{% extends "base.html" %}

{% block title %}Queue - NextSnap{% endblock %}

{% block content %}
<div class="container">
    <div class="queue-header">
        <h2>Upload Queue</h2>
        <div class="queue-actions">
            <button class="btn btn-secondary btn-small" id="sync-now-btn" disabled>
                <span class="btn-icon">🔄</span> Sync Now
            </button>
        </div>
    </div>

    <div class="queue-stats" id="queue-stats">
        <div class="stat">
            <span class="stat-value" id="pending-stat">0</span>
            <span class="stat-label">Pending</span>
        </div>
        <div class="stat">
            <span class="stat-value" id="uploading-stat">0</span>
            <span class="stat-label">Uploading</span>
        </div>
        <div class="stat">
            <span class="stat-value" id="total-size-stat">0 MB</span>
            <span class="stat-label">Total Size</span>
        </div>
    </div>

    <div class="queue-list" id="queue-list">
        <p class="empty-state" id="empty-state">No photos in queue</p>
    </div>
</div>

<!-- Delete Confirmation Modal -->
<div class="modal" id="delete-modal" style="display: none;">
    <div class="modal-content">
        <h3>Delete Photo?</h3>
        <p>Are you sure you want to delete this photo from the queue?</p>
        <p class="warning-text">⚠️ This action cannot be undone.</p>
        <div class="modal-actions">
            <button class="btn btn-secondary" id="cancel-delete-btn">Cancel</button>
            <button class="btn btn-danger" id="confirm-delete-btn">Delete</button>
        </div>
    </div>
</div>
{% endblock %}

{% block extra_css %}
<style>
.queue-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    border-bottom: 1px solid var(--bg-tertiary);
}

.queue-header h2 {
    font-size: 1.5rem;
    margin: 0;
}

.queue-actions {
    display: flex;
    gap: 0.5rem;
}

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    min-height: auto;
}

.btn-icon {
    display: inline-block;
    margin-right: 0.25rem;
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--accent);
}

.btn-secondary:active:not(:disabled) {
    opacity: 0.8;
    transform: scale(0.98);
}

.btn-secondary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--text-secondary);
}

.btn-danger {
    background: var(--error);
    color: white;
}

.queue-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin: 1.5rem 0;
}

.stat {
    background: var(--bg-secondary);
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
}

.stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 0.25rem;
}

.stat-label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.queue-list {
    margin-bottom: 2rem;
}

.empty-state {
    text-align: center;
    color: var(--text-secondary);
    padding: 3rem 1rem;
}

.queue-item {
    background: var(--bg-secondary);
    border-radius: 8px;
    padding: 0.75rem;
    margin-bottom: 0.75rem;
    display: flex;
    gap: 0.75rem;
    align-items: center;
    position: relative;
}

.queue-item.uploading {
    border: 2px solid var(--accent);
}

.queue-item.verified {
    border: 1px solid var(--success, #4caf50);
}

.queue-item.error {
    border: 2px solid var(--error);
}

.queue-item.completed {
    opacity: 0.7;
}

.queue-divider {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 1rem 0 0.5rem;
    margin-top: 0.5rem;
    border-top: 1px solid var(--bg-tertiary);
}

.thumbnail-placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
    font-size: 2rem;
}

.queue-item-thumbnail {
    width: 80px;
    height: 80px;
    border-radius: 6px;
    overflow: hidden;
    flex-shrink: 0;
    background: var(--bg-tertiary);
}

.queue-item-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.queue-item-info {
    flex: 1;
    min-width: 0;
}

.queue-item-filename {
    font-weight: 600;
    margin-bottom: 0.25rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.queue-item-meta {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

.queue-item-status {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
}

.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
}

.status-badge.pending {
    background: var(--warning);
    color: var(--bg-primary);
}

.status-badge.uploading {
    background: var(--accent);
    color: white;
}

.status-badge.verified {
    background: var(--success, #4caf50);
    color: white;
}

.status-badge.failed {
    background: var(--error);
    color: white;
}

.status-badge.error {
    background: var(--error);
    color: white;
}

.retry-info {
    color: var(--text-secondary);
    font-size: 0.75rem;
}

.error-message {
    color: var(--error);
    font-size: 0.75rem;
    margin-top: 0.25rem;
}

.queue-item-actions {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.queue-item-delete {
    background: var(--error);
    color: white;
    border: none;
    padding: 0.5rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1.25rem;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.queue-item-delete:active {
    opacity: 0.8;
    transform: scale(0.95);
}

.queue-item-retry {
    background: var(--accent);
    color: white;
    border: none;
    padding: 0.5rem;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    width: 2.5rem;
    height: 2.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.queue-item-retry:active {
    transform: scale(0.95);
    opacity: 0.8;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    padding: 1rem;
}

.modal-content {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: 12px;
    max-width: 400px;
    width: 100%;
}

