<?php
/**
 * Question and answer query filters.
 *
 * @package AnsPress
 * @since 4.0.0
 */

/**
 * Query hooks
 */
class AP_QA_Query_Hooks {

	/**
	 * Alter WP_Query mysql query for question and answers.
	 *
	 * @param  array  $sql  Sql query.
	 * @param  Object $args Instance.
	 * @return array
	 */
	public static function sql_filter( $sql, $args ) {
		global $wpdb;

		// Do not filter if wp-admin.
		if ( is_admin() ) {
			return $sql;
		}

		if ( isset( $args->query['ap_query'] ) ) {
			$sql['join'] = $sql['join'] . " LEFT JOIN {$wpdb->ap_qameta} qameta ON qameta.post_id = {$wpdb->posts}.ID";
			$sql['fields'] = $sql['fields'] . ', qameta.*, qameta.votes_up - qameta.votes_down AS votes_net';
			$post_status = '';
			$query_status = $args->query['post_status'];

			if ( isset( $args->query['ap_current_user_ignore'] ) && false === $args->query['ap_current_user_ignore'] ) {
				// Build the post_status mysql query.
				if ( ! empty( $query_status ) ) {
					if ( is_array( $query_status ) ) {
						$i = 1;

						foreach ( get_post_stati() as $status ) {

							if ( in_array( $status, $args->query['post_status'], true ) ) {
								$post_status .= $wpdb->posts.".post_status = '" . $status . "'";

								if ( count( $query_status ) != $i ) {
									$post_status .= ' OR ';
								} else {
									$post_status .= ')';
								}
								$i++;
							}
						}
					} else {
						$post_status .= $wpdb->posts.".post_status = '".$query_status."' ";
					}
				}

				// Replace post_status query.
				if ( is_user_logged_in() && false !== ( $pos = strpos( $sql['where'], $post_status ) ) ) {
					$pos = $pos + strlen( $post_status );
					$author_query = $wpdb->prepare( " OR ( {$wpdb->posts}.post_author = %d AND {$wpdb->posts}.post_status IN ('publish', 'private_post', 'trash', 'moderate') ) ", get_current_user_id() );
					$sql['where'] = substr_replace( $sql['where'], $author_query, $pos, 0 );
				}
			}

			// Hack to fix WP_Query for fetching anonymous author posts.
			if ( isset( $args->query['author'] ) && 0 === $args->query['author'] ) {
				$sql['where'] = $sql['where'] . $wpdb->prepare( " AND {$wpdb->posts}.post_author = %d", $args->query['author'] );
			}

			$ap_order_by = isset( $args->query['ap_order_by'] ) ? $args->query['ap_order_by'] : 'active';
			$answer_query = isset( $args->query['ap_answers_query'] );

			if ( 'answers' === $ap_order_by && ! $answer_query ) {
				$sql['orderby'] = 'IFNULL(qameta.answers, 0) DESC, ' . $sql['orderby'];
			} elseif ( 'views' === $ap_order_by && ! $answer_query ) {
				$sql['orderby'] = 'IFNULL(qameta.views, 0) DESC, ' . $sql['orderby'];
			} elseif ( 'unanswered' === $ap_order_by && ! $answer_query ) {
				$sql['orderby'] = 'IFNULL(qameta.answers, 0) ASC,' . $sql['orderby'];
			} elseif ( 'voted' === $ap_order_by ) {
				$sql['orderby'] = 'CASE WHEN IFNULL(votes_net, 0) >= 0 THEN 1 ELSE 2 END ASC, ABS(votes_net) DESC, ' . $sql['orderby'];
			} elseif ( 'unsolved' === $ap_order_by && ! $answer_query ) {
				$sql['orderby'] = "if( qameta.selected_id = '' or qameta.selected_id is null, 1, 0 ) ASC," . $sql['orderby'];
			} elseif ( 'oldest' === $ap_order_by ) {
				$sql['orderby'] = "{$wpdb->posts}.post_date ASC";
			} elseif ( 'newest' === $ap_order_by ) {
				$sql['orderby'] = "{$wpdb->posts}.post_date DESC";
			} else {
				$sql['orderby'] = 'qameta.last_updated DESC ';
			}

			// Keep featured posts on top.
			if ( ! $answer_query ) {
				$sql['orderby'] = 'CASE WHEN IFNULL(qameta.featured, 0) =1 THEN 1 ELSE 2 END ASC, ' . $sql['orderby'];
			}

			// Keep best answer to top.
			if ( $answer_query && ! $args->query['ignore_selected_answer'] ) {
				$sql['orderby'] = 'qameta.selected <> 1 , ' . $sql['orderby'];
			}

			// Allow filtering sql query.
			$sql = apply_filters( 'ap_qa_sql', $sql );

			$args->count_request = $sql;
		}

		return $sql;
	}

	/**
	 * Add qameta fields to post and prefetch metas and users.
	 *
	 * @param  array  $posts Post array.
	 * @param  object $instance QP_Query instance.
	 * @return array
	 */
	public static function posts_results( $posts, $instance ) {

		foreach ( (array) $posts as $k => $p ) {
			if ( in_array( $p->post_type, [ 'question', 'answer' ], true ) ) {
				// Convert object as array to prevent using __isset of WP_Post.
				$p_arr = (array) $p;

				// Check if ptype exists which is a qameta feild.
				if ( ! empty( $p_arr['ptype'] ) ) {
					$qameta = ap_qameta_fields();
				} else {
					$qameta = ap_get_qameta( $p->ID );
				}

				foreach ( (array) $qameta as $fields_name => $val ) {
					if ( ! isset( $p_arr[ $fields_name ] ) || empty( $p_arr[ $fields_name ] ) ) {
						$p->$fields_name = $val;
					}

					// Serialize fields and activities.
					$p->activities = maybe_unserialize( $p->activities );
					$p->fields = maybe_unserialize( $p->fields );

					$p->ap_qameta_wrapped = true;
					$p->votes_net = $p->votes_up - $p->votes_down;

					if ( ! ap_user_can_view_post( $p ) ) {
						$p->post_content = __( 'Restricted content', 'anspress-question-answer' );
					}

					$posts[ $k ] = $p;
				}
			}
		}

		if ( isset( $instance->query['ap_question_query'] ) || isset( $instance->query['ap_answers_query'] ) ) {
			$instance->pre_fetch();
		}

		return $posts;
	}

	/**
	 * Filter to override default WP method to count total found posts
	 * using SQL_CALC_FOUND_ROWS. Prevent AnsPress quries to use SQL_CALC_FOUND_ROWS
	 * which is an old MySql function. Query takes too much time SQL_CALC_FOUND_ROWS in a site
	 * where there are more then a million posts.
	 */
	public static function posts_pre_query( $query = null, $instance) {
		if ( isset( $instance->query['ap_query'] ) ) {
			global $wpdb;

			$instance->request = str_replace( 'SQL_CALC_FOUND_ROWS', '', $instance->request );

			$instance->query_vars['no_found_rows'] = 1;
			$instance->found_posts = $wpdb->get_var( "SELECT count({$wpdb->posts}.ID) FROM {$wpdb->posts} {$instance->count_request['join']} WHERE 1=1 {$instance->count_request['where']}" );

			$instance->found_posts = apply_filters_ref_array( 'found_posts', array( $instance->found_posts, &$instance ) );

			$posts_per_page = ( ! empty( $instance->query_vars['posts_per_page'] ) ? $instance->query_vars['posts_per_page'] : get_option( 'posts_per_page' ) );
			$instance->max_num_pages = ceil( $instance->found_posts / $posts_per_page );
		}

	}
}