<?php
/**
 * Where the form is, and whether a link to it is in the footer or a menu (N-02).
 *
 * @package Careback
 */

namespace Careback;

defined( 'ABSPATH' ) || exit;

/**
 * The pages that carry the form, and a link to one of them where customers
 * find it from every page: a menu, a navigation or a template part of a block
 * theme, a widget. Searched when the Setup tab is drawn, never on the site.
 * A page builder is out of sight, so the shop can say it added the link
 * ("I have added the link"), which a small form of its own stores with the day.
 */
class Setup_Link {

	/** The admin-post action of "I have added the link". */
	const ACTION = 'careback_link_added';

	/** The most pages read for the shortcode. */
	const MAX_PAGES = 50;

	/** Statuses of a page that can carry the form now or once published. */
	const STATUSES = array( 'publish', 'draft', 'pending', 'private', 'future' );

	/**
	 * Hooks the form of "I have added the link".
	 *
	 * @return void
	 */
	public static function init() {
		add_action( 'admin_post_' . self::ACTION, array( __CLASS__, 'handle' ) );
	}

	/**
	 * The posts that carry the form's shortcode, oldest first, in any status a
	 * page may be published from.
	 *
	 * @return \WP_Post[]
	 */
	public static function form_pages() {
		global $wpdb;

		$types = array_values( array_diff( get_post_types( array( 'public' => true ) ), array( 'attachment' ) ) );

		if ( ! $types ) {
			return array();
		}

		$params = array_merge( array( '%' . $wpdb->esc_like( '[careback' ) . '%' ), self::STATUSES, $types, array( self::MAX_PAGES ) );
		$ids    = $wpdb->get_col( // phpcs:ignore WordPress.DB.DirectDatabaseQuery -- the Setup tab only; WP_Query cannot search the content for a shortcode.
			$wpdb->prepare(
				"SELECT ID FROM {$wpdb->posts} WHERE post_content LIKE %s AND post_status IN (" . implode( ',', array_fill( 0, count( self::STATUSES ), '%s' ) ) . ') AND post_type IN (' . implode( ',', array_fill( 0, count( $types ), '%s' ) ) . ') ORDER BY ID ASC LIMIT %d', // phpcs:ignore WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare,WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- one placeholder per item.
				$params
			)
		);

		$regex = '/' . get_shortcode_regex( array( 'careback' ) ) . '/';
		$out   = array();

		foreach ( (array) $ids as $id ) {
			$post = get_post( (int) $id );

			if ( $post && 1 === preg_match( $regex, (string) $post->post_content ) ) {
				$out[] = $post;
			}
		}

		return $out;
	}

	/**
	 * The published ones of those.
	 *
	 * @param \WP_Post[] $pages Posts carrying the form.
	 * @return \WP_Post[]
	 */
	public static function published( array $pages ) {
		return array_values(
			array_filter(
				$pages,
				static function ( $post ) {
					return 'publish' === $post->post_status;
				}
			)
		);
	}

	/**
	 * Where a link to the page is found: the menus, the navigations and the
	 * template parts of a block theme, and the widgets — each place named.
	 *
	 * @param \WP_Post $page The page that carries the form.
	 * @return string[]
	 */
	public static function find( \WP_Post $page ) {
		$url   = (string) get_permalink( $page );
		$found = array();

		foreach ( wp_get_nav_menus() as $menu ) {
			foreach ( (array) wp_get_nav_menu_items( $menu->term_id, array( 'post_status' => 'publish' ) ) as $item ) {
				$to_page = 'post_type' === $item->type && (int) $item->object_id === (int) $page->ID;

				if ( $to_page || self::same_address( (string) $item->url, $url ) ) {
					/* translators: %s: name of a menu. */
					$found[] = sprintf( __( '%s (menu)', 'careback' ), $menu->name );
					break;
				}
			}
		}