.modal-content h3 {
    margin-bottom: 1rem;
}

.modal-content p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.warning-text {
    color: var(--warning) !important;
    font-weight: 600;
}

.modal-actions {
    display: flex;
    gap: 0.5rem;
    margin-top: 1.5rem;
}

.modal-actions .btn {
    flex: 1;
}
</style>
{% endblock %}

{% block extra_js %}
<script src="{{ url_for('static', filename='lib/dexie.min.js') }}"></script>
<script src="{{ url_for('static', filename='js/storage.js') }}"></script>
<script src="{{ url_for('static', filename='js/sync.js') }}"></script>
<script src="{{ url_for('static', filename='js/auth.js') }}"></script>

<script>
const currentUsername = '{{ username }}';
let deletePhotoId = null;

// Safe blob accessor — works even if old storage.js is cached without getBlob()
function safeGetBlob(photo) {
    if (!photo || !photo.blob) return null;
    if (typeof Storage.getBlob === 'function') return Storage.getBlob(photo);
    if (photo.blob instanceof Blob) return photo.blob;
    // ArrayBuffer stored by new storage.js but old storage.js loaded (no getBlob)
    try { return new Blob([photo.blob], { type: 'image/jpeg' }); } catch (e) { return null; }
}

// Initialize storage and load queue
Storage.init().then(() => {
    SyncEngine.init(currentUsername);
    loadQueue();
    updateStats();
});

async function loadQueue() {
    const queueList = document.getElementById('queue-list');

    const photos = await Storage.db.photos
        .where('username').equals(currentUsername)
        .sortBy('timestamp');

    // Split into active and completed
    const activePhotos = photos.filter(p =>
        p.status === 'pending' || p.status === 'uploading' || p.status === 'uploaded');
    const completedPhotos = photos.filter(p =>
        p.status === 'verified' || p.status === 'failed');

    // Revoke old ObjectURLs before rebuilding to prevent memory leaks
    queueList.querySelectorAll('img[src^="blob:"]').forEach(img => {
        URL.revokeObjectURL(img.src);
    });
    queueList.innerHTML = '';

    if (photos.length === 0) {
        queueList.innerHTML = '<p class="empty-state">No photos in queue</p>';
        document.getElementById('sync-now-btn').disabled = true;
        return;
    }

    // Show active uploads first (newest first)
    for (const photo of activePhotos.reverse()) {
        queueList.appendChild(createQueueItem(photo, false));
    }

    // Show completed history (newest first, last 20 kept by pruneHistory)
    if (completedPhotos.length > 0) {
        const divider = document.createElement('div');
        divider.className = 'queue-divider';
        divider.textContent = 'Recent Uploads';
        queueList.appendChild(divider);

        for (const photo of completedPhotos.reverse()) {
            queueList.appendChild(createQueueItem(photo, true));
        }
    }

    hasActiveUploads = activePhotos.length > 0;
    document.getElementById('sync-now-btn').disabled = !hasActiveUploads || !navigator.onLine;
}

function createQueueItem(photo, isCompleted) {
    const item = document.createElement('div');
    item.className = 'queue-item';

    if (isCompleted) {
        item.classList.add('completed');
    }

    if (photo.status === 'uploading' || photo.status === 'uploaded') {
        item.classList.add('uploading');
    } else if (photo.status === 'verified') {
        item.classList.add('verified');
    } else if (photo.status === 'failed' || photo.lastError || photo.error) {
        item.classList.add('error');
    }

    // Create thumbnail (use placeholder if blob was stripped)
    const thumbnail = document.createElement('div');
    thumbnail.className = 'queue-item-thumbnail';
    const photoBlob = safeGetBlob(photo);
    if (photoBlob && photoBlob.size > 0) {
        const img = document.createElement('img');
        img.src = URL.createObjectURL(photoBlob);
        thumbnail.appendChild(img);
    } else {
        thumbnail.innerHTML = '<span class="thumbnail-placeholder">' +
            (photo.status === 'verified' ? '\u2705' : '\u274C') + '</span>';
    }

    // Create info section
    const info = document.createElement('div');
    info.className = 'queue-item-info';

    const filename = document.createElement('div');
    filename.className = 'queue-item-filename';
    filename.textContent = photo.filename;

    const meta = document.createElement('div');
    meta.className = 'queue-item-meta';
    const date = new Date(photo.completedAt || photo.timestamp).toLocaleString();
    if (photoBlob && photoBlob.size > 0) {
        const size = (photoBlob.size / 1024 / 1024).toFixed(2);
        meta.textContent = size + ' MB \u2022 ' + date;
    } else {
        meta.textContent = date;
    }

    const status = document.createElement('div');
    status.className = 'queue-item-status';

    const badge = document.createElement('span');
    badge.className = 'status-badge ' + photo.status;
    badge.textContent = photo.status.charAt(0).toUpperCase() + photo.status.slice(1);
    status.appendChild(badge);

    if (photo.retryCount >= 3 && !isCompleted) {
        const retry = document.createElement('span');
        retry.className = 'retry-info';
        retry.textContent = 'Retry #' + photo.retryCount;
        status.appendChild(retry);
    }

    info.appendChild(filename);
    info.appendChild(meta);
    info.appendChild(status);

