) const {
    double waitTime = calculateWaitTime(item);
    return waitTime > config_.maxLatency;
}

bool FrameQueue::shouldDropByRatio() const {
    if (config_.dropRatio <= 1) {
        return false;
    }
    
    uint64_t count = frameCounter_.fetch_add(1);
    return (count % config_.dropRatio) == 0;
}

// 多流帧队列实现
MultiStreamFrameQueue::MultiStreamFrameQueue(const FrameQueueConfig& config)
    : defaultConfig_(config) {
    Logger::instance().debug("MultiStreamFrameQueue created");
}

MultiStreamFrameQueue::~MultiStreamFrameQueue() {
    clear();
    Logger::instance().debug("MultiStreamFrameQueue destroyed");
}

ErrorCode MultiStreamFrameQueue::addStream(int streamIndex, const FrameQueueConfig& config) {
    std::unique_lock<std::shared_mutex> lock(streamsMutex_);
    
    if (streamQueues_.find(streamIndex) != streamQueues_.end()) {
        Logger::instance().warningf("Stream {} already exists", streamIndex);
        return ErrorCode::ALREADY_EXISTS;
    }
    
    streamQueues_[streamIndex] = std::make_unique<FrameQueue>(config);
    Logger::instance().debugf("Added stream: {}", streamIndex);
    
    return ErrorCode::SUCCESS;
}

ErrorCode MultiStreamFrameQueue::removeStream(int streamIndex) {
    std::unique_lock<std::shared_mutex> lock(streamsMutex_);
    
    auto it = streamQueues_.find(streamIndex);
    if (it == streamQueues_.end()) {
        Logger::instance().warningf("Stream {} not found", streamIndex);
        return ErrorCode::NOT_FOUND;
    }
    
    streamQueues_.erase(it);
    Logger::instance().debugf("Removed stream: {}", streamIndex);
    
    return ErrorCode::SUCCESS;
}

bool MultiStreamFrameQueue::hasStream(int streamIndex) const {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    return streamQueues_.find(streamIndex) != streamQueues_.end();
}

std::vector<int> MultiStreamFrameQueue::getStreamIndices() const {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    std::vector<int> indices;
    for (const auto& pair : streamQueues_) {
        indices.push_back(pair.first);
    }
    
    return indices;
}

ErrorCode MultiStreamFrameQueue::enqueue(AVFrame* frame, int streamIndex) {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    auto it = streamQueues_.find(streamIndex);
    if (it == streamQueues_.end()) {
        // 自动创建流队列
        lock.unlock();
        addStream(streamIndex, defaultConfig_);
        lock.lock();
        
        it = streamQueues_.find(streamIndex);
        if (it == streamQueues_.end()) {
            return ErrorCode::NOT_FOUND;
        }
    }
    
    return it->second->enqueue(frame, streamIndex);
}

AVFrame* MultiStreamFrameQueue::dequeue(int streamIndex) {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    auto it = streamQueues_.find(streamIndex);
    if (it == streamQueues_.end()) {
        return nullptr;
    }
    
    return it->second->dequeueFrame();
}

AVFrame* MultiStreamFrameQueue::dequeue(int streamIndex, int timeoutMs) {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    auto it = streamQueues_.find(streamIndex);
    if (it == streamQueues_.end()) {
        return nullptr;
    }
    
    return it->second->dequeueFrame(timeoutMs);
}

ErrorCode MultiStreamFrameQueue::enqueueToAll(AVFrame* frame) {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    ErrorCode result = ErrorCode::SUCCESS;
    for (const auto& pair : streamQueues_) {
        // 为每个流创建帧的副本
        AVFrame* frameCopy = av_frame_alloc();
        if (!frameCopy) {
            result = ErrorCode::MEMORY_ALLOC_FAILED;
            continue;
        }
        
        if (av_frame_ref(frameCopy, frame) < 0) {
            av_frame_free(&frameCopy);
            result = ErrorCode::COPY_FAILED;
            continue;
        }
        
        ErrorCode enqueueResult = pair.second->enqueue(frameCopy, pair.first);
        if (enqueueResult != ErrorCode::SUCCESS) {
            av_frame_free(&frameCopy);
            result = enqueueResult;
        }
    }
    
    return result;
}

std::vector<AVFrame*> MultiStreamFrameQueue::dequeueFromAll() {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    std::vector<AVFrame*> frames;
    for (const auto& pair : streamQueues_) {
        AVFrame* frame = pair.second->dequeueFrame();
        frames.push_back(frame); // 可能为nullptr
    }
    
    return frames;
}

void MultiStreamFrameQueue::clear() {
    std::unique_lock<std::shared_mutex> lock(streamsMutex_);
    
    for (auto& pair : streamQueues_) {
        pair.second->clear();
    }
    
    Logger::instance().debug("All stream queues cleared");
}

void MultiStreamFrameQueue::clearStream(int streamIndex) {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    auto it = streamQueues_.find(streamIndex);
    if (it != streamQueues_.end()) {
        it->second->clear();
        Logger::instance().debugf("Stream {} queue cleared", streamIndex);
    }
}

void MultiStreamFrameQueue::flush() {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    for (auto& pair : streamQueues_) {
        pair.second->flush();
    }
    
