<?php
/**
 * Metadata class
 *
 * @package Parsely
 * @since   3.3.0
 */

declare(strict_types=1);

namespace Parsely;

use WP_User;
use WP_Post;

/**
 * Generates and inserts metadata readable by the Parse.ly Crawler.
 *
 * @since 1.0.0
 * @since 3.3.0 Logic extracted from Parsely\Parsely class to separate file/class.
 */
class Metadata {
	/**
	 * Instance of Parsely class.
	 *
	 * @var Parsely
	 */
	private $parsely;

	/**
	 * Constructor.
	 *
	 * @param Parsely $parsely Instance of Parsely class.
	 */
	public function __construct( Parsely $parsely ) {
		$this->parsely = $parsely;
	}

	/**
	 * Creates Parse.ly metadata object from post metadata.
	 *
	 * @param WP_Post $post object.
	 *
	 * @return array<string, mixed>
	 */
	public function construct_metadata( WP_Post $post ): array {
		$options = $this->parsely->get_options();

		$parsely_page      = array(
			'@context' => 'https://schema.org',
			'@type'    => 'WebPage',
		);
		$current_url       = $this->get_current_url();
		$queried_object_id = get_queried_object_id();

		if ( is_front_page() && ! is_paged() ) {
			$parsely_page['headline'] = $this->get_clean_parsely_page_value( get_bloginfo( 'name', 'raw' ) );
			$parsely_page['url']      = home_url();
		} elseif ( is_front_page() && is_paged() ) {
			$parsely_page['headline'] = $this->get_clean_parsely_page_value( get_bloginfo( 'name', 'raw' ) );
			$parsely_page['url']      = $current_url;
		} elseif (
			is_home() && (
				! ( 'page' === get_option( 'show_on_front' ) && ! get_option( 'page_on_front' ) ) ||
				$queried_object_id && (int) get_option( 'page_for_posts' ) === $queried_object_id
			)
		) {
			$parsely_page['headline'] = get_the_title( get_option( 'page_for_posts', true ) );
			$parsely_page['url']      = $current_url;
		} elseif ( is_author() ) {
			// TODO: why can't we have something like a WP_User object for all the other cases? Much nicer to deal with than functions.
			$author                   = ( get_query_var( 'author_name' ) ) ? get_user_by( 'slug', get_query_var( 'author_name' ) ) : get_userdata( get_query_var( 'author' ) );
			$parsely_page['headline'] = $this->get_clean_parsely_page_value( 'Author - ' . $author->data->display_name );
			$parsely_page['url']      = $current_url;
		} elseif ( is_category() || is_post_type_archive() || is_tax() ) {
			$category                 = get_queried_object();
			$parsely_page['headline'] = $this->get_clean_parsely_page_value( $category->name );
			$parsely_page['url']      = $current_url;
		} elseif ( is_date() ) {
			if ( is_year() ) {
				/* translators: %s: Archive year */
				$parsely_page['headline'] = sprintf( __( 'Yearly Archive - %s', 'wp-parsely' ), get_the_time( 'Y' ) );
			} elseif ( is_month() ) {
				/* translators: %s: Archive month, formatted as F, Y */
				$parsely_page['headline'] = sprintf( __( 'Monthly Archive - %s', 'wp-parsely' ), get_the_time( 'F, Y' ) );
			} elseif ( is_day() ) {
				/* translators: %s: Archive day, formatted as F jS, Y */
				$parsely_page['headline'] = sprintf( __( 'Daily Archive - %s', 'wp-parsely' ), get_the_time( 'F jS, Y' ) );
			} elseif ( is_time() ) {
				/* translators: %s: Archive time, formatted as F jS g:i:s A */
				$parsely_page['headline'] = sprintf( __( 'Hourly, Minutely, or Secondly Archive - %s', 'wp-parsely' ), get_the_time( 'F jS g:i:s A' ) );
			}
			$parsely_page['url'] = $current_url;
		} elseif ( is_tag() ) {
			$tag = single_tag_title( '', false );
			if ( empty( $tag ) ) {
				$tag = single_term_title( '', false );
			}
			/* translators: %s: Tag name */
			$parsely_page['headline'] = $this->get_clean_parsely_page_value( sprintf( __( 'Tagged - %s', 'wp-parsely' ), $tag ) );
			$parsely_page['url']      = $current_url;
		} elseif ( in_array( get_post_type( $post ), $options['track_post_types'], true ) && Parsely::post_has_trackable_status( $post ) ) {
			$authors  = $this->get_author_names( $post );
			$category = $this->get_category_name( $post, $options );

