*
		 * Add to the POST parameters stored internally. If a user has already
		 * set these manually (via `set_body_params`), don't override them.
		 */
		$this->params['POST'] = array_merge( $params, $this->params['POST'] );
	}

	/**
	 * Retrieves the route that matched the request.
	 *
	 * @since 4.4.0
	 *
	 * @return string Route matching regex.
	 */
	public function get_route() {
		return $this->route;
	}

	/**
	 * Sets the route that matched the request.
	 *
	 * @since 4.4.0
	 *
	 * @param string $route Route matching regex.
	 */
	public function set_route( $route ) {
		$this->route = $route;
	}

	/**
	 * Retrieves the attributes for the request.
	 *
	 * These are the options for the route that was matched.
	 *
	 * @since 4.4.0
	 *
	 * @return array Attributes for the request.
	 */
	public function get_attributes() {
		return $this->attributes;
	}

	/**
	 * Sets the attributes for the request.
	 *
	 * @since 4.4.0
	 *
	 * @param array $attributes Attributes for the request.
	 */
	public function set_attributes( $attributes ) {
		$this->attributes = $attributes;
	}

	/**
	 * Sanitizes (where possible) the params on the request.
	 *
	 * This is primarily based off the sanitize_callback param on each registered
	 * argument.
	 *
	 * @since 4.4.0
	 *
	 * @return true|WP_Error True if parameters were sanitized, WP_Error if an error occurred during sanitization.
	 */
	public function sanitize_params() {
		$attributes = $this->get_attributes();

		// No arguments set, skip sanitizing.
		if ( empty( $attributes['args'] ) ) {
			return true;
		}

		$order = $this->get_parameter_order();

		$invalid_params = array();

		foreach ( $order as $type ) {
			if ( empty( $this->params[ $type ] ) ) {
				continue;
			}
			foreach ( $this->params[ $type ] as $key => $value ) {
				if ( ! isset( $attributes['args'][ $key ] ) ) {
					continue;
				}
				$param_args = $attributes['args'][ $key ];

				// If the arg has a type but no sanitize_callback attribute, default to rest_parse_request_arg.
				if ( ! array_key_exists( 'sanitize_callback', $param_args ) && ! empty( $param_args['type'] ) ) {
					$param_args['sanitize_callback'] = 'rest_parse_request_arg';
				}
				// If there's still no sanitize_callback, nothing to do here.
				if ( empty( $param_args['sanitize_callback'] ) ) {
					continue;
				}

				$sanitized_value = call_user_func( $param_args['sanitize_callback'], $value, $this, $key );

				if ( is_wp_error( $sanitized_value ) ) {
					$invalid_params[ $key ] = $sanitized_value->get_error_message();
				} else {
					$this->params[ $type ][ $key ] = $sanitized_value;
				}
			}
		}

		if ( $invalid_params ) {
			return new WP_Error( 'rest_invalid_param', sprintf( __( 'Invalid parameter(s): %s' ), implode( ', ', array_keys( $invalid_params ) ) ), array( 'status' => 400, 'params' => $invalid_params ) );
		}

		return true;
	}

	/**
	 * Checks whether this request is valid according to its attributes.
	 *
	 * @since 4.4.0
	 *
	 * @return bool|WP_Error True if there are no parameters to validate or if all pass validation,
	 *                       WP_Error if required parameters are missing.
	 */
	public function has_valid_params() {
		// If JSON data was passed, check for errors.
		$json_error = $this->parse_json_params();
		if ( is_wp_error( $json_error ) ) {
			return $json_error;
		}

		$attributes = $this->get_attributes();
		$required = array();

		// No arguments set, skip validation.
		if ( empty( $attributes['args'] ) ) {
			return true;
		}

		foreach ( $attributes['args'] as $key => $arg ) {

			$param = $this->get_param( $key );
			if ( isset( $arg['required'] ) && true === $arg['required'] && null === $param ) {
				$required[] = $key;
			}
		}

		if ( ! empty( $required ) ) {
			return new WP_Error( 'rest_missing_callback_param', sprintf( __( 'Missing parameter(s): %s' ), implode( ', ', $required ) ), array( 'status' => 400, 'params' => $required ) );
		}

