/**
 * WP Data Optimizer — Admin JS (native fetch, no jQuery)
 *
 * @package WP_Data_Optimizer
 */

( function () {
	'use strict';

	var WPDO = window.wpdoAdmin || {};
	var i18n = WPDO.i18n || {};

	document.addEventListener(
		'DOMContentLoaded',
		function () {
			bindFlushCacheButtons();
			bindStatusRefresh();
		}
	);

	/**
	 * Announce a message via the shared aria-live region.
	 * Falls back to creating the region on first call.
	 */
	function announce( message ) {
		var region = document.getElementById( 'wpdo-aria-live' );
		if ( ! region ) {
			region           = document.createElement( 'div' );
			region.id        = 'wpdo-aria-live';
			region.className = 'wpdo-sr-only';
			region.setAttribute( 'role', 'status' );
			region.setAttribute( 'aria-live', 'polite' );
			region.setAttribute( 'aria-atomic', 'true' );
			document.body.appendChild( region );
		}
		region.textContent = '';
		setTimeout(
			function () {
				region.textContent = message; },
			50
		);
	}

	/**
	 * Render an inline admin notice at the top of .wpdo-wrap.
	 * Dismissable by user. Replaces legacy alert() for errors.
	 */
	function showNotice( message, type ) {
		type     = type || 'error';
		var wrap = document.querySelector( '.wpdo-wrap' );
		if ( ! wrap ) {
			return;
		}

		var notice       = document.createElement( 'div' );
		notice.className = 'notice notice-' + type + ' is-dismissible';
		notice.setAttribute( 'role', type === 'error' ? 'alert' : 'status' );

		var p         = document.createElement( 'p' );
		p.textContent = message;
		notice.appendChild( p );

		var dismiss       = document.createElement( 'button' );
		dismiss.type      = 'button';
		dismiss.className = 'notice-dismiss';
		dismiss.setAttribute( 'aria-label', i18n.dismiss || 'Dismiss' );
		dismiss.addEventListener(
			'click',
			function () {
				notice.remove();
			}
		);
		notice.appendChild( dismiss );

		// Insert after the H1 so it appears at the top of the content area.
		var h1 = wrap.querySelector( 'h1' );
		if ( h1 && h1.nextSibling ) {
			wrap.insertBefore( notice, h1.nextSibling );
		} else {
			wrap.prepend( notice );
		}

		announce( message );
	}

	/**
	 * POST to admin-ajax.php using native fetch + FormData.
	 * Returns a Promise resolving to the parsed JSON response.
	 */
	function wpdoAjax( actionType, data ) {
		var body = new FormData();
		body.append( 'action', 'wpdo_admin_action' );
		body.append( 'nonce', WPDO.nonce || '' );
		body.append( 'action_type', actionType );
		Object.keys( data || {} ).forEach(
			function ( key ) {
				body.append( key, data[ key ] );
			}
		);

		return fetch(
			WPDO.ajaxUrl,
			{
				method: 'POST',
				credentials: 'same-origin',
				body: body,
			}
		)
			.then(
				function ( res ) {
					if ( ! res.ok ) {
							throw new Error( 'HTTP ' + res.status );
					}
					return res.json();
				}
			);
	}

	/**
	 * Flush cache button handler — delegated click listener.
	 */
	function bindFlushCacheButtons() {
		document.addEventListener(
			'click',
			function ( e ) {
				var btn = e.target.closest( '.wpdo-flush-cache' );
				if ( ! btn ) {
					return;
				}
				e.preventDefault();

				var postType = btn.getAttribute( 'data-post-type' );
				if ( ! postType ) {
					return;
				}

				var originalLabel = btn.textContent;
				btn.disabled      = true;
				btn.textContent   = i18n.flushing || 'Flushing…';
				announce( btn.textContent );

				wpdoAjax( 'flush_cache', { post_type: postType } )
				.then(
					function ( response ) {
						if ( response && response.success ) {
								btn.textContent = i18n.flushed || 'Flushed!';
								announce( btn.textContent );
								setTimeout(
									function () {
										btn.disabled    = false;
										btn.textContent = i18n.flushLabel || originalLabel;
									},
									2000
								);
						} else {
							btn.disabled    = false;
							btn.textContent = i18n.flushLabel || originalLabel;
							var msg         = ( response && response.data ) ? String( response.data ) : ( i18n.error || 'Unknown error' );
							showNotice( msg, 'error' );
						}
					}
				)
				.catch(
					function () {
						btn.disabled    = false;
						btn.textContent = i18n.flushLabel || originalLabel;
						showNotice( i18n.error || 'Request failed.', 'error' );
					}
				);
			}
		);
	}

	/**
	 * Auto-refresh module status on the Dashboard tab (every 30s).
	 */
	function bindStatusRefresh() {
		var isDashboard = document.querySelector( '.wpdo-wrap' )
			&& window.location.search.indexOf( 'tab=dashboard' ) !== -1;
		if ( ! isDashboard ) {
			return;
		}

		var timer = setInterval(
			function () {
				if ( ! document.hidden ) {
						refreshStatus();
				}
			},
			30000
		);

		window.addEventListener(
			'beforeunload',
			function () {
				clearInterval( timer );
			}
		);
	}

	function refreshStatus() {
		wpdoAjax( 'module_status', {} )
			.then(
				function ( response ) {
					if ( ! response || ! response.success || ! response.data ) {
						return;
					}
					var data             = response.data;
					var changed          = 0;
					var changedSummaries = [];

					document.querySelectorAll( '.wpdo-state' ).forEach(
						function ( el ) {
							var row    = el.closest( 'tr' );
							var codeEl = row ? row.querySelector( 'code' ) : null;
							if ( ! codeEl ) {
								return;
							}
							var module = codeEl.textContent;
							if ( ! module || ! ( module in data ) ) {
								return;
							}
							var newState = data[ module ];
							if ( el.textContent === newState ) {
								return;
							}
							el.textContent = newState;
							el.className   = 'wpdo-state wpdo-state-' + newState;
							changed++;
							changedSummaries.push( module + ' → ' + newState );
						}
					);

					if ( changed > 0 ) {
						announce( changedSummaries.join( '、' ) );
					}
				}
			)
			.catch(
				function () {
					// Fail silently on polling — user will see the stale state; not worth a notice.
				}
			);
	}

} )();