			// Get featured image and thumbnail.
			$image_url = get_the_post_thumbnail_url( $post, 'full' );
			if ( ! is_string( $image_url ) ) {
				$image_url = '';
			}
			$thumb_url = get_the_post_thumbnail_url( $post, 'thumbnail' );
			if ( ! is_string( $thumb_url ) ) {
				$thumb_url = '';
			}

			$tags = $this->get_tags( $post->ID );
			if ( $options['cats_as_tags'] ) {
				$tags = array_merge( $tags, $this->get_categories( $post->ID ) );
				// add custom taxonomy values.
				$tags = array_merge( $tags, $this->get_custom_taxonomy_values( $post ) );
			}
			// The function 'mb_strtolower' is not enabled by default in php, so this check
			// falls back to the native php function 'strtolower' if necessary.
			if ( function_exists( 'mb_strtolower' ) ) {
				$lowercase_callback = 'mb_strtolower';
			} else {
				$lowercase_callback = 'strtolower';
			}
			if ( $options['lowercase_tags'] ) {
				$tags = array_map( $lowercase_callback, $tags );
			}

			/**
			 * Filters the post tags that are used as metadata keywords.
			 *
			 * @param string[] $tags Post tags.
			 * @param int $ID Post ID.
			 *
			 * @since 1.8.0
			 */
			$tags = apply_filters( 'wp_parsely_post_tags', $tags, $post->ID );
			$tags = array_map( array( $this, 'get_clean_parsely_page_value' ), $tags );
			$tags = array_values( array_unique( $tags ) );

			/**
			 * Filters the JSON-LD @type.
			 *
			 * @param array $jsonld_type JSON-LD @type value, default is NewsArticle.
			 * @param int $id Post ID.
			 * @param string $post_type The Post type in WordPress.
			 *
			 * @since 2.5.0
			 */
			$type = (string) apply_filters( 'wp_parsely_post_type', 'NewsArticle', $post->ID, $post->post_type );

			// TODO: Merge only once, not every execution.
			$supported_types = array_merge( Parsely::SUPPORTED_JSONLD_POST_TYPES, Parsely::SUPPORTED_JSONLD_NON_POST_TYPES );

			// Validate type before passing it further as an invalid type will not be recognized by Parse.ly.
			if ( ! in_array( $type, $supported_types, true ) ) {
				$error = sprintf(
				/* translators: 1: JSON @type like NewsArticle, 2: URL */
					__( '@type %1$s is not supported by Parse.ly. Please use a type mentioned in %2$s', 'wp-parsely' ),
					$type,
					'https://www.parse.ly/help/integration/jsonld#distinguishing-between-posts-and-pages'
				);
				// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error
				trigger_error( esc_html( $error ), E_USER_WARNING );
				$type = 'NewsArticle';
			}

			$parsely_page['@type']            = $type;
			$parsely_page['mainEntityOfPage'] = array(
				'@type' => 'WebPage',
				'@id'   => $this->get_current_url( 'post' ),
			);
			$parsely_page['headline']         = $this->get_clean_parsely_page_value( get_the_title( $post ) );
			$parsely_page['url']              = $this->get_current_url( 'post', $post->ID );
			$parsely_page['thumbnailUrl']     = $thumb_url;
			$parsely_page['image']            = array(
				'@type' => 'ImageObject',
				'url'   => $image_url,
			);

