<?php

/**

 * WP_Date_Query will generate a MySQL WHERE clause for the specified date-based parameters.

 *

 * Initialize the class by passing an array of arrays of parameters.

 *

 * @link http://codex.wordpress.org/Function_Reference/WP_Query Codex page.

 *

 * @since 3.7.0

 */

class WP_Date_Query {

	/**

	 * List of date queries.

	 *

	 * @since 3.7.0

	 * @access public

	 * @var array

	 */

	public $queries = array();

	/**

	 * The relation between the queries. Can be either 'AND' or 'OR' and can be changed via the query arguments.

	 *

	 * @since 3.7.0

	 * @access public

	 * @var string

	 */

	public $relation = 'AND';

	/**

	 * The column to query against. Can be changed via the query arguments.

	 *

	 * @since 3.7.0

	 * @access public

	 * @var string

	 */

	public $column = 'post_date';

	/**

	 * The value comparison operator. Can be changed via the query arguments.

	 *

	 * @since 3.7.0

	 * @access public

	 * @var array

	 */

	public $compare = '=';

	/**

	 * Constructor.

	 *

	 * @param array $date_query {

	 *     One or more associative arrays of date query parameters.

	 *

	 *     @type array {

	 *         @type string $column   Optional. The column to query against. If undefined, inherits the value of

	 *                                the $default_column parameter. Default 'post_date'. Accepts 'post_date',

	 *                                'post_date_gmt', 'post_modified','post_modified_gmt', 'comment_date',

	 *                                'comment_date_gmt'.

	 *         @type string $compare  Optional. The comparison operator.

	 *                                Default '='. Accepts '=', '!=', '>', '>=', '<', '<=', 'IN', 'NOT IN',

	 *                                'BETWEEN', 'NOT BETWEEN'.

	 *         @type string $relation Optional. The boolean relationship between the date queryies.

	 *                                Default 'OR'. Accepts 'OR', 'AND'.

	 *         @type array {

	 *             @type string|array $before Optional. Date to retrieve posts before. Accepts strtotime()-compatible

	 *                                        string, or array of 'year', 'month', 'day' values. {

	 *

	 *                 @type string $year  The four-digit year. Default empty. Accepts any four-digit year.

	 *                 @type string $month Optional when passing array.The month of the year.

	 *                                     Default (string:empty)|(array:1). Accepts numbers 1-12.

	 *                 @type string $day   Optional when passing array.The day of the month.

	 *                                     Default (string:empty)|(array:1). Accepts numbers 1-31.

	 *             }

	 *             @type string|array $after Optional. Date to retrieve posts before. Accepts strtotime()-compatible

	 *                                       string, or array of 'year', 'month', 'day' values. {

	 *

	 *                 @type string $year  The four-digit year. Default empty. Accepts any four-digit year.

	 *                 @type string $month Optional when passing array.The month of the year.

	 *                                     Default (string:empty)|(array:12). Accepts numbers 1-12.

	 *                 @type string $day   Optional when passing array.The day of the month.

	 *                                     Default (string:empty)|(array:last day of month). Accepts numbers 1-31.

	 *             }

	 *             @type string       $column    Optional. Used to add a clause comparing a column other than the column

	 *                                           specified in the top-level $column paramater.  Default is the value

	 *                                           of top-level $column. Accepts 'post_date', 'post_date_gmt',

	 *                                           'post_modified', 'post_modified_gmt', 'comment_date', 'comment_date_gmt'.

	 *             @type string       $compare   Optional. The comparison operator. Default '='. Accepts '=', '!=',

	 *                                           '>', '>=', '<', '<=', 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN'.

	 *             @type bool         $inclusive Optional. Include results from dates specified in 'before' or 'after'.

	 *                                           Default. Accepts.

	 *             @type int          $year      Optional. The four-digit near number. Default empty. Accepts any

	 *                                           four-digit year.

	 *             @type int          $month     Optional. The two-digit month number. Default empty. Accepts numbers 1-12.

