package org.jdetect;

import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.awt.image.DataBufferInt;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;
import javax.swing.filechooser.FileNameExtensionFilter;
import org.opencv.core.*;
import org.opencv.core.Point;
import org.opencv.dnn.Dnn;
import org.opencv.dnn.Net;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import org.opencv.videoio.VideoCapture;
import org.opencv.videoio.Videoio;

public class CameraApp extends JFrame {
    static {
        // Load OpenCV native library
        nu.pattern.OpenCV.loadLocally();
    }

    // GUI Components
    private JLabel videoLabel;
    private JComboBox<CameraInfo> cameraSelect;
    private JCheckBox detectionCheckbox;
    private JLabel statusLabel;

    // Camera and detection attributes
    private int cameraIndex = 1;
    private VideoCapture cap;
    private Timer timer;
    private final List<CameraInfo> availableCameras;
    private DetectionThread detectionThread;
    private Net net;
    private List<String> classes;
    private List<String> outputLayers;
    private boolean detectionEnabled = true;
    private boolean modelLoaded = false;
    private int frameCount = 0;
    private long lastFpsUpdate = System.currentTimeMillis();

    public CameraApp() {
        setTitle("Advanced Object Detection Camera Viewer");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 1000, 800);

        // Initialize attributes
        availableCameras = new ArrayList<>();

        // Initialize UI
        initUI();

        // Load YOLO after UI is ready
        SwingUtilities.invokeLater(this::loadYolo);
    }

    private void initUI() {
        Container contentPane = getContentPane();
        contentPane.setLayout(new BorderLayout());

        // Main panel
        JPanel mainPanel = new JPanel(new BorderLayout());

        // Video display
        videoLabel = new JLabel();
        videoLabel.setHorizontalAlignment(SwingConstants.CENTER);
        videoLabel.setVerticalAlignment(SwingConstants.CENTER);
        videoLabel.setPreferredSize(new Dimension(640, 480));
        videoLabel.setBorder(BorderFactory.createLoweredBevelBorder());
        mainPanel.add(videoLabel, BorderLayout.CENTER);

        // Controls panel
        JPanel controlsPanel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(5, 5, 5, 5);
        gbc.fill = GridBagConstraints.HORIZONTAL;

        // Camera selection
        gbc.gridx = 0; gbc.gridy = 0;
        controlsPanel.add(new JLabel("Camera:"), gbc);
        gbc.gridx = 1;
        cameraSelect = new JComboBox<>();
        cameraSelect.addActionListener(_ -> changeCamera());
        controlsPanel.add(cameraSelect, gbc);

        // Detection checkbox
        gbc.gridx = 0; gbc.gridy = 1; gbc.gridwidth = 2;
        detectionCheckbox = new JCheckBox("Enable Object Detection", true);
        detectionCheckbox.addActionListener(_ -> toggleDetection());
        controlsPanel.add(detectionCheckbox, gbc);

        // Buttons
        gbc.gridwidth = 1;
        gbc.gridx = 0; gbc.gridy = 2;
        JButton startButton = new JButton("Start Camera");
        startButton.addActionListener(_ -> startCamera());
        controlsPanel.add(startButton, gbc);

        gbc.gridx = 1;
        JButton stopButton = new JButton("Stop Camera");
        stopButton.addActionListener(_ -> stopCamera());
        controlsPanel.add(stopButton, gbc);

        gbc.gridx = 0; gbc.gridy = 3; gbc.gridwidth = 2;
        JButton snapshotButton = new JButton("Take Snapshot");
        snapshotButton.addActionListener(_ -> takeSnapshot());
        controlsPanel.add(snapshotButton, gbc);

        mainPanel.add(controlsPanel, BorderLayout.SOUTH);
        contentPane.add(mainPanel, BorderLayout.CENTER);

        // Status bar
        statusLabel = new JLabel("Initializing...");
        statusLabel.setBorder(BorderFactory.createLoweredBevelBorder());
        contentPane.add(statusLabel, BorderLayout.SOUTH);

