/**
 * S1 SEO Meta — Admin Scripts
 * Live character counter with colour feedback.
 */
( function ( $ ) {
	'use strict';

	/**
	 * Update a counter element with the current length and apply colour classes.
	 *
	 * @param {jQuery} $counter  The <span> element showing the count.
	 * @param {number} len       Current character length.
	 * @param {number} soft      Ideal upper boundary (turns amber above this).
	 * @param {number} hard      Hard limit (turns red at or above this).
	 */
	function updateCounter( $counter, len, soft, hard ) {
		$counter.text( len );
		$counter
			.removeClass( 's1-count-ok s1-count-warn s1-count-over' )
			.addClass(
				len >= hard  ? 's1-count-over' :
				len >= soft  ? 's1-count-warn' :
				len > 0      ? 's1-count-ok'   : ''
			);
	}

	function initCounters() {
		// Title field
		var $titleInput   = $( '#s1_seo_title' );
		var $titleCounter = $( '#s1_seo_title_count' );

		if ( $titleInput.length && $titleCounter.length ) {
			// Initialise on page load.
			updateCounter( $titleCounter, $titleInput.val().length, 50, 60 );

			$titleInput.on( 'input', function () {
				updateCounter( $titleCounter, $( this ).val().length, 50, 60 );
			} );
		}

		// Description field
		var $descInput   = $( '#s1_seo_description' );
		var $descCounter = $( '#s1_seo_desc_count' );

		if ( $descInput.length && $descCounter.length ) {
			updateCounter( $descCounter, $descInput.val().length, 120, 160 );

			$descInput.on( 'input', function () {
				updateCounter( $descCounter, $( this ).val().length, 120, 160 );
			} );
		}
	}

	$( document ).ready( initCounters );

} )( jQuery );