	 *             @type int          $week      Optional. The week number of the year. Default empty. Accepts numbers 0-53.

	 *             @type int          $day       Optional. The day of the month. Default empty. Accepts numbers 1-31.

	 *             @type int          $hour      Optional. The hour of the day. Default empty. Accepts numbers 0-23.

	 *             @type int          $minute    Optional. The minute of the hour. Default empty. Accepts numbers 0-60.

	 *             @type int          $second    Optional. The second of the minute. Default empty. Accepts numbers 0-60.

	 *         }

	 *     }

	 * }

	 * @param array $default_column Optional. Default column to query against. Default 'post_date'.

	 *                              Accepts 'post_date', 'post_date_gmt', 'post_modified', 'post_modified_gmt',

	 *                              'comment_date', 'comment_date_gmt'.

	 */

	function __construct( $date_query, $default_column = 'post_date' ) {

		if ( empty( $date_query ) || ! is_array( $date_query ) )

			return;

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

			$this->relation = 'OR';

		else

			$this->relation = 'AND';

		if ( ! empty( $date_query['column'] ) )

			$this->column = esc_sql( $date_query['column'] );

		else

			$this->column = esc_sql( $default_column );

		$this->column = $this->validate_column( $this->column );

		$this->compare = $this->get_compare( $date_query );

		// If an array of arrays wasn't passed, fix it

		if ( ! isset( $date_query[0] ) )

			$date_query = array( $date_query );

		$this->queries = array();

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

			if ( ! is_array( $query ) )

				continue;

			$this->queries[$key] = $query;

		}

	}

	/**

	 * Determines and validates what comparison operator to use.

	 *

	 * @since 3.7.0

	 * @access public

	 *

	 * @param array $query A date query or a date subquery

	 * @return string The comparison operator

	 */

	public function get_compare( $query ) {

		if ( ! empty( $query['compare'] ) && in_array( $query['compare'], array( '=', '!=', '>', '>=', '<', '<=', 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ) ) )

			return strtoupper( $query['compare'] );

		return $this->compare;

	}

	/**

	 * Validates a column name parameter.

	 *

	 * @since 3.7.0

	 * @access public

	 *

	 * @param string $column The user-supplied column name.

	 * @return string A validated column name value.

	 */

	public function validate_column( $column ) {

		$valid_columns = array(

			'post_date', 'post_date_gmt', 'post_modified',

			'post_modified_gmt', 'comment_date', 'comment_date_gmt'

		);

		/**

		 * Filter the list of valid date query columns.

		 *

		 * @since 3.7.0

		 *

		 * @param array $valid_columns An array of valid date query columns. Defaults are 'post_date', 'post_date_gmt',

		 *                             'post_modified', 'post_modified_gmt', 'comment_date', 'comment_date_gmt'

		 */

		if ( ! in_array( $column, apply_filters( 'date_query_valid_columns', $valid_columns ) ) )

			$column = 'post_date';

		return $column;

	}

	/**

	 * Turns an array of date query parameters into a MySQL string.

	 *

	 * @since 3.7.0

	 * @access public

	 *

	 * @return string MySQL WHERE parameters

	 */

	public function get_sql() {

		// The parts of the final query

		$where = array();

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

			$where_parts = $this->get_sql_for_subquery( $query );

			if ( $where_parts ) {

				// Combine the parts of this subquery into a single string

				$where[ $key ] = '( ' . implode( ' AND ', $where_parts ) . ' )';

			}

		}

		// Combine the subquery strings into a single string

		if ( $where )

			$where = ' AND ( ' . implode( " {$this->relation} ", $where ) . ' )';

		else

			$where = '';

		/**

		 * Filter the date query WHERE clause.

		 *

		 * @since 3.7.0

		 *

		 * @param string        $where WHERE clause of the date query.

		 * @param WP_Date_Query $this  The WP_Date_Query instance.