        // Set up timer
        timer = new Timer(30, _ -> updateFrame());

        // Detect cameras after UI is ready
        SwingUtilities.invokeLater(this::detectCameras);
    }

    private void toggleDetection() {
        detectionEnabled = detectionCheckbox.isSelected();
        statusLabel.setText("Detection " + (detectionEnabled ? "enabled" : "disabled"));
    }

    private void detectCameras() {
        cameraSelect.removeAllItems();
        availableCameras.clear();

        // Check for available cameras
        int maxCamerasToCheck = 10;

        for (int i = 0; i < maxCamerasToCheck; i++) {
            try {
                VideoCapture testCap = new VideoCapture(i);
                if (testCap.isOpened()) {
                    // Get camera properties
                    int width = (int) testCap.get(Videoio.CAP_PROP_FRAME_WIDTH);
                    int height = (int) testCap.get(Videoio.CAP_PROP_FRAME_HEIGHT);
                    double fps = testCap.get(Videoio.CAP_PROP_FPS);

                    String name = String.format("Camera %d (%dx%d)", i, width, height);
                    if (fps > 0) {
                        name += String.format(" @ %.1fFPS", fps);
                    }

                    CameraInfo cameraInfo = new CameraInfo(i, name);
                    availableCameras.add(cameraInfo);
                    cameraSelect.addItem(cameraInfo);
                    testCap.release();
                }
            } catch (Exception e) {
                // Ignore errors for non-existent cameras
            }
        }

        if (availableCameras.isEmpty()) {
            statusLabel.setText("No cameras detected");
            JOptionPane.showMessageDialog(this, "No cameras detected!", "Warning", JOptionPane.WARNING_MESSAGE);
        } else {
            statusLabel.setText(String.format("Found %d cameras", availableCameras.size()));
        }
    }

    private void changeCamera() {
        CameraInfo selected = (CameraInfo) cameraSelect.getSelectedItem();
        if (selected != null) {
            cameraIndex = selected.index();
            if (cap != null && cap.isOpened()) {
                stopCamera();
                startCamera();
            }
        }
    }

    private void startCamera() {
        if (cap != null) {
            stopCamera();
        }

        if (availableCameras.isEmpty()) {
            JOptionPane.showMessageDialog(this, "No cameras available", "Error", JOptionPane.ERROR_MESSAGE);
            return;
        }

        try {
            CameraInfo selected = (CameraInfo) cameraSelect.getSelectedItem();
            if (selected != null) {
                cameraIndex = selected.index();
            }

            cap = new VideoCapture(cameraIndex);
            if (!cap.isOpened()) {
                JOptionPane.showMessageDialog(this,
                        String.format("Cannot open camera %d", cameraIndex),
                        "Error", JOptionPane.ERROR_MESSAGE);
                statusLabel.setText(String.format("Failed to open camera %d", cameraIndex));
                return;
            }

            // Set camera properties
            cap.set(Videoio.CAP_PROP_FRAME_WIDTH, 1280);
            cap.set(Videoio.CAP_PROP_FRAME_HEIGHT, 720);
            cap.set(Videoio.CAP_PROP_FPS, 60);
            cap.set(Videoio.CAP_PROP_AUTOFOCUS, 0);

            timer.start();
            statusLabel.setText(String.format("Camera %d started", cameraIndex));

        } catch (Exception e) {
            JOptionPane.showMessageDialog(this,
                    String.format("Error starting camera: %s", e.getMessage()),
                    "Error", JOptionPane.ERROR_MESSAGE);
            statusLabel.setText(String.format("Error: %s", e.getMessage()));
        }
    }

    private void stopCamera() {
        if (cap != null) {
            timer.stop();
            cap.release();
            cap = null;
            videoLabel.setIcon(null);
            statusLabel.setText("Camera stopped");
        }

        if (detectionThread != null) {
            detectionThread.stop();
            detectionThread = null;
        }
    }

    private void loadYolo() {
        String weightsUrl = "https://github.com/AlexeyAB/darknet/releases/download/darknet_yolo_v4_pre/yolov4-tiny.weights";
        String configUrl = "https://raw.githubusercontent.com/AlexeyAB/darknet/master/cfg/yolov4-tiny.cfg";
        String classesUrl = "https://raw.githubusercontent.com/AlexeyAB/darknet/master/data/coco.names";

