<?php
/**
 * Contextual Related Posts: Main CRP Class
 *
 * @package Contextual_Related_Posts
 * @since 3.5.0
 */

namespace WebberZone\Contextual_Related_Posts;

use WebberZone\Contextual_Related_Posts\Frontend\Display;
use WebberZone\Contextual_Related_Posts\Util\Cache;
use WebberZone\Contextual_Related_Posts\Util\Helpers;

// If this file is called directly, abort.
if ( ! defined( 'WPINC' ) ) {
	die;
}

/**
 * Contextual Related Posts: Main CRP Class.
 *
 * @since 3.0.0
 */
class CRP_Core_Query {

	/**
	 * Source Post to find related posts for.
	 *
	 * @var \WP_Post A WP_Post instance.
	 */
	public $source_post;

	/**
	 * Query vars, before parsing
	 *
	 * @since 3.0.2
	 * @var array
	 */
	public $input_query_args = array();

	/**
	 * Query vars, after parsing
	 *
	 * @since 3.0.0
	 * @var array
	 */
	public $query_args = array();

	/**
	 * Flag to check if it is a CRP query.
	 *
	 * @since 3.5.0
	 * @var bool
	 */
	public $is_crp_query = false;

	/**
	 * Flag to turn relevance matching ON or OFF.
	 *
	 * @since 3.0.0
	 * @var bool
	 */
	public $enable_relevance = true;

	/**
	 * Random order flag.
	 *
	 * @since 3.0.0
	 * @var bool
	 */
	public $random_order = false;

	/**
	 * CRP Post Meta.
	 *
	 * @since 3.0.0
	 * @var mixed
	 */
	public $crp_post_meta;

	/**
	 * Array of manual related post IDs.
	 *
	 * @since 3.3.0
	 * @var array
	 */
	public $manual_related = array();

	/**
	 * Number of manual related posts.
	 *
	 * @since 3.3.0
	 * @var int
	 */
	public $no_of_manual_related = 0;

	/**
	 * Fields to be matched.
	 *
	 * @since 3.0.0
	 * @var string
	 */
	public $match_fields = '';

	/**
	 * Match SQL.
	 *
	 * @since 4.0.0
	 * @var string
	 */
	public $match_sql = '';

	/**
	 * Holds the text to be matched.
	 *
	 * @since 3.0.0
	 * @var string
	 */
	public $stuff = '';

	/**
	 * Cache set flag.
	 *
	 * @since 3.0.0
	 * @var bool
	 */
	public $in_cache = false;

	/**
	 * Array of SQL LIKE statements when using the Include Words functionality.
	 *
	 * @since 3.4.2
	 * @var array
	 */
	public $include_orderby_title = array();

	/**
	 * Main constructor.
	 *
	 * @since 3.0.0
	 *
	 * @param array|string $args The Query variables. Accepts an array or a query string.
	 */
	public function __construct( $args = array() ) {
		$this->prepare_query_args( $args );

		if ( isset( $args['crp_query'] ) && true === $args['crp_query'] && ! $this->is_crp_query ) {
			$this->hooks();
		}
	}

	/**
	 * Initialise search hooks.
	 *
	 * @since 3.5.0
	 */
	public function hooks() {
		add_filter( 'pre_get_posts', array( $this, 'pre_get_posts' ), 10 );
		add_filter( 'posts_fields', array( $this, 'posts_fields' ), 10, 2 );
		add_filter( 'posts_join', array( $this, 'posts_join' ), 10, 2 );
		add_filter( 'posts_where', array( $this, 'posts_where' ), 10, 2 );
		add_filter( 'posts_orderby', array( $this, 'posts_orderby' ), 10, 2 );
		add_filter( 'posts_groupby', array( $this, 'posts_groupby' ), 10, 2 );
		add_filter( 'posts_request', array( $this, 'posts_request' ), 10, 2 );
		add_filter( 'posts_pre_query', array( $this, 'posts_pre_query' ), 10, 2 );
		add_filter( 'the_posts', array( $this, 'the_posts' ), 10, 2 );
	}

	/**
	 * Prepare the query variables.
	 *
	 * @since 3.0.0
	 * @see WP_Query::parse_query()
	 * @see crp_get_registered_settings()
	 *
	 * @param string|array $args {
	 *     Optional. Array or string of Query parameters.
	 *
	 *     @type array|string  $include_cat_ids  An array or comma-separated string of category or custom taxonomy term_taxonoy_id.
	 *     @type array|string  $include_post_ids An array or comma-separated string of post IDs.
	 *     @type bool          $offset           Offset the related posts returned by this number.
	 *     @type int           $postid           Get related posts for a specific post ID.
	 *     @type bool          $strict_limit     If this is set to false, then it will fetch 3x posts.
	 * }
	 */
	public function prepare_query_args( $args = array() ) {
		global $post;
		$crp_settings = crp_get_settings();

		$defaults = array(
			'include_cat_ids'  => 0,
			'include_post_ids' => null,
			'offset'           => 0,
			'postid'           => false,
			'strict_limit'     => true,
		);
		$defaults = array_merge( $defaults, $crp_settings );
		$args     = wp_parse_args( $args, $defaults );
		$args     = Helpers::parse_wp_query_arguments( $args );

		// Set necessary variables.
		$args['crp_query']           = true;
		$args['suppress_filters']    = false;
		$args['ignore_sticky_posts'] = true;
		$args['no_found_rows']       = true;

		// Store query args before we manipulate them.
		$this->input_query_args = $args;
		$this->is_crp_query     = isset( $this->input_query_args['is_crp_query'] ) ? $this->input_query_args['is_crp_query'] : false;

		// Set the source post.
		$source_post = empty( $args['postid'] ) && empty( $args['post_id'] ) ? $post : ( isset( $args['postid'] ) ? get_post( $args['postid'] ) : get_post( $args['post_id'] ) );
		if ( ! $source_post ) {
			$source_post = get_post();
		}
		$this->source_post = $source_post;