		 */

		return apply_filters( 'get_date_sql', $where, $this );

	}

	/**

	 * Turns a single date subquery into pieces for a WHERE clause.

	 *

	 * @since 3.7.0

	 * return array

	 */

	protected function get_sql_for_subquery( $query ) {

		global $wpdb;

		// The sub-parts of a $where part

		$where_parts = array();

		$column = ( ! empty( $query['column'] ) ) ? esc_sql( $query['column'] ) : $this->column;

		$column = $this->validate_column( $column );

		$compare = $this->get_compare( $query );

		$lt = '<';

		$gt = '>';

		if ( ! empty( $query['inclusive'] ) ) {

			$lt .= '=';

			$gt .= '=';

		}

		// Range queries

		if ( ! empty( $query['after'] ) )

			$where_parts[] = $wpdb->prepare( "$column $gt %s", $this->build_mysql_datetime( $query['after'], true ) );

		if ( ! empty( $query['before'] ) )

			$where_parts[] = $wpdb->prepare( "$column $lt %s", $this->build_mysql_datetime( $query['before'], false ) );

		// Specific value queries

		if ( isset( $query['year'] ) && $value = $this->build_value( $compare, $query['year'] ) )

			$where_parts[] = "YEAR( $column ) $compare $value";

		if ( isset( $query['month'] ) && $value = $this->build_value( $compare, $query['month'] ) )

			$where_parts[] = "MONTH( $column ) $compare $value";

		// Legacy

		if ( isset( $query['monthnum'] ) && $value = $this->build_value( $compare, $query['monthnum'] ) )

			$where_parts[] = "MONTH( $column ) $compare $value";

		if ( isset( $query['week'] ) && false !== ( $value = $this->build_value( $compare, $query['week'] ) ) )

			$where_parts[] = _wp_mysql_week( $column ) . " $compare $value";

		// Legacy

		if ( isset( $query['w'] ) && false !== ( $value = $this->build_value( $compare, $query['w'] ) ) )

			$where_parts[] = _wp_mysql_week( $column ) . " $compare $value";

		if ( isset( $query['dayofyear'] ) && $value = $this->build_value( $compare, $query['dayofyear'] ) )

			$where_parts[] = "DAYOFYEAR( $column ) $compare $value";

		if ( isset( $query['day'] ) && $value = $this->build_value( $compare, $query['day'] ) )

			$where_parts[] = "DAYOFMONTH( $column ) $compare $value";

		if ( isset( $query['dayofweek'] ) && $value = $this->build_value( $compare, $query['dayofweek'] ) )

			$where_parts[] = "DAYOFWEEK( $column ) $compare $value";

		if ( isset( $query['hour'] ) || isset( $query['minute'] ) || isset( $query['second'] ) ) {

			// Avoid notices

			foreach ( array( 'hour', 'minute', 'second' ) as $unit ) {

				if ( ! isset( $query[$unit] ) ) {

					$query[$unit] = null;

				}

			}

			if ( $time_query = $this->build_time_query( $column, $compare, $query['hour'], $query['minute'], $query['second'] ) ) {

				$where_parts[] = $time_query;

			}

		}

		return $where_parts;

	}

	/**

	 * Builds and validates a value string based on the comparison operator.

	 *

	 * @since 3.7.0

	 * @access public

	 *

	 * @param string $compare The compare operator to use

	 * @param string|array $value The value

	 * @return string|int|false The value to be used in SQL or false on error.

	 */

	public function build_value( $compare, $value ) {

		if ( ! isset( $value ) )

			return false;

		switch ( $compare ) {

			case 'IN':

			case 'NOT IN':

				return '(' . implode( ',', array_map( 'intval', (array) $value ) ) . ')';

			case 'BETWEEN':

			case 'NOT BETWEEN':

				if ( ! is_array( $value ) || 2 != count( $value ) || ! isset( $value[0] ) || ! isset( $value[1] ) )

					$value = array( $value, $value );

				$value = array_map( 'intval', $value );

				return $value[0] . ' AND ' . $value[1];

			default;

				return (int) $value;

		}

	}

	/**

	 * Builds a MySQL format date/time based on some query parameters.