    // Only show error messages after 3+ retries or for failed status
    // (first couple of retries are usually transient network blips)
    const errorMsg = photo.lastError || photo.error;
    const retries = photo.retryCount || 0;
    if (errorMsg && photo.status !== 'verified' && (retries >= 3 || photo.status === 'failed')) {
        const error = document.createElement('div');
        error.className = 'error-message';
        error.textContent = errorMsg;
        info.appendChild(error);
    }

    item.appendChild(thumbnail);
    item.appendChild(info);

    // Only show action buttons for active (non-completed) photos
    if (!isCompleted) {
        const actions = document.createElement('div');
        actions.className = 'queue-item-actions';

        if (photo.status === 'failed' || photo.status === 'pending' || photo.lastError || photo.error) {
            const retryBtn = document.createElement('button');
            retryBtn.className = 'queue-item-retry';
            retryBtn.textContent = '\uD83D\uDD04';
            retryBtn.title = 'Retry upload';
            retryBtn.addEventListener('click', async () => {
                retryBtn.textContent = '\u23F3';
                retryBtn.disabled = true;
                await Storage.updatePhoto(photo.id, { status: 'pending', lastError: null, error: null, retryCount: 0 });
                if (typeof SyncEngine !== 'undefined') {
                    SyncEngine.triggerSync();
                }
                setTimeout(() => loadQueue(), 500);
            });
            actions.appendChild(retryBtn);
        }

        const deleteBtn = document.createElement('button');
        deleteBtn.className = 'queue-item-delete';
        deleteBtn.textContent = '\uD83D\uDDD1\uFE0F';
        deleteBtn.title = 'Delete photo';
        deleteBtn.addEventListener('click', () => showDeleteModal(photo.id));
        actions.appendChild(deleteBtn);

        item.appendChild(actions);
    }

    return item;
}

async function updateStats() {
    const photos = await Storage.db.photos
        .where('username').equals(currentUsername)
        .toArray();

    const pendingCount = photos.filter(p => p.status === 'pending').length;
    const uploadingCount = photos.filter(p => p.status === 'uploading').length;
    const totalSize = photos
        .map(p => safeGetBlob(p))
        .filter(b => b && b.size)
        .reduce((sum, b) => sum + b.size, 0) / 1024 / 1024;

    document.getElementById('pending-stat').textContent = pendingCount;
    document.getElementById('uploading-stat').textContent = uploadingCount;
    document.getElementById('total-size-stat').textContent = totalSize.toFixed(1) + ' MB';
}

function showDeleteModal(photoId) {
    deletePhotoId = photoId;
    document.getElementById('delete-modal').style.display = 'flex';
}

function hideDeleteModal() {
    deletePhotoId = null;
    document.getElementById('delete-modal').style.display = 'none';
}

// Event Listeners
document.getElementById('sync-now-btn').addEventListener('click', async () => {
    if (navigator.onLine) {
        await SyncEngine.triggerSync();
        setTimeout(() => {
            loadQueue();
            updateStats();
        }, 500);
    }
});

document.getElementById('cancel-delete-btn').addEventListener('click', hideDeleteModal);

document.getElementById('confirm-delete-btn').addEventListener('click', async () => {
    if (deletePhotoId) {
        await Storage.deletePhoto(deletePhotoId);
        hideDeleteModal();
        loadQueue();
        updateStats();
    }
});

// Close modal on outside click
document.getElementById('delete-modal').addEventListener('click', (e) => {
    if (e.target.id === 'delete-modal') {
        hideDeleteModal();
    }
});

// Listen for sync updates
window.addEventListener('online', () => {
    document.getElementById('sync-now-btn').disabled = false;
});

window.addEventListener('offline', () => {
    document.getElementById('sync-now-btn').disabled = true;
});

// Live updates: listen for photo status changes from the sync engine
let refreshTimer = null;
function scheduleRefresh() {
    if (refreshTimer) clearTimeout(refreshTimer);
    refreshTimer = setTimeout(() => {
        refreshTimer = null;
        refreshUI();
    }, 300);
}
window.addEventListener('photo-updated', scheduleRefresh);

// Safe refresh wrapper — prevents silent failures from killing updates
async function refreshUI() {
    try { await loadQueue(); } catch (e) { console.error('[QUEUE] loadQueue error:', e); }
    try { await updateStats(); } catch (e) { console.error('[QUEUE] updateStats error:', e); }
}

// Poll every 3s while uploads are active, 15s when idle
let hasActiveUploads = true; // assume active until first check
setInterval(() => {
    if (hasActiveUploads) refreshUI();
}, 3000);

// Slower fallback poll for idle state
setInterval(refreshUI, 15000);
</script>
{% endblock %}