<?php

/**

 * Meta API: WP_Meta_Query class

 *

 * @package WordPress

 * @subpackage Meta

 * @since 4.4.0

 */

/**

 * Core class used to implement meta queries for the Meta API.

 *

 * Used for generating SQL clauses that filter a primary query according to metadata keys and values.

 *

 * WP_Meta_Query is a helper that allows primary query classes, such as WP_Query and WP_User_Query,

 *

 * to filter their results by object metadata, by generating `JOIN` and `WHERE` subclauses to be attached

 * to the primary SQL query string.

 *

 * @since 3.2.0

 */

class WP_Meta_Query {

	/**

	 * Array of metadata queries.

	 *

	 * See WP_Meta_Query::__construct() for information on meta query arguments.

	 *

	 * @since 3.2.0

	 * @var array

	 */

	public $queries = array();

	/**

	 * The relation between the queries. Can be one of 'AND' or 'OR'.

	 *

	 * @since 3.2.0

	 * @var string

	 */

	public $relation;

	/**

	 * Database table to query for the metadata.

	 *

	 * @since 4.1.0

	 * @var string

	 */

	public $meta_table;

	/**

	 * Column in meta_table that represents the ID of the object the metadata belongs to.

	 *

	 * @since 4.1.0

	 * @var string

	 */

	public $meta_id_column;

	/**

	 * Database table that where the metadata's objects are stored (eg $wpdb->users).

	 *

	 * @since 4.1.0

	 * @var string

	 */

	public $primary_table;

	/**

	 * Column in primary_table that represents the ID of the object.

	 *

	 * @since 4.1.0

	 * @var string

	 */

	public $primary_id_column;

	/**

	 * A flat list of table aliases used in JOIN clauses.

	 *

	 * @since 4.1.0

	 * @var array

	 */

	protected $table_aliases = array();

	/**

	 * A flat list of clauses, keyed by clause 'name'.

	 *

	 * @since 4.2.0

	 * @var array

	 */

	protected $clauses = array();

	/**

	 * Whether the query contains any OR relations.

	 *

	 * @since 4.3.0

	 * @var bool

	 */

	protected $has_or_relation = false;

	/**

	 * Constructor.

	 *

	 * @since 3.2.0

	 * @since 4.2.0 Introduced support for naming query clauses by associative array keys.

	 *

	 *

	 * @param array $meta_query {

	 *     Array of meta query clauses. When first-order clauses or sub-clauses use strings as

	 *     their array keys, they may be referenced in the 'orderby' parameter of the parent query.

	 *

	 *     @type string $relation Optional. The MySQL keyword used to join

	 *                            the clauses of the query. Accepts 'AND', or 'OR'. Default 'AND'.

	 *     @type array {

	 *         Optional. An array of first-order clause parameters, or another fully-formed meta query.

	 *

	 *         @type string $key     Meta key to filter by.

	 *         @type string $value   Meta value to filter by.

	 *         @type string $compare MySQL operator used for comparing the $value. Accepts '=',

	 *                               '!=', '>', '>=', '<', '<=', 'LIKE', 'NOT LIKE',

	 *                               'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN', 'REGEXP',

	 *                               'NOT REGEXP', 'RLIKE', 'EXISTS' or 'NOT EXISTS'.

	 *                               Default is 'IN' when `$value` is an array, '=' otherwise.

	 *         @type string $type    MySQL data type that the meta_value column will be CAST to for

	 *                               comparisons. Accepts 'NUMERIC', 'BINARY', 'CHAR', 'DATE',

	 *                               'DATETIME', 'DECIMAL', 'SIGNED', 'TIME', or 'UNSIGNED'.

	 *                               Default is 'CHAR'.

	 *     }

	 * }

	 */

	public function __construct( $meta_query = false ) {

		if ( !$meta_query )

			return;

		if ( isset( $meta_query['relation'] ) && strtoupper( $meta_query['relation'] ) == 'OR' ) {

			$this->relation = 'OR';

		} else {

			$this->relation = 'AND';

		}

		$this->queries = $this->sanitize_query( $meta_query );

	}

	/**

	 * Ensure the 'meta_query' argument passed to the class constructor is well-formed.

	 *

	 * Eliminates empty items and ensures that a 'relation' is set.

	 *

	 * @since 4.1.0

	 *

	 * @param array $queries Array of query clauses.

	 * @return array Sanitized array of query clauses.

	 */

	public function sanitize_query( $queries ) {

		$clean_queries = array();

		if ( ! is_array( $queries ) ) {

			return $clean_queries;

		}

		foreach ( $queries as $key => $query ) {

			if ( 'relation' === $key ) {

				$relation = $query;

			} elseif ( ! is_array( $query ) ) {

				continue;

			// First-order clause.