		/**
		 * Applies filters to the query arguments before executing the query.
		 *
		 * This function allows developers to modify the query arguments before the query is executed.
		 *
		 * @since 3.5.0
		 *
		 * @param array     $args         The query arguments.
		 * @param \WP_Post  $source_post  The source post.
		 */
		$args = apply_filters( 'crp_query_args_before', $args, $source_post );

		// Save post meta into a class-wide variable.
		$this->crp_post_meta = get_post_meta( $source_post->ID, 'crp_post_meta', true );

		// Handle manual_related argument.
		if ( isset( $args['manual_related'] ) ) {
			$this->manual_related = ( 0 === (int) $args['manual_related'] ) ? array() : wp_parse_id_list( $args['manual_related'] );
		} else {
			$args['manual_related'] = ! empty( $this->crp_post_meta['manual_related'] ) ? $this->crp_post_meta['manual_related'] : '';
			$this->manual_related   = wp_parse_id_list( $args['manual_related'] );
		}

		// Handle include_post_ids argument.
		if ( isset( $args['include_post_ids'] ) ) {
			$include_post_ids     = ( 0 === (int) $args['include_post_ids'] ) ? array() : wp_parse_id_list( $args['include_post_ids'] );
			$this->manual_related = array_merge( $this->manual_related, $include_post_ids );
		}

		$this->no_of_manual_related = count( $this->manual_related );

		if ( empty( $args['keyword'] ) ) {
			$args['keyword'] = ! empty( $this->crp_post_meta['keyword'] ) ? $this->crp_post_meta['keyword'] : '';
		}

		// Set the random order and save it in a class-wide variable.
		$random_order = ( $args['random_order'] || ( isset( $args['ordering'] ) && 'random' === $args['ordering'] ) ) ? true : false;
		// If we need to order randomly then set strict_limit to false.
		if ( $random_order ) {
			$args['strict_limit'] = false;
		}
		$this->random_order = $random_order;

		// Set the number of posts to be retrieved. Use posts_per_page if set else use limit.
		if ( empty( $args['posts_per_page'] ) ) {
			$args['posts_per_page'] = ( $args['strict_limit'] ) ? absint( $args['limit'] ) : ( absint( $args['limit'] ) * 3 );
		}

		if ( empty( $args['post_type'] ) ) {
			// If post_types is empty or contains a query string then use parse_str else consider it comma-separated.
			if ( ! empty( $args['post_types'] ) && is_array( $args['post_types'] ) ) {
				$post_types = $args['post_types'];
			} elseif ( ! empty( $args['post_types'] ) && false === strpos( $args['post_types'], '=' ) ) {
				$post_types = explode( ',', $args['post_types'] );
			} else {
				parse_str( $args['post_types'], $post_types );  // Save post types in $post_types variable.
			}

			// If post_types is empty or if we want all the post types.
			if ( empty( $post_types ) || 'all' === $args['post_types'] ) {
				$post_types = get_post_types(
					array(
						'public' => true,
					)
				);
			}

			// If we only want posts from the same post type.
			if ( $args['same_post_type'] ) {
				$post_types = (array) $source_post->post_type;
			}

			/**
			 * Filter the post_types passed to the query.
			 *
			 * @since 2.2.0
			 * @since 3.0.0 Changed second argument from post ID to WP_Post object.
			 *
			 * @param array   $post_types  Array of post types to filter by.
			 * @param \WP_Post $source_post Source Post instance.
			 * @param array   $args        Arguments array.
			 */
			$args['post_type'] = apply_filters( 'crp_posts_post_types', $post_types, $source_post, $args );
		}

		// Tax Query.
		if ( ! empty( $args['tax_query'] ) && is_array( $args['tax_query'] ) ) {
			$tax_query = $args['tax_query'];
		} else {
			$tax_query = array();
		}

		if ( ! empty( $args['include_cat_ids'] ) ) {
			$tax_query[] = array(
				'field'            => 'term_taxonomy_id',
				'terms'            => wp_parse_id_list( $args['include_cat_ids'] ),
				'include_children' => false,
			);
		}

		if ( ! empty( $args['exclude_categories'] ) ) {
			$tax_query[] = array(
				'field'            => 'term_taxonomy_id',
				'terms'            => wp_parse_id_list( $args['exclude_categories'] ),
				'operator'         => 'NOT IN',
				'include_children' => false,
			);
		}

		if ( ! empty( $args['primary_term'] ) ) {
			// Get the taxonomies used by the post type.
			$post_taxonomies = get_object_taxonomies( $source_post );

			foreach ( (array) $post_taxonomies as $term ) {
				if ( empty( $primary_term['primary'] ) ) {
					$primary_term = Helpers::get_primary_term( $source_post, $term );
				}
			}

			if ( ! empty( $primary_term['primary'] ) ) {

				$tax_query[] = array(
					'field'            => 'term_taxonomy_id',
					'terms'            => wp_parse_id_list( $primary_term['primary']->term_taxonomy_id ),
					'include_children' => false,
				);
			}
		}

		// Process same taxonomies option.
		if ( isset( $args['same_taxes'] ) && $args['same_taxes'] ) {
			$taxonomies = explode( ',', $args['same_taxes'] );

			// Get the taxonomies used by the post type.
			if ( empty( $post_taxonomies ) ) {
				$post_taxonomies = get_object_taxonomies( $source_post );
			}

			// Only limit the taxonomies to what is selected for the current post.
			$current_taxonomies = array_values( array_intersect( $taxonomies, $post_taxonomies ) );

			// Store the number of common taxonomies.
			$args['taxonomy_count'] = count( $current_taxonomies );

			// Get the terms for the current post.
			$terms = wp_get_object_terms( $source_post->ID, (array) $current_taxonomies );
			if ( ! is_wp_error( $terms ) && ! empty( $terms ) ) {
				$term_taxonomy_ids = array_unique( wp_list_pluck( $terms, 'term_taxonomy_id' ) );

