<?php
namespace AIOSEO\Plugin\Common\Sitemap;

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Determines which content should be included in the sitemap.
 *
 * @since 4.0.0
 */
class Content {
	/**
	 * Returns the entries for the requested sitemap.
	 *
	 * @since 4.0.0
	 *
	 * @return array The sitemap entries.
	 */
	public function get() {
		if ( ! in_array( aioseo()->sitemap->type, [ 'general', 'rss' ], true ) || ! $this->isEnabled() ) {
			return [];
		}

		if ( 'rss' === aioseo()->sitemap->type ) {
			return $this->rss();
		}

		if ( 'general' !== aioseo()->sitemap->type ) {
			return [];
		}

		$indexesEnabled = aioseo()->options->sitemap->general->indexes;
		if ( ! $indexesEnabled ) {
			if ( 'root' === aioseo()->sitemap->indexName ) {
				// If indexes are disabled, throw all entries together into one big file.
				return $this->nonIndexed();
			}

			return [];
		}

		if ( 'root' === aioseo()->sitemap->indexName ) {
			return aioseo()->sitemap->root->indexes();
		}

		// Check if requested index has a dedicated method.
		$methodName = aioseo()->helpers->dashesToCamelCase( aioseo()->sitemap->indexName );
		if ( method_exists( $this, $methodName ) ) {
			return $this->$methodName();
		}

		// Check if requested index is a registered post type.
		if ( in_array( aioseo()->sitemap->indexName, aioseo()->sitemap->helpers->includedPostTypes(), true ) ) {
			return $this->posts( aioseo()->sitemap->indexName );
		}

		// Check if requested index is a registered taxonomy.
		if ( in_array( aioseo()->sitemap->indexName, aioseo()->sitemap->helpers->includedTaxonomies(), true ) ) {
			return $this->terms( aioseo()->sitemap->indexName );
		}

		return [];
	}

	/**
	 * Returns the total entries number for the requested sitemap.
	 *
	 * @since 4.1.5
	 *
	 * @return int The total entries number.
	 */
	public function getTotal() {
		if ( ! in_array( aioseo()->sitemap->type, [ 'general', 'rss' ], true ) || ! $this->isEnabled() ) {
			return 0;
		}

		if ( 'rss' === aioseo()->sitemap->type ) {
			return count( $this->rss() );
		}

		if ( 'general' !== aioseo()->sitemap->type ) {
			return 0;
		}

		$indexesEnabled = aioseo()->options->sitemap->general->indexes;
		if ( ! $indexesEnabled ) {
			if ( 'root' === aioseo()->sitemap->indexName ) {
				// If indexes are disabled, throw all entries together into one big file.
				return count( $this->nonIndexed() );
			}

			return 0;
		}

		if ( 'root' === aioseo()->sitemap->indexName ) {
			return count( aioseo()->sitemap->root->indexes() );
		}

		// Check if requested index has a dedicated method.
		$methodName = aioseo()->helpers->dashesToCamelCase( aioseo()->sitemap->indexName );
		if ( method_exists( $this, $methodName ) ) {
			return count( $this->$methodName() );
		}

		// Check if requested index is a registered post type.
		if ( in_array( aioseo()->sitemap->indexName, aioseo()->sitemap->helpers->includedPostTypes(), true ) ) {
			return aioseo()->sitemap->query->posts( aioseo()->sitemap->indexName, [ 'count' => true ] );
		}

		// Check if requested index is a registered taxonomy.
		if ( in_array( aioseo()->sitemap->indexName, aioseo()->sitemap->helpers->includedTaxonomies(), true ) ) {
			return aioseo()->sitemap->query->terms( aioseo()->sitemap->indexName, [ 'count' => true ] );
		}

		return 0;
	}

	/**
	 * Checks if the requested sitemap is enabled.
	 *
	 * @since 4.0.0
	 *
	 * @return boolean Whether the sitemap is enabled.
	 */
	public function isEnabled() {
		$options = aioseo()->options->noConflict();
		if ( ! $options->sitemap->{aioseo()->sitemap->type}->enable ) {
			return false;
		}

		if ( $options->sitemap->{aioseo()->sitemap->type}->postTypes->all ) {
			return true;
		}