	 *

	 * You can pass an array of values (year, month, etc.) with missing parameter values being defaulted to

	 * either the maximum or minimum values (controlled by the $default_to parameter). Alternatively you can

	 * pass a string that that will be run through strtotime().

	 *

	 * @since 3.7.0

	 * @access public

	 *

	 * @param string|array $datetime An array of parameters or a strotime() string

	 * @param string $default_to Controls what values default to if they are missing from $datetime. Pass "min" or "max".

	 * @return string|false A MySQL format date/time or false on failure

	 */

	public function build_mysql_datetime( $datetime, $default_to_max = false ) {

		$now = current_time( 'timestamp' );

		if ( ! is_array( $datetime ) ) {

			// @todo Timezone issues here possibly

			return gmdate( 'Y-m-d H:i:s', strtotime( $datetime, $now ) );

		}

		$datetime = array_map( 'absint', $datetime );

		if ( ! isset( $datetime['year'] ) )

			$datetime['year'] = gmdate( 'Y', $now );

		if ( ! isset( $datetime['month'] ) )

			$datetime['month'] = ( $default_to_max ) ? 12 : 1;

		if ( ! isset( $datetime['day'] ) )

			$datetime['day'] = ( $default_to_max ) ? (int) date( 't', mktime( 0, 0, 0, $datetime['month'], 1, $datetime['year'] ) ) : 1;

		if ( ! isset( $datetime['hour'] ) )

			$datetime['hour'] = ( $default_to_max ) ? 23 : 0;

		if ( ! isset( $datetime['minute'] ) )

			$datetime['minute'] = ( $default_to_max ) ? 59 : 0;

		if ( ! isset( $datetime['second'] ) )

			$datetime['second'] = ( $default_to_max ) ? 59 : 0;

		return sprintf( '%04d-%02d-%02d %02d:%02d:%02d', $datetime['year'], $datetime['month'], $datetime['day'], $datetime['hour'], $datetime['minute'], $datetime['second'] );

	}

	/**

	 * Builds a query string for comparing time values (hour, minute, second).

	 *

	 * If just hour, minute, or second is set than a normal comparison will be done.

	 * However if multiple values are passed, a pseudo-decimal time will be created

	 * in order to be able to accurately compare against.

	 *

	 * @since 3.7.0

	 * @access public

	 *

	 * @param string $column The column to query against. Needs to be pre-validated!

	 * @param string $compare The comparison operator. Needs to be pre-validated!

	 * @param int|null $hour Optional. An hour value (0-23).

	 * @param int|null $minute Optional. A minute value (0-59).

	 * @param int|null $second Optional. A second value (0-59).

	 * @return string|false A query part or false on failure.

	 */

	public function build_time_query( $column, $compare, $hour = null, $minute = null, $second = null ) {

		global $wpdb;

		// Have to have at least one

		if ( ! isset( $hour ) && ! isset( $minute ) && ! isset( $second ) )

			return false;

		// Complex combined queries aren't supported for multi-value queries

		if ( in_array( $compare, array( 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ) ) ) {

			$return = array();

			if ( isset( $hour ) && false !== ( $value = $this->build_value( $compare, $hour ) ) )

				$return[] = "HOUR( $column ) $compare $value";

			if ( isset( $minute ) && false !== ( $value = $this->build_value( $compare, $minute ) ) )

				$return[] = "MINUTE( $column ) $compare $value";

			if ( isset( $second ) && false !== ( $value = $this->build_value( $compare, $second ) ) )

				$return[] = "SECOND( $column ) $compare $value";

			return implode( ' AND ', $return );

		}

		// Cases where just one unit is set

		if ( isset( $hour ) && ! isset( $minute ) && ! isset( $second ) && false !== ( $value = $this->build_value( $compare, $hour ) ) ) {

			return "HOUR( $column ) $compare $value";