    Logger::instance().debug("All stream queues flushed");
}

void MultiStreamFrameQueue::flushStream(int streamIndex) {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    auto it = streamQueues_.find(streamIndex);
    if (it != streamQueues_.end()) {
        it->second->flush();
        Logger::instance().debugf("Stream {} queue flushed", streamIndex);
    }
}

size_t MultiStreamFrameQueue::size() const {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    size_t totalSize = 0;
    for (const auto& pair : streamQueues_) {
        totalSize += pair.second->size();
    }
    
    return totalSize;
}

size_t MultiStreamFrameQueue::size(int streamIndex) const {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    auto it = streamQueues_.find(streamIndex);
    if (it != streamQueues_.end()) {
        return it->second->size();
    }
    
    return 0;
}

bool MultiStreamFrameQueue::empty() const {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    for (const auto& pair : streamQueues_) {
        if (!pair.second->empty()) {
            return false;
        }
    }
    
    return true;
}

bool MultiStreamFrameQueue::empty(int streamIndex) const {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    auto it = streamQueues_.find(streamIndex);
    if (it != streamQueues_.end()) {
        return it->second->empty();
    }
    
    return true;
}

std::map<int, FrameQueueStats> MultiStreamFrameQueue::getAllStats() const {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    std::map<int, FrameQueueStats> allStats;
    for (const auto& pair : streamQueues_) {
        allStats[pair.first] = pair.second->getStats();
    }
    
    return allStats;
}

FrameQueueStats MultiStreamFrameQueue::getStats(int streamIndex) const {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    auto it = streamQueues_.find(streamIndex);
    if (it != streamQueues_.end()) {
        return it->second->getStats();
    }
    
    return FrameQueueStats();
}

void MultiStreamFrameQueue::resetStats() {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    for (auto& pair : streamQueues_) {
        pair.second->resetStats();
    }
    
    Logger::instance().debug("All stream queue stats reset");
}

void MultiStreamFrameQueue::resetStats(int streamIndex) {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    auto it = streamQueues_.find(streamIndex);
    if (it != streamQueues_.end()) {
        it->second->resetStats();
        Logger::instance().debugf("Stream {} queue stats reset", streamIndex);
    }
}

void MultiStreamFrameQueue::setBlocking(bool blocking) {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    for (auto& pair : streamQueues_) {
        pair.second->setBlocking(blocking);
    }
    
    Logger::instance().debugf("All stream queues blocking mode: {}", blocking);
}

void MultiStreamFrameQueue::wakeupAll() {
    std::shared_lock<std::shared_mutex> lock(streamsMutex_);
    
    for (auto& pair : streamQueues_) {
        pair.second->wakeup();
    }
}

// 工厂类实现
std::unique_ptr<FrameQueue> FrameQueueFactory::createStandardQueue(size_t maxSize) {
    FrameQueueConfig config;
    config.maxSize = maxSize;
    config.dropOnFull = true;
    config.dropOldest = true;
    config.timeoutMs = 1000;
    config.enableStats = true;
    
    return std::make_unique<FrameQueue>(config);
}

std::unique_ptr<FrameQueue> FrameQueueFactory::createLowLatencyQueue(size_t maxSize) {
    FrameQueueConfig config;
    config.maxSize = maxSize;
    config.dropOnFull = true;
    config.dropOldest = true;
    config.timeoutMs = 100;
    config.enableStats = true;
    config.enableFrameDrop = true;
    config.maxLatency = 50.0;
    config.dropRatio = 3;
    
    return std::make_unique<FrameQueue>(config);
}

std::unique_ptr<FrameQueue> FrameQueueFactory::createHighCapacityQueue(size_t maxSize) {
    FrameQueueConfig config;
    config.maxSize = maxSize;
    config.dropOnFull = false; // 不丢帧，等待
    config.dropOldest = true;
    config.timeoutMs = 5000;
    config.enableStats = true;
    config.enableFrameDrop = false;
    
    return std::make_unique<FrameQueue>(config);
}

std::unique_ptr<FrameQueue> FrameQueueFactory::createRealtimeQueue(size_t maxSize, double maxLatency) {
    FrameQueueConfig config;
    config.maxSize = maxSize;
    config.dropOnFull = true;
    config.dropOldest = true;
    config.timeoutMs = 50;
    config.enableStats = true;
    config.enableFrameDrop = true;
    config.maxLatency = maxLatency;
    config.dropRatio = 2;
    
    return std::make_unique<FrameQueue>(config);
}

std::unique_ptr<MultiStreamFrameQueue> FrameQueueFactory::createMultiStreamQueue(const FrameQueueConfig& config) {
    return std::make_unique<MultiStreamFrameQueue>(config);
}

} // namespace utils
} // namespace av