		/*
		 * Check the validation callbacks for each registered arg.
		 *
		 * This is done after required checking as required checking is cheaper.
		 */
		$invalid_params = array();

		foreach ( $attributes['args'] as $key => $arg ) {

			$param = $this->get_param( $key );

			if ( null !== $param && ! empty( $arg['validate_callback'] ) ) {
				$valid_check = call_user_func( $arg['validate_callback'], $param, $this, $key );

				if ( false === $valid_check ) {
					$invalid_params[ $key ] = __( 'Invalid parameter.' );
				}

				if ( is_wp_error( $valid_check ) ) {
					$invalid_params[ $key ] = $valid_check->get_error_message();
				}
			}
		}

		if ( $invalid_params ) {
			return new WP_Error( 'rest_invalid_param', sprintf( __( 'Invalid parameter(s): %s' ), implode( ', ', array_keys( $invalid_params ) ) ), array( 'status' => 400, 'params' => $invalid_params ) );
		}

		return true;

	}

	/**
	 * Checks if a parameter is set.
	 *
	 * @since 4.4.0
	 *
	 * @param string $offset Parameter name.
	 * @return bool Whether the parameter is set.
	 */
	public function offsetExists( $offset ) {
		$order = $this->get_parameter_order();

		foreach ( $order as $type ) {
			if ( isset( $this->params[ $type ][ $offset ] ) ) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Retrieves a parameter from the request.
	 *
	 * @since 4.4.0
	 *
	 * @param string $offset Parameter name.
	 * @return mixed|null Value if set, null otherwise.
	 */
	public function offsetGet( $offset ) {
		return $this->get_param( $offset );
	}

	/**
	 * Sets a parameter on the request.
	 *
	 * @since 4.4.0
	 *
	 * @param string $offset Parameter name.
	 * @param mixed  $value  Parameter value.
	 */
	public function offsetSet( $offset, $value ) {
		$this->set_param( $offset, $value );
	}

	/**
	 * Removes a parameter from the request.
	 *
	 * @since 4.4.0
	 *
	 * @param string $offset Parameter name.
	 */
	public function offsetUnset( $offset ) {
		$order = $this->get_parameter_order();

		// Remove the offset from every group.
		foreach ( $order as $type ) {
			unset( $this->params[ $type ][ $offset ] );
		}
	}

	/**
	 * Retrieves a WP_REST_Request object from a full URL.
	 *
	 * @static
	 * @since 4.5.0
	 *
	 * @param string $url URL with protocol, domain, path and query args.
	 * @return WP_REST_Request|false WP_REST_Request object on success, false on failure.
	 */
	public static function from_url( $url ) {
		$bits = parse_url( $url );
		$query_params = array();

		if ( ! empty( $bits['query'] ) ) {
			wp_parse_str( $bits['query'], $query_params );
		}

		$api_root = rest_url();
		if ( get_option( 'permalink_structure' ) && 0 === strpos( $url, $api_root ) ) {
			// Pretty permalinks on, and URL is under the API root.
			$api_url_part = substr( $url, strlen( untrailingslashit( $api_root ) ) );
			$route = parse_url( $api_url_part, PHP_URL_PATH );
		} elseif ( ! empty( $query_params['rest_route'] ) ) {
			// ?rest_route=... set directly
			$route = $query_params['rest_route'];
			unset( $query_params['rest_route'] );
		}

		$request = false;
		if ( ! empty( $route ) ) {
			$request = new WP_REST_Request( 'GET', $route );
			$request->set_query_params( $query_params );
		}

		/**
		 * Filters the request generated from a URL.
		 *
		 * @since 4.5.0
		 *
		 * @param WP_REST_Request|false $request Generated request object, or false if URL
		 *                                       could not be parsed.
		 * @param string                $url     URL the request was generated from.
		 */
		return apply_filters( 'rest_request_from_url', $request, $url );
	}
}