		$included = aioseo()->sitemap->helpers->includedPostTypes();

		return ! empty( $included );
	}

	/**
	 * Returns all sitemap entries if indexing is disabled.
	 *
	 * @since 4.0.0
	 *
	 * @return array $entries The sitemap entries.
	 */
	private function nonIndexed() {
		$additional       = $this->addl();
		$postTypes        = aioseo()->sitemap->helpers->includedPostTypes();
		$isStaticHomepage = 'page' === get_option( 'show_on_front' );
		$blogPageEntry    = [];
		$homePageEntry    = ! $isStaticHomepage ? [ array_shift( $additional ) ] : [];
		$entries          = array_merge( $additional, $this->author(), $this->date(), $this->postArchive() );

		if ( $postTypes ) {
			foreach ( $postTypes as $postType ) {
				$postTypeEntries = $this->posts( $postType );

				// If we don't have a static homepage, it's business as usual.
				if ( ! $isStaticHomepage ) {
					$entries = array_merge( $entries, $postTypeEntries );
					continue;
				}

				$homePageId = (int) get_option( 'page_on_front' );
				$blogPageId = (int) get_option( 'page_for_posts' );

				if ( 'post' === $postType && $blogPageId ) {
					$blogPageEntry[] = array_shift( $postTypeEntries );
				}

				if ( 'page' === $postType && $homePageId ) {
					$homePageEntry[] = array_shift( $postTypeEntries );
				}

				$entries = array_merge( $entries, $postTypeEntries );
			}
		}

		$taxonomies = aioseo()->sitemap->helpers->includedTaxonomies();
		if ( $taxonomies ) {
			foreach ( $taxonomies as $taxonomy ) {
				$entries = array_merge( $entries, $this->terms( $taxonomy ) );
			}
		}

		// Sort first by priority, then by last modified date.
		usort( $entries, function ( $a, $b ) {
			// If the priorities are equal, sort by last modified date.
			if ( $a['priority'] === $b['priority'] ) {
				return $a['lastmod'] > $b['lastmod'] ? -1 : 1;
			}

			return $a['priority'] > $b['priority'] ? -1 : 1;
		} );

		// Merge the arrays with the home page always first.
		return array_merge( $homePageEntry, $blogPageEntry, $entries );
	}

	/**
	 * Returns all post entries for a given post type.
	 *
	 * @since 4.0.0
	 *
	 * @param  string $postType       The name of the post type.
	 * @param  array  $additionalArgs Any additional arguments for the post query.
	 * @return array                  The sitemap entries.
	 */
	public function posts( $postType, $additionalArgs = [] ) {
		$posts = aioseo()->sitemap->query->posts( $postType, $additionalArgs );
		if ( ! $posts ) {
			return [];
		}

		// Return if we're determining the root indexes.
		if ( ! empty( $additionalArgs['root'] ) && $additionalArgs['root'] ) {
			return $posts;
		}

		$entries          = [];
		$isStaticHomepage = 'page' === get_option( 'show_on_front' );
		$homePageId       = (int) get_option( 'page_on_front' );
		$excludeImages    = aioseo()->sitemap->helpers->excludeImages();
		foreach ( $posts as $post ) {
			$entry = [
				'loc'        => get_permalink( $post->ID ),
				'lastmod'    => aioseo()->helpers->dateTimeToIso8601( $this->getLastModified( $post ) ),
				'changefreq' => aioseo()->sitemap->priority->frequency( 'postTypes', $post, $postType ),
				'priority'   => aioseo()->sitemap->priority->priority( 'postTypes', $post, $postType ),
			];

			if ( ! $excludeImages ) {
				$entry['images'] = ! empty( $post->images ) ? json_decode( $post->images ) : [];
			}

			// Override priority/frequency for static homepage.
			if ( $isStaticHomepage && ( $homePageId === $post->ID || aioseo()->helpers->wpmlIsHomePage( $post->ID ) ) ) {
				$entry['loc']        = aioseo()->helpers->maybeRemoveTrailingSlash( aioseo()->helpers->wpmlHomeUrl( $post->ID ) ?: $entry['loc'] );
				$entry['changefreq'] = aioseo()->sitemap->priority->frequency( 'homePage' );
				$entry['priority']   = aioseo()->sitemap->priority->priority( 'homePage' );
			}

			$entries[] = apply_filters( 'aioseo_sitemap_post', $entry, $post->ID, $postType, 'post' );
		}

		// We can't remove the post type here because other plugins rely on it.
		return apply_filters( 'aioseo_sitemap_posts', $entries, $postType );
	}