			$this->set_metadata_post_times( $parsely_page, $post );

			$parsely_page['articleSection'] = $category;
			$author_objects                 = array();
			foreach ( $authors as $author ) {
				$author_tag       = array(
					'@type' => 'Person',
					'name'  => $author,
				);
				$author_objects[] = $author_tag;
			}
			$parsely_page['author']    = $author_objects;
			$parsely_page['creator']   = $authors;
			$parsely_page['publisher'] = array(
				'@type' => 'Organization',
				'name'  => get_bloginfo( 'name' ),
				'logo'  => $options['logo'],
			);
			$parsely_page['keywords']  = $tags;
		} elseif ( in_array( get_post_type(), $options['track_page_types'], true ) && Parsely::post_has_trackable_status( $post ) ) {
			$parsely_page['headline'] = $this->get_clean_parsely_page_value( get_the_title( $post ) );
			$parsely_page['url']      = $this->get_current_url( 'post' );
		} elseif ( 'page' === get_option( 'show_on_front' ) && ! get_option( 'page_on_front' ) ) {
			$parsely_page['headline'] = $this->get_clean_parsely_page_value( get_bloginfo( 'name', 'raw' ) );
			$parsely_page['url']      = home_url();
		}

		/**
		 * Filters the structured metadata.
		 *
		 * @param array $parsely_page Existing structured metadata for a page.
		 * @param WP_Post $post Post object.
		 * @param array $options The Parse.ly options.
		 *
		 * @since 2.5.0
		 */
		$filtered = apply_filters( 'wp_parsely_metadata', $parsely_page, $post, $options );
		if ( is_array( $filtered ) ) {
			return $filtered;
		}

		return array();
	}

	/**
	 * Sanitizes content.
	 *
	 * @since 2.6.0
	 * @since 3.3.0 Moved to class-metadata
	 *
	 * @param string|null $val The content you'd like sanitized.
	 * @return string
	 */
	private function get_clean_parsely_page_value( ?string $val ): string {
		if ( null === $val ) {
			return '';
		}

		$val = str_replace( "\n", '', $val );
		$val = str_replace( "\r", '', $val );
		$val = wp_strip_all_tags( $val );
		return trim( $val );
	}

	/**
	 * Retrieves all the authors for a post as an array. Can include multiple
	 * authors if coauthors plugin is in use.
	 *
	 * @since 3.3.0 Moved to class-metadata
	 *
	 * @param WP_Post $post The post object.
	 * @return array<string>
	 */
	private function get_author_names( WP_Post $post ): array {
		$authors = $this->get_coauthor_names( $post->ID );
		if ( 0 === count( $authors ) ) {
			$post_author = get_user_by( 'id', $post->post_author );
			if ( false !== $post_author ) {
				$authors = array( $post_author );
			}
		}

		/**
		 * Filters the list of author WP_User objects for a post.
		 *
		 * @since 1.14.0
		 *
		 * @param WP_User[] $authors One or more authors as WP_User objects.
		 * @param WP_Post   $post    Post object.
		 */
		$authors = apply_filters( 'wp_parsely_pre_authors', $authors, $post );

		// Getting the author name for each author.
		$authors = array_map( array( $this, 'get_author_name' ), $authors );

		/**
		 * Filters the list of author names for a post.
		 *
		 * @since 1.14.0
		 *
		 * @param string[] $authors One or more author names.
		 * @param WP_Post  $post    Post object.
		 */
		$authors = apply_filters( 'wp_parsely_post_authors', $authors, $post );