				$tax_query[] = array(
					'field'            => 'term_taxonomy_id',
					'terms'            => wp_parse_id_list( $term_taxonomy_ids ),
					'operator'         => 'IN',
					'include_children' => false,
				);
			}
		}

		/**
		 * Filter the tax_query passed to the query.
		 *
		 * @since 3.0.0
		 *
		 * @param array    $tax_query   Array of tax_query parameters.
		 * @param \WP_Post $source_post Source Post instance.
		 * @param array    $args        Arguments array.
		 */
		$tax_query = apply_filters( 'crp_query_tax_query', $tax_query, $source_post, $args );

		// Add a relation key if more than one $tax_query.
		if ( count( $tax_query ) > 1 && ! isset( $tax_query['relation'] ) ) {
			/**
			 * Filter the tax_query relation parameter.
			 *
			 * @since 3.5.3
			 *
			 * @param string  $relation The logical relationship between each inner taxonomy array when there is more than one. Default is 'AND'.
			 * @param array   $args     Arguments array.
			 */
			$tax_query['relation'] = apply_filters( 'crp_query_tax_query_relation', 'AND', $args );
		}

		$args['tax_query'] = $tax_query; // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_tax_query

		// Set date_query.
		$date_query = array(
			array(
				'after'     => ( 0 === absint( $args['daily_range'] ) ) ? '' : gmdate( 'Y-m-d', strtotime( current_time( 'mysql' ) ) - ( absint( $args['daily_range'] ) * DAY_IN_SECONDS ) ),
				'before'    => current_time( 'mysql' ),
				'inclusive' => true,
			),
		);

		/**
		 * Filter the date_query passed to WP_Query.
		 *
		 * @since 3.3.0
		 *
		 * @param array   $date_query Array of date parameters to be passed to WP_Query.
		 * @param array   $args       Arguments array.
		 */
		$args['date_query'] = apply_filters( 'crp_query_date_query', $date_query, $args );

		// Meta Query.
		if ( ! empty( $args['meta_query'] ) && is_array( $args['meta_query'] ) ) {
			$meta_query = $args['meta_query'];
		} else {
			$meta_query = array();
		}

		/**
		 * Filter the meta_query passed to WP_Query.
		 *
		 * @since 3.3.0
		 *
		 * @param array   $meta_query Array of meta_query parameters.
		 * @param array   $args       Arguments array.
		 */
		$meta_query = apply_filters( 'crp_query_meta_query', $meta_query, $args ); // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query

		// Validate meta_query structure.
		if ( ! is_array( $meta_query ) ) {
			$meta_query = array();
		}

		// Add a relation key if more than one $meta_query and if 'relation' is not already set.
		if ( count( $meta_query ) > 1 && ! isset( $meta_query['relation'] ) ) {
			/**
			 * Filter the meta_query relation parameter.
			 *
			 * @since 3.3.0
			 *
			 * @param string  $relation The logical relationship between each inner meta_query array when there is more than one. Default is 'AND'.
			 * @param array   $args     Arguments array.
			 */
			$meta_query['relation'] = apply_filters( 'crp_query_meta_query_relation', 'AND', $args );
		}

		$args['meta_query'] = $meta_query; // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query

		// Set post_status.
		$args['post_status'] = empty( $args['post_status'] ) ? array( 'publish', 'inherit' ) : $args['post_status'];

		// Set post__not_in for WP_Query using exclude_post_ids.
		$args['post__not_in'] = $this->exclude_post_ids( $args );

		// Same author.
		if ( isset( $args['same_author'] ) && $args['same_author'] ) {
			$args['author'] = $source_post->post_author;
		}

		// Disable contextual matching.
		if ( ! empty( $args['disable_contextual'] ) ) {
			/* If post or page and we're not disabling custom post types */
			if ( ( 'post' === $source_post->post_type || 'page' === $source_post->post_type ) && ( $args['disable_contextual_cpt'] ) ) {
				$this->enable_relevance = true;
			} else {
				$this->enable_relevance = false;
			}
		}

		// Unset what we don't need.
		unset( $args['title'] );
		unset( $args['blank_output'] );
		unset( $args['blank_output_text'] );
		unset( $args['show_excerpt'] );
		unset( $args['excerpt_length'] );
		unset( $args['show_date'] );
		unset( $args['show_author'] );
		unset( $args['title_length'] );
		unset( $args['link_new_window'] );
		unset( $args['link_nofollow'] );
		unset( $args['before_list'] );
		unset( $args['after_list'] );
		unset( $args['before_list_item'] );
		unset( $args['after_list_item'] );
		unset( $args['more_link_text'] );
		unset( $args['extra_class'] );
		unset( $args['className'] );
		unset( $args['other_attributes'] );

		/**
		 * Filters the arguments of the query.
		 *
		 * @since 3.0.0
		 *
		 * @param array      $args The arguments of the query.
		 * @param \CRP_Query $query The CRP_Query instance (passed by reference).
		 */
		$this->query_args = apply_filters_ref_array( 'crp_query_args', array( $args, &$this ) );
	}

	/**
	 * Get the MATCH sql.
	 *
	 * @since 3.0.0
	 *
	 * @return string  Updated Fields
	 */
	public function get_match_sql() {
		global $wpdb;

		/**
		 * Filter the source post before getting the match SQL.
		 *
		 * @since 3.5.0
		 *
		 * @param string    $match_sql   The match SQL.
		 * @param \WP_Post  $source_post Source Post instance.
		 * @param array     $query_args  Arguments array.
		 */
		$match = apply_filters( 'crp_query_pre_get_match_sql', '', $this->source_post, $this->query_args );

		if ( ! empty( $match ) ) {
			return $match;
		}

		// Are we matching only the title or the post content as well?
		$match_fields = array(
			"$wpdb->posts.post_title",
		);

