/**
 * @file webcam.cpp
 * @brief Real-time face detection using webcam
 */

#include <chrono>
#include <iostream>

#include <opencv2/highgui.hpp>
#include <opencv2/imgproc.hpp>
#include <opencv2/videoio.hpp>
#include <uniface/uniface.hpp>

int main(int argc, char** argv) {
    if (argc < 2) {
        std::cout << "Usage: " << argv[0] << " <model_path> [camera_id]" << std::endl;
        std::cout << "  camera_id: Camera device ID (default: 0)" << std::endl;
        return 1;
    }

    const std::string model_path = argv[1];
    const int camera_id = (argc >= 3) ? std::atoi(argv[2]) : 0;

    try {
        std::cout << "Loading model: " << model_path << std::endl;
        uniface::RetinaFace detector(model_path);
        std::cout << "Model loaded successfully!" << std::endl;

        cv::VideoCapture cap(camera_id);
        if (!cap.isOpened()) {
            std::cerr << "Error: Cannot open camera " << camera_id << std::endl;
            return 1;
        }

        const int frame_width = static_cast<int>(cap.get(cv::CAP_PROP_FRAME_WIDTH));
        const int frame_height = static_cast<int>(cap.get(cv::CAP_PROP_FRAME_HEIGHT));
        std::cout << "Camera opened: " << frame_width << "x" << frame_height << std::endl;
        std::cout << "Press 'q' to quit, 's' to save screenshot" << std::endl;

        cv::Mat frame;
        int frame_count = 0;
        double total_time = 0.0;

        while (true) {
            cap >> frame;
            if (frame.empty()) {
                std::cerr << "Error: Empty frame captured" << std::endl;
                break;
            }

            const auto start = std::chrono::high_resolution_clock::now();
            const auto faces = detector.detect(frame);
            const auto end = std::chrono::high_resolution_clock::now();

            const std::chrono::duration<double, std::milli> elapsed = end - start;
            const double inference_time = elapsed.count();

            ++frame_count;
            total_time += inference_time;
            const double avg_time = total_time / static_cast<double>(frame_count);
            const double fps = 1000.0 / avg_time;

            // Draw results
            for (const auto& face : faces) {
                cv::rectangle(frame, face.bbox, cv::Scalar(0, 255, 0), 2);

                for (size_t i = 0; i < face.landmarks.size(); ++i) {
                    cv::Scalar color;
                    if (i < 2) {
                        color = cv::Scalar(255, 0, 0);  // Eyes - Blue
                    } else if (i == 2) {
                        color = cv::Scalar(0, 255, 0);  // Nose - Green
                    } else {
                        color = cv::Scalar(0, 0, 255);  // Mouth - Red
                    }
                    cv::circle(frame, face.landmarks[i], 3, color, -1);
                }

                // Draw confidence
                const std::string conf_text = cv::format("%.2f", face.confidence);
                const cv::Point text_org(
                    static_cast<int>(face.bbox.x), static_cast<int>(face.bbox.y) - 5
                );
                cv::putText(
                    frame,
                    conf_text,
                    text_org,
                    cv::FONT_HERSHEY_SIMPLEX,
                    0.5,
                    cv::Scalar(0, 255, 0),
                    1
                );
            }

            // Draw FPS info
            const std::string info_text = cv::format(
                "FPS: %.1f | Faces: %zu | Time: %.1fms", fps, faces.size(), inference_time
            );
            cv::putText(
                frame,
                info_text,
                cv::Point(10, 30),
                cv::FONT_HERSHEY_SIMPLEX,
                0.7,
                cv::Scalar(0, 255, 0),
                2
            );

            cv::imshow("Uniface - Face Detection", frame);

            const char key = static_cast<char>(cv::waitKey(1));
            if (key == 'q' || key == 27) {
                break;
            } else if (key == 's') {
                const std::string filename = cv::format("screenshot_%d.jpg", frame_count);
                cv::imwrite(filename, frame);
                std::cout << "Screenshot saved: " << filename << std::endl;
            }
        }

        cap.release();
        cv::destroyAllWindows();

        std::cout << "\n=== Statistics ===" << std::endl;
        std::cout << "Total frames: " << frame_count << std::endl;
        std::cout << "Average inference time: " << (total_time / frame_count) << " ms" << std::endl;

    } catch (const cv::Exception& e) {
        std::cerr << "OpenCV Error: " << e.what() << std::endl;
        return 1;
    } catch (const std::exception& e) {
        std::cerr << "Error: " << e.what() << std::endl;
        return 1;
    }

    return 0;
}