		return array_map( array( $this, 'get_clean_parsely_page_value' ), $authors );
	}

	/**
	 * Returns a properly cleaned category/taxonomy value and will optionally
	 * use the top-level category/taxonomy value, if so instructed via the
	 * `use_top_level_cats` option.
	 *
	 * @since 3.3.0 Moved to class-metadata
	 *
	 * @param WP_Post              $post_obj The object for the post.
	 * @param array<string, mixed> $parsely_options The parsely options.
	 * @return string Cleaned category name for the post in question.
	 */
	private function get_category_name( WP_Post $post_obj, array $parsely_options ): string {
		$taxonomy_dropdown_choice = get_the_terms( $post_obj->ID, $parsely_options['custom_taxonomy_section'] );
		// Get top-level taxonomy name for chosen taxonomy and assign to $parent_name; it will be used
		// as the category value if 'use_top_level_cats' option is checked.
		// Assign as the default category name if no value is checked for the chosen taxonomy.
		$category_name = get_cat_name( get_option( 'default_category' ) );
		if ( ! empty( $taxonomy_dropdown_choice ) && ! is_wp_error( $taxonomy_dropdown_choice ) ) {
			if ( $parsely_options['use_top_level_cats'] ) {
				$first_term = array_shift( $taxonomy_dropdown_choice );
				$term_name  = $this->get_top_level_term( $first_term->term_id, $first_term->taxonomy );
			} else {
				$term_name = $this->get_bottom_level_term( $post_obj->ID, $parsely_options['custom_taxonomy_section'] );
			}

			if ( is_string( $term_name ) && 0 < strlen( $term_name ) ) {
				$category_name = $term_name;
			}
		}

		/**
		 * Filters the constructed category name that are used as metadata keywords.
		 *
		 * @since 1.8.0
		 *
		 * @param string  $category    Category name.
		 * @param WP_Post $post_obj    Post object.
		 * @param array<string, mixed> $parsely_options The Parsely options.
		 */
		$category_name = apply_filters( 'wp_parsely_post_category', $category_name, $post_obj, $parsely_options );

		return $this->get_clean_parsely_page_value( $category_name );
	}

	/**
	 * Returns the tags associated with this page or post.
	 *
	 * @since 3.3.0 Moved to class-metadata
	 *
	 * @param int $post_id   The id of the post you're trying to get tags for.
	 * @return array<string> The tags of the post represented by the post id.
	 */
	private function get_tags( int $post_id ): array {
		$tags      = array();
		$post_tags = wp_get_post_tags( $post_id );
		if ( ! is_wp_error( $post_tags ) ) {
			foreach ( $post_tags as $wp_tag ) {
				$tags[] = $wp_tag->name;
			}
		}
		return $tags;
	}

	/**
	 * Returns an array of all the child categories for the current post.
	 *
	 * @since 3.3.0 Moved to class-metadata
	 *
	 * @param int    $post_id The id of the post you're trying to get categories for.
	 * @param string $delimiter What character will delimit the categories.
	 * @return array<string> All the child categories of the current post.
	 */
	private function get_categories( int $post_id, string $delimiter = '/' ): array {
		$tags = array();
		foreach ( get_the_category( $post_id ) as $category ) {
			$hierarchy = get_category_parents( $category->term_id, false, $delimiter );
			if ( ! is_wp_error( $hierarchy ) ) {
				$tags[] = rtrim( $hierarchy, '/' );
			}
		}
		// take last element in the hierarchy, a string representing the full parent->child tree,
		// and split it into individual category names.
		$last_tag = end( $tags );
		if ( false !== $last_tag ) {
			$tags = explode( '/', $last_tag );
		}

		// Remove default category name from tags if needed.
		$default_category_name = get_cat_name( get_option( 'default_category' ) );
		return array_diff( $tags, array( $default_category_name ) );
	}

	/**
	 * Gets all term values from custom taxonomies.
	 *
	 * @since 3.3.0 Moved to class-metadata
	 *
	 * @param WP_Post $post_obj The post object.
	 * @return array<string>
	 */
	private function get_custom_taxonomy_values( WP_Post $post_obj ): array {
		// filter out default WordPress taxonomies.
		$all_taxonomies = array_diff( get_taxonomies(), array( 'post_tag', 'nav_menu', 'author', 'link_category', 'post_format' ) );
		$all_values     = array();