	/**
	 * Returns all post archive entries.
	 *
	 * @since 4.0.0
	 *
	 * @return array $entries The sitemap entries.
	 */
	private function postArchive() {
		$entries = [];
		foreach ( aioseo()->sitemap->helpers->includedPostTypes( true ) as $postType ) {
			if (
				aioseo()->dynamicOptions->noConflict()->searchAppearance->archives->has( $postType ) &&
				! aioseo()->dynamicOptions->searchAppearance->archives->$postType->advanced->robotsMeta->default &&
				aioseo()->dynamicOptions->searchAppearance->archives->$postType->advanced->robotsMeta->noindex
			) {
				continue;
			}

			$post = aioseo()->core->db
				->start( aioseo()->core->db->db->posts . ' as p', true )
				->select( 'p.ID' )
				->where( 'p.post_status', 'publish' )
				->where( 'p.post_type', $postType )
				->limit( 1 )
				->run()
				->result();

			if ( ! $post ) {
				continue;
			}

			$url = get_post_type_archive_link( $postType );
			if ( $url ) {
				$entries[] = [
					'loc'        => $url,
					'lastmod'    => aioseo()->sitemap->helpers->lastModifiedPostTime( $postType ),
					'changefreq' => aioseo()->sitemap->priority->frequency( 'archive' ),
					'priority'   => aioseo()->sitemap->priority->priority( 'archive' ),
				];
			}
		}

		return apply_filters( 'aioseo_sitemap_post_archives', $entries );
	}

	/**
	 * Returns all term entries for a given taxonomy.
	 *
	 * @since 4.0.0
	 *
	 * @param  string $taxonomy       The name of the taxonomy.
	 * @param  array  $additionalArgs Any additional arguments for the term query.
	 * @return array                  The sitemap entries.
	 */
	public function terms( $taxonomy, $additionalArgs = [] ) {
		$terms = aioseo()->sitemap->query->terms( $taxonomy, $additionalArgs );
		if ( ! $terms ) {
			return [];
		}

		// Get all registered post types for the taxonomy.
		$postTypes = [];
		foreach ( get_post_types() as $postType ) {
			$taxonomies = get_object_taxonomies( $postType );
			foreach ( $taxonomies as $name ) {
				if ( $taxonomy === $name ) {
					$postTypes[] = $postType;
				}
			}
		}

		// Return if we're determining the root indexes.
		if ( ! empty( $additionalArgs['root'] ) && $additionalArgs['root'] ) {
			return $terms;
		}

		$entries = [];
		foreach ( $terms as $term ) {
			$entry = [
				'loc'        => get_term_link( $term->term_id ),
				'lastmod'    => $this->getTermLastModified( $term->term_id ),
				'changefreq' => aioseo()->sitemap->priority->frequency( 'taxonomies', $term, $taxonomy ),
				'priority'   => aioseo()->sitemap->priority->priority( 'taxonomies', $term, $taxonomy ),
				'images'     => aioseo()->sitemap->image->term( $term )
			];

			$entries[] = apply_filters( 'aioseo_sitemap_term', $entry, $term->term_id, $term->taxonomy, 'term' );
		}

		return apply_filters( 'aioseo_sitemap_terms', $entries );
	}

	/**
	 * Returns the last modified date for a given term.
	 *
	 * @since 4.0.0
	 *
	 * @param  int    $termId The term ID.
	 * @return string         The lastmod timestamp.
	 */
	public function getTermLastModified( $termId ) {
		$termRelationshipsTable = aioseo()->core->db->db->prefix . 'term_relationships';
		$lastModified = aioseo()->core->db
			->start( aioseo()->core->db->db->posts . ' as p', true )
			->select( 'MAX(`p`.`post_modified_gmt`) as last_modified' )
			->where( 'p.post_status', 'publish' )
			->whereRaw( "
			( `p`.`ID` IN
				(
					SELECT `tr`.`object_id`
					FROM `$termRelationshipsTable` as tr
					WHERE `tr`.`term_taxonomy_id` = '$termId'
				)
			)" )
			->run()
			->result();

		if ( empty( $lastModified[0]->last_modified ) ) {
			return '';
		}

		return aioseo()->helpers->dateTimeToIso8601( $lastModified[0]->last_modified );
	}

	/**
	 * Returns all additional pages.
	 *
	 * @since 4.0.0
	 *
	 * @param  bool  $shouldChunk Whether the entries should be chuncked. Is set to false when the static sitemap is generated.
	 * @return array              The sitemap entries.
	 */
	public function addl( $shouldChunk = true ) {
		$additionalPages = [];
		if ( aioseo()->options->sitemap->general->additionalPages->enable ) {
			$additionalPages = array_map( 'json_decode', aioseo()->options->sitemap->general->additionalPages->pages );
			$additionalPages = array_filter( $additionalPages, function( $additionalPage ) {
				return ! empty( $additionalPage->url );
			} );
		}