		$match_fields_content = array(
			Helpers::strip_stopwords( $this->source_post->post_title ),
		);

		if ( isset( $this->query_args['match_content'] ) && $this->query_args['match_content'] ) {
			$match_fields[]         = "$wpdb->posts.post_content";
			$match_fields_content[] = Helpers::strip_stopwords(
				Display::get_the_excerpt(
					$this->source_post,
					min( $this->query_args['match_content_words'], CRP_MAX_WORDS ),
					false
				)
			);
		}

		if ( ! empty( $this->query_args['keyword'] ) ) {
			$match_fields_content = array(
				$this->query_args['keyword'],
			);
		}

		/**
		 * Filter the fields that are to be matched.
		 *
		 * @since 4.0.0
		 *
		 * @param array    $match_fields Array of fields to be matched.
		 * @param \WP_Post $source_post  Source Post instance.
		 * @param array    $query_args   Arguments array.
		 */
		$match_fields = apply_filters( 'crp_query_posts_match_fields', $match_fields, $this->source_post, $this->query_args );

		/**
		 * Filter the content of the fields that are to be matched.
		 *
		 * @since 4.0.0
		 *
		 * @param array $match_fields_content Array of content of fields to be matched
		 * @param \WP_Post $source_post  Source Post instance.
		 * @param array   $query_args   Arguments array.
		 */
		$match_fields_content = apply_filters( 'crp_query_posts_match_fields_content', $match_fields_content, $this->source_post, $this->query_args );

		// Convert our arrays into their corresponding strings after they have been filtered.
		$this->match_fields = implode( ',', $match_fields );
		$this->stuff        = implode( ' ', $match_fields_content );

		// Create the base MATCH clause.
		$match = $wpdb->prepare( ' MATCH (' . $this->match_fields . ') AGAINST (%s) ', $this->stuff ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared

		/**
		 * Filter the match SQL.
		 *
		 * @since 4.0.0
		 *
		 * @param string   $match       The match SQL.
		 * @param \WP_Post $source_post Source Post instance.
		 * @param array    $query_args  Arguments array.
		 * @param string   $match_fields The fields to be matched.
		 * @param string   $stuff      The content of the fields to be matched.
		 */
		return apply_filters( 'crp_query_match_sql', $match, $this->source_post, $this->query_args, $this->match_fields, $this->stuff );
	}

	/**
	 * Modify the pre_get_posts clause.
	 *
	 * @since 3.5.0
	 *
	 * @param \WP_Query $query The WP_Query instance.
	 */
	public function pre_get_posts( $query ) {

		if ( true === $query->get( 'crp_query' ) ) {
			if ( ! empty( $this->query_args['date_query'] ) ) {
				$query->set( 'date_query', $this->query_args['date_query'] );
			}
			if ( ! empty( $this->query_args['tax_query'] ) ) {
				$query->set( 'tax_query', $this->query_args['tax_query'] );
			}
			if ( ! empty( $this->query_args['meta_query'] ) ) {
				$query->set( 'meta_query', $this->query_args['meta_query'] );
			}
			if ( ! empty( $this->query_args['post_type'] ) ) {
				$query->set( 'post_type', $this->query_args['post_type'] );
			}
			if ( ! empty( $this->query_args['post__not_in'] ) ) {
				$query->set( 'post__not_in', $this->query_args['post__not_in'] );
			}
			if ( ! empty( $this->query_args['post_status'] ) ) {
				$query->set( 'post_status', $this->query_args['post_status'] );
			}
			if ( ! empty( $this->query_args['posts_per_page'] ) ) {
				$query->set( 'posts_per_page', $this->query_args['posts_per_page'] );
			}
			if ( ! empty( $this->query_args['author'] ) ) {
				$query->set( 'author', $this->query_args['author'] );
			}

			$query->set( 'suppress_filters', false );
			$query->set( 'no_found_rows', true );
			$query->set( 'ignore_sticky_posts', true );

			remove_filter( 'pre_get_posts', array( $this, 'pre_get_posts' ) );
		}
	}

	/**
	 * Modify the SELECT clause - posts_fields.
	 *
	 * @since 3.0.0
	 *
	 * @param string               $fields The SELECT clause of the query.
	 * @param \WP_Query|\CRP_Query $query  The WP_Query or CRP_Query instance.
	 * @return string  Updated Fields
	 */
	public function posts_fields( $fields, $query ) {

		// Return if it is not a CRP_Query.
		if ( true !== $query->get( 'crp_query' ) ) {
			return $fields;
		}

		if ( $this->enable_relevance ) {
			if ( empty( $this->match_sql ) ) {
				$this->match_sql = $this->get_match_sql();
			}

			$match   = ', ' . $this->match_sql . ' as score ';
			$fields .= $match;
		}

		/**
		 * Filters the fields returned by the SELECT clause.
		 *
		 * @since 3.2.0
		 * @since 4.0.0 Added $instance
		 *
		 * @param string                $fields The fields returned by the SELECT clause.
		 * @param \WP_Query|\CRP_Query  $query  The WP_Query or CRP_Query instance.
		 * @param CRP_Core_Query        $instance The CRP_Core_Query instance.
		 */
		$fields = apply_filters_ref_array( 'crp_query_posts_fields', array( $fields, $query, &$this ) );

		remove_filter( 'posts_fields', array( $this, 'posts_fields' ) );

		return $fields;
	}

	/**
	 * Modify the posts_join clause.
	 *
	 * @since 3.0.0
	 *
	 * @param string               $join  The JOIN clause of the query.
	 * @param \WP_Query|\CRP_Query $query The WP_Query or CRP_Query instance.
	 * @return string  Updated JOIN
	 */
	public function posts_join( $join, $query ) {
		global $wpdb;

