<?php
/**
 * Front-end assets and small touches on the WordPress login screen.
 *
 * @package PAYGRAB
 */

defined( 'ABSPATH' ) || exit;

/**
 * Front-end glue.
 */
class Paygrab_Frontend {

	/**
	 * Hooks.
	 *
	 * @return void
	 */
	public static function init() {
		add_action( 'wp_enqueue_scripts', array( __CLASS__, 'maybe_enqueue' ) );
		add_action( 'login_form', array( __CLASS__, 'login_register_link' ) );
		add_filter( 'template_include', array( __CLASS__, 'page_layout' ), 99 );
		add_filter( 'body_class', array( __CLASS__, 'page_layout_class' ) );
		add_filter( 'wp_robots', array( __CLASS__, 'robots' ) );
	}

	/** The pages kept out of search results: the buyer's own screens, which mean nothing to a searcher. */
	const NOINDEX_PAGES = array( 'checkout', 'mypage', 'login', 'register' );

	/**
	 * Ask search engines not to list the checkout, My page, log in and sign-up pages.
	 *
	 * The legal notice page is left out on purpose: it may be listed.
	 *
	 * @param array $robots Robots directives.
	 * @return array
	 */
	public static function robots( $robots ) {
		/**
		 * Filters the PAYGRAB pages that carry "noindex" (checkout, mypage, login, register).
		 *
		 * @param string[] $pages Page keys.
		 */
		$pages = (array) apply_filters( 'paygrab_noindex_pages', self::NOINDEX_PAGES );
		foreach ( $pages as $page ) {
			if ( paygrab_is_page( $page ) ) {
				return wp_robots_no_robots( $robots );
			}
		}
		return $robots;
	}

	/** The pages PAYGRAB draws in its own centered frame. */
	const LAYOUT_PAGES = array( 'checkout', 'mypage', 'login', 'register', 'tokushoho' );

	/**
	 * Which PAYGRAB page is being shown in PAYGRAB's own frame.
	 *
	 * @return string Page key, or '' when the theme's page template is used.
	 */
	public static function layout_page() {
		$key = '';
		foreach ( self::LAYOUT_PAGES as $page ) {
			if ( paygrab_is_page( $page ) ) {
				$key = $page;
				break;
			}
		}
		/**
		 * Filters whether a PAYGRAB page is drawn in PAYGRAB's centered frame (830px) between the
		 * theme's header and footer. Return '' to use the theme's page template instead.
		 *
		 * @param string $key Page key (checkout, mypage, login, register, tokushoho) or ''.
		 */
		$key = (string) apply_filters( 'paygrab_page_layout', $key );
		return $key;
	}

	/**
	 * Use PAYGRAB's page frame for PAYGRAB's pages, whatever the theme's page layout is
	 * (one column, sidebar, wide). The theme's header and footer stay.
	 *
	 * @param string $template Template chosen by WordPress.
	 * @return string
	 */
	public static function page_layout( $template ) {
		if ( ! self::own_frame() ) {
			return $template;
		}
		$file = locate_template( 'paygrab/page-layout.php' );
		return $file ? $file : PAYGRAB_PATH . 'templates/page-layout.php';
	}

	/**
	 * Whether PAYGRAB draws the page frame itself. Block themes build the header and footer from
	 * blocks (get_header() prints nothing there), so they keep their own page template and the
	 * PAYGRAB screen is centered inside it with CSS instead.
	 *
	 * @return bool
	 */
	public static function own_frame() {
		return '' !== self::layout_page() && ! is_embed() && ! wp_is_block_theme();
	}

	/**
	 * Mark the body of a page in PAYGRAB's frame.
	 *
	 * @param string[] $classes Classes.
	 * @return string[]
	 */
	public static function page_layout_class( $classes ) {
		if ( '' !== self::layout_page() ) {
			$classes[] = 'paygrab-page-layout';
			$classes[] = 'paygrab-page-' . self::layout_page();
			$classes[] = self::own_frame() ? 'paygrab-own-frame' : 'paygrab-theme-frame';
		}
		return $classes;
	}

	/**
	 * Register the stylesheet.
	 *
	 * @return void
	 */
	private static function register() {
		if ( ! wp_style_is( 'paygrab', 'registered' ) ) {
			wp_register_style( 'paygrab', PAYGRAB_URL . 'assets/css/paygrab.css', array(), PAYGRAB_VERSION );
			wp_register_script( 'paygrab', PAYGRAB_URL . 'assets/js/paygrab.js', array(), PAYGRAB_VERSION, array( 'in_footer' => true, 'strategy' => 'defer' ) );
		}
	}

	/**
	 * Load the stylesheet only where PAYGRAB shows something.
	 *
	 * @return void
	 */
	public static function maybe_enqueue() {
		$post = get_post();
		$need = false;
		if ( is_singular() && $post ) {
			foreach ( array( Paygrab_Product::SHORTCODE, 'paygrab_checkout', 'paygrab_mypage', 'paygrab_register', 'paygrab_login', 'paygrab_tokushoho' ) as $tag ) {
				if ( has_shortcode( $post->post_content, $tag ) ) {
					$need = true;
					break;
				}
			}
		}
		// A page set as one of PAYGRAB's pages is drawn in PAYGRAB's frame even without a shortcode (the seller's own
		// legal notice table, for one), so the frame needs the stylesheet too.
		if ( ! $need && '' !== self::layout_page() ) {
			$need = true;
		}
		if ( $need ) {
			self::enqueue();
		}
	}

	/**
	 * Load the stylesheet (also called by shortcodes used in unusual places).
	 *
	 * @return void
	 */
	public static function enqueue() {
		self::register();
		wp_enqueue_style( 'paygrab' );
		static $vars = false;
		if ( ! $vars ) {
			wp_add_inline_style( 'paygrab', Paygrab_Styles::css() );
			$vars = true;
		}
		wp_enqueue_script( 'paygrab' );
	}

	/**
	 * "New here? Sign up" under the login form.
	 *
	 * @return void
	 */
	public static function login_register_link() {
		if ( ! paygrab_page_url( 'register' ) ) {
			return;
		}
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$redirect = isset( $_REQUEST['redirect_to'] ) ? wp_validate_redirect( esc_url_raw( wp_unslash( $_REQUEST['redirect_to'] ) ), '' ) : '';
		printf(
			'<p style="margin:0 0 16px">%1$s <a href="%2$s">%3$s</a></p>',
			esc_html__( 'New here?', 'paygrab' ),
			esc_url( paygrab_register_url( $redirect ) ),
			esc_html__( 'Sign up for free', 'paygrab' )
		);
	}
}