<?php

class Akismet {

	const API_HOST = 'rest.akismet.com';

	const API_PORT = 80;

	const MAX_DELAY_BEFORE_MODERATION_EMAIL = 86400; // One day in seconds

	private static $last_comment = '';

	private static $initiated = false;

	private static $prevent_moderation_email_for_these_comments = array();

	private static $last_comment_result = null;

	private static $comment_as_submitted_allowed_keys = array( 'blog' => '', 'blog_charset' => '', 'blog_lang' => '', 'blog_ua' => '', 'comment_agent' => '', 'comment_author' => '', 'comment_author_IP' => '', 'comment_author_email' => '', 'comment_author_url' => '', 'comment_content' => '', 'comment_date_gmt' => '', 'comment_tags' => '', 'comment_type' => '', 'guid' => '', 'is_test' => '', 'permalink' => '', 'reporter' => '', 'site_domain' => '', 'submit_referer' => '', 'submit_uri' => '', 'user_ID' => '', 'user_agent' => '', 'user_id' => '', 'user_ip' => '' );

	private static $is_rest_api_call = false;

	public static function init() {

		if ( ! self::$initiated ) {

			self::init_hooks();

		}

	}

	/**

	 * Initializes WordPress hooks

	 */

	private static function init_hooks() {

		self::$initiated = true;

		add_action( 'wp_insert_comment', array( 'Akismet', 'auto_check_update_meta' ), 10, 2 );

		add_filter( 'preprocess_comment', array( 'Akismet', 'auto_check_comment' ), 1 );

		add_filter( 'rest_pre_insert_comment', array( 'Akismet', 'rest_auto_check_comment' ), 1 );

		add_action( 'akismet_scheduled_delete', array( 'Akismet', 'delete_old_comments' ) );

		add_action( 'akismet_scheduled_delete', array( 'Akismet', 'delete_old_comments_meta' ) );

		add_action( 'akismet_scheduled_delete', array( 'Akismet', 'delete_orphaned_commentmeta' ) );

		add_action( 'akismet_schedule_cron_recheck', array( 'Akismet', 'cron_recheck' ) );

		add_action( 'comment_form',  array( 'Akismet',  'add_comment_nonce' ), 1 );

		add_action( 'admin_head-edit-comments.php', array( 'Akismet', 'load_form_js' ) );

		add_action( 'comment_form', array( 'Akismet', 'load_form_js' ) );

		add_action( 'comment_form', array( 'Akismet', 'inject_ak_js' ) );

		add_filter( 'script_loader_tag', array( 'Akismet', 'set_form_js_async' ), 10, 3 );

		add_filter( 'comment_moderation_recipients', array( 'Akismet', 'disable_moderation_emails_if_unreachable' ), 1000, 2 );

		add_filter( 'pre_comment_approved', array( 'Akismet', 'last_comment_status' ), 10, 2 );

		add_action( 'transition_comment_status', array( 'Akismet', 'transition_comment_status' ), 10, 3 );

		// Run this early in the pingback call, before doing a remote fetch of the source uri

		add_action( 'xmlrpc_call', array( 'Akismet', 'pre_check_pingback' ) );

		// Jetpack compatibility

		add_filter( 'jetpack_options_whitelist', array( 'Akismet', 'add_to_jetpack_options_whitelist' ) );

		add_action( 'update_option_wordpress_api_key', array( 'Akismet', 'updated_option' ), 10, 2 );

		add_action( 'add_option_wordpress_api_key', array( 'Akismet', 'added_option' ), 10, 2 );

		add_action( 'comment_form_after',  array( 'Akismet',  'display_comment_form_privacy_notice' ) );

	}

	public static function get_api_key() {

		return apply_filters( 'akismet_get_api_key', defined('WPCOM_API_KEY') ? constant('WPCOM_API_KEY') : get_option('wordpress_api_key') );

	}

	public static function check_key_status( $key, $ip = null ) {

		return self::http_post( Akismet::build_query( array( 'key' => $key, 'blog' => get_option( 'home' ) ) ), 'verify-key', $ip );

	}

	public static function verify_key( $key, $ip = null ) {

		// Shortcut for obviously invalid keys.

		if ( strlen( $key ) != 12 ) {

			return 'invalid';

		}

		$response = self::check_key_status( $key, $ip );

		if ( $response[1] != 'valid' && $response[1] != 'invalid' )

			return 'failed';

		return $response[1];

	}

	public static function deactivate_key( $key ) {

		$response = self::http_post( Akismet::build_query( array( 'key' => $key, 'blog' => get_option( 'home' ) ) ), 'deactivate' );

		if ( $response[1] != 'deactivated' )

			return 'failed';

		return $response[1];

	}

	/**

	 * Add the akismet option to the Jetpack options management whitelist.