        String weightsPath = "./yolov4-tiny.weights";
        String configPath = "./yolov4-tiny.cfg";
        String classesPath = "./coco.names";

        boolean filesValid = true;
        try {
            Path path = Paths.get(weightsPath);
            if (!Files.exists(path) || Files.size(path) < 10000000) {
                filesValid = false;
            }
            final Path path1 = Paths.get(configPath);
            if (!Files.exists(path1) || Files.size(path1) < 10000) {
                filesValid = false;
            }
            final Path path2 = Paths.get(classesPath);
            if (!Files.exists(path2) || Files.size(path2) < 1000) {
                filesValid = false;
            }
        } catch (IOException e) {
            filesValid = false;
        }
        if (!filesValid) {
            int reply = JOptionPane.showConfirmDialog(this,
                    "YOLO model files need to be downloaded (~25MB). Continue?",
                    "Download Files", JOptionPane.YES_NO_OPTION);

            if (reply == JOptionPane.NO_OPTION) {
                statusLabel.setText("Object detection disabled - model not loaded");
                return;
            }

            downloadYoloFiles(weightsUrl, configUrl, classesUrl);
        }

        try {
            net = Dnn.readNetFromDarknet(configPath, weightsPath);

            // Try to use GPU if available (OpenCV Java doesn't have CUDA detection, so we'll use CPU)
            net.setPreferableBackend(Dnn.DNN_BACKEND_OPENCV);
            net.setPreferableTarget(Dnn.DNN_TARGET_CPU);
            statusLabel.setText("Using CPU backend");

            // Load class names
            classes = new ArrayList<>();
            try (BufferedReader br = new BufferedReader(new FileReader(classesPath))) {
                String line;
                while ((line = br.readLine()) != null) {
                    classes.add(line.trim());
                }
            }

            // Get output layer names
            List<String> layerNames = net.getLayerNames();
            MatOfInt unconnectedOutLayers = new MatOfInt();
            net.getUnconnectedOutLayers();
            int[] indices = unconnectedOutLayers.toArray();

            outputLayers = new ArrayList<>();
            for (int idx : indices) {
                outputLayers.add(layerNames.get(idx - 1));
            }

            modelLoaded = true;
            statusLabel.setText("YOLOv4 model loaded successfully");

        } catch (Exception e) {
            modelLoaded = false;
            statusLabel.setText(String.format("Error loading model: %s", e.getMessage()));
            JOptionPane.showMessageDialog(this, "Failed to load object detection model", "Error", JOptionPane.WARNING_MESSAGE);
        }
    }

    private void downloadYoloFiles(String weightsUrl, String configUrl, String classesUrl) {
        String[][] files = {
                {"yolov4-tiny.weights", weightsUrl},
                {"yolov4-tiny.cfg", configUrl},
                {"coco.names", classesUrl}
        };

        DownloadProgressBar progressDialog = new DownloadProgressBar(this);
        progressDialog.setVisible(true);

        try {
            for (String[] fileInfo : files) {
                String fileName = fileInfo[0];
                String url = fileInfo[1];

                final Path path = Paths.get(fileName);

                if (Files.exists(path)) {
                    try {
                        long fileSize = Files.size(path);
                        if ((fileName.equals("yolov4-tiny.weights") && fileSize < 10000000) ||
                                (fileName.equals("yolov4-tiny.cfg") && fileSize < 10000) ||
                                (fileName.equals("coco.names") && fileSize < 1000)) {
                            throw new RuntimeException("Incomplete file");
                        }
                        continue;
                    } catch (Exception e) {
                        System.out.printf("Existing file %s is invalid: %s%n", fileName, e.getMessage());
                    }
                }