		// Return if it is not a CRP_Query.
		if ( true !== $query->get( 'crp_query' ) ) {
			return $join;
		}

		if (
			! empty( $this->query_args['match_all'] ) ||
			( isset( $this->query_args['no_of_common_terms'] ) && absint( $this->query_args['no_of_common_terms'] ) > 1 )
		) {
			if ( strpos( $join, 'crp_tr' ) === false ) {
				$join .= " INNER JOIN $wpdb->term_relationships AS crp_tr ON ($wpdb->posts.ID = crp_tr.object_id) ";
			}

			if ( strpos( $join, 'crp_tt' ) === false ) {
				$join .= " INNER JOIN $wpdb->term_taxonomy AS crp_tt ON (crp_tr.term_taxonomy_id = crp_tt.term_taxonomy_id) ";
			}
		}

		/**
		 * Filters the posts_join of CRP_Query after processing and before returning.
		 *
		 * @since 3.2.0
		 * @since 4.0.0 Added $instance
		 *
		 * @param string                $join  The JOIN clause of the query.
		 * @param \WP_Query|\CRP_Query  $query The WP_Query or CRP_Query instance.
		 * @param CRP_Core_Query        $instance The CRP_Core_Query instance.
		 */
		$join = apply_filters_ref_array( 'crp_query_posts_join', array( $join, $query, &$this ) );

		remove_filter( 'posts_join', array( $this, 'posts_join' ) );

		return $join;
	}

	/**
	 * Modify the posts_where clause.
	 *
	 * @since 3.0.0
	 *
	 * @param string               $where The WHERE clause of the query.
	 * @param \WP_Query|\CRP_Query $query The WP_Query or CRP_Query instance.
	 * @return string  Updated WHERE
	 */
	public function posts_where( $where, $query ) {
		global $wpdb;

		// Return if it is not a CRP_Query.
		if ( true !== $query->get( 'crp_query' ) ) {
			return $where;
		}

		$match_clause   = '';
		$include        = '';
		$exclude        = '';
		$search_columns = array( 'post_title', 'post_excerpt', 'post_content' );

		if ( $this->enable_relevance ) {

			$match_clause = ! empty( $this->match_sql ) ? $this->match_sql : $this->get_match_sql();

			/**
			 * Filter the MATCH clause of the WHERE clause of the query.
			 *
			 * @since 4.0.0
			 *
			 * @param string               $match_clause    The MATCH section of the WHERE clause of the query.
			 * @param string               $where           The WHERE clause of the query.
			 * @param \WP_Query|\CRP_Query $query           The WP_Query or CRP_Query instance.
			 * @param CRP_Core_Query       $instance        The CRP_Core_Query instance.
			 */
			$match_clause = apply_filters_ref_array( 'crp_query_posts_where_match', array( $match_clause, $where, $query, &$this ) );
		}

		if ( isset( $this->query_args['include_words'] ) ) {

			$n          = '%';
			$includeand = '';

			$include_words = preg_split( '/[,\s]+/', $this->query_args['include_words'] );
			$include_words = array_filter( $include_words );
			foreach ( (array) $include_words as $word ) {
				$like_op  = 'LIKE';
				$andor_op = 'OR';

				$like                          = $n . $wpdb->esc_like( strtolower( $word ) ) . $n;
				$this->include_orderby_title[] = $wpdb->prepare( "{$wpdb->posts}.post_title LIKE %s", $like );

				$search_columns_parts = array();
				foreach ( $search_columns as $search_column ) {
					$search_columns_parts[ $search_column ] = $wpdb->prepare( "({$wpdb->posts}.$search_column $like_op %s)", $like ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
				}
				$include .= "$includeand(" . implode( " $andor_op ", $search_columns_parts ) . ')';

				$includeand = ' OR ';
			}
		}

		// if both $match and $include are not empty, then join them using OR. Else, use the one that is not empty.
		if ( ! empty( $match_clause ) && ! empty( $include ) ) {
			$where .= " AND ( $match_clause OR $include )";
		} elseif ( ! empty( $match_clause ) ) {
			$where .= " AND ( $match_clause )";
		} elseif ( ! empty( $include ) ) {
			$where .= " AND ( 1=1 OR $include )";
		}

		if ( isset( $this->crp_post_meta['exclude_words'] ) ) {

			$n          = '%';
			$excludeand = '';

			$exclude_words = preg_split( '/[,\s]+/', $this->crp_post_meta['exclude_words'] );
			$exclude_words = array_filter( $exclude_words );
			foreach ( (array) $exclude_words as $word ) {
				$like_op  = 'NOT LIKE';
				$andor_op = 'AND';
				$like     = $n . $wpdb->esc_like( strtolower( $word ) ) . $n;

				$search_columns_parts = array();
				foreach ( $search_columns as $search_column ) {
					$search_columns_parts[ $search_column ] = $wpdb->prepare( "({$wpdb->posts}.$search_column $like_op %s)", $like ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
				}
				$exclude .= "$excludeand(" . implode( " $andor_op ", $search_columns_parts ) . ')';

				$excludeand = ' AND ';
			}

			if ( ! empty( $exclude ) ) {
				$where .= " AND ({$exclude}) ";
			}
		}

		/**
		 * Filters the posts_where of CRP_Query after processing and before returning.
		 *
		 * @since 3.2.0
		 * @since 4.0.0 Added $instance
		 *
		 * @param string                $where The WHERE clause of the query.
		 * @param \WP_Query|\CRP_Query  $query  The WP_Query or CRP_Query instance.
		 * @param CRP_Core_Query        $instance The CRP_Core_Query instance.
		 */
		$where = apply_filters_ref_array( 'crp_query_posts_where', array( $where, $query, &$this ) );

		remove_filter( 'posts_where', array( $this, 'posts_where' ) );

		return $where;
	}

	/**
	 * Modify the posts_orderby clause.
	 *
	 * @since 3.0.0
	 *
	 * @param string               $orderby  The ORDER BY clause of the query.
	 * @param \WP_Query|\CRP_Query $query The WP_Query or CRP_Query instance.
	 * @return string  Updated ORDER BY
	 */
	public function posts_orderby( $orderby, $query ) {
		global $wpdb;

		// Return if it is not a CRP_Query.
		if ( true !== $query->get( 'crp_query' ) ) {
			return $orderby;
		}

