// Assembly Steps Data
const YOUTUBE_VIDEO_ID = "XGMdd38vHd0";

const stepsData = [
    { timestamp: "00:16", title: "Set all parts aside" },
    { timestamp: "00:30", title: "Stick Foot Pads" },
    { timestamp: "01:22", title: "Fix the USB Extension Cable and add the protective sleeve" },
    { timestamp: "02:58", title: "Insert the Power Board" },
    { timestamp: "03:17", title: "Fix the Power Board" },
    { timestamp: "04:06", title: "Connect the cables to the Power Board" },
    { timestamp: "05:26", title: "Position the Bottom Assembly" },
    { timestamp: "07:20", title: "Fix the Foot Assembly to the Bottom Assembly" },
    { timestamp: "08:15", title: "Connect the Foot Motor" },
    { timestamp: "09:15", title: "Screw the link rods onto the motors' arms" },
    { timestamp: "12:22", title: "Connect Motor 1 to 2" },
    { timestamp: "13:11", title: "Connect Motor 2 to 3" },
    { timestamp: "13:36", title: "Connect Motor 4 to 5" },
    { timestamp: "13:55", title: "Connect Motor 5 to 6" },
    { timestamp: "14:27", title: "Insert all motors into the Bottom Assembly" },
    { timestamp: "15:54", title: "Clip the motors' cables into the Bottom Assembly" },
    { timestamp: "19:00", title: "Position the Tricap" },
    { timestamp: "19:20", title: "Route the cables" },
    { timestamp: "19:51", title: "Connect Motor 3 to 4" },
    { timestamp: "20:40", title: "Route the cables" },
    { timestamp: "22:50", title: "Check rotation" },
    { timestamp: "24:36", title: "Screw the Tricap" },
    { timestamp: "26:05", title: "Screw the Bottom Head onto the link rods" },
    { timestamp: "30:00", title: "Route the cables through the Bottom Head" },
    { timestamp: "30:53", title: "Connect the flexible camera cable (step for reference only)" },
    { timestamp: "31:02", title: "Route the cables through the Head PCB" },
    { timestamp: "31:25", title: "Screw the Head PCB" },
    { timestamp: "32:31", title: "Position the Top Shell" },
    { timestamp: "33:02", title: "Screw the Top Shell" },
    { timestamp: "34:29", title: "Place the lenses in the Glasses Holder" },
    { timestamp: "34:39", title: "Insert the Fisheye Lenses into the caps" },
    { timestamp: "35:00", title: "Snap the Fisheye Lenses" },
    { timestamp: "35:47", title: "Screw the Glasses Assembly onto the Front Head Shell" },
    { timestamp: "36:49", title: "Attach the cases to Antennas' motors" },
    { timestamp: "37:07", title: "Fix Antennas' Assembly to Back Head Shell" },
    { timestamp: "38:39", title: "Connect the Antennas' motors" },
    { timestamp: "39:02", title: "Slide the Back Head Assembly onto the Reachy Mini body" },
    { timestamp: "39:22", title: "Screw the Back Head" },
    { timestamp: "40:07", title: "Fix the Cable Holder" },
    { timestamp: "41:53", title: "Connect Speaker and Motors' Cables" },
    { timestamp: "42:17", title: "Connect Power and USB Extension Cables" },
    { timestamp: "42:33", title: "Slide the Top Head Assembly onto the Back Head" },
    { timestamp: "42:49", title: "Connect the Flexible Printed Cable to the Head PCB" },
    { timestamp: "42:58", title: "Connect the Flexible Camera Cable on the Front Head" },
    { timestamp: "43:50", title: "Fix the Front Head" },
    { timestamp: "45:03", title: "Fix the Antennas" },
];

// Parse timestamp to seconds (MM:SS format)
function parseTimestamp(ts) {
    const parts = ts.split(':').map(Number);
    return parts[0] * 60 + parts[1];
}