                System.out.printf("Downloading %s...%n", fileName);
                progressDialog.updateLabel(fileName);

                try {
                    downloadFile(url, fileName, progressDialog);
                    System.out.printf("Downloaded %s%n", fileName);
                } catch (Exception e) {
                    System.out.printf("Error downloading %s: %s%n", fileName, e.getMessage());
                    JOptionPane.showMessageDialog(this, String.format("Failed to download %s", fileName), "Error", JOptionPane.ERROR_MESSAGE);
                    progressDialog.setVisible(false);
                    return;
                }
            }
        } finally {
            progressDialog.setVisible(false);
        }
    }

    private void downloadFile(String urlString, String fileName, DownloadProgressBar progressDialog) throws IOException {
        URL url = new URL(urlString);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestProperty("User-Agent", "Mozilla/5.0");

        // Handle redirects
        int status = connection.getResponseCode();
        if (status == HttpURLConnection.HTTP_MOVED_TEMP ||
                status == HttpURLConnection.HTTP_MOVED_PERM ||
                status == HttpURLConnection.HTTP_SEE_OTHER) {
            String newUrl = connection.getHeaderField("Location");
            connection = (HttpURLConnection) new URL(newUrl).openConnection();
        }

        int totalSize = connection.getContentLength();

        try (InputStream in = new BufferedInputStream(connection.getInputStream());
             FileOutputStream out = new FileOutputStream(fileName)) {

            byte[] buffer = new byte[8192];
            int bytesRead;
            int totalBytesRead = 0;
            long lastUpdate = 0;

            while ((bytesRead = in.read(buffer)) != -1) {
                out.write(buffer, 0, bytesRead);
                totalBytesRead += bytesRead;

                long currentTime = System.currentTimeMillis();
                if (currentTime - lastUpdate > 100) {
                    progressDialog.updateProgress(totalBytesRead, totalSize);
                    lastUpdate = currentTime;
                }
            }
        }
    }

    private void updateFrame() {
        if (cap == null || !cap.isOpened()) {
            return;
        }


        Mat frame = new Mat();
        boolean ret = cap.read(frame);
        if (!ret || frame.empty()) {
            statusLabel.setText("Failed to capture frame");
            return;
        }

        // Remove this conversion - we'll do it in matToBufferedImage
        // Mat rgbFrame = new Mat();
        // Imgproc.cvtColor(frame, rgbFrame, Imgproc.COLOR_BGR2RGB);

        if (detectionEnabled && modelLoaded) {
            if (detectionThread == null || !detectionThread.isRunning()) {
                detectionThread = new DetectionThread(net, classes, outputLayers, frame.clone(), this);
                detectionThread.execute();
            } else {
                displayFrame(frame);
            }
        } else {
            displayFrame(frame);
        }
    }

    public void displayFrame(Mat frame) {
        SwingUtilities.invokeLater(() -> {
            BufferedImage bufferedImage = matToBufferedImage(frame);
            ImageIcon imageIcon = new ImageIcon(bufferedImage);

            // Scale to fit label
            Dimension labelSize = videoLabel.getSize();
            if (labelSize.width > 0 && labelSize.height > 0) {
                Image scaledImage = imageIcon.getImage().getScaledInstance(
                        labelSize.width, labelSize.height, Image.SCALE_SMOOTH);
                imageIcon = new ImageIcon(scaledImage);
            }

            videoLabel.setIcon(imageIcon);
        });
    }

    private BufferedImage matToBufferedImage(Mat mat) {
        // Convert from BGR to RGB
        Mat rgbMat = new Mat();
        if (mat.channels() > 1) {
            Imgproc.cvtColor(mat, rgbMat, Imgproc.COLOR_BGR2RGB);
        } else {
            mat.copyTo(rgbMat);
        }

        int type;
        if (rgbMat.channels() == 1) {
            type = BufferedImage.TYPE_BYTE_GRAY;
        } else {
            type = BufferedImage.TYPE_INT_RGB;
        }