		foreach ( $all_taxonomies as $taxonomy ) {
			$custom_taxonomy_objects = get_the_terms( $post_obj->ID, $taxonomy );
			if ( is_array( $custom_taxonomy_objects ) ) {
				foreach ( $custom_taxonomy_objects as $custom_taxonomy_object ) {
					$all_values[] = $custom_taxonomy_object->name;
				}
			}
		}

		return $all_values;
	}

	/**
	 * Gets the URL of the current PHP script.
	 *
	 * A fall-back implementation to determine permalink.
	 *
	 * @since 3.0.0 $parsely_type Default parameter changed to `non-post`.
	 * @since 3.3.0 Moved to class-metadata
	 *
	 * @param string $parsely_type Optional. Parse.ly post type you're interested in, either 'post'
	 *                             or 'non-post'. Default is 'non-post'.
	 * @param int    $post_id      Optional. ID of the post you want to get the URL for. Default is
	 *                             0, which means the global `$post` is used.
	 * @return string
	 */
	private function get_current_url( string $parsely_type = 'non-post', int $post_id = 0 ): string {
		if ( 'post' === $parsely_type ) {
			$permalink = (string) get_permalink( $post_id );

			/**
			 * Filters the permalink for a post.
			 *
			 * @since 1.14.0
			 * @since 2.5.0  Added $post_id.
			 *
			 * @param string $permalink    The permalink URL or false if post does not exist.
			 * @param string $parsely_type Parse.ly type ("post" or "non-post").
			 * @param int    $post_id      ID of the post you want to get the URL for. May be 0, so
			 *                             $permalink will be for the global $post.
			 */
			$url = apply_filters( 'wp_parsely_permalink', $permalink, $parsely_type, $post_id );
		} else {
			$request_uri = isset( $_SERVER['REQUEST_URI'] )
				? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) )
				: '';

			$url = home_url( $request_uri );
		}

		$options = $this->parsely->get_options();
		return $options['force_https_canonicals']
			? str_replace( 'http://', 'https://', $url )
			: str_replace( 'https://', 'http://', $url );
	}

	/**
	 * Sets all metadata values related to post time.
	 *
	 * @since 3.0.2
	 * @since 3.3.0 Moved to class-metadata
	 *
	 * @param array   $metadata Array containing all metadata. It will be potentially mutated to add
	 *                          keys: dateCreated, dateModified, & datePublished.
	 * @param WP_Post $post     Post object from which to extract time data.
	 */
	private function set_metadata_post_times( array &$metadata, WP_Post $post ): void {
		$date_format      = 'Y-m-d\TH:i:s\Z';
		$post_created_gmt = get_post_time( $date_format, true, $post );

		if ( false === $post_created_gmt ) {
			return;
		}

		$metadata['dateCreated']   = $post_created_gmt;
		$metadata['datePublished'] = $post_created_gmt;
		$metadata['dateModified']  = $post_created_gmt;

		$post_modified_gmt = get_post_modified_time( $date_format, true, $post );

		if ( false !== $post_modified_gmt && $post_modified_gmt > $post_created_gmt ) {
			$metadata['dateModified'] = $post_modified_gmt;
		}
	}

	/**
	 * Returns a list of coauthors for a post assuming the Co-Authors Plus plugin
	 * is installed.
	 *
	 * Borrowed from
	 * https://github.com/Automattic/Co-Authors-Plus/blob/master/template-tags.php#L3-35
	 *
	 * @since 3.3.0 Moved to class-metadata
	 *
	 * @param int $post_id The id of the post.
	 * @return array<WP_User>
	 */
	private function get_coauthor_names( int $post_id ): array {
		$coauthors = array();
		if ( class_exists( 'coauthors_plus' ) ) {
			global $post, $post_ID, $coauthors_plus;

			if ( ! $post_id && $post_ID ) {
				$post_id = $post_ID;
			}

			if ( ! $post_id && $post ) {
				$post_id = $post->ID;
			}

			if ( $post_id ) {
				$coauthor_terms = get_the_terms( $post_id, $coauthors_plus->coauthor_taxonomy );