// Create assembly steps with parsed timestamps
const assemblySteps = stepsData.map((step, index) => ({
    id: index + 1,
    title: step.title,
    timestamp: step.timestamp,
    timestampSeconds: parseTimestamp(step.timestamp)
}));

const TOTAL_STEPS = assemblySteps.length;

// Available step images
const availableImages = {
    1: "assets/step1.jpg",
    2: "assets/step2.jpg",
    3: "assets/step3.jpg",
    4: "assets/step4.jpg",
    5: "assets/step5.jpg",
    6: "assets/step6.jpg",
    7: "assets/step7.jpg",
    8: "assets/step8.jpg",
    9: "assets/step9.jpg",
    10: "assets/step10.jpg",
    11: "assets/step11.jpg",
    12: "assets/step12.jpg",
    13: "assets/step13.jpg",
    14: "assets/step14.jpg",
    15: "assets/step15.jpg",
    16: "assets/step16.jpg",
    17: "assets/step17.jpg",
    18: "assets/step18.jpg",
    19: "assets/step19.jpg",
    20: "assets/step20.jpg",
    21: "assets/step21.jpg",
    22: "assets/step22.jpg",
    23: "assets/step23.jpg",
    24: "assets/step24.jpg",
    25: "assets/step25.jpg",
    26: "assets/step26.jpg",
    27: "assets/step27.jpg",
    28: "assets/step28.jpg",
    29: "assets/step29.jpg",
    30: "assets/step30.jpg",
    31: "assets/step31.jpg",
    32: "assets/step32.jpg",
    33: "assets/step33.jpg",
    34: "assets/step34.jpg",
    35: "assets/step35.jpg",
    36: "assets/step36.jpg",
    37: "assets/step37.jpg",
    38: "assets/step38.jpg",
    39: "assets/step39.jpg",
    40: "assets/step40.jpg",
    41: "assets/step41.jpg",
    42: "assets/step42.jpg",
    43: "assets/step43.jpg",
    44: "assets/step44.jpg",
    45: "assets/step45.jpg",
    46: "assets/step46.jpg",
    47: "assets/step47.jpg",
};

function getStepImage(stepId) {
    return availableImages[stepId] || null;
}

// App State
let currentStep = 1;
let isFullscreen = false;
let scale = 1;
let position = { x: 0, y: 0 };
let isDragging = false;
let dragStart = { x: 0, y: 0 };

// DOM Elements
const stepCounterText = document.getElementById('step-counter-text');
const stepImage = document.getElementById('step-image');
const placeholder = document.getElementById('placeholder');
const placeholderNumber = document.getElementById('placeholder-number');
const imageWrapper = document.getElementById('image-wrapper');
const youtubeIframeDesktop = document.getElementById('youtube-iframe-desktop');
const youtubeIframeMobile = document.getElementById('youtube-iframe-mobile');
const prevBtn = document.getElementById('prev-btn');
const nextBtn = document.getElementById('next-btn');
const stepIndicators = document.getElementById('step-indicators');
const progressBar = document.getElementById('progress-bar');
const fullscreenBtn = document.getElementById('fullscreen-btn');
const fullscreenModal = document.getElementById('fullscreen-modal');
const closeFullscreenBtn = document.getElementById('close-fullscreen-btn');
const fullscreenStepTitle = document.getElementById('fullscreen-step-title');
const fullscreenImage = document.getElementById('fullscreen-image');
const fullscreenPlaceholder = document.getElementById('fullscreen-placeholder');
const fullscreenPlaceholderNumber = document.getElementById('fullscreen-placeholder-number');
const fullscreenImageContainer = document.getElementById('fullscreen-image-container');
const fullscreenYoutubeIframeDesktop = document.getElementById('fullscreen-youtube-iframe-desktop');
const fullscreenYoutubeIframeMobile = document.getElementById('fullscreen-youtube-iframe-mobile');
const fullscreenPrevBtn = document.getElementById('fullscreen-prev-btn');
const fullscreenNextBtn = document.getElementById('fullscreen-next-btn');
const fullscreenStepIndicators = document.getElementById('fullscreen-step-indicators');
const fullscreenProgressBar = document.getElementById('fullscreen-progress-bar');
const zoomInBtn = document.getElementById('zoom-in-btn');
const zoomOutBtn = document.getElementById('zoom-out-btn');
const zoomLevel = document.getElementById('zoom-level');