        BufferedImage image = new BufferedImage(rgbMat.cols(), rgbMat.rows(), type);

        if (type == BufferedImage.TYPE_BYTE_GRAY) {
            // Handle grayscale images
            byte[] buffer = new byte[rgbMat.channels() * rgbMat.cols() * rgbMat.rows()];
            rgbMat.get(0, 0, buffer);
            byte[] targetPixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
            System.arraycopy(buffer, 0, targetPixels, 0, buffer.length);
        } else {
            // Handle color images
            byte[] buffer = new byte[rgbMat.channels() * rgbMat.cols() * rgbMat.rows()];
            rgbMat.get(0, 0, buffer);
            int[] targetPixels = ((DataBufferInt) image.getRaster().getDataBuffer()).getData();

            // Convert from byte array to int array
            for (int i = 0; i < targetPixels.length; i++) {
                int r = buffer[i * 3] & 0xFF;
                int g = buffer[i * 3 + 1] & 0xFF;
                int b = buffer[i * 3 + 2] & 0xFF;
                targetPixels[i] = (r << 16) | (g << 8) | b;
            }
        }

        return image;
    }

    private void takeSnapshot() {
        if (cap == null || !cap.isOpened()) {
            JOptionPane.showMessageDialog(this, "No active camera to take snapshot from", "Warning", JOptionPane.WARNING_MESSAGE);
            return;
        }

        Mat frame = new Mat();
        boolean ret = cap.read(frame);
        if (!ret || frame.empty()) {
            JOptionPane.showMessageDialog(this, "Failed to capture frame", "Warning", JOptionPane.WARNING_MESSAGE);
            return;
        }

        JFileChooser fileChooser = new JFileChooser();
        fileChooser.setDialogTitle("Save Snapshot");
        FileNameExtensionFilter filter = new FileNameExtensionFilter("Image files", "jpg", "jpeg", "png");
        fileChooser.setFileFilter(filter);

        int userSelection = fileChooser.showSaveDialog(this);
        if (userSelection == JFileChooser.APPROVE_OPTION) {
            File fileToSave = fileChooser.getSelectedFile();
            String fileName = fileToSave.getAbsolutePath();

            // Add extension if not present
            if (!fileName.toLowerCase().endsWith(".jpg") &&
                    !fileName.toLowerCase().endsWith(".jpeg") &&
                    !fileName.toLowerCase().endsWith(".png")) {
                fileName += ".jpg";
            }

            // Convert BGR to RGB for saving
            Mat rgbFrame = new Mat();
            Imgproc.cvtColor(frame, rgbFrame, Imgproc.COLOR_BGR2RGB);

            boolean success = Imgcodecs.imwrite(fileName, rgbFrame);
            if (success) {
                statusLabel.setText(String.format("Snapshot saved to %s", fileName));
            } else {
                JOptionPane.showMessageDialog(this, "Failed to save snapshot", "Error", JOptionPane.ERROR_MESSAGE);
            }
        }
    }

    @Override
    protected void processWindowEvent(WindowEvent e) {
        if (e.getID() == WindowEvent.WINDOW_CLOSING) {
            stopCamera();
            if (detectionThread != null) {
                detectionThread.stop();
            }
        }
        super.processWindowEvent(e);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            try {
                UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
            } catch (Exception e) {
                e.printStackTrace();
            }

            CameraApp window = new CameraApp();
            window.setVisible(true);
        });
    }
}

record CameraInfo(int index, String name) {

    @Override
    public String toString() {
        return name;
    }
}

class DownloadProgressBar extends JDialog {
    private final JLabel label;
    private final JProgressBar progress;

    public DownloadProgressBar(JFrame parent) {
        super(parent, "Downloading YOLO Files", true);
        setSize(400, 100);
        setLocationRelativeTo(parent);
        setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);

        JPanel panel = new JPanel(new BorderLayout());

        label = new JLabel("Downloading YOLO files...");
        panel.add(label, BorderLayout.NORTH);

        progress = new JProgressBar(0, 100);
        panel.add(progress, BorderLayout.CENTER);

