<?php

/**

 * Sitemaps: WP_Sitemaps_Taxonomies class

 *

 * Builds the sitemaps for the 'taxonomy' object type.

 *

 * @package WordPress

 * @subpackage Sitemaps

 * @since 5.5.0

 */

/**

 * Taxonomies XML sitemap provider.

 *

 * @since 5.5.0

 */

class WP_Sitemaps_Taxonomies extends WP_Sitemaps_Provider {

	/**

	 * WP_Sitemaps_Taxonomies constructor.

	 *

	 * @since 5.5.0

	 */

	public function __construct() {

		$this->name        = 'taxonomies';

		$this->object_type = 'term';

	}

	/**

	 * Returns all public, registered taxonomies.

	 *

	 * @since 5.5.0

	 *

	 * @return WP_Taxonomy[] Array of registered taxonomy objects keyed by their name.

	 */

	public function get_object_subtypes() {

		$taxonomies = get_taxonomies( array( 'public' => true ), 'objects' );

		$taxonomies = array_filter( $taxonomies, 'is_taxonomy_viewable' );

		/**

		 * Filter the list of taxonomy object subtypes available within the sitemap.

		 *

		 * @since 5.5.0

		 *

		 * @param WP_Taxonomy[] $taxonomies Array of registered taxonomy objects keyed by their name.

		 */

		return apply_filters( 'wp_sitemaps_taxonomies', $taxonomies );

	}

	/**

	 * Gets a URL list for a taxonomy sitemap.

	 *

	 * @since 5.5.0

	 *

	 * @param int    $page_num Page of results.

	 * @param string $taxonomy Optional. Taxonomy name. Default empty.

	 * @return array Array of URLs for a sitemap.

	 */

	public function get_url_list( $page_num, $taxonomy = '' ) {

		$supported_types = $this->get_object_subtypes();

		// Bail early if the queried taxonomy is not supported.

		if ( ! isset( $supported_types[ $taxonomy ] ) ) {

			return array();

		}

		/**

		 * Filters the taxonomies URL list before it is generated.

		 *

		 * Passing a non-null value will effectively short-circuit the generation,

		 * returning that value instead.

		 *

		 * @since 5.5.0

		 *

		 * @param array  $url_list The URL list. Default null.

		 * @param string $taxonomy Taxonomy name.

		 * @param int    $page_num Page of results.

		 */

		$url_list = apply_filters(

			'wp_sitemaps_taxonomies_pre_url_list',

			null,

			$taxonomy,

			$page_num

		);

		if ( null !== $url_list ) {

			return $url_list;

		}

		$url_list = array();

		// Offset by how many terms should be included in previous pages.

		$offset = ( $page_num - 1 ) * wp_sitemaps_get_max_urls( $this->object_type );

		$args           = $this->get_taxonomies_query_args( $taxonomy );

		$args['offset'] = $offset;

		$taxonomy_terms = new WP_Term_Query( $args );

		if ( ! empty( $taxonomy_terms->terms ) ) {

			foreach ( $taxonomy_terms->terms as $term ) {

				$sitemap_entry = array(

					'loc' => get_term_link( $term ),

				);

				/**

				 * Filters the sitemap entry for an individual term.

				 *

				 * @since 5.5.0

				 *

				 * @param array   $sitemap_entry Sitemap entry for the term.

				 * @param WP_Term $term          Term object.

				 * @param string  $taxonomy      Taxonomy name.

				 */

				$sitemap_entry = apply_filters( 'wp_sitemaps_taxonomies_entry', $sitemap_entry, $term, $taxonomy );

				$url_list[]    = $sitemap_entry;

			}

		}

		return $url_list;

	}

	/**

	 * Gets the max number of pages available for the object type.

	 *

	 * @since 5.5.0

	 *

	 * @param string $taxonomy Taxonomy name.

	 * @return int Total number of pages.

	 */

	public function get_max_num_pages( $taxonomy = '' ) {

		if ( empty( $taxonomy ) ) {

			return 0;

		}

		/**

		 * Filters the max number of pages before it is generated.

		 *

		 * Passing a non-null value will short-circuit the generation,

		 * returning that value instead.

		 *

		 * @since 5.5.0

		 *

		 * @param int    $max_num_pages The maximum number of pages. Default null.

		 * @param string $taxonomy      Taxonomy name.

		 */

		$max_num_pages = apply_filters( 'wp_sitemaps_taxonomies_pre_max_num_pages', null, $taxonomy );

		if ( null !== $max_num_pages ) {

			return $max_num_pages;

		}

		$term_count = wp_count_terms( $taxonomy, $this->get_taxonomies_query_args( $taxonomy ) );

		return (int) ceil( $term_count / wp_sitemaps_get_max_urls( $this->object_type ) );

	}

	/**

	 * Returns the query args for retrieving taxonomy terms to list in the sitemap.

	 *

	 * @since 5.5.0

	 *

	 * @param string $taxonomy Taxonomy name.

	 * @return array Array of WP_Term_Query arguments.

	 */

	protected function get_taxonomies_query_args( $taxonomy ) {

		/**

		 * Filters the taxonomy terms query arguments.

		 *

		 * Allows modification of the taxonomy query arguments before querying.

		 *

		 * @see WP_Term_Query for a full list of arguments

		 *

		 * @since 5.5.0

		 *

		 * @param array  $args     Array of WP_Term_Query arguments.

		 * @param string $taxonomy Taxonomy name.

		 */

		$args = apply_filters(

			'wp_sitemaps_taxonomies_query_args',

			array(

				'fields'                 => 'ids',

				'taxonomy'               => $taxonomy,

				'orderby'                => 'term_order',

				'number'                 => wp_sitemaps_get_max_urls( $this->object_type ),

				'hide_empty'             => true,

				'hierarchical'           => false,

				'update_term_meta_cache' => false,

			),

			$taxonomy

		);

		return $args;

	}

}