		$entries = [];
		foreach ( $additionalPages as $additionalPage ) {
			$entries[] = [
				'loc'        => $additionalPage->url,
				'lastmod'    => aioseo()->sitemap->helpers->lastModifiedAdditionalPage( $additionalPage ),
				'changefreq' => $additionalPage->frequency->value,
				'priority'   => $additionalPage->priority->value,
				'isTimezone' => true
			];
		}

		$postTypes             = aioseo()->sitemap->helpers->includedPostTypes();
		$shouldIncludeHomepage = 'posts' === get_option( 'show_on_front' ) || ! in_array( 'page', $postTypes, true );
		if ( $shouldIncludeHomepage ) {
			$frontPageId  = (int) get_option( 'page_on_front' );
			$frontPageUrl = aioseo()->helpers->localizedUrl( '/' );
			$post         = aioseo()->helpers->getPost( $frontPageId );

			$homepageEntry = [
				'loc'        => aioseo()->helpers->maybeRemoveTrailingSlash( $frontPageUrl ),
				'lastmod'    => $post ? aioseo()->helpers->dateTimeToIso8601( $this->getLastModified( $post ) ) : aioseo()->sitemap->helpers->lastModifiedPostTime(),
				'changefreq' => aioseo()->sitemap->priority->frequency( 'homePage' ),
				'priority'   => aioseo()->sitemap->priority->priority( 'homePage' )
			];

			$translatedHomepages = aioseo()->helpers->wpmlHomePages();
			foreach ( $translatedHomepages as $languageCode => $translatedHomepage ) {
				if ( untrailingslashit( $translatedHomepage['url'] ) !== untrailingslashit( $homepageEntry['loc'] ) ) {
					$homepageEntry['languages'][] = [
						'language' => $languageCode,
						'location' => $translatedHomepage['url']
					];
				}
			}

			// Add homepage to the first position.
			array_unshift( $entries, $homepageEntry );
		}

		if ( aioseo()->options->sitemap->general->additionalPages->enable ) {
			$entries = apply_filters( 'aioseo_sitemap_additional_pages', $entries );
		}

		if ( empty( $entries ) ) {
			return [];
		}

		if ( aioseo()->options->sitemap->general->indexes && $shouldChunk ) {
			$entries = aioseo()->sitemap->helpers->chunkEntries( $entries );
			$entries = $entries[ aioseo()->sitemap->pageNumber ];
		}

		return $entries;
	}

	/**
	 * Returns all author archive entries.
	 *
	 * @since 4.0.0
	 *
	 * @return array The sitemap entries.
	 */
	public function author() {
		if (
			! aioseo()->sitemap->helpers->lastModifiedPost() ||
			! aioseo()->options->sitemap->general->author ||
			! aioseo()->options->searchAppearance->archives->author->show ||
			(
				! aioseo()->options->searchAppearance->archives->author->advanced->robotsMeta->default &&
				aioseo()->options->searchAppearance->archives->author->advanced->robotsMeta->noindex
			) ||
			(
				aioseo()->options->searchAppearance->archives->author->advanced->robotsMeta->default &&
				(
					! aioseo()->options->searchAppearance->advanced->globalRobotsMeta->default &&
					aioseo()->options->searchAppearance->advanced->globalRobotsMeta->noindex
				)
			)
		) {
			return [];
		}

		// Allow users to filter the authors in case their sites use a membership plugin or have custom code that affect the authors on their site.
		// e.g. there might be additional roles/conditions that need to be checked here.
		$authors = apply_filters( 'aioseo_sitemap_authors', [] );
		if ( empty( $authors ) ) {
			$usersTableName = aioseo()->core->db->db->users; // We get the table name from WPDB since multisites share the same table.
			$authors        = aioseo()->core->db->start( "$usersTableName as u", true )
				->select( 'u.ID as ID, u.user_nicename as nicename, MAX(p.post_modified_gmt) as lastModified' )
				->join( 'posts as p', 'u.ID = p.post_author' )
				->where( 'p.post_status', 'publish' )
				->whereIn( 'p.post_type', aioseo()->sitemap->helpers->getAuthorPostTypes() )
				->groupBy( 'u.ID' )
				->orderBy( 'lastModified DESC' )
				->limit( aioseo()->sitemap->linksPerIndex, aioseo()->sitemap->pageNumber * aioseo()->sitemap->linksPerIndex )
				->run()
				->result();
		}