		// If orderby is set, then this was done intentionally and we don't make any modifications.
		if ( ! empty( $query->get( 'orderby' ) ) ) {
			// if orderby is set to relevance, then we need to set the orderby to the match clause.
			if ( 'relevance' === $query->get( 'orderby' ) || 'relatedness' === $query->get( 'orderby' ) ) {
				if ( empty( $this->match_sql ) ) {
					$this->match_sql = $this->get_match_sql();
				}
				$orderby = ' ' . $this->match_sql . ' DESC ';
			}
			return apply_filters( 'crp_query_posts_orderby', $orderby, $query );
		}

		// Initialize an array to build the orderby clauses.
		$orderby_clauses = array();

		// Add include_words at the beginning.
		if ( ! empty( $this->query_args['include_words'] ) ) {
			$include_orderby = $this->parse_include_words_order();
			if ( ! empty( $include_orderby ) ) {
				$orderby_clauses[] = $include_orderby;
			}
		}

		if ( $this->enable_relevance && isset( $this->query_args['ordering'] ) && 'date' !== $this->query_args['ordering'] ) {
			if ( empty( $this->match_sql ) ) {
				$this->match_sql = $this->get_match_sql();
			}
			$orderby_clauses[] = ' ' . $this->match_sql . ' DESC ';
		}

		// Set order by in case of date.
		if ( isset( $this->query_args['ordering'] ) && 'date' === $this->query_args['ordering'] ) {
			$orderby_clauses[] = " $wpdb->posts.post_date DESC ";
		}

		/**
		 * Filters the posts_orderby of CRP_Query after processing and before returning.
		 *
		 * @since 3.5.2
		 * @since 4.0.0 Added $instance
		 *
		 * @param string[]             $orderby_clauses The SELECT clause of the query.
		 * @param \WP_Query|\CRP_Query $query           The WP_Query or CRP_Query instance.
		 * @param CRP_Core_Query       $instance The CRP_Core_Query instance.
		 */
		$orderby_clauses = apply_filters_ref_array( 'crp_query_posts_orderby_clauses', array( $orderby_clauses, $query, &$this ) );

		// Combine all the orderby clauses.
		if ( ! empty( $orderby_clauses ) ) {
			$orderby = implode( ', ', $orderby_clauses );
		}

		/**
		 * Filters the posts_orderby of CRP_Query after processing and before returning.
		 *
		 * @since 3.2.0
		 * @since 4.0.0 Added $instance
		 *
		 * @param string               $orderby The SELECT clause of the query.
		 * @param \WP_Query|\CRP_Query $query   The WP_Query or CRP_Query instance.
		 * @param CRP_Core_Query       $instance The CRP_Core_Query instance.
		 */
		$orderby = apply_filters_ref_array( 'crp_query_posts_orderby', array( $orderby, $query, &$this ) );

		remove_filter( 'posts_orderby', array( $this, 'posts_orderby' ) );

		return $orderby;
	}

	/**
	 * Modify the posts_groupby clause.
	 *
	 * @since 3.0.0
	 *
	 * @param string               $groupby  The GROUP BY clause of the query.
	 * @param \WP_Query|\CRP_Query $query    The WP_Query or CRP_Query instance.
	 * @return string  Updated GROUP BY
	 */
	public function posts_groupby( $groupby, $query ) {

		if ( true !== $query->get( 'crp_query' ) ) {
			return $groupby;
		}

		/**
		 * Filters the GROUP BY clause of the CRP_Query.
		 *
		 * @since 3.0.0
		 * @since 4.0.0 Added $instance
		 *
		 * @param string               $groupby The GROUP BY clause of the query.
		 * @param \WP_Query|\CRP_Query $query   The WP_Query or CRP_Query instance.
		 * @param CRP_Core_Query       $instance The CRP_Core_Query instance.
		 */
		$groupby = apply_filters_ref_array( 'crp_query_posts_groupby', array( $groupby, $query, &$this ) );

		remove_filter( 'posts_groupby', array( $this, 'posts_groupby' ) );

		return $groupby;
	}

	/**
	 * Modify the completed SQL query before sending.
	 *
	 * @since 3.0.0
	 *
	 * @param string               $sql   The complete SQL query.
	 * @param \WP_Query|\CRP_Query $query The WP_Query or CRP_Query instance.
	 * @return string  Updated SQL query.
	 */
	public function posts_request( $sql, $query ) {
		global $wpdb;

		$conditions = array();

		// Return if it is not a CRP_Query.
		if ( true !== $query->get( 'crp_query' ) ) {
			return $sql;
		}

		if ( ! empty( $this->query_args['match_all'] ) && ! empty( $this->query_args['taxonomy_count'] ) ) {
			$conditions[] = $wpdb->prepare( 'COUNT(DISTINCT crp_tt.taxonomy) = %d', $this->query_args['taxonomy_count'] );
		}
		if ( isset( $this->query_args['no_of_common_terms'] ) && absint( $this->query_args['no_of_common_terms'] ) > 1 ) {
			$conditions[] = $wpdb->prepare( 'COUNT(DISTINCT crp_tt.term_id) >= %d', absint( $this->query_args['no_of_common_terms'] ) );
		}

		if ( ! empty( $conditions ) ) {
			$conditions = implode( ' AND ', $conditions );
			$having     = "HAVING ( {$conditions} ) ORDER BY";

			$sql = str_replace(
				'ORDER BY',
				$having,
				$sql
			);

