// J621-style multi-upload for the gallery "add media" page. Files are
// uploaded one at a time to /api/uploads/ (kind=media) and previewed; on
// submit the pending uploads are moved into the project's gallery.
(function () {
    const zone = document.querySelector('.upload-zone[data-upload="media"]');
    if (!zone) return;

    const csrf = getCookie('csrftoken');
    const csrfHeader = csrf ? { 'X-CSRFToken': csrf } : {};
    const preview = document.getElementById('media-preview');
    const batch = document.getElementById('media-batch');
    const input = document.getElementById('media-input');
    const drop = zone.querySelector('.drop-zone');

    const pending = JSON.parse(
        (document.getElementById('packs-pending-uploads') || { textContent: '[]' }).textContent
    );

    pending.forEach(renderCard);

    function renderCard(upload) {
        const card = document.createElement('div');
        card.className = 'file-preview-card';
        card.dataset.uuid = upload.uuid;

        if ((upload.content_type || '').startsWith('image/')) {
            const img = document.createElement('img');
            img.src = upload.url;
            img.alt = upload.filename;
            card.appendChild(img);
        } else if ((upload.content_type || '').startsWith('video/')) {
            const video = document.createElement('video');
            video.src = upload.url;
            video.muted = true;
            video.autoplay = true;
            video.loop = true;
            card.appendChild(video);
        } else {
            const icon = document.createElement('div');
            icon.className = 'file-preview-icon';
            icon.innerHTML = '<i class="fas fa-file"></i>';
            card.appendChild(icon);
        }

        const name = document.createElement('span');
        name.className = 'file-preview-name';
        name.textContent = upload.filename;
        card.appendChild(name);

        const remove = document.createElement('button');
        remove.type = 'button';
        remove.className = 'file-preview-remove';
        remove.innerHTML = '<i class="fas fa-times"></i>';
        remove.addEventListener('click', () => {
            const xhr = new XMLHttpRequest();
            xhr.open('POST', '/api/uploads/' + upload.uuid + '/delete/');
            for (const k in csrfHeader) xhr.setRequestHeader(k, csrfHeader[k]);
            xhr.onload = () => { if (card.parentNode) card.parentNode.removeChild(card); };
            xhr.onerror = () => alert('Network error.');
            xhr.send();
        });
        card.appendChild(remove);
        preview.appendChild(card);
    }

    function uploadFile(file) {
        const fd = new FormData();
        fd.append('file', file);
        fd.append('kind', 'media');

        const xhr = new XMLHttpRequest();
        xhr.open('POST', '/api/uploads/');
        for (const k in csrfHeader) xhr.setRequestHeader(k, csrfHeader[k]);
        xhr.onload = function () {
            if (xhr.status !== 200) {
                try {
                    alert(JSON.parse(xhr.responseText).error || 'Upload failed.');
                } catch (e) {
                    alert('Upload failed.');
                }
            } else {
                renderCard(JSON.parse(xhr.responseText));
            }
            batchDone++;
            updateBatch();
        };
        xhr.onerror = function () {
            alert('Network error during upload.');
            batchDone++;
            updateBatch();
        };
        xhr.send(fd);
    }

    let batchTotal = 0;
    let batchDone = 0;
    function updateBatch() {
        if (batchTotal === 0) { batch.hidden = true; return; }
        batch.hidden = false;
        document.getElementById('media-batch-status').textContent =
            'Uploading ' + batchDone + ' of ' + batchTotal + ' files';
        if (batchDone >= batchTotal && batchTotal > 0) {
            setTimeout(() => { batch.hidden = true; batchTotal = 0; batchDone = 0; }, 2500);
        }
    }

    function handleFiles(files) {
        batchTotal += files.length;
        updateBatch();
        files.forEach((file) => uploadFile(file));
    }

    drop.addEventListener('click', () => input.click());
    drop.addEventListener('keydown', (e) => {
        if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); input.click(); }
    });
    ['dragenter', 'dragover'].forEach((evt) => drop.addEventListener(evt, (e) => {
        e.preventDefault();
        e.stopPropagation();
        drop.classList.add('dragover');
    }));
    ['dragleave', 'drop'].forEach((evt) => drop.addEventListener(evt, (e) => {
        e.preventDefault();
        e.stopPropagation();
        drop.classList.remove('dragover');
    }));
    drop.addEventListener('drop', (e) => {
        if (e.dataTransfer && e.dataTransfer.files.length) {
            handleFiles(Array.from(e.dataTransfer.files));
        }
    });
    input.addEventListener('change', () => {
        handleFiles(Array.from(input.files));
        input.value = '';
    });

    ['dragover', 'drop'].forEach((evt) => window.addEventListener(evt, (e) => e.preventDefault()));

    function getCookie(name) {
        let cookieValue = null;
        if (document.cookie && document.cookie !== '') {
            const cookies = document.cookie.split(';');
            for (let i = 0; i < cookies.length; i++) {
                const cookie = cookies[i].trim();
                if (cookie.substring(0, name.length + 1) === (name + '=')) {
                    cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
                    break;
                }
            }
        }
        return cookieValue;
    }
})();