	 *

	 * @param array $options The list of whitelisted option names.

	 * @return array The updated whitelist

	 */

	public static function add_to_jetpack_options_whitelist( $options ) {

		$options[] = 'wordpress_api_key';

		return $options;

	}

	/**

	 * When the akismet option is updated, run the registration call.

	 *

	 * This should only be run when the option is updated from the Jetpack/WP.com

	 * API call, and only if the new key is different than the old key.

	 *

	 * @param mixed  $old_value   The old option value.

	 * @param mixed  $value       The new option value.

	 */

	public static function updated_option( $old_value, $value ) {

		// Not an API call

		if ( ! class_exists( 'WPCOM_JSON_API_Update_Option_Endpoint' ) ) {

			return;

		}

		// Only run the registration if the old key is different.

		if ( $old_value !== $value ) {

			self::verify_key( $value );

		}

	}

	/**

	 * Treat the creation of an API key the same as updating the API key to a new value.

	 *

	 * @param mixed  $option_name   Will always be "wordpress_api_key", until something else hooks in here.

	 * @param mixed  $value         The option value.

	 */

	public static function added_option( $option_name, $value ) {

		if ( 'wordpress_api_key' === $option_name ) {

			return self::updated_option( '', $value );

		}

	}

	public static function rest_auto_check_comment( $commentdata ) {

		self::$is_rest_api_call = true;

		return self::auto_check_comment( $commentdata );

	}

	public static function auto_check_comment( $commentdata ) {

		self::$last_comment_result = null;

		$comment = $commentdata;

		$comment['user_ip']      = self::get_ip_address();

		$comment['user_agent']   = self::get_user_agent();

		$comment['referrer']     = self::get_referer();

		$comment['blog']         = get_option( 'home' );

		$comment['blog_lang']    = get_locale();

		$comment['blog_charset'] = get_option('blog_charset');

		$comment['permalink']    = get_permalink( $comment['comment_post_ID'] );

		if ( ! empty( $comment['user_ID'] ) ) {

			$comment['user_role'] = Akismet::get_user_roles( $comment['user_ID'] );

		}

		/** See filter documentation in init_hooks(). */

		$akismet_nonce_option = apply_filters( 'akismet_comment_nonce', get_option( 'akismet_comment_nonce' ) );

		$comment['akismet_comment_nonce'] = 'inactive';

		if ( $akismet_nonce_option == 'true' || $akismet_nonce_option == '' ) {

			$comment['akismet_comment_nonce'] = 'failed';

			if ( isset( $_POST['akismet_comment_nonce'] ) && wp_verify_nonce( $_POST['akismet_comment_nonce'], 'akismet_comment_nonce_' . $comment['comment_post_ID'] ) )

				$comment['akismet_comment_nonce'] = 'passed';

			// comment reply in wp-admin

			if ( isset( $_POST['_ajax_nonce-replyto-comment'] ) && check_ajax_referer( 'replyto-comment', '_ajax_nonce-replyto-comment' ) )

				$comment['akismet_comment_nonce'] = 'passed';

		}

		if ( self::is_test_mode() )

			$comment['is_test'] = 'true';

		foreach( $_POST as $key => $value ) {

			if ( is_string( $value ) )

				$comment["POST_{$key}"] = $value;

		}

		foreach ( $_SERVER as $key => $value ) {

			if ( ! is_string( $value ) ) {

				continue;

			}

			if ( preg_match( "/^HTTP_COOKIE/", $key ) ) {

				continue;

			}

			// Send any potentially useful $_SERVER vars, but avoid sending junk we don't need.

			if ( preg_match( "/^(HTTP_|REMOTE_ADDR|REQUEST_URI|DOCUMENT_URI)/", $key ) ) {

				$comment[ "$key" ] = $value;

			}

		}

		$post = get_post( $comment['comment_post_ID'] );

		if ( ! is_null( $post ) ) {

			// $post can technically be null, although in the past, it's always been an indicator of another plugin interfering.