		$navigations = get_posts(
			array(
				'post_type'      => 'wp_navigation',
				'post_status'    => 'publish',
				'posts_per_page' => 50,
				'no_found_rows'  => true,
			)
		);

		foreach ( $navigations as $navigation ) {
			if ( self::mentions( (string) $navigation->post_content, $page, $url ) ) {
				/* translators: %s: name of a navigation of the theme. */
				$found[] = sprintf( __( '%s (navigation)', 'careback' ), '' !== $navigation->post_title ? $navigation->post_title : __( 'Navigation', 'careback' ) );
			}
		}

		if ( function_exists( 'wp_is_block_theme' ) && wp_is_block_theme() && function_exists( 'get_block_templates' ) ) {
			foreach ( get_block_templates( array(), 'wp_template_part' ) as $part ) {
				if ( self::mentions( (string) $part->content, $page, $url ) ) {
					/* translators: %s: name of a template part, such as "Footer". */
					$found[] = sprintf( __( '%s (template part)', 'careback' ), (string) $part->title );
				}
			}
		}

		foreach ( array( 'widget_block', 'widget_text', 'widget_custom_html' ) as $option ) {
			if ( self::mentions( (string) wp_json_encode( get_option( $option, array() ) ), $page, $url ) ) {
				$found[] = __( 'Widgets', 'careback' );
				break;
			}
		}

		return array_values( array_unique( $found ) );
	}

	/**
	 * True when two addresses lead to the same page: equal, or equal paths on
	 * this site (a path alone, as a menu item may hold it).
	 *
	 * @param string $given  An address as stored.
	 * @param string $target The page's address.
	 * @return bool
	 */
	private static function same_address( $given, $target ) {
		$given = trim( $given );

		if ( '' === $given ) {
			return false;
		}

		if ( untrailingslashit( $given ) === untrailingslashit( $target ) ) {
			return true;
		}

		$path = (string) wp_parse_url( $target, PHP_URL_PATH );
		$host = (string) wp_parse_url( $given, PHP_URL_HOST );

		return '' !== trim( $path, '/' ) && ( '' === $host || (string) wp_parse_url( $target, PHP_URL_HOST ) === $host )
			&& untrailingslashit( (string) wp_parse_url( $given, PHP_URL_PATH ) ) === untrailingslashit( $path );
	}

	/**
	 * True when block or widget content links the page: its address, its path
	 * (not the front page's "/"), its "page_id" address, or a navigation link
	 * naming its id.
	 *
	 * @param string   $content Markup or JSON.
	 * @param \WP_Post $page    The page.
	 * @param string   $url     Its address.
	 * @return bool
	 */
	private static function mentions( $content, \WP_Post $page, $url ) {
		if ( '' === $content ) {
			return false;
		}

		$content = str_replace( '\\/', '/', $content );

		if ( false !== strpos( $content, untrailingslashit( $url ) ) || false !== strpos( $content, 'page_id=' . $page->ID ) ) {
			return true;
		}

		if ( 1 === preg_match( '/"id":' . (int) $page->ID . '\b[^}]*"(type|kind)":"(page|post-type)"|"(type|kind)":"(page|post-type)"[^}]*"id":' . (int) $page->ID . '\b/', $content ) ) {
			return true;
		}

		$path = untrailingslashit( (string) wp_parse_url( $url, PHP_URL_PATH ) );

		return '' !== trim( $path, '/' ) && 1 === preg_match( '#["\']' . preg_quote( $path, '#' ) . '/?["\'?\#]#', $content );
	}

	/**
	 * Stores "I have added the link" with the day, or clears it. Nonce first,
	 * then the capability; then back to Setup, which says "Saved.".
	 *
	 * @return void
	 */
	public static function handle() {
		check_admin_referer( self::ACTION );

		if ( ! current_user_can( 'manage_woocommerce' ) ) {
			wp_die( esc_html__( 'Permission denied.', 'careback' ) );
		}

		( new Settings() )->update( array( 'link_added_at' => empty( $_POST['link_added'] ) ? 0 : time() ) );

		wp_safe_redirect( add_query_arg( 'careback_link', 'saved', admin_url( 'admin.php?page=careback-setup' ) ) . '#careback-setup-step-3' );
		exit;
	}
}