// Update YouTube embed
function updateYouTubeEmbed(timestampSeconds) {
    const embedUrl = `https://www.youtube.com/embed/${YOUTUBE_VIDEO_ID}?start=${timestampSeconds}&rel=0&autoplay=1&mute=1`;
    youtubeIframeDesktop.src = embedUrl;
    youtubeIframeMobile.src = embedUrl;
    fullscreenYoutubeIframeDesktop.src = embedUrl;
    fullscreenYoutubeIframeMobile.src = embedUrl;
}

// Render step indicators
function renderStepIndicators(containerId, currentStep, onClick) {
    const container = document.getElementById(containerId);
    container.innerHTML = '';
    
    const groupStart = Math.floor((currentStep - 1) / 10) * 10 + 1;
    
    for (let i = 0; i < 10; i++) {
        const stepNum = groupStart + i;
        if (stepNum > TOTAL_STEPS) break;
        
        const isActive = stepNum === currentStep;
        const button = document.createElement('button');
        button.className = `step-indicator ${isActive ? 'step-indicator-active' : 'step-indicator-inactive'}`;
        button.setAttribute('aria-label', `Go to step ${stepNum}`);
        button.addEventListener('click', () => onClick(stepNum));
        container.appendChild(button);
    }
}

// Update UI
function updateUI() {
    const step = assemblySteps[currentStep - 1];
    const imageSrc = getStepImage(step.id);
    
    // Update step counter
    stepCounterText.textContent = `Step ${step.id}/${TOTAL_STEPS}`;
    
    // Update image
    if (imageSrc) {
        stepImage.src = imageSrc;
        stepImage.alt = `Assembly step ${step.id}`;
        stepImage.classList.remove('hidden');
        placeholder.classList.add('hidden');
    } else {
        stepImage.classList.add('hidden');
        placeholder.classList.remove('hidden');
        placeholderNumber.textContent = step.id;
    }
    
    // Update YouTube embed
    updateYouTubeEmbed(step.timestampSeconds);
    
    // Update buttons
    prevBtn.disabled = currentStep === 1;
    nextBtn.disabled = currentStep === TOTAL_STEPS;
    
    // Update step indicators
    renderStepIndicators('step-indicators', currentStep, goToStep);
    
    // Update progress bar
    const progress = (currentStep / TOTAL_STEPS) * 100;
    progressBar.style.width = `${progress}%`;
    
    // Update fullscreen UI
    updateFullscreenUI();
}

// Update fullscreen UI
function updateFullscreenUI() {
    const step = assemblySteps[currentStep - 1];
    const imageSrc = getStepImage(step.id);
    
    fullscreenStepTitle.textContent = `Step ${step.id}/${TOTAL_STEPS} - ${step.title}`;
    
    if (imageSrc) {
        fullscreenImage.src = imageSrc;
        fullscreenImage.alt = `Step ${step.id}`;
        fullscreenImage.classList.remove('hidden');
        fullscreenPlaceholder.classList.add('hidden');
    } else {
        fullscreenImage.classList.add('hidden');
        fullscreenPlaceholder.classList.remove('hidden');
        fullscreenPlaceholderNumber.textContent = step.id;
    }
    
    fullscreenPrevBtn.disabled = currentStep === 1;
    fullscreenNextBtn.disabled = currentStep === TOTAL_STEPS;
    
    renderStepIndicators('fullscreen-step-indicators', currentStep, goToStepFullscreen);
    
    const progress = (currentStep / TOTAL_STEPS) * 100;
    fullscreenProgressBar.style.width = `${progress}%`;
    
    updateZoomDisplay();
}

// Navigation functions
function goToPrevious() {
    if (currentStep > 1) {
        currentStep--;
        updateUI();
    }
}