			$comment[ 'comment_post_modified_gmt' ] = $post->post_modified_gmt;

		}

		$response = self::http_post( Akismet::build_query( $comment ), 'comment-check' );

		do_action( 'akismet_comment_check_response', $response );

		$commentdata['comment_as_submitted'] = array_intersect_key( $comment, self::$comment_as_submitted_allowed_keys );

		$commentdata['akismet_result']       = $response[1];

		if ( isset( $response[0]['x-akismet-pro-tip'] ) )

	        $commentdata['akismet_pro_tip'] = $response[0]['x-akismet-pro-tip'];

		if ( isset( $response[0]['x-akismet-error'] ) ) {

			// An error occurred that we anticipated (like a suspended key) and want the user to act on.

			// Send to moderation.

			self::$last_comment_result = '0';

		}

		else if ( 'true' == $response[1] ) {

			// akismet_spam_count will be incremented later by comment_is_spam()

			self::$last_comment_result = 'spam';

			$discard = ( isset( $commentdata['akismet_pro_tip'] ) && $commentdata['akismet_pro_tip'] === 'discard' && self::allow_discard() );

			do_action( 'akismet_spam_caught', $discard );

			if ( $discard ) {

				// The spam is obvious, so we're bailing out early. 

				// akismet_result_spam() won't be called so bump the counter here

				if ( $incr = apply_filters( 'akismet_spam_count_incr', 1 ) ) {

					update_option( 'akismet_spam_count', get_option( 'akismet_spam_count' ) + $incr );

				}

				if ( self::$is_rest_api_call ) {

					return new WP_Error( 'akismet_rest_comment_discarded', __( 'Comment discarded.', 'akismet' ) );

				}

				else {

					// Redirect back to the previous page, or failing that, the post permalink, or failing that, the homepage of the blog.

					$redirect_to = isset( $_SERVER['HTTP_REFERER'] ) ? $_SERVER['HTTP_REFERER'] : ( $post ? get_permalink( $post ) : home_url() );

					wp_safe_redirect( esc_url_raw( $redirect_to ) );

					die();

				}

			}

			else if ( self::$is_rest_api_call ) {

				// The way the REST API structures its calls, we can set the comment_approved value right away.

				$commentdata['comment_approved'] = 'spam';

			}

		}

		// if the response is neither true nor false, hold the comment for moderation and schedule a recheck

		if ( 'true' != $response[1] && 'false' != $response[1] ) {

			if ( !current_user_can('moderate_comments') ) {

				// Comment status should be moderated

				self::$last_comment_result = '0';

			}

			if ( ! wp_next_scheduled( 'akismet_schedule_cron_recheck' ) ) {

				wp_schedule_single_event( time() + 1200, 'akismet_schedule_cron_recheck' );

				do_action( 'akismet_scheduled_recheck', 'invalid-response-' . $response[1] );

			}

			self::$prevent_moderation_email_for_these_comments[] = $commentdata;

		}

		// Delete old comments daily

		if ( ! wp_next_scheduled( 'akismet_scheduled_delete' ) ) {

			wp_schedule_event( time(), 'daily', 'akismet_scheduled_delete' );

		}

		self::set_last_comment( $commentdata );

		self::fix_scheduled_recheck();

		return $commentdata;

	}

	public static function get_last_comment() {

		return self::$last_comment;

	}

	public static function set_last_comment( $comment ) {

		if ( is_null( $comment ) ) {

			self::$last_comment = null;

		}

		else {

			// We filter it here so that it matches the filtered comment data that we'll have to compare against later.

