<?php

/**
 * Class ActionScheduler_wpCommentLogger
 */
class ActionScheduler_wpCommentLogger extends ActionScheduler_Logger {
	const AGENT = 'ActionScheduler';
	const TYPE  = 'action_log';

	/**
	 * Create log entry.
	 *
	 * @param string        $action_id Action ID.
	 * @param string        $message   Action log's message.
	 * @param DateTime|null $date      Action log's timestamp.
	 *
	 * @return string The log entry ID
	 */
	public function log( $action_id, $message, ?DateTime $date = null ) {
		if ( empty( $date ) ) {
			$date = as_get_datetime_object();
		} else {
			$date = as_get_datetime_object( clone $date );
		}
		$comment_id = $this->create_wp_comment( $action_id, $message, $date );
		return $comment_id;
	}

	/**
	 * Create comment.
	 *
	 * @param int      $action_id Action ID.
	 * @param string   $message Action log's message.
	 * @param DateTime $date Action log entry's timestamp.
	 */
	protected function create_wp_comment( $action_id, $message, DateTime $date ) {

		$comment_date_gmt = $date->format( 'Y-m-d H:i:s' );
		ActionScheduler_TimezoneHelper::set_local_timezone( $date );
		$comment_data = array(
			'comment_post_ID'  => $action_id,
			'comment_date'     => $date->format( 'Y-m-d H:i:s' ),
			'comment_date_gmt' => $comment_date_gmt,
			'comment_author'   => self::AGENT,
			'comment_content'  => $message,
			'comment_agent'    => self::AGENT,
			'comment_type'     => self::TYPE,
		);

		return wp_insert_comment( $comment_data );
	}

	/**
	 * Get single log entry for action.
	 *
	 * @param string $entry_id Entry ID.
	 *
	 * @return ActionScheduler_LogEntry
	 */
	public function get_entry( $entry_id ) {
		$comment = $this->get_comment( $entry_id );

		if ( empty( $comment ) || self::TYPE !== $comment->comment_type ) {
			return new ActionScheduler_NullLogEntry();
		}

		$date = as_get_datetime_object( $comment->comment_date_gmt );
		ActionScheduler_TimezoneHelper::set_local_timezone( $date );
		return new ActionScheduler_LogEntry( $comment->comment_post_ID, $comment->comment_content, $date );
	}

	/**
	 * Get action's logs.
	 *
	 * @param string $action_id Action ID.
	 *
	 * @return ActionScheduler_LogEntry[]
	 */
	public function get_logs( $action_id ) {
		$status = 'all';
		$logs   = array();

		if ( get_post_status( $action_id ) === 'trash' ) {
			$status = 'post-trashed';
		}

		$comments = get_comments(
			array(
				'post_id' => $action_id,
				'orderby' => 'comment_date_gmt',
				'order'   => 'ASC',
				'type'    => self::TYPE,
				'status'  => $status,
			)
		);

		foreach ( $comments as $c ) {
			$entry = $this->get_entry( $c );

			if ( ! empty( $entry ) ) {
				$logs[] = $entry;
			}
		}

		return $logs;
	}

	/**
	 * Get comment.
	 *
	 * @param int $comment_id Comment ID.
	 */
	protected function get_comment( $comment_id ) {
		return get_comment( $comment_id );
	}

	/**
	 * Filter comment queries.
	 *
	 * @param WP_Comment_Query $query Comment query object.
	 */
	public function filter_comment_queries( $query ) {
		foreach ( array( 'ID', 'parent', 'post_author', 'post_name', 'post_parent', 'type', 'post_type', 'post_id', 'post_ID' ) as $key ) {
			if ( ! empty( $query->query_vars[ $key ] ) ) {
				return; // don't slow down queries that wouldn't include action_log comments anyway.
			}
		}
		$query->query_vars['action_log_filter'] = true;
		add_filter( 'comments_clauses', array( $this, 'filter_comment_query_clauses' ), 10, 2 );
	}

	/**
	 * Filter comment queries.
	 *
	 * @param array            $clauses Query's clauses.
	 * @param WP_Comment_Query $query Query object.
	 *
	 * @return array
	 */
	public function filter_comment_query_clauses( $clauses, $query ) {
		if ( ! empty( $query->query_vars['action_log_filter'] ) ) {
			$clauses['where'] .= $this->get_where_clause();
		}
		return $clauses;
	}