			} elseif ( $this->is_first_order_clause( $query ) ) {

				if ( isset( $query['value'] ) && array() === $query['value'] ) {

					unset( $query['value'] );

				}

				$clean_queries[ $key ] = $query;

			// Otherwise, it's a nested query, so we recurse.

			} else {

				$cleaned_query = $this->sanitize_query( $query );

				if ( ! empty( $cleaned_query ) ) {

					$clean_queries[ $key ] = $cleaned_query;

				}

			}

		}

		if ( empty( $clean_queries ) ) {

			return $clean_queries;

		}

		// Sanitize the 'relation' key provided in the query.

		if ( isset( $relation ) && 'OR' === strtoupper( $relation ) ) {

			$clean_queries['relation'] = 'OR';

			$this->has_or_relation = true;

		/*

		 * If there is only a single clause, call the relation 'OR'.

		 * This value will not actually be used to join clauses, but it

		 * simplifies the logic around combining key-only queries.

		 */

		} elseif ( 1 === count( $clean_queries ) ) {

			$clean_queries['relation'] = 'OR';

		// Default to AND.

		} else {

			$clean_queries['relation'] = 'AND';

		}

		return $clean_queries;

	}

	/**

	 * Determine whether a query clause is first-order.

	 *

	 * A first-order meta query clause is one that has either a 'key' or

	 * a 'value' array key.

	 *

	 * @since 4.1.0

	 *

	 * @param array $query Meta query arguments.

	 * @return bool Whether the query clause is a first-order clause.

	 */

	protected function is_first_order_clause( $query ) {

		return isset( $query['key'] ) || isset( $query['value'] );

	}

	/**

	 * Constructs a meta query based on 'meta_*' query vars

	 *

	 * @since 3.2.0

	 *

	 * @param array $qv The query variables

	 */

	public function parse_query_vars( $qv ) {

		$meta_query = array();

		/*

		 * For orderby=meta_value to work correctly, simple query needs to be

		 * first (so that its table join is against an unaliased meta table) and

		 * needs to be its own clause (so it doesn't interfere with the logic of

		 * the rest of the meta_query).

		 */

		$primary_meta_query = array();

		foreach ( array( 'key', 'compare', 'type' ) as $key ) {

			if ( ! empty( $qv[ "meta_$key" ] ) ) {

				$primary_meta_query[ $key ] = $qv[ "meta_$key" ];

			}

		}

		// WP_Query sets 'meta_value' = '' by default.

		if ( isset( $qv['meta_value'] ) && '' !== $qv['meta_value'] && ( ! is_array( $qv['meta_value'] ) || $qv['meta_value'] ) ) {

			$primary_meta_query['value'] = $qv['meta_value'];

		}

		$existing_meta_query = isset( $qv['meta_query'] ) && is_array( $qv['meta_query'] ) ? $qv['meta_query'] : array();

		if ( ! empty( $primary_meta_query ) && ! empty( $existing_meta_query ) ) {

			$meta_query = array(

				'relation' => 'AND',

				$primary_meta_query,

				$existing_meta_query,

			);

		} elseif ( ! empty( $primary_meta_query ) ) {

			$meta_query = array(

				$primary_meta_query,

			);

		} elseif ( ! empty( $existing_meta_query ) ) {

			$meta_query = $existing_meta_query;

		}

		$this->__construct( $meta_query );

	}

	/**

	 * Return the appropriate alias for the given meta type if applicable.

	 *

	 * @since 3.7.0

	 *

	 * @param string $type MySQL type to cast meta_value.

	 * @return string MySQL type.

	 */

	public function get_cast_for_type( $type = '' ) {

		if ( empty( $type ) )

			return 'CHAR';

		$meta_type = strtoupper( $type );

		if ( ! preg_match( '/^(?:BINARY|CHAR|DATE|DATETIME|SIGNED|UNSIGNED|TIME|NUMERIC(?:\(\d+(?:,\s?\d+)?\))?|DECIMAL(?:\(\d+(?:,\s?\d+)?\))?)$/', $meta_type ) )

			return 'CHAR';

		if ( 'NUMERIC' == $meta_type )

			$meta_type = 'SIGNED';

		return $meta_type;

	}

	/**

	 * Generates SQL clauses to be appended to a main query.

	 *

	 * @since 3.2.0

	 *

	 * @param string $type              Type of meta, eg 'user', 'post'.

	 * @param string $primary_table     Database table where the object being filtered is stored (eg wp_users).

	 * @param string $primary_id_column ID column for the filtered object in $primary_table.

	 * @param object $context           Optional. The main query object.

	 * @return false|array {

	 *     Array containing JOIN and WHERE SQL clauses to append to the main query.

	 *

	 *     @type string $join  SQL fragment to append to the main JOIN clause.

	 *     @type string $where SQL fragment to append to the main WHERE clause.