function goToNext() {
    if (currentStep < TOTAL_STEPS) {
        currentStep++;
        updateUI();
    }
}

function goToStep(step) {
    if (step >= 1 && step <= TOTAL_STEPS) {
        currentStep = step;
        updateUI();
    }
}

function goToStepFullscreen(step) {
    resetZoom();
    goToStep(step);
}

function goToPreviousFullscreen() {
    resetZoom();
    goToPrevious();
}

function goToNextFullscreen() {
    resetZoom();
    goToNext();
}

// Fullscreen functions
function openFullscreen() {
    isFullscreen = true;
    fullscreenModal.classList.remove('hidden');
    document.body.style.overflow = 'hidden';
    updateFullscreenUI();
}

function closeFullscreen() {
    isFullscreen = false;
    fullscreenModal.classList.add('hidden');
    document.body.style.overflow = '';
    resetZoom();
}

// Zoom functions
function zoomIn() {
    scale = Math.min(scale + 0.5, 4);
    updateZoomDisplay();
}

function zoomOut() {
    scale = Math.max(scale - 0.5, 0.5);
    updateZoomDisplay();
}

function resetZoom() {
    scale = 1;
    position = { x: 0, y: 0 };
    updateZoomDisplay();
}

function updateZoomDisplay() {
    zoomLevel.textContent = `${Math.round(scale * 100)}%`;
    fullscreenImage.style.transform = `translate(${position.x}px, ${position.y}px) scale(${scale})`;
}

// Drag functions for fullscreen image
function handleMouseDown(e) {
    if (scale > 1) {
        isDragging = true;
        dragStart = {
            x: e.clientX - position.x,
            y: e.clientY - position.y
        };
        fullscreenImageContainer.style.cursor = 'grabbing';
    }
}

function handleMouseMove(e) {
    if (isDragging && scale > 1) {
        position = {
            x: e.clientX - dragStart.x,
            y: e.clientY - dragStart.y
        };
        updateZoomDisplay();
    }
}

function handleMouseUp() {
    isDragging = false;
    fullscreenImageContainer.style.cursor = 'grab';
}

function handleWheel(e) {
    e.preventDefault();
    const delta = e.deltaY > 0 ? -0.2 : 0.2;
    scale = Math.max(0.5, Math.min(4, scale + delta));
    updateZoomDisplay();
}

// Event Listeners
prevBtn.addEventListener('click', goToPrevious);
nextBtn.addEventListener('click', goToNext);
fullscreenBtn.addEventListener('click', openFullscreen);
stepImage.addEventListener('click', openFullscreen);
closeFullscreenBtn.addEventListener('click', closeFullscreen);
fullscreenPrevBtn.addEventListener('click', goToPreviousFullscreen);
fullscreenNextBtn.addEventListener('click', goToNextFullscreen);
zoomInBtn.addEventListener('click', zoomIn);
zoomOutBtn.addEventListener('click', zoomOut);

fullscreenImageContainer.addEventListener('mousedown', handleMouseDown);
fullscreenImageContainer.addEventListener('mousemove', handleMouseMove);
fullscreenImageContainer.addEventListener('mouseup', handleMouseUp);
fullscreenImageContainer.addEventListener('mouseleave', handleMouseUp);
fullscreenImageContainer.addEventListener('wheel', handleWheel, { passive: false });

// Keyboard navigation
document.addEventListener('keydown', (e) => {
    if (isFullscreen) {
        if (e.key === 'Escape') closeFullscreen();
        if (e.key === '+' || e.key === '=') zoomIn();
        if (e.key === '-') zoomOut();
        if (e.key === '0') resetZoom();
        if (e.key === 'ArrowLeft' && currentStep > 1) goToPreviousFullscreen();
        if (e.key === 'ArrowRight' && currentStep < TOTAL_STEPS) goToNextFullscreen();
    } else {
        if (e.key === 'ArrowRight') goToNext();
        if (e.key === 'ArrowLeft') goToPrevious();
    }
});

// Initialize
updateUI();