		}

		/**
		 * Filters the posts_request of CRP_Query after processing and before returning.
		 *
		 * @since 3.2.0
		 * @since 4.0.0 Added $instance
		 *
		 * @param string               $sql   The SQL Query.
		 * @param \WP_Query|\CRP_Query $query The WP_Query or CRP_Query instance.
		 * @param CRP_Core_Query       $instance The CRP_Core_Query instance.
		 */
		$sql = apply_filters_ref_array( 'crp_query_posts_request', array( $sql, $query, &$this ) );

		remove_filter( 'posts_request', array( $this, 'posts_request' ) );

		return $sql;
	}

	/**
	 * Filter posts_pre_query to allow caching to work.
	 *
	 * @since 3.0.0
	 *
	 * @param \WP_Post[]           $posts Array of post data.
	 * @param \WP_Query|\CRP_Query $query The WP_Query or CRP_Query instance.
	 * @return \WP_Post[] Updated Array of post objects.
	 */
	public function posts_pre_query( $posts, $query ) {

		// Return if it is not a CRP_Query.
		if ( true !== $query->get( 'crp_query' ) ) {
			return $posts;
		}

		$post_ids = array();

		// Check the cache if there are any posts saved.
		if ( ! empty( $this->query_args['cache_posts'] ) && ! ( is_preview() || is_admin() || ( defined( 'REST_REQUEST' ) && REST_REQUEST ) ) ) {

			$meta_key = Cache::get_key( $this->input_query_args );

			$cached_data = Cache::get_cache( $this->source_post->ID, $meta_key );
			if ( ! empty( $cached_data ) ) {
				$post_ids       = $cached_data;
				$this->in_cache = true;
			}
		}

		if ( ! empty( $this->manual_related ) && ( $this->no_of_manual_related >= $this->query_args['limit'] ) ) {
			$post_ids = array_merge( $post_ids, $this->manual_related );
		}

		if ( ! empty( $post_ids ) ) {
			$posts                = get_posts(
				array(
					'post__in'    => array_unique( $post_ids ),
					'fields'      => $query->get( 'fields' ),
					'orderby'     => 'post__in',
					'numberposts' => $query->get( 'posts_per_page' ),
					'post_type'   => $query->get( 'post_type' ),
					'post_status' => $query->get( 'post_status' ),
				)
			);
			$query->found_posts   = count( $posts );
			$query->max_num_pages = (int) ceil( $query->found_posts / $query->get( 'posts_per_page' ) );
		}

		/**
		 * Filters the posts_pre_query of CRP_Query after processing and before returning.
		 *
		 * @since 3.2.0
		 * @since 4.0.0 Added $instance
		 *
		 * @param \WP_Post[]    $posts    Array of post data.
		 * @param \WP_Query     $query    The WP_Query or CRP_Query instance.
		 * @param CRP_Core_Query $instance The CRP_Core_Query instance.
		 */
		$posts = apply_filters_ref_array( 'crp_query_posts_pre_query', array( $posts, $query, &$this ) );

		remove_filter( 'posts_pre_query', array( $this, 'posts_pre_query' ) );

		return $posts;
	}

	/**
	 * Modify the array of retrieved posts.
	 *
	 * @since 3.0.0
	 *
	 * @param \WP_Post[]           $posts Array of post objects.
	 * @param \WP_Query|\CRP_Query $query The WP_Query or CRP_Query instance (passed by reference).
	 * @return \WP_Post[] Updated Array of post objects.
	 */
	public function the_posts( $posts, $query ) {

		// Return if it is not a CRP_Query.
		if ( true !== $query->get( 'crp_query' ) ) {
			return $posts;
		}

		// Support caching to speed up retrieval.
		if ( ! empty( $this->query_args['cache_posts'] ) && ! $this->in_cache && ! ( is_preview() || is_admin() || ( defined( 'REST_REQUEST' ) && REST_REQUEST ) ) ) {
			$meta_key = Cache::get_key( $this->input_query_args );
			$post_ids = wp_list_pluck( $query->posts, 'ID' );

			Cache::set_cache( $this->source_post->ID, $meta_key, $post_ids );
		}

		// Shuffle posts if random order is set.
		if ( $this->random_order ) {
			shuffle( $posts );
		}

		// Related posts by meta_key.
		if ( ! empty( $this->query_args['related_meta_keys'] ) ) {
			$related_meta_query = array();
			$related_meta_keys  = wp_parse_list( $this->query_args['related_meta_keys'] );
			foreach ( $related_meta_keys as $related_meta_key ) {
				$related_meta_value = (string) get_post_meta( $this->source_post->ID, $related_meta_key, true );
				if ( ! empty( $related_meta_value ) ) {
					$related_meta_query[] = array(
						'key'   => $related_meta_key,
						'value' => $related_meta_value,
					);
				}
			}

			if ( count( $related_meta_query ) > 1 ) {
				/**
				 * Filter the meta_query relation parameter for related posts by meta_key.
				 *
				 * @since 3.3.0
				 *
				 * @param string  $relation The logical relationship between each inner meta_query array when there is more than one. Default is 'OR'.
				 */
				$related_meta_query['relation'] = apply_filters( 'crp_query_related_meta_query_relation', 'OR' );
			}

			if ( ! empty( $related_meta_query ) ) {
				$meta_posts = get_posts(
					array(
						'post__not_in' => $this->exclude_post_ids( $this->query_args ),
						'fields'       => $query->get( 'fields' ),
						'numberposts'  => $query->get( 'posts_per_page' ),
						'post_type'    => $query->get( 'post_type' ),
						'meta_query'   => $related_meta_query, // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
					)
				);
				$posts      = array_merge( $meta_posts, $posts );
			}
		}

		// Manual Posts (manual_related - set via the Post Meta) or Include Posts (can be set as a parameter).
		$post_ids = array();

		if ( ! empty( $this->manual_related ) && ( $this->no_of_manual_related < $this->query_args['limit'] ) ) {
			$post_ids = array_merge( $post_ids, $this->manual_related );
		}
		if ( ! empty( $post_ids ) ) {
			$extra_posts = get_posts(
				array(
					'post__in'    => array_unique( $post_ids ),
					'fields'      => $query->get( 'fields' ),
					'orderby'     => 'post__in',
					'numberposts' => -1,
					'post_type'   => 'any',
					'post_status' => $query->get( 'post_status' ),
				)
			);
			$posts       = array_merge( $extra_posts, $posts );
		}