	 * }

	 */

	public function get_sql( $type, $primary_table, $primary_id_column, $context = null ) {

		if ( ! $meta_table = _get_meta_table( $type ) ) {

			return false;

		}

		$this->table_aliases = array();

		$this->meta_table     = $meta_table;

		$this->meta_id_column = sanitize_key( $type . '_id' );

		$this->primary_table     = $primary_table;

		$this->primary_id_column = $primary_id_column;

		$sql = $this->get_sql_clauses();

		/*

		 * If any JOINs are LEFT JOINs (as in the case of NOT EXISTS), then all JOINs should

		 * be LEFT. Otherwise posts with no metadata will be excluded from results.

		 */

		if ( false !== strpos( $sql['join'], 'LEFT JOIN' ) ) {

			$sql['join'] = str_replace( 'INNER JOIN', 'LEFT JOIN', $sql['join'] );

		}

		/**

		 * Filters the meta query's generated SQL.

		 *

		 * @since 3.1.0

		 *

		 * @param array  $clauses           Array containing the query's JOIN and WHERE clauses.

		 * @param array  $queries           Array of meta queries.

		 * @param string $type              Type of meta.

		 * @param string $primary_table     Primary table.

		 * @param string $primary_id_column Primary column ID.

		 * @param object $context           The main query object.

		 */

		return apply_filters_ref_array( 'get_meta_sql', array( $sql, $this->queries, $type, $primary_table, $primary_id_column, $context ) );

	}

	/**

	 * Generate SQL clauses to be appended to a main query.

	 *

	 * Called by the public WP_Meta_Query::get_sql(), this method is abstracted

	 * out to maintain parity with the other Query classes.

	 *

	 * @since 4.1.0

	 *

	 * @return array {

	 *     Array containing JOIN and WHERE SQL clauses to append to the main query.

	 *

	 *     @type string $join  SQL fragment to append to the main JOIN clause.

	 *     @type string $where SQL fragment to append to the main WHERE clause.

	 * }

	 */

	protected function get_sql_clauses() {

		/*

		 * $queries are passed by reference to get_sql_for_query() for recursion.

		 * To keep $this->queries unaltered, pass a copy.

		 */

		$queries = $this->queries;

		$sql = $this->get_sql_for_query( $queries );

		if ( ! empty( $sql['where'] ) ) {

			$sql['where'] = ' AND ' . $sql['where'];

		}

		return $sql;

	}

	/**

	 * Generate SQL clauses for a single query array.

	 *

	 * If nested subqueries are found, this method recurses the tree to

	 * produce the properly nested SQL.

	 *

	 * @since 4.1.0

	 *

	 * @param array $query Query to parse (passed by reference).

	 * @param int   $depth Optional. Number of tree levels deep we currently are.

	 *                     Used to calculate indentation. Default 0.

	 * @return array {

	 *     Array containing JOIN and WHERE SQL clauses to append to a single query array.

	 *

	 *     @type string $join  SQL fragment to append to the main JOIN clause.

	 *     @type string $where SQL fragment to append to the main WHERE clause.

	 * }

	 */

	protected function get_sql_for_query( &$query, $depth = 0 ) {

		$sql_chunks = array(

			'join'  => array(),

			'where' => array(),

		);

		$sql = array(

			'join'  => '',

			'where' => '',

		);

		$indent = '';

		for ( $i = 0; $i < $depth; $i++ ) {

			$indent .= "  ";

		}

		foreach ( $query as $key => &$clause ) {

			if ( 'relation' === $key ) {

				$relation = $query['relation'];

			} elseif ( is_array( $clause ) ) {

				// This is a first-order clause.

				if ( $this->is_first_order_clause( $clause ) ) {

					$clause_sql = $this->get_sql_for_clause( $clause, $query, $key );

					$where_count = count( $clause_sql['where'] );

					if ( ! $where_count ) {

						$sql_chunks['where'][] = '';

					} elseif ( 1 === $where_count ) {

						$sql_chunks['where'][] = $clause_sql['where'][0];

					} else {

						$sql_chunks['where'][] = '( ' . implode( ' AND ', $clause_sql['where'] ) . ' )';

					}

					$sql_chunks['join'] = array_merge( $sql_chunks['join'], $clause_sql['join'] );

				// This is a subquery, so we recurse.

				} else {

					$clause_sql = $this->get_sql_for_query( $clause, $depth + 1 );

					$sql_chunks['where'][] = $clause_sql['where'];

					$sql_chunks['join'][]  = $clause_sql['join'];

				}

			}

		}

		// Filter to remove empties.

		$sql_chunks['join']  = array_filter( $sql_chunks['join'] );

		$sql_chunks['where'] = array_filter( $sql_chunks['where'] );

		if ( empty( $relation ) ) {

			$relation = 'AND';

		}