Amp_Admin_Notices

class Amp_Admin_Notices {
	/**
	 * ID of admin screen on which to display the notice.
	 *
	 * @var string
	 */
	private $screen_id;


	/**
	 * Whether the AMP for WordPress plugin is active.
	 *
	 * @var bool
	 */
	private $amp_is_enabled;

	/**
	 * Whether the site uses SSL.
	 *
	 * @var bool
	 */
	private $is_ssl;

	/**
	 * List of notice items.
	 *
	 * @var array
	 */
	private $notices = [];

	/**
	 * Constructor
	 *
	 * @param string $screen_id ID of string on which to display the notice.
	 * @param bool   $amp_is_enabled Whether the AMP for WordPress plugin is active.
	 * @param bool   $is_ssl Whether the site uses SSL.
	 */
	public function __construct( $screen_id, $amp_is_enabled = false, $is_ssl = null ) {
		$this->screen_id      = $screen_id;
		$this->amp_is_enabled = $amp_is_enabled;
		$this->is_ssl         = is_bool( $is_ssl ) ? $is_ssl : is_ssl();
	}

	/**
	 * Provides the instance's notices.
	 *
	 * @return array
	 */
	public function get_notices() {
		return $this->notices;
	}

	/**
	 * Adds a notice to the instance's notices.
	 *
	 * @param string $notice Notice text.
	 */
	public function add_notice( $notice ) {
		if ( ! in_array( $notice, $this->notices, true ) ) {
			$this->notices[] = $notice;
		}
	}

	/**
	 * Adds the SSL notice if applicable.
	 */
	private function ssl_notice() {
		if ( $this->is_ssl ) {
			return;
		}

		$notice = sprintf(
			// Translators: Placeholder is an external URL about HTTPS.
			__(
				'This site is using <a href="https://wordpress.org/plugins/amp/">AMP</a>, the official AMP plugin for WordPress. HTTPS is required for some features of BigCommerce for WordPress to work correctly with AMP. Read about updating to HTTPS <a href="%s">here</a>.',
				'bigcommerce'
			),
			/**
			 * Filters the URL with information about updating the current site to HTTPS.
			 *
			 * @param string URL.
			 */
			apply_filters(
				'bigcommerce/amp/https_help_url',
				esc_url( 'https://make.wordpress.org/support/user-manual/web-publishing/https-for-wordpress/' )
			)
		);

		/**
		 * Filters the AMP SSL notice text.
		 *
		 * @param string
		 */
		$notice = apply_filters( 'bigcommerce/amp/amp_ssl_notice', $notice );

		$this->add_notice( $notice );
	}

	/**
	 * Displays an admin notice if AMP is active an SSL is not enabled.
	 */
	public function render_amp_admin_notices() {
		if ( ! $this->amp_is_enabled ) {
			return;
		}

		$screen = get_current_screen();
		if ( ! is_a( $screen, WP_Screen::class ) || $this->screen_id !== $screen->id ) {
			return;
		}

		$this->ssl_notice();

		/**
		 * Filters AMP admin notices.
		 *
		 * @param array Array of string messages.
		 */
		if ( empty( apply_filters( 'bigcommerce/amp/admin_notices', $this->notices ) ) ) {
			return;
		}

		$list = sprintf(
			'<ul class="bigcommerce-notice__list">%s</ul>',
			implode(
				'',
				array_map(
					function ( $message ) {
						return sprintf( '<li class="bigcommerce-notice__list-item">%s</li>', $message );
					},
					$this->notices
				)
			)
		);

		echo wp_kses_post(
			sprintf(
				'<div class="notice notice-error bigcommerce-notice"><h3 class="bigcommerce-notice__heading">%s</h3>%s</div>',
				__( 'AMP and BigCommerce', 'bigcommerce' ),
				$list
			)
		);
	}
}