<?php
/**
 * Integrate with WP_Query
 *
 * @since  1.0
 * @package elasticpress
 */

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

class EP_WP_Query_Integration {

	/**
	 * Is set only when we are within a multisite loop
	 *
	 * @var bool|WP_Query
	 */
	private $query_stack = array();

	private $posts_by_query = array();

	/**
	 * Placeholder method
	 *
	 * @since 0.9
	 */
	public function __construct() { }

	/**
	 * Checks to see if we should be integrating and if so, sets up the appropriate actions and filters.
	 * @since 0.9
	 */
	public function setup() {
		// Ensure that we are currently allowing ElasticPress to override the normal WP_Query
		if ( ep_is_indexing() ) {
			return;
		}

		// Make sure we return nothing for MySQL posts query
		add_filter( 'posts_request', array( $this, 'filter_posts_request' ), 10, 2 );

		// Add header
		add_action( 'pre_get_posts', array( $this, 'action_pre_get_posts' ), 5 );

		// Nukes the FOUND_ROWS() database query
		add_filter( 'found_posts_query', array( $this, 'filter_found_posts_query' ), 5, 2 );

    // Query and filter in EP_Posts to WP_Query
    // Added to caster for early return of result set if id field is filtered
    add_filter( 'posts_pre_query', array( $this, 'filter_the_posts' ), 10, 2 );

		// Query and filter in EP_Posts to WP_Query
		add_filter( 'the_posts', array( $this, 'filter_the_posts' ), 10, 2 );

		// Ensure we're in a loop before we allow blog switching
		add_action( 'loop_start', array( $this, 'action_loop_start' ), 10, 1 );

		// Properly restore blog if necessary
		add_action( 'loop_end', array( $this, 'action_loop_end' ), 10, 1 );

		// Properly switch to blog if necessary
		add_action( 'the_post', array( $this, 'action_the_post' ), 10, 1 );
	}

	/**
	 * Disables cache_results, adds header.
	 *
	 * @param $query
	 * @since 0.9
	 */
	public function action_pre_get_posts( $query ) {
		if ( ! ep_elasticpress_enabled( $query ) || apply_filters( 'ep_skip_query_integration', false, $query ) ) {
			return;
		}

		/**
		 * `cache_results` defaults to false but can be enabled.
		 *
		 * @since 1.5
		 */
		$query->set( 'cache_results', false );
		if ( ! empty( $query->query['cache_results'] ) ) {
			$query->set( 'cache_results', true );
		}

		if ( ! headers_sent() ) {
			/**
			 * Manually setting a header as $wp_query isn't yet initialized
			 * when we call: add_filter('wp_headers', 'filter_wp_headers');
			 */
			header( 'X-ElasticPress-Search: true' );
		}
	}

	/**
	 * Switch to the correct site if the post site id is different than the actual one
	 *
	 * @param array $post
	 * @since 0.9
	 */
	public function action_the_post( $post ) {
		if ( ! is_multisite() ) {
			return;
		}

		if ( empty( $this->query_stack ) ) {
			return;
		}

		if ( ! ep_elasticpress_enabled( $this->query_stack[0] ) || apply_filters( 'ep_skip_query_integration', false, $this->query_stack[0] ) ) {
			return;
		}

		if ( ! empty( $post->site_id ) && get_current_blog_id() != $post->site_id ) {
			restore_current_blog();

			switch_to_blog( $post->site_id );

			remove_action( 'the_post', array( $this, 'action_the_post' ), 10, 1 );
			setup_postdata( $post );
			add_action( 'the_post', array( $this, 'action_the_post' ), 10, 1 );
		}

	}

	/**
	 * Ensure we've started a loop before we allow ourselves to change the blog
	 *
	 * @since 0.9.2
	 */
	public function action_loop_start( $query ) {
		if ( ! is_multisite() ) {
			return;
		}

		array_unshift( $this->query_stack, $query );
	}

	/**
	 * Make sure the correct blog is restored
	 *
	 * @since 0.9
	 */
	public function action_loop_end( $query ) {
		if ( ! is_multisite() ) {
			return;
		}

		array_pop( $this->query_stack );

		if ( ! ep_elasticpress_enabled( $query ) || apply_filters( 'ep_skip_query_integration', false, $query )  ) {
			return;
		}

		if ( ! empty( $GLOBALS['switched'] ) ) {
			restore_current_blog();
		}
	}

	/**
	 * Filter the posts array to contain ES query results in EP_Post form. Pull previously queried posts.
	 *
	 * @param array $posts
	 * @param object &$query
	 * @return array
	 */
	public function filter_the_posts( $posts, &$query ) {
		if ( ! ep_elasticpress_enabled( $query ) || apply_filters( 'ep_skip_query_integration', false, $query ) || ! isset( $this->posts_by_query[spl_object_hash( $query )] ) ) {
			return $posts;
		}

