Source

File: wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php

protected function prepare_item_for_database( $request ) {
		$prepared_comment = array();

		/*
		 * Allow the comment_content to be set via the 'content' or
		 * the 'content.raw' properties of the Request object.
		 */
		if ( isset( $request['content'] ) && is_string( $request['content'] ) ) {
			$prepared_comment['comment_content'] = $request['content'];
		} elseif ( isset( $request['content']['raw'] ) && is_string( $request['content']['raw'] ) ) {
			$prepared_comment['comment_content'] = $request['content']['raw'];
		}

		if ( isset( $request['post'] ) ) {
			$prepared_comment['comment_post_ID'] = (int) $request['post'];
		}

		if ( isset( $request['parent'] ) ) {
			$prepared_comment['comment_parent'] = $request['parent'];
		}

		if ( isset( $request['author'] ) ) {
			$user = new WP_User( $request['author'] );

			if ( $user->exists() ) {
				$prepared_comment['user_id']              = $user->ID;
				$prepared_comment['comment_author']       = $user->display_name;
				$prepared_comment['comment_author_email'] = $user->user_email;
				$prepared_comment['comment_author_url']   = $user->user_url;
			} else {
				return new WP_Error(
					'rest_comment_author_invalid',
					__( 'Invalid comment author ID.' ),
					array( 'status' => 400 )
				);
			}
		}

		if ( isset( $request['author_name'] ) ) {
			$prepared_comment['comment_author'] = $request['author_name'];
		}

		if ( isset( $request['author_email'] ) ) {
			$prepared_comment['comment_author_email'] = $request['author_email'];
		}

		if ( isset( $request['author_url'] ) ) {
			$prepared_comment['comment_author_url'] = $request['author_url'];
		}

		if ( isset( $request['author_ip'] ) && current_user_can( 'moderate_comments' ) ) {
			$prepared_comment['comment_author_IP'] = $request['author_ip'];
		} elseif ( ! empty( $_SERVER['REMOTE_ADDR'] ) && rest_is_ip_address( $_SERVER['REMOTE_ADDR'] ) ) {
			$prepared_comment['comment_author_IP'] = $_SERVER['REMOTE_ADDR'];
		} else {
			$prepared_comment['comment_author_IP'] = '127.0.0.1';
		}

		if ( ! empty( $request['author_user_agent'] ) ) {
			$prepared_comment['comment_agent'] = $request['author_user_agent'];
		} elseif ( $request->get_header( 'user_agent' ) ) {
			$prepared_comment['comment_agent'] = $request->get_header( 'user_agent' );
		}

		if ( ! empty( $request['date'] ) ) {
			$date_data = rest_get_date_with_gmt( $request['date'] );

			if ( ! empty( $date_data ) ) {
				list( $prepared_comment['comment_date'], $prepared_comment['comment_date_gmt'] ) = $date_data;
			}
		} elseif ( ! empty( $request['date_gmt'] ) ) {
			$date_data = rest_get_date_with_gmt( $request['date_gmt'], true );

			if ( ! empty( $date_data ) ) {
				list( $prepared_comment['comment_date'], $prepared_comment['comment_date_gmt'] ) = $date_data;
			}
		}

		/**
		 * Filters a comment after it is prepared for the database.
		 *
		 * Allows modification of the comment right after it is prepared for the database.
		 *
		 * @since 4.7.0
		 *
		 * @param array           $prepared_comment The prepared comment data for `wp_insert_comment`.
		 * @param WP_REST_Request $request          The current request.
		 */
		return apply_filters( 'rest_preprocess_comment', $prepared_comment, $request );
	}