<?php
/**
 * Conditional asset loading.
 *
 * Nothing is enqueued globally. The base stylesheet loads only when a Display is
 * actually going to render, and the carousel script only when a carousel layout
 * or the carousel template is in play.
 *
 * @package Stunning_Related
 */

defined( 'ABSPATH' ) || exit;

/**
 * Assets.
 */
class SRPP_Assets {

	/**
	 * Whether base CSS has been requested.
	 *
	 * @var bool
	 */
	protected static $base = false;

	/**
	 * Whether carousel assets have been requested.
	 *
	 * @var bool
	 */
	protected static $carousel = false;

	/**
	 * Constructor.
	 */
	public function __construct() {
		add_action( 'wp_enqueue_scripts', array( $this, 'register' ), 5 );
		add_action( 'wp', array( $this, 'preload' ), 30 );
	}

	/**
	 * Register handles without enqueueing them.
	 */
	public function register() {
		wp_register_style( 'srpp', SRPP_URL . 'public/css/srpp.css', array(), SRPP_VERSION );
		wp_register_script( 'srpp-carousel', SRPP_URL . 'public/js/carousel.js', array(), SRPP_VERSION, true );
		wp_register_script( 'srpp-analytics', SRPP_URL . 'public/js/analytics.js', array(), SRPP_VERSION, true );

		wp_localize_script(
			'srpp-analytics',
			'SRPP_A',
			array(
				'url'     => admin_url( 'admin-ajax.php' ),
				'action'  => 'srpp_track',
				'nonce'   => wp_create_nonce( 'srpp_track' ),
				'enabled' => (int) srpp_get_option( 'analytics_enabled', 1 ),
			)
		);
	}

	/**
	 * Work out ahead of output which Displays will run, so their CSS can go in
	 * the head rather than the footer.
	 */
	public function preload() {
		if ( is_admin() || is_feed() ) {
			return;
		}

		$post_id = is_singular() ? get_queried_object_id() : 0;

		foreach ( SRPP_Display::active() as $display ) {
			$placement = $display->opt( 'placement' );
			$is_woo    = SRPP_Woo::is_woo_placement( $placement );

			if ( ! $is_woo && ! SRPP_Placement::is_content_placement( $placement ) ) {
				continue;
			}

			if ( ! $is_woo && ! $post_id ) {
				continue;
			}

			$context = $is_woo ? 'shop' : 'singular';

			if ( ! SRPP_Conditions::passes( $display, $post_id, $context ) ) {
				continue;
			}

			self::mark_used( $display->opt( 'layout' ), $display->opt( 'template' ) );
		}
	}

	/**
	 * Flag the assets a rendered block needs.
	 *
	 * @param string $layout   Layout key.
	 * @param string $template Template ID.
	 */
	public static function mark_used( $layout, $template ) {
		if ( ! self::$base && srpp_get_option( 'load_base_css', 1 ) ) {
			self::$base = true;
			wp_enqueue_style( 'srpp' );
		}

		if ( srpp_get_option( 'analytics_enabled', 1 ) ) {
			wp_enqueue_script( 'srpp-analytics' );
		}

		if ( ! self::$carousel && ( 'carousel' === $layout || 'tpl-12' === $template ) ) {
			self::$carousel = true;
			wp_enqueue_script( 'srpp-carousel' );
		}
	}
}