// Shared J621-style uploader for UGC pages.
// Wires every `.upload-zone[data-upload]` on the page: dropzone click/drag,
// per-file XHR to /api/uploads/, preview cards, removal, batch progress.
// Single slots (thumbnail/version) hold one file; media is multi.
(function () {
    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;
    }

    function init(options) {
        const opts = options || {};
        const pending = opts.pending || [];
        const csrf = getCookie('csrftoken');
        const csrfHeader = csrf ? { 'X-CSRFToken': csrf } : {};

        const zones = {};
        document.querySelectorAll('.upload-zone[data-upload]').forEach((zone) => {
            const kind = zone.dataset.upload;
            zones[kind] = {
                zone,
                kind,
                single: kind === 'thumbnail' || kind === 'version',
                drop: zone.querySelector('.drop-zone'),
                input: zone.querySelector('input[type=file]'),
                preview: zone.querySelector('.upload-preview, #media-preview'),
                batch: zone.querySelector('.upload-batch'),
                current: null,
                busy: false,
                batchTotal: 0,
                batchDone: 0,
            };
        });

        // Render uploads that survived from a previous session.
        pending.forEach((u) => {
            const z = zones[u.kind];
            if (z) addCard(u, z);
        });

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

            const ct = upload.content_type || '';
            if (ct.startsWith('image/')) {
                const img = document.createElement('img');
                img.src = upload.url;
                img.alt = upload.filename || '';
                card.appendChild(img);
            } else if (ct.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-archive"></i>';
                card.appendChild(icon);
            }

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

            if (upload.removable !== false) {
                const remove = document.createElement('button');
                remove.type = 'button';
                remove.className = 'file-preview-remove';
                remove.innerHTML = '<i class="fas fa-times"></i>';
                remove.addEventListener('click', () => deleteUpload(upload.uuid, card, z));
                card.appendChild(remove);
            }
            return card;
        }

        function addCard(upload, z) {
            if (z.single) {
                z.preview.innerHTML = '';
                z.preview.appendChild(previewCard(upload, z));
                if (upload.removable !== false) z.current = upload;
            } else {
                z.preview.appendChild(previewCard(upload, z));
            }
        }

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

            const xhr = new XMLHttpRequest();
            xhr.open('POST', '/api/uploads/');
            for (const k in csrfHeader) xhr.setRequestHeader(k, csrfHeader[k]);

            xhr.onload = function () {
                z.busy = false;
                if (!z.single) { z.batchDone++; updateBatch(z); }
                if (xhr.status !== 200) {
                    try { alert(JSON.parse(xhr.responseText).error || 'Upload failed.'); }
                    catch (e) { alert('Upload failed.'); }
                    return;
                }
                addCard(JSON.parse(xhr.responseText), z);
            };
            xhr.onerror = function () {
                z.busy = false;
                if (!z.single) { z.batchDone++; updateBatch(z); }
                alert('Network error during upload.');
            };
            xhr.send(fd);
        }

        function deleteUpload(uuid, card, z) {
            const xhr = new XMLHttpRequest();
            xhr.open('POST', '/api/uploads/' + uuid + '/delete/');
            for (const k in csrfHeader) xhr.setRequestHeader(k, csrfHeader[k]);
            xhr.onload = function () {
                if (card && card.parentNode) card.parentNode.removeChild(card);
                if (z && z.current && z.current.uuid === uuid) z.current = null;
                if (opts.onRemove) opts.onRemove(uuid);
            };
            xhr.onerror = function () {
                alert('Network error.');
            };
            xhr.send();
        }

        function handleFiles(files, z) {
            // Single slots: take one file, replace the current upload, and
            // ignore further drops while one is in flight.
            if (z.single) {
                if (z.busy) return;
                const file = files[0];
                if (z.current) deleteUpload(z.current.uuid, null, z);
                z.busy = true;
                uploadFile(file, z);
                return;
            }
            z.batchTotal += files.length;
            updateBatch(z);
            files.forEach((file) => uploadFile(file, z));
        }

        function updateBatch(z) {
            if (!z.batch) return;
            if (z.batchTotal === 0) { z.batch.hidden = true; return; }
            z.batch.hidden = false;
            const status = z.batch.querySelector('.upload-batch-status');
            if (status) {
                status.textContent = 'Uploading ' + z.batchDone + ' of ' + z.batchTotal + ' files';
            }
            if (z.batchDone >= z.batchTotal && z.batchTotal > 0) {
                setTimeout(() => {
                    z.batch.hidden = true;
                    z.batchTotal = 0;
                    z.batchDone = 0;
                }, 2500);
            }
        }

        Object.keys(zones).forEach((kind) => {
            const z = zones[kind];
            if (!z.drop || !z.input) return;

            z.drop.addEventListener('click', () => z.input.click());
            z.drop.addEventListener('keydown', (e) => {
                if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); z.input.click(); }
            });

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

        // Prevent the browser opening files dropped outside a zone.
        ['dragover', 'drop'].forEach((evt) => window.addEventListener(evt, (e) => e.preventDefault()));

        if (opts.onReady) opts.onReady();
    }

    window.PacksUploads = { init: init };
})();