	/**
	 * Make sure Action Scheduler logs are excluded from comment feeds, which use WP_Query, not
	 * the WP_Comment_Query class handled by @see self::filter_comment_queries().
	 *
	 * @param string   $where Query's `where` clause.
	 * @param WP_Query $query Query object.
	 *
	 * @return string
	 */
	public function filter_comment_feed( $where, $query ) {
		if ( is_comment_feed() ) {
			$where .= $this->get_where_clause();
		}
		return $where;
	}

	/**
	 * Return a SQL clause to exclude Action Scheduler comments.
	 *
	 * @return string
	 */
	protected function get_where_clause() {
		global $wpdb;
		return sprintf( " AND {$wpdb->comments}.comment_type != '%s'", self::TYPE );
	}

	/**
	 * Remove action log entries from wp_count_comments()
	 *
	 * @param array $stats   Comment count.
	 * @param int   $post_id Post ID.
	 *
	 * @return object
	 */
	public function filter_comment_count( $stats, $post_id ) {
		global $wpdb;

		if ( 0 === $post_id ) {
			$stats = $this->get_comment_count();
		}

		return $stats;
	}

	/**
	 * Retrieve the comment counts from our cache, or the database if the cached version isn't set.
	 *
	 * @return object
	 */
	protected function get_comment_count() {
		global $wpdb;

		$stats = get_transient( 'as_comment_count' );

		if ( ! $stats ) {
			$stats    = array();
			$count    = $wpdb->get_results( "SELECT comment_approved, COUNT( * ) AS num_comments FROM {$wpdb->comments} WHERE comment_type NOT IN('order_note','action_log') GROUP BY comment_approved", ARRAY_A );
			$total    = 0;
			$stats    = array();
			$approved = array(
				'0'            => 'moderated',
				'1'            => 'approved',
				'spam'         => 'spam',
				'trash'        => 'trash',
				'post-trashed' => 'post-trashed',
			);

			foreach ( (array) $count as $row ) {
				// Don't count post-trashed toward totals.
				if ( 'post-trashed' !== $row['comment_approved'] && 'trash' !== $row['comment_approved'] ) {
					$total += $row['num_comments'];
				}
				if ( isset( $approved[ $row['comment_approved'] ] ) ) {
					$stats[ $approved[ $row['comment_approved'] ] ] = $row['num_comments'];
				}
			}

			$stats['total_comments'] = $total;
			$stats['all']            = $total;

			foreach ( $approved as $key ) {
				if ( empty( $stats[ $key ] ) ) {
					$stats[ $key ] = 0;
				}
			}

			$stats = (object) $stats;
			set_transient( 'as_comment_count', $stats );
		}

		return $stats;
	}

	/**
	 * Delete comment count cache whenever there is new comment or the status of a comment changes. Cache
	 * will be regenerated next time ActionScheduler_wpCommentLogger::filter_comment_count() is called.
	 */
	public function delete_comment_count_cache() {
		delete_transient( 'as_comment_count' );
	}

	/**
	 * Initialize.
	 *
	 * @codeCoverageIgnore
	 */
	public function init() {
		add_action( 'action_scheduler_before_process_queue', array( $this, 'disable_comment_counting' ), 10, 0 );
		add_action( 'action_scheduler_after_process_queue', array( $this, 'enable_comment_counting' ), 10, 0 );

		parent::init();

		add_action( 'pre_get_comments', array( $this, 'filter_comment_queries' ), 10, 1 );
		add_action( 'wp_count_comments', array( $this, 'filter_comment_count' ), 20, 2 ); // run after WC_Comments::wp_count_comments() to make sure we exclude order notes and action logs.
		add_action( 'comment_feed_where', array( $this, 'filter_comment_feed' ), 10, 2 );

		// Delete comments count cache whenever there is a new comment or a comment status changes.
		add_action( 'wp_insert_comment', array( $this, 'delete_comment_count_cache' ) );
		add_action( 'wp_set_comment_status', array( $this, 'delete_comment_count_cache' ) );
	}

	/**
	 * Defer comment counting.
	 */
	public function disable_comment_counting() {
		wp_defer_comment_counting( true );
	}

	/**
	 * Enable comment counting.
	 */
	public function enable_comment_counting() {
		wp_defer_comment_counting( false );
	}

}