#include "OpenCVAlgorithm.h"
#include "Core/Logger.h"
#include <opencv2/objdetect.hpp>
#include <opencv2/opencv.hpp>

class OpenCVAlgorithmPrivate {
public:
    cv::HOGDescriptor hog;
    std::array<uint8_t, OpenCVAlgorithm::DetectImageWidth * OpenCVAlgorithm::DetectImageHeight * 3> bgrBuffer;

    cv::Mat convertNV21ToMat(int width, int height, const uint8_t *nv21_data) {
        cv::Mat yuv(height + height / 2, width, CV_8UC1, (void *)nv21_data);
        cv::Mat bgr(height, width, CV_8UC3, bgrBuffer.data());
        cv::cvtColor(yuv, bgr, cv::COLOR_YUV2BGR_NV21);
        return bgr;
    }
};

OpenCVAlgorithm::OpenCVAlgorithm() : m_d{new OpenCVAlgorithmPrivate()} {
    m_d->hog.setSVMDetector(cv::HOGDescriptor::getDefaultPeopleDetector());
}

void OpenCVAlgorithm::detect(const uint8_t *imageData, int width, int height) {
    using namespace std::chrono;
    auto begin = system_clock::now();
    auto frame = m_d->convertNV21ToMat(width, height, imageData);
    auto elapsed = duration_cast<milliseconds>(system_clock::now() - begin);
    LOG(info) << "convert image(" << width << "x" << height << ") elapsed: " << elapsed;
    std::vector<cv::Rect> detectedPeople;
    begin = system_clock::now();
    m_d->hog.detectMultiScale(frame, detectedPeople, 0, cv::Size(16, 16), // 增大步长，减少窗口数量
                              cv::Size(32, 32), 1.05,                     // 增大缩放因子，减少金字塔层数
                              2);
    elapsed = duration_cast<milliseconds>(system_clock::now() - begin);
    LOG(info) << "people number: " << detectedPeople.size() << ", elapsed: " << elapsed;
}

OpenCVAlgorithm::~OpenCVAlgorithm() {
    if (m_d != nullptr) {
        delete m_d;
    }
}