<?php
/**
 * Titles of the site's own pages.
 *
 * @package Dealroot
 */

namespace Dealroot;

defined( 'ABSPATH' ) || exit;

/**
 * Finds the title of a page of this site from the path the tracker recorded, so that
 * screens can say "Contact" instead of /kontakt/.
 */
class Pages {

	/**
	 * Title of a page: the page, post or product title, the category name, or the site name
	 * for the home page.
	 *
	 * @param string $path Path as recorded, e.g. /kontakt/?utm_source=x.
	 * @return string '' when the page is not known.
	 */
	public static function title( $path ) {
		static $titles = array();

		$path = (string) strtok( (string) $path, '?#' );

		if ( '' === $path || '/' !== $path[0] ) {
			return '';
		}

		if ( isset( $titles[ $path ] ) ) {
			return $titles[ $path ];
		}

		$home = trailingslashit( (string) wp_parse_url( home_url( '/' ), PHP_URL_PATH ) );

		if ( trailingslashit( $path ) === $home ) {
			// The home page goes by the name of the site, which says more than a title like "Home".
			$front = 'page' === get_option( 'show_on_front' ) ? (int) get_option( 'page_on_front' ) : 0;
			$title = '' !== get_bloginfo( 'name' ) ? get_bloginfo( 'name' ) : ( $front ? get_the_title( $front ) : '' );
		} else {
			$title = self::post_title( $path );

			if ( '' === $title ) {
				$title = self::term_title( $path );
			}
		}

		$titles[ $path ] = trim( wp_strip_all_tags( html_entity_decode( (string) $title, ENT_QUOTES, 'UTF-8' ) ) );

		return $titles[ $path ];
	}

	/**
	 * Title of a published post, page or product at a path.
	 *
	 * @param string $path Path without query.
	 * @return string
	 */
	private static function post_title( $path ) {
		$origin = (string) preg_replace( '#^(https?://[^/]+).*$#', '$1', home_url() );
		$id     = url_to_postid( $origin . $path );

		// Pages that a plugin shows as an archive, e.g. the WooCommerce shop, are found by their path.
		if ( ! $id ) {
			$home = (string) wp_parse_url( home_url( '/' ), PHP_URL_PATH );
			$page = get_page_by_path( trim( substr( $path, strlen( rtrim( $home, '/' ) ) ), '/' ) );
			$id   = $page ? (int) $page->ID : 0;
		}

		return $id && 'publish' === get_post_status( $id ) && is_post_type_viewable( get_post_type( $id ) ) ? (string) get_the_title( $id ) : '';
	}

	/**
	 * Name of a category, tag or product category whose archive is at a path.
	 *
	 * @param string $path Path without query.
	 * @return string
	 */
	private static function term_title( $path ) {
		$slug = basename( untrailingslashit( $path ) );

		if ( '' === $slug ) {
			return '';
		}

		foreach ( get_taxonomies( array( 'public' => true ) ) as $taxonomy ) {
			$term = get_term_by( 'slug', sanitize_title( $slug ), $taxonomy );

			if ( ! $term ) {
				continue;
			}

			$link = get_term_link( $term );

			if ( ! is_wp_error( $link ) && untrailingslashit( (string) wp_parse_url( $link, PHP_URL_PATH ) ) === untrailingslashit( $path ) ) {
				return $term->name;
			}
		}

		return '';
	}
}