// Elements
const videoElement = document.getElementById("live-preview");
const canvas = document.getElementById("output-canvas");
const ctx = canvas.getContext("2d");
const videoSourceSelect = document.getElementById("video-source");
const videoStatus = document.getElementById("video-status");
const enableBgRemoval = document.getElementById("enable-bg-removal");
const showPreview = document.getElementById("show-preview");
const modelQuality = document.getElementById("model-quality");
const edgeSmoothness = document.getElementById("edge-smoothness");
const backgroundBlur = document.getElementById("background-blur");
const foregroundBrightness = document.getElementById("foreground-brightness");
const processingTimeDisplay = document.getElementById("processing-time");
const fpsDisplay = document.getElementById("fps");
const copyUrlButton = document.getElementById("copy-url");
const customImageInput = document.getElementById("custom-image-input");
const customVideoInput = document.getElementById("custom-video-input");

// Canvas setup
canvas.width = 1920;
canvas.height = 1080;

// Variables
let customImage = null;
let customVideo = null;
let lastFrameTime = performance.now();
let currentBackground = "transparent";

// Populate video sources
async function populateVideoSources() {
    try {
        const devices = await navigator.mediaDevices.enumerateDevices();
        videoSourceSelect.innerHTML = '<option value="">Select a video source</option>';
        devices
            .filter((device) => device.kind === "videoinput")
            .forEach((device) => {
                const option = document.createElement("option");
                option.value = device.deviceId;
                option.text = device.label || `Camera ${videoSourceSelect.options.length}`;
                videoSourceSelect.appendChild(option);
            });
    } catch (err) {
        console.error("Lỗi khi liệt kê thiết bị video:", err);
        videoStatus.textContent = "Không thể liệt kê thiết bị video.";
    }
}

// Start video stream
async function startVideo(deviceId) {
    try {
        const stream = await navigator.mediaDevices.getUserMedia({
            video: { deviceId: deviceId ? { exact: deviceId } : undefined },
        });
        videoElement.srcObject = stream;
        videoElement.play();
        videoStatus.textContent = "";
        processFrame();
    } catch (err) {
        console.error("Lỗi khi truy cập webcam:", err);
        videoStatus.textContent = "Không thể truy cập webcam. Vui lòng kiểm tra quyền camera.";
    }
}

// Simulated background removal (replace with real AI model in production)
function simulateBackgroundRemoval(imageData) {
    const data = imageData.data;
    for (let i = 0; i < data.length; i += 4) {
        // Simple green-screen-like removal (replace with AI model output)
        const r = data[i];
        const g = data[i + 1];
        const b = data[i + 2];
        // Example: Remove pixels with high green value
        if (g > 150 && r < 100 && b < 100) {
            data[i + 3] = 0; // Set alpha to 0 (transparent)
        }
    }
    return imageData;
}

// Process video frame
function processFrame() {
    const startTime = performance.now();

    // Draw video to canvas
    ctx.drawImage(videoElement, 0, 0, canvas.width, canvas.height);

    // Apply background removal if enabled
    if (enableBgRemoval.checked) {
        let imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
        imageData = simulateBackgroundRemoval(imageData); // Replace with AI model
        ctx.putImageData(imageData, 0, 0);

        // Apply background
        const tempCanvas = document.createElement("canvas");
        tempCanvas.width = canvas.width;
        tempCanvas.height = canvas.height;
        const tempCtx = tempCanvas.getContext("2d");

        // Draw background
        if (currentBackground === "solid-black") {
            tempCtx.fillStyle = "black";
            tempCtx.fillRect(0, 0, canvas.width, canvas.height);
        } else if (currentBackground === "solid-gray") {
            tempCtx.fillStyle = "gray";
            tempCtx.fillRect(0, 0, canvas.width, canvas.height);
        } else if (currentBackground === "solid-green") {
            tempCtx.fillStyle = "green";
            tempCtx.fillRect(0, 0, canvas.width, canvas.height);
        } else if (currentBackground === "custom-image" && customImage) {
            tempCtx.drawImage(customImage, 0, 0, canvas.width, canvas.height);
        } else if (currentBackground === "custom-video" && customVideo) {
            tempCtx.drawImage(customVideo, 0, 0, canvas.width, canvas.height);
        } else if (currentBackground === "blurred") {
            tempCtx.filter = `blur(${backgroundBlur.value}px)`;
            tempCtx.drawImage(videoElement, 0, 0, canvas.width, canvas.height);
        }

        // Draw foreground
        tempCtx.globalCompositeOperation = "destination-over";
        tempCtx.drawImage(canvas, 0, 0);

        // Apply brightness
        tempCtx.filter = `brightness(${foregroundBrightness.value})`;
        tempCtx.drawImage(tempCanvas, 0, 0);

        // Copy to main canvas
        ctx.filter = `blur(${edgeSmoothness.value}px)`; // Edge smoothness
        ctx.drawImage(tempCanvas, 0, 0);
    }

    // Update performance metrics
    const endTime = performance.now();
    const processingTime = endTime - startTime;
    processingTimeDisplay.textContent = `${processingTime.toFixed(2)} ms`;
    fpsDisplay.textContent = `${(1000 / processingTime).toFixed(2)}`;
    lastFrameTime = endTime;

    // Continue processing
    requestAnimationFrame(processFrame);
}

// Event listeners
videoSourceSelect.addEventListener("change", () => {
    startVideo(videoSourceSelect.value);
});

showPreview.addEventListener("change", () => {
    videoElement.style.display = showPreview.checked ? "block" : "none";
});

document.querySelectorAll('input[name="background"]').forEach((input) => {
    input.addEventListener("change", () => {
        currentBackground = input.value;
    });
});

customImageInput.addEventListener("change", (e) => {
    const file = e.target.files[0];
    if (file) {
        customImage = new Image();
        customImage.src = URL.createObjectURL(file);
        currentBackground = "custom-image";
        document.querySelector('input[value="custom-image"]').checked = true;
    }
});

customVideoInput.addEventListener("change", (e) => {
    const file = e.target.files[0];
    if (file) {
        customVideo = document.createElement("video");
        customVideo.src = URL.createObjectURL(file);
        customVideo.loop = true;
        customVideo.play();
        currentBackground = "custom-video";
        document.querySelector('input[value="custom-video"]').checked = true;
    }
});

copyUrlButton.addEventListener("click", () => {
    const url = window.location.href;
    navigator.clipboard.writeText(url).then(() => {
        alert("Đã sao chép URL nguồn trình duyệt OBS!");
    });
});

// Initialize
populateVideoSources();