/*
 * VizionStreamer - Streaming Engine Implementation
 * Copyright (c) 2025 Maik Jurischka
 *
 * Licensed under CC BY-NC-SA 4.0
 * https://creativecommons.org/licenses/by-nc-sa/4.0/
 */

#include "StreamingEngine.h"
#include <iostream>
#include <chrono>
#include <utility>

StreamingEngine::StreamingEngine(std::shared_ptr<VxCamera> camera)
    : camera_(std::move(camera)), running_(false), currentFormat_(), bufferSize_(0) {
    gstPipeline_ = std::make_unique<GStreamerPipeline>("");
}

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

void StreamingEngine::setPipelineDescription(const std::string& pipeline) {
    std::lock_guard<std::mutex> lock(mutex_);
    if (!running_) {
        gstPipeline_->setPipelineDescription(pipeline);
    }
}

bool StreamingEngine::start(const std::string& gstPipeline) {
    std::lock_guard<std::mutex> lock(mutex_);

    if (running_) {
        std::cerr << "Streaming engine already running" << std::endl;
        return false;
    }

    // Set pipeline description
    gstPipeline_->setPipelineDescription(gstPipeline);

    // Start camera streaming
    if (VxStartStreaming(camera_) != 0) {
        std::cerr << "Failed to start camera streaming" << std::endl;
        return false;
    }

    // Get current format to allocate buffer
    std::vector<VxFormat> fmtList;
    if (VxGetFormatList(camera_, fmtList) != 0 || fmtList.empty()) {
        std::cerr << "Failed to get format list" << std::endl;
        VxStopStreaming(camera_);
        return false;
    }
    currentFormat_ = fmtList[0];

    // Allocate buffer (assume worst case: uncompressed)
    const size_t calculatedBufferSize = currentFormat_.width * currentFormat_.height * 4;
    bufferSize_ = calculatedBufferSize;
    buffer_ = std::make_unique<uint8_t[]>(bufferSize_);

    // Start GStreamer pipeline
    if (!gstPipeline_->start()) {
        std::cerr << "Failed to start GStreamer pipeline" << std::endl;
        VxStopStreaming(camera_);
        return false;
    }

    // Start acquisition thread
    running_ = true;
    acquisitionThread_ = std::make_unique<std::thread>(&StreamingEngine::acquisitionLoop, this);

    std::cout << "Streaming engine started" << std::endl;
    return true;
}

void StreamingEngine::stop() {
    if (!running_) {
        return;
    }

    running_ = false;

    // Wait for acquisition thread to finish
    if (acquisitionThread_ && acquisitionThread_->joinable()) {
        acquisitionThread_->join();
    }

    // Stop GStreamer pipeline
    gstPipeline_->stop();

    // Stop camera streaming
    VxStopStreaming(camera_);

    std::cout << "Streaming engine stopped" << std::endl;
}

void StreamingEngine::setFormat(const VxFormat& format) {
    std::lock_guard<std::mutex> lock(mutex_);
    if (!running_) {
        currentFormat_ = format;
        if (VxSetFormat(camera_, format) != 0) {
            std::cerr << "Failed to set format" << std::endl;
        }
    }
}

void StreamingEngine::acquisitionLoop() {
    uint64_t frameCount = 0;
    auto lastStatsTime = std::chrono::steady_clock::now();
    uint64_t framesInLastSecond = 0;

    std::cout << "Acquisition loop started" << std::endl;

    while (running_) {
        int dataSize = 0;
        const VX_CAPTURE_RESULT result = VxGetImage(camera_, buffer_.get(), &dataSize, 1000);

        if (result == VX_CAPTURE_RESULT::VX_SUCCESS && dataSize > 0) {
            // Push frame to GStreamer pipeline
            std::string formatStr;
            switch (currentFormat_.format) {
                case VX_IMAGE_FORMAT::YUY2: formatStr = "YUY2"; break;
                case VX_IMAGE_FORMAT::UYVY: formatStr = "UYVY"; break;
                case VX_IMAGE_FORMAT::MJPG: formatStr = "MJPG"; break;
                case VX_IMAGE_FORMAT::BGR: formatStr = "BGR"; break;
                case VX_IMAGE_FORMAT::RGB: formatStr = "RGB"; break;
                default: formatStr = "UNKNOWN"; break;
            }

            if (!gstPipeline_->pushBuffer(buffer_.get(), dataSize,
                                         currentFormat_.width, currentFormat_.height,
                                         formatStr)) {
                std::cerr << "Failed to push frame to GStreamer pipeline" << std::endl;
            }

            frameCount++;
            framesInLastSecond++;

            // Print statistics every second
            const auto now = std::chrono::steady_clock::now();
            const auto elapsed = std::chrono::duration_cast<std::chrono::seconds>(now - lastStatsTime);
            if (elapsed.count() >= 1) {
                std::cout << "FPS: " << framesInLastSecond
                         << " | Total frames: " << frameCount
                         << " | Frame size: " << dataSize << " bytes" << std::endl;
                framesInLastSecond = 0;
                lastStatsTime = now;
            }
        } else if (result == VX_CAPTURE_RESULT::VX_TIMEOUT) {
            // Timeout is normal, just continue
            continue;
        } else {
            std::cerr << "Failed to capture frame: " << static_cast<int>(result) << std::endl;
            // Don't break on error, just continue trying
            std::this_thread::sleep_for(std::chrono::milliseconds(10));
        }
    }

    std::cout << "Acquisition loop stopped. Total frames captured: " << frameCount << std::endl;
}