			// wp_filter_comment expects comment_author_IP

			self::$last_comment = wp_filter_comment(

				array_merge(

					array( 'comment_author_IP' => self::get_ip_address() ),

					$comment

				)

			);

		}

	}

	// this fires on wp_insert_comment.  we can't update comment_meta when auto_check_comment() runs

	// because we don't know the comment ID at that point.

	public static function auto_check_update_meta( $id, $comment ) {

		// wp_insert_comment() might be called in other contexts, so make sure this is the same comment

		// as was checked by auto_check_comment

		if ( is_object( $comment ) && !empty( self::$last_comment ) && is_array( self::$last_comment ) ) {

			if ( self::matches_last_comment( $comment ) ) {

					load_plugin_textdomain( 'akismet' );

					// normal result: true or false

					if ( self::$last_comment['akismet_result'] == 'true' ) {

						update_comment_meta( $comment->comment_ID, 'akismet_result', 'true' );

						self::update_comment_history( $comment->comment_ID, '', 'check-spam' );

						if ( $comment->comment_approved != 'spam' )

							self::update_comment_history(

								$comment->comment_ID,

								'',

								'status-changed-'.$comment->comment_approved

							);

					}

					elseif ( self::$last_comment['akismet_result'] == 'false' ) {

						update_comment_meta( $comment->comment_ID, 'akismet_result', 'false' );

						self::update_comment_history( $comment->comment_ID, '', 'check-ham' );

						// Status could be spam or trash, depending on the WP version and whether this change applies:

						// https://core.trac.wordpress.org/changeset/34726

						if ( $comment->comment_approved == 'spam' || $comment->comment_approved == 'trash' ) {

							if ( wp_blacklist_check($comment->comment_author, $comment->comment_author_email, $comment->comment_author_url, $comment->comment_content, $comment->comment_author_IP, $comment->comment_agent) )

								self::update_comment_history( $comment->comment_ID, '', 'wp-blacklisted' );

							else

								self::update_comment_history( $comment->comment_ID, '', 'status-changed-'.$comment->comment_approved );

						}

					} // abnormal result: error

					else {

						update_comment_meta( $comment->comment_ID, 'akismet_error', time() );

						self::update_comment_history(

							$comment->comment_ID,

							'',

							'check-error',

							array( 'response' => substr( self::$last_comment['akismet_result'], 0, 50 ) )

						);

					}

					// record the complete original data as submitted for checking

					if ( isset( self::$last_comment['comment_as_submitted'] ) )

						update_comment_meta( $comment->comment_ID, 'akismet_as_submitted', self::$last_comment['comment_as_submitted'] );

					if ( isset( self::$last_comment['akismet_pro_tip'] ) )

						update_comment_meta( $comment->comment_ID, 'akismet_pro_tip', self::$last_comment['akismet_pro_tip'] );

			}

		}

	}

	public static function delete_old_comments() {

		global $wpdb;

		/**

		 * Determines how many comments will be deleted in each batch.

		 *

		 * @param int The default, as defined by AKISMET_DELETE_LIMIT.

		 */

		$delete_limit = apply_filters( 'akismet_delete_comment_limit', defined( 'AKISMET_DELETE_LIMIT' ) ? AKISMET_DELETE_LIMIT : 10000 );

		$delete_limit = max( 1, intval( $delete_limit ) );

		/**

		 * Determines how many days a comment will be left in the Spam queue before being deleted.

		 *

		 * @param int The default number of days.

		 */

		$delete_interval = apply_filters( 'akismet_delete_comment_interval', 15 );

		$delete_interval = max( 1, intval( $delete_interval ) );

		while ( $comment_ids = $wpdb->get_col( $wpdb->prepare( "SELECT comment_id FROM {$wpdb->comments} WHERE DATE_SUB(NOW(), INTERVAL %d DAY) > comment_date_gmt AND comment_approved = 'spam' LIMIT %d", $delete_interval, $delete_limit ) ) ) {

			if ( empty( $comment_ids ) )

				return;

			$wpdb->queries = array();

			foreach ( $comment_ids as $comment_id ) {

				do_action( 'delete_comment', $comment_id );

				do_action( 'akismet_batch_delete_count', __FUNCTION__ );

			}

			// Prepared as strings since comment_id is an unsigned BIGINT, and using %d will constrain the value to the maximum signed BIGINT.

			$format_string = implode( ", ", array_fill( 0, count( $comment_ids ), '%s' ) );

			$wpdb->query( $wpdb->prepare( "DELETE FROM {$wpdb->comments} WHERE comment_id IN ( " . $format_string . " )", $comment_ids ) );

			$wpdb->query( $wpdb->prepare( "DELETE FROM {$wpdb->commentmeta} WHERE comment_id IN ( " . $format_string . " )", $comment_ids ) );

			clean_comment_cache( $comment_ids );

			do_action( 'akismet_delete_comment_batch', count( $comment_ids ) );

		}