/**
 * WP Data Optimizer — Settings per-section instant save.
 *
 * Each .wpdo-settings-section card has a "儲存此區塊" button that posts only
 * that section's fields via AJAX, updating options without a full page reload.
 *
 * @since 3.0.2
 */
/* global wpdoSettings */
( function () {
	'use strict';

	if ( typeof wpdoSettings === 'undefined' ) {
		return;
	}

	const { ajaxUrl, nonce, i18n } = wpdoSettings;

	/**
	 * Collect form fields within a section into a FormData object.
	 * Unchecked checkboxes are intentionally omitted (server does isset() ? '1' : '0').
	 *
	 * @param {HTMLElement} section
	 * @returns {FormData}
	 */
	function collectFields( section ) {
		const fd = new FormData();
		section.querySelectorAll( 'input, select, textarea' ).forEach( ( el ) => {
			if ( ! el.name ) {
				return;
			}
			if ( el.type === 'checkbox' ) {
				if ( el.checked ) {
					fd.append( el.name, el.value );
				}
			} else if ( el.type === 'radio' ) {
				if ( el.checked ) {
					fd.append( el.name, el.value );
				}
			} else {
				fd.append( el.name, el.value );
			}
		} );
		return fd;
	}

	/**
	 * Show a transient status message, then fade it out after 2.5s.
	 *
	 * @param {HTMLElement} statusEl
	 * @param {string}      message
	 * @param {boolean}     isError
	 */
	function showStatus( statusEl, message, isError ) {
		statusEl.textContent = message;
		statusEl.style.color = isError ? 'var(--color-error, #b03d3d)' : 'var(--color-success, #5a8c5a)';
		statusEl.classList.add( 'visible' );
		clearTimeout( statusEl._wpdo_timer );
		statusEl._wpdo_timer = setTimeout( () => {
			statusEl.classList.remove( 'visible' );
		}, 2500 );
	}

	document.addEventListener( 'click', function ( e ) {
		const btn = e.target.closest( '.wpdo-section-save' );
		if ( ! btn ) {
			return;
		}
		const section    = btn.closest( '.wpdo-settings-section' );
		const statusEl   = btn.nextElementSibling;
		const sectionKey = section ? section.dataset.section : '';
		if ( ! sectionKey ) {
			return;
		}

		const originalLabel = btn.textContent;
		btn.disabled        = true;
		btn.textContent     = i18n.saving;

		const fd = collectFields( section );
		fd.append( 'action', 'wpdo_save_settings_section' );
		fd.append( '_ajax_nonce', nonce );
		fd.append( 'section', sectionKey );

		fetch( ajaxUrl, {
			method      : 'POST',
			credentials : 'same-origin',
			body        : fd,
		} )
			.then( ( r ) => r.json() )
			.then( ( data ) => {
				if ( data.success ) {
					showStatus( statusEl, i18n.saved, false );
				} else {
					showStatus( statusEl, i18n.error, true );
				}
			} )
			.catch( () => {
				showStatus( statusEl, i18n.error, true );
			} )
			.finally( () => {
				btn.disabled    = false;
				btn.textContent = originalLabel;
			} );
	} );
} )();