		/**
		 * Set the flag if CRP should fill random posts if there is a shortage of related posts.
		 *
		 * @since 3.2.0
		 *
		 * @param bool                  $fill_random_posts Fill random posts flag. Default false.
		 * @param \WP_Post[]            $posts             Array of post objects.
		 * @param \WP_Query|\CRP_Query  $query The WP_Query or CRP_Query instance.
		 */
		$fill_random_posts = apply_filters( 'crp_fill_random_posts', false, $posts, $query );

		if ( $fill_random_posts ) {
			$no_of_random_posts = $this->query_args['limit'] - count( $posts );
			if ( $no_of_random_posts > 0 ) {
				$random_posts = get_posts(
					array(
						'fields'      => $query->get( 'fields' ),
						'orderby'     => 'rand',
						'numberposts' => $no_of_random_posts,
						'post_type'   => $query->get( 'post_type' ),
						'post_status' => $query->get( 'post_status' ),
					)
				);
				$posts        = array_merge( $posts, $random_posts );
			}
		}

		/**
		 * Filter array of WP_Post objects before it is returned to the CRP_Query instance.
		 *
		 * @since 1.9
		 * @since 2.9.3 Added $args
		 * @since 4.0.0 Added $instance
		 *
		 * @param \WP_Post[]       $posts    Array of post objects.
		 * @param array            $args     Arguments array.
		 * @param \WP_Query|\CRP_Query $query   The WP_Query or CRP_Query instance.
		 * @param CRP_Core_Query   $instance The CRP_Core_Query instance.
		 */
		$posts = apply_filters_ref_array( 'crp_query_the_posts', array( $posts, $this->query_args, $query, &$this ) );

		remove_filter( 'the_posts', array( $this, 'the_posts' ) );

		return $posts;
	}

	/**
	 * Exclude Post IDs. Allows other plugins/functions to hook onto this and extend the list.
	 *
	 * @param array $args Array of arguments for CRP_Query.
	 * @return array Array of post IDs to exclude.
	 */
	public function exclude_post_ids( $args ) {
		static $exclude_post_ids_cache = array();

		$post_id = absint( $this->source_post->ID );

		if ( isset( $exclude_post_ids_cache[ $post_id ] ) ) {
			return $exclude_post_ids_cache[ $post_id ];
		}

		global $wpdb;

		$exclude_post_ids = empty( $args['exclude_post_ids'] ) ? array() : wp_parse_id_list( $args['exclude_post_ids'] );

		// Exclude posts with exclude_this_post set to true or exclude_post_ids set.
		$crp_post_metas = $wpdb->get_results( "SELECT post_id, meta_value FROM {$wpdb->postmeta} WHERE `meta_key` = 'crp_post_meta'", ARRAY_A ); // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching

		foreach ( $crp_post_metas as $crp_post_meta ) {
			$meta_value = maybe_unserialize( $crp_post_meta['meta_value'] );

			if ( isset( $meta_value['exclude_this_post'] ) && $meta_value['exclude_this_post'] ) {
				$exclude_post_ids[] = $crp_post_meta['post_id'];
			}
			if ( isset( $meta_value['exclude_post_ids'] ) && $meta_value['exclude_post_ids'] ) {
				$exclude_post_ids = array_merge( $exclude_post_ids, explode( ',', $meta_value['exclude_post_ids'] ) );
			}
		}

		/**
		 * Filter exclude post IDs array.
		 *
		 * @since 2.3.0
		 * @since 2.9.3 Added $args
		 * @since 3.2.0 Added $source_post
		 *
		 * @param array   $exclude_post_ids Array of post IDs.
		 * @param array   $args             Arguments array.
		 * @param \WP_Post $source_post      Source post.
		 */
		$exclude_post_ids = apply_filters( 'crp_exclude_post_ids', $exclude_post_ids, $args, $this->source_post );

		$exclude_post_ids[] = $this->source_post->ID;

		$exclude_post_ids_cache[ $post_id ] = array_unique( $exclude_post_ids );

		return $exclude_post_ids_cache[ $post_id ];
	}

	/**
	 * Generates SQL for the ORDER BY condition based on passed include words.
	 *
	 * @since 3.4.2
	 *
	 * @global \wpdb $wpdb WordPress database abstraction object.
	 *
	 * @return string ORDER BY clause.
	 */
	protected function parse_include_words_order() {
		global $wpdb;

		if ( ! isset( $this->query_args['include_words'] ) ) {
			return '';
		}

		$num_terms = count( $this->include_orderby_title );

		if ( $num_terms > 1 ) {

			// Sentence match in 'post_title'.
			$like           = '%' . $wpdb->esc_like( $this->query_args['include_words'] ) . '%';
			$search_orderby = $wpdb->prepare( "WHEN {$wpdb->posts}.post_title LIKE %s THEN 1 ", $like );

			/*
			 * Sanity limit, sort as sentence when more than 6 terms
			 * (few searches are longer than 6 terms and most titles are not).
			 */
			if ( $num_terms < 7 ) {
				// All words in title.
				$search_orderby .= 'WHEN ' . implode( ' AND ', $this->include_orderby_title ) . ' THEN 2 ';
				$search_orderby .= 'WHEN ' . implode( ' OR ', $this->include_orderby_title ) . ' THEN 3 ';
			}

			// Sentence match in 'post_content' and 'post_excerpt'.
			$search_orderby .= $wpdb->prepare( "WHEN {$wpdb->posts}.post_excerpt LIKE %s THEN 4 ", $like );
			$search_orderby .= $wpdb->prepare( "WHEN {$wpdb->posts}.post_content LIKE %s THEN 5 ", $like );
			$search_orderby  = '(CASE ' . $search_orderby . 'ELSE 6 END)';
		} else {
			// Single word or sentence search.
			$search_orderby = reset( $this->include_orderby_title ) . ' DESC';
		}

		return $search_orderby;
	}
}