				if ( is_array( $coauthor_terms ) ) {
					foreach ( $coauthor_terms as $coauthor ) {
						$coauthor_slug = preg_replace( '#^cap-#', '', $coauthor->slug );
						$post_author   = $coauthors_plus->get_coauthor_by( 'user_nicename', $coauthor_slug );
						// In case the user has been deleted while plugin was deactivated.
						if ( ! empty( $post_author ) ) {
							$coauthors[] = new WP_User( $post_author );
						}
					}
				} elseif ( ! $coauthors_plus->force_guest_authors ) {
					if ( $post && $post_id === $post->ID ) {
						$post_author = get_userdata( $post->post_author );
					}
					if ( ! empty( $post_author ) ) {
						$coauthors[] = $post_author;
					}
				}
				// The empty else case is because if we force guest authors, we don't ever care what value wp_posts.post_author has.
			}
		}
		return $coauthors;
	}

	/**
	 * Determines author name from display name, falling back to firstname
	 * lastname, then nickname and finally the nicename.
	 *
	 * @since 3.3.0 Moved to class-metadata
	 *
	 * @param ?WP_User $author The author of the post.
	 * @return string
	 */
	private function get_author_name( ?WP_User $author ): string {
		// Gracefully handle situation where no author is available.
		if ( null === $author ) {
			return '';
		}

		if ( ! empty( $author->display_name ) ) {
			return $author->display_name;
		}

		$author_name = $author->user_firstname . ' ' . $author->user_lastname;
		if ( ' ' !== $author_name ) {
			return $author_name;
		}

		if ( ! empty( $author->nickname ) ) {
			return $author->nickname;
		}

		if ( ! empty( $author->user_nicename ) ) {
			return $author->user_nicename;
		}

		return '';
	}

	/**
	 * Returns the top-most category/taxonomy value in a hierarcy given a
	 * taxonomy value's ID.
	 *
	 * (WordPress calls taxonomy values 'terms').
	 *
	 * @since 3.3.0 Moved to class-metadata
	 *
	 * @param int    $term_id The id of the top level term.
	 * @param string $taxonomy_name The name of the taxonomy.
	 * @return string|false $parent The top level name of the category / taxonomy.
	 */
	private function get_top_level_term( int $term_id, string $taxonomy_name ) {
		$parent = get_term_by( 'id', $term_id, $taxonomy_name );
		while ( false !== $parent && 0 !== $parent->parent ) {
			$parent = get_term_by( 'id', $parent->parent, $taxonomy_name );
		}
		return $parent ? $parent->name : false;
	}

	/**
	 * Returns the bottom-most category/taxonomy value in a hierarchy given a
	 * post ID.
	 *
	 * (WordPress calls taxonomy values 'terms').
	 *
	 * @since 3.3.0 Moved to class-metadata
	 *
	 * @param int    $post_id The post id you're interested in.
	 * @param string $taxonomy_name The name of the taxonomy.
	 * @return string Name of the custom taxonomy.
	 */
	private function get_bottom_level_term( int $post_id, string $taxonomy_name ): string {
		$terms = get_the_terms( $post_id, $taxonomy_name );

		if ( ! is_array( $terms ) ) {
			return '';
		}

		$term_ids = wp_list_pluck( $terms, 'term_id' );
		$parents  = array_filter( wp_list_pluck( $terms, 'parent' ) );

		// Get array of IDs of terms which are not parents.
		$term_ids_not_parents = array_diff( $term_ids, $parents );
		// Get corresponding term objects, which are mapped to array index keys.
		$terms_not_parents = array_intersect_key( $terms, $term_ids_not_parents );
		// remove array index keys.
		$terms_not_parents_cleaned = array_values( $terms_not_parents );

		if ( ! empty( $terms_not_parents_cleaned ) ) {
			// if you assign multiple child terms in a custom taxonomy, will only return the first.
			return $terms_not_parents_cleaned[0]->name ?? '';
		}

		return '';
	}
}