		$new_posts = $this->posts_by_query[spl_object_hash( $query )];

		return $new_posts;
	}

	/**
	 * Remove the found_rows from the SQL Query
	 *
	 * @param string $sql
	 * @param object $query
	 * @since 0.9
	 * @return string
	 */
	public function filter_found_posts_query( $sql, $query ) {
		if ( ! ep_elasticpress_enabled( $query ) || apply_filters( 'ep_skip_query_integration', false, $query )  ) {
			return $sql;
		}

		return '';
	}

	/**
	 * Filter query string used for get_posts(). Query for posts and save for later.
	 * Return a query that will return nothing.
	 *
	 * @param string $request
	 * @param object $query
	 * @since 0.9
	 * @return string
	 */
	public function filter_posts_request( $request, $query ) {
		global $wpdb;

		if ( ! ep_elasticpress_enabled( $query ) || apply_filters( 'ep_skip_query_integration', false, $query ) ) {
			return $request;
		}

		$query_vars = $query->query_vars;

		/**
		 * Allows us to filter in searchable post types if needed
		 *
		 * @since  2.1
		 */
		$query_vars['post_type'] = apply_filters( 'ep_query_post_type', $query_vars['post_type'], $query );

		if ( 'any' === $query_vars['post_type'] ) {
			unset( $query_vars['post_type'] );
		}

		/**
		 * If not search and not set default to post. If not set and is search, use searchable post tpyes
		 */
		if ( empty( $query_vars['post_type'] ) ) {
			if ( empty( $query_vars['s'] ) ) {
				$query_vars['post_type'] = 'post';
			} else {
				$query_vars['post_type'] = array_values( get_post_types( array( 'exclude_from_search' => false ) ) );
			}
		}

		if ( empty( $query_vars['post_type'] ) ) {
			$this->posts_by_query[spl_object_hash( $query )] = array();

			return "SELECT * FROM $wpdb->posts WHERE 1=0";
		}

		$new_posts = apply_filters( 'ep_wp_query_search_cached_posts', array(), $query );

		$ep_query = array();

		if( count( $new_posts ) < 1 ) {

			$scope = 'current';
			if ( ! empty( $query_vars['sites'] ) ) {
				$scope = $query_vars['sites'];
			}

			$formatted_args = ep_format_args( $query_vars );

			/**
			 * Filter search scope
			 *
			 * @since 2.1
			 *
			 * @param mixed $scope The search scope. Accepts `all` (string), a single
			 *                     site id (int or string), or an array of site ids (array).
			 */
			$scope = apply_filters( 'ep_search_scope', $scope );

			$ep_query = ep_query( $formatted_args, $query->query_vars, $scope );

			if ( false === $ep_query ) {
				return $request;
			}

			$query->found_posts = $ep_query['found_posts'];
			$query->max_num_pages = ceil( $ep_query['found_posts'] / $query->get( 'posts_per_page' ) );

			foreach ( $ep_query['posts'] as $post_array ) {
        //prepare result based on fields
        if ($query->query_vars['fields'] == 'ids') {
	  $post = $post_array['post_id'];
	} elseif ($query->query_vars['fields'] == 'id=>parent') {
          $post = new stdClass();
          $post->ID = $post_array['post_id'];
          $post->parent_id = $post_array['post_parent'];
        } else {
          $post = new stdClass();

          $post->ID = $post_array['post_id'];
          $post->site_id = get_current_blog_id();

          if ( ! empty( $post_array['site_id'] ) ) {
            $post->site_id = $post_array['site_id'];
          }
          // ep_search_request_args
          $post_return_args = apply_filters( 'ep_search_post_return_args',
            array(
              'post_type',
              'post_author',
              'post_name',
              'post_status',
              'post_title',
              'post_parent',
              'post_content',
              'post_excerpt',
              'post_date',
              'post_date_gmt',
              'post_modified',
              'post_modified_gmt',
              'post_mime_type',
              'comment_count',
              'comment_status',
              'ping_status',
              'menu_order',
              'permalink',
              'terms',
              'post_meta',
              'meta',
            )
          );

          foreach ( $post_return_args as $key ) {
            if( $key === 'post_author' ) {
              $post->$key = $post_array[$key]['id'];
            } elseif ( isset( $post_array[ $key ] ) ) {
              $post->$key = $post_array[$key];
            }
          }

				  $post->elasticsearch = true; // Super useful for debugging
        }

				if ( $post ) {
					$new_posts[] = $post;
				}
			}

			do_action( 'ep_wp_query_non_cached_search', $new_posts, $ep_query, $query );
		}

		$this->posts_by_query[spl_object_hash( $query )] = $new_posts;

		do_action( 'ep_wp_query_search', $new_posts, $ep_query, $query );

		return "SELECT * FROM $wpdb->posts WHERE 1=0";
	}


	/**
	 * Return a singleton instance of the current class
	 *
	 * @since 0.9
	 * @return object
	 */
	public static function factory() {
		static $instance = false;

		if ( ! $instance ) {
			$instance = new self();
			add_action( 'init', array( $instance, 'setup' ) );
		}

		return $instance;
	}
}

EP_WP_Query_Integration::factory();