        JButton cancelButton = new JButton("Cancel");
        cancelButton.addActionListener(_ -> setVisible(false));
        panel.add(cancelButton, BorderLayout.SOUTH);

        add(panel);
    }

    public void updateProgress(int current, int total) {
        if (total > 0) {
            int percentage = (int) ((current * 100L) / total);
            progress.setValue(percentage);
        }
    }

    public void updateLabel(String filename) {
        label.setText(String.format("Downloading %s...", filename));
    }
}

class DetectionThread extends SwingWorker<Mat, Void> {
    private final Net net;
    private final List<String> classes;
    private final List<String> outputLayers;
    private final Mat frame;
    private final CameraApp parent;
    private volatile boolean running = true;

    public DetectionThread(Net net, List<String> classes, List<String> outputLayers, Mat frame, CameraApp parent) {
        this.net = net;
        this.classes = classes;
        this.outputLayers = outputLayers;
        this.frame = frame.clone();
        this.parent = parent;
    }

    @Override
    protected Mat doInBackground() {
        if (!running || net == null || classes == null) {
            return frame;
        }

        Size frameSize = frame.size();
        int height = (int) frameSize.height;
        int width = (int) frameSize.width;

        // Create blob from image
        Mat blob = Dnn.blobFromImage(frame, 1.0/255.0, new Size(416, 416), new Scalar(0), true, false);

        // Set input to the network
        net.setInput(blob);

        // Run forward pass
        List<Mat> outs = new ArrayList<>();
        net.forward(outs, outputLayers);

        // Parse detections
        List<Integer> classIds = new ArrayList<>();
        List<Float> confidences = new ArrayList<>();
        List<Rect2d> boxes = new ArrayList<>();

        for (Mat out : outs) {
            for (int i = 0; i < out.rows(); i++) {
                Mat row = out.row(i);
                Mat scores = row.colRange(5, row.cols());
                Core.MinMaxLocResult mmr = Core.minMaxLoc(scores);
                double confidence = mmr.maxVal;

                if (confidence > 0.5) {
                    Point classIdPoint = mmr.maxLoc;
                    int classId = (int) classIdPoint.x;

                    double[] detection = row.get(0, 0);
                    double centerX = detection[0] * width;
                    double centerY = detection[1] * height;
                    double boxWidth = detection[2] * width;
                    double boxHeight = detection[3] * height;

                    double x = centerX - (boxWidth / 2);
                    double y = centerY - (boxHeight / 2);

                    boxes.add(new Rect2d(x, y, boxWidth, boxHeight));
                    confidences.add((float) confidence);
                    classIds.add(classId);
                }
            }
        }

        // Apply Non-Maximum Suppression
        MatOfRect2d boxesMat = new MatOfRect2d();
        boxesMat.fromList(boxes);
        MatOfFloat confidencesMat = new MatOfFloat();
        confidencesMat.fromList(confidences);
        MatOfInt indices = new MatOfInt();

        Dnn.NMSBoxes(boxesMat, confidencesMat, 0.5f, 0.4f, indices);

        // Draw detections
        int[] indicesArray = indices.toArray();
        for (int i : indicesArray) {
            if (i < boxes.size() && i < classIds.size() && i < confidences.size()) {
                Rect2d box = boxes.get(i);
                String label = classes.get(classIds.get(i));
                float confidence = confidences.get(i);

                Scalar color = new Scalar(0, 255, 0);
                Point topLeft = new Point(box.x, box.y);
                Point bottomRight = new Point(box.x + box.width, box.y + box.height);

                Imgproc.rectangle(frame, topLeft, bottomRight, color, 2);

                String text = String.format("%s: %.2f", label, confidence);
                Point textPoint = new Point(box.x, box.y - 5);
                Imgproc.putText(frame, text, textPoint, Imgproc.FONT_HERSHEY_SIMPLEX, 0.5, color, 2);
            }
        }

        return frame;
    }

    @Override
    protected void done() {
        try {
            Mat result = get();
            parent.displayFrame(result);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void stop() {
        running = false;
        cancel(true);
    }

    public boolean isRunning() {
        return !isDone() && !isCancelled();
    }
}