/**
 * upload-progress.js
 *
 * Intercepts admin form submissions (add.php / edit.php) and submits via
 * XMLHttpRequest to display a progress bar for large file uploads.
 * Falls back to native form POST when JavaScript is unavailable.
 *
 * Requires an element with id="upload-progress-bar" inside the form.
 * The progress bar is normally hidden (display:none), shown only during upload.
 */
(() => {
    'use strict';

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

    for (const form of FORMS) {
        const progressWrap = form.querySelector('#upload-progress-wrap');
        const progressBar  = form.querySelector('#upload-progress-bar');
        const progressText = form.querySelector('#upload-progress-text');
        const submitBtn    = form.querySelector('button[type="submit"]');

        if (!progressBar || !progressWrap) continue;

        form.addEventListener('submit', function (e) {
            // Only intercept if files are actually attached (FilePond inputs have files)
            const fileInputs = form.querySelectorAll('input[type="file"]');
            let hasFiles = false;
            for (const fi of fileInputs) {
                if (fi.files && fi.files.length > 0) {
                    hasFiles = true;
                    break;
                }
            }
            if (!hasFiles) return; // let native submit handle it

            e.preventDefault();

            // Show progress bar
            progressWrap.style.display = 'block';
            progressBar.value = 0;
            progressText.textContent = '0%';
            if (submitBtn) submitBtn.disabled = true;

            // Build FormData
            const fd = new FormData(form);
            // Ensure any FilePond-managed files are included — FilePond with
            // storeAsFile:true copies files into the <input>.files, so FormData
            // picks them up automatically from the DOM inputs.
            // But we must also respect queue_order hidden inputs.
            // FormData(form) already handles this since it reads all form fields.

            const xhr = new XMLHttpRequest();

            xhr.upload.addEventListener('progress', function (evt) {
                if (evt.lengthComputable) {
                    const pct = Math.round((evt.loaded / evt.total) * 100);
                    progressBar.value = pct;
                    progressText.textContent = pct + '%';
                }
            });

            xhr.addEventListener('load', function () {
                // Server returns a redirect (302) on success, or re-renders the form on error.
                // We can't follow 302 with XHR directly — the response body is the target page.
                // Check if we got a redirect by examining the response URL.
                const finalUrl = xhr.responseURL || '';
                const isRedirect = xhr.status >= 200 && xhr.status < 300 && finalUrl !== '' && !finalUrl.endsWith(form.action);

                if (isRedirect) {
                    // Success — navigate to the redirect target
                    window.location.href = finalUrl;
                } else {
                    // Error — the server returned the form HTML with flash messages.
                    // Replace the current page content.
                    document.open();
                    document.write(xhr.responseText);
                    document.close();
                }
            });

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

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

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