		if ( empty( $authors ) ) {
			return [];
		}

		$entries = [];
		foreach ( $authors as $authorData ) {
			$nicename  = $authorData->nicename ? $authorData->nicename : null;
			$entries[] = [
				'loc'        => ! empty( $authorData->authorUrl ) ? $authorData->authorUrl : get_author_posts_url( $authorData->ID, $nicename ),
				'lastmod'    => aioseo()->helpers->dateTimeToIso8601( $authorData->lastModified ),
				'changefreq' => aioseo()->sitemap->priority->frequency( 'author' ),
				'priority'   => aioseo()->sitemap->priority->priority( 'author' )
			];
		}

		return apply_filters( 'aioseo_sitemap_author_archives', $entries );
	}

	/**
	 * Returns all data archive entries.
	 *
	 * @since 4.0.0
	 *
	 * @return array The sitemap entries.
	 */
	public function date() {
		if (
			! aioseo()->sitemap->helpers->lastModifiedPost() ||
			! aioseo()->options->sitemap->general->date ||
			! aioseo()->options->searchAppearance->archives->date->show ||
			(
				! aioseo()->options->searchAppearance->archives->date->advanced->robotsMeta->default &&
				aioseo()->options->searchAppearance->archives->date->advanced->robotsMeta->noindex
			) ||
			(
				aioseo()->options->searchAppearance->archives->date->advanced->robotsMeta->default &&
				(
					! aioseo()->options->searchAppearance->advanced->globalRobotsMeta->default &&
					aioseo()->options->searchAppearance->advanced->globalRobotsMeta->noindex
				)
			)
		) {
			return [];
		}

		$postsTable = aioseo()->core->db->db->posts;
		$dates      = aioseo()->core->db->execute(
			"SELECT
				YEAR(post_date) AS `year`,
				MONTH(post_date) AS `month`,
				post_date_gmt,
				post_modified_gmt
			FROM {$postsTable}
			WHERE post_type = 'post' AND post_status = 'publish'
			GROUP BY
				YEAR(post_date),
				MONTH(post_date)
			ORDER BY post_date ASC 
			LIMIT 50000",
			true
		)->result();

		if ( empty( $dates ) ) {
			return [];
		}

		$entries = [];
		$year    = '';
		foreach ( $dates as $date ) {
			$entry = [
				'lastmod'    => aioseo()->helpers->dateTimeToIso8601( $this->getLastModified( $date ) ),
				'changefreq' => aioseo()->sitemap->priority->frequency( 'date' ),
				'priority'   => aioseo()->sitemap->priority->priority( 'date' ),
			];

			// Include each year only once.
			if ( $year !== $date->year ) {
				$year         = $date->year;
				$entry['loc'] = get_year_link( $date->year );
				$entries[]    = $entry;
			}
			$entry['loc'] = get_month_link( $date->year, $date->month );
			$entries[]    = $entry;
		}

		return apply_filters( 'aioseo_sitemap_date_archives', $entries );
	}

	/**
	 * Returns all entries for the RSS Sitemap.
	 *
	 * @since 4.0.0
	 *
	 * @return array The sitemap entries.
	 */
	public function rss() {
		$posts = aioseo()->sitemap->query->posts(
			aioseo()->sitemap->helpers->includedPostTypes(),
			[ 'orderBy' => '`p`.`post_modified_gmt` DESC' ]
		);

		if ( ! count( $posts ) ) {
			return [];
		}

		$entries = [];
		foreach ( $posts as $post ) {
			$entry = [
				'guid'        => get_permalink( $post->ID ),
				'title'       => get_the_title( $post ),
				'description' => get_post_field( 'post_excerpt', $post->ID ),
				'pubDate'     => aioseo()->helpers->dateTimeToRfc822( $this->getLastModified( $post ) )
			];

			$entries[] = apply_filters( 'aioseo_sitemap_post_rss', $entry, $post->ID, $post->post_type, 'post' );
		}

		usort( $entries, function( $a, $b ) {
			return $a['pubDate'] < $b['pubDate'] ? 1 : 0;
		});

		return apply_filters( 'aioseo_sitemap_rss', $entries );
	}

	/**
	 * Returns the last modified date for a given post.
	 *
	 * @since 4.6.3
	 *
	 * @param  object $post The post object.
	 *
	 * @return string The last modified date.
	 */
	public function getLastModified( $post ) {
		$publishDate      = $post->post_date_gmt;
		$lastModifiedDate = $post->post_modified_gmt;

		// Get the date which is the latest.
		return $lastModifiedDate > $publishDate ? $lastModifiedDate : $publishDate;
	}
}