/**
 * upload-progress.js
 *
 * Intercepts admin form submissions with files and submits via XMLHttpRequest.
 * Polls GET /admin/actions/upload-progress.php?token=xxx for server-side
 * processing progress (PeerTube uploads, file moves).
 *
 * Progress display:
 *   0%–25%  : browser → server upload (XHR upload.progress)
 *   25%–99% : server processing (polled from progress endpoint)
 *   100%    : response received — "Téléversé avec succès", then redirect
 */
(() => {
    'use strict';

    const FORMS = document.querySelectorAll('form[data-upload-progress]');
    if (!FORMS.length) return;

    const POLL_INTERVAL = 400;
    const UPLOAD_CAP = 25;
    const PROCESSING_MAX = 99;
    const SUCCESS_DELAY = 800;

    for (const form of FORMS) {
        const progressWrap  = form.querySelector('#upload-progress-wrap');
        const progressBar   = form.querySelector('#upload-progress-bar');
        const progressLabel = form.querySelector('#upload-progress-label');
        const progressFile  = form.querySelector('#upload-progress-file');
        const submitBtn     = form.querySelector('button[type="submit"]');
        const tokenInput    = form.querySelector('input[name="progress_token"]');

        if (!progressBar || !progressWrap) continue;

        function collectFileNames() {
            const names = [];
            const inputs = form.querySelectorAll('input[type="file"]');
            for (const fi of inputs) {
                if (fi.files) {
                    for (const f of fi.files) {
                        if (f.name) names.push(f.name);
                    }
                }
            }
            return names;
        }

        form.addEventListener('submit', function (e) {
            const fileNames = collectFileNames();
            if (!fileNames.length) return;

            e.preventDefault();

            const token = tokenInput ? tokenInput.value : '';

            progressWrap.style.display = '';
            progressBar.value = 0;
            progressBar.removeAttribute('data-complete');
            progressLabel.textContent = 'Téléversement en cours…';
            progressFile.textContent = fileNames.length === 1
                ? fileNames[0]
                : fileNames.length + ' fichiers';
            if (submitBtn) submitBtn.disabled = true;

            const fd = new FormData(form);
            const xhr = new XMLHttpRequest();

            let uploadDone = false;
            let lastUploadPct = 0;
            let pollingTimer = null;

            /** Poll server-side progress */
            function startPolling() {
                if (pollingTimer || !token) return;
                progressLabel.textContent = 'Traitement en cours…';
                pollingTimer = setInterval(function () {
                    fetch('/admin/actions/upload-progress.php?token=' + encodeURIComponent(token))
                        .then(function (r) { return r.json(); })
                        .then(function (data) {
                            if (data && data.stage && data.stage !== 'upload') {
                                const pct = Math.min(PROCESSING_MAX, Math.max(UPLOAD_CAP, data.pct || UPLOAD_CAP));
                                progressBar.value = pct;
                                if (data.file) {
                                    progressFile.textContent = data.file;
                                }
                            }
                        })
                        .catch(function () { /* ignore poll errors */ });
                }, POLL_INTERVAL);
            }

            function stopPolling() {
                if (pollingTimer) {
                    clearInterval(pollingTimer);
                    pollingTimer = null;
                }
            }

            function finishSuccess() {
                stopPolling();
                progressBar.value = 100;
                progressBar.setAttribute('data-complete', '');
                progressLabel.textContent = 'Téléversé avec succès';
                progressFile.textContent = '';
            }

            // ── Upload phase (0% → UPLOAD_CAP) ──
            xhr.upload.addEventListener('progress', function (evt) {
                if (evt.lengthComputable) {
                    const rawPct = Math.round((evt.loaded / evt.total) * 100);
                    const scaled = Math.round((rawPct / 100) * UPLOAD_CAP);
                    if (scaled > lastUploadPct) {
                        lastUploadPct = scaled;
                        progressBar.value = scaled;
                    }
                }
            });

            xhr.upload.addEventListener('loadend', function () {
                uploadDone = true;
                progressBar.value = UPLOAD_CAP;
                startPolling();
            });

            // ── Response handling ──
            xhr.addEventListener('readystatechange', function () {
                if (xhr.readyState !== XMLHttpRequest.DONE) return;

                stopPolling();

                if (xhr.status >= 200 && xhr.status < 300) {
                    finishSuccess();

                    setTimeout(function () {
                        const finalUrl = xhr.responseURL || '';
                        if (finalUrl && finalUrl !== form.action) {
                            window.location.href = finalUrl;
                        } else {
                            document.open();
                            document.write(xhr.responseText);
                            document.close();
                        }
                    }, SUCCESS_DELAY);
                } else {
                    progressLabel.textContent = 'Erreur';
                    progressFile.textContent = 'Échec du téléversement';
                    document.open();
                    document.write(xhr.responseText);
                    document.close();
                }
            });

            xhr.addEventListener('error', function () {
                stopPolling();
                progressLabel.textContent = 'Erreur réseau';
                progressFile.textContent = '';
                if (submitBtn) submitBtn.disabled = false;
            });

            xhr.addEventListener('abort', function () {
                stopPolling();
                progressWrap.style.display = 'none';
                if (submitBtn) submitBtn.disabled = false;
            });

            xhr.open('POST', form.action, true);
            xhr.send(fd);
        });
    }
})();