<?php

/**

 * REST API: WP_REST_Settings_Controller class

 *

 * @package WordPress

 * @subpackage REST_API

 * @since 4.7.0

 */

/**

 * Core class used to manage a site's settings via the REST API.

 *

 * @since 4.7.0

 *

 * @see WP_REST_Controller

 */

class WP_REST_Settings_Controller extends WP_REST_Controller {

	/**

	 * Constructor.

	 *

	 * @since 4.7.0

	 */

	public function __construct() {

		$this->namespace = 'wp/v2';

		$this->rest_base = 'settings';

	}

	/**

	 * Registers the routes for the objects of the controller.

	 *

	 * @since 4.7.0

	 *

	 * @see register_rest_route()

	 */

	public function register_routes() {

		register_rest_route( $this->namespace, '/' . $this->rest_base, array(

			array(

				'methods'             => WP_REST_Server::READABLE,

				'callback'            => array( $this, 'get_item' ),

				'args'                => array(),

				'permission_callback' => array( $this, 'get_item_permissions_check' ),

			),

			array(

				'methods'             => WP_REST_Server::EDITABLE,

				'callback'            => array( $this, 'update_item' ),

				'args'                => $this->get_endpoint_args_for_item_schema( WP_REST_Server::EDITABLE ),

				'permission_callback' => array( $this, 'get_item_permissions_check' ),

			),

			'schema' => array( $this, 'get_public_item_schema' ),

		) );

	}

	/**

	 * Checks if a given request has access to read and manage settings.

	 *

	 * @since 4.7.0

	 *

	 * @param WP_REST_Request $request Full details about the request.

	 * @return bool True if the request has read access for the item, otherwise false.

	 */

	public function get_item_permissions_check( $request ) {

		return current_user_can( 'manage_options' );

	}

	/**

	 * Retrieves the settings.

	 *

	 * @since 4.7.0

	 *

	 * @param WP_REST_Request $request Full details about the request.

	 * @return array|WP_Error Array on success, or WP_Error object on failure.

	 */

	public function get_item( $request ) {

		$options  = $this->get_registered_options();

		$response = array();

		foreach ( $options as $name => $args ) {

			/**

			 * Filters the value of a setting recognized by the REST API.

			 *

			 * Allow hijacking the setting value and overriding the built-in behavior by returning a

			 * non-null value.  The returned value will be presented as the setting value instead.

			 *

			 * @since 4.7.0

			 *

			 * @param mixed  $result Value to use for the requested setting. Can be a scalar

			 *                       matching the registered schema for the setting, or null to

			 *                       follow the default get_option() behavior.

			 * @param string $name   Setting name (as shown in REST API responses).

			 * @param array  $args   Arguments passed to register_setting() for this setting.

			 */

			$response[ $name ] = apply_filters( 'rest_pre_get_setting', null, $name, $args );

			if ( is_null( $response[ $name ] ) ) {

				// Default to a null value as "null" in the response means "not set".

				$response[ $name ] = get_option( $args['option_name'], $args['schema']['default'] );

			}

			/*

			 * Because get_option() is lossy, we have to

			 * cast values to the type they are registered with.

			 */

			$response[ $name ] = $this->prepare_value( $response[ $name ], $args['schema'] );

		}

		return $response;

	}

	/**

	 * Prepares a value for output based off a schema array.

	 *

	 * @since 4.7.0

	 *

	 * @param mixed $value  Value to prepare.

	 * @param array $schema Schema to match.

	 * @return mixed The prepared value.

	 */

	protected function prepare_value( $value, $schema ) {

		// If the value is not valid by the schema, set the value to null. Null

		// values are specifcally non-destructive so this will not cause overwriting

		// the current invalid value to null.

		if ( is_wp_error( rest_validate_value_from_schema( $value, $schema ) ) ) {

			return null;

		}

		return rest_sanitize_value_from_schema( $value, $schema );

	}

	/**

	 * Updates settings for the settings object.

	 *

	 * @since 4.7.0

	 *

	 * @param WP_REST_Request $request Full details about the request.

	 * @return array|WP_Error Array on success, or error object on failure.

	 */

	public function update_item( $request ) {

		$options = $this->get_registered_options();

		$params  = $request->get_params();

		foreach ( $options as $name => $args ) {

			if ( ! array_key_exists( $name, $params ) ) {

				continue;

			}

			/**

			 * Filters whether to preempt a setting value update.

			 *

			 * Allows hijacking the setting update logic and overriding the built-in behavior by

			 * returning true.

			 *

			 * @since 4.7.0

			 *

			 * @param bool   $result Whether to override the default behavior for updating the

			 *                       value of a setting.

			 * @param string $name   Setting name (as shown in REST API responses).

			 * @param mixed  $value  Updated setting value.

			 * @param array  $args   Arguments passed to register_setting() for this setting.

			 */

			$updated = apply_filters( 'rest_pre_update_setting', false, $name, $request[ $name ], $args );

			if ( $updated ) {

				continue;

			}

			/*

			 * A null value for an option would have the same effect as

			 * deleting the option from the database, and relying on the

			 * default value.

			 */

			if ( is_null( $request[ $name ] ) ) {

				/*

				 * A null value is returned in the response for any option

				 * that has a non-scalar value.

				 *

				 * To protect clients from accidentally including the null

				 * values from a response object in a request, we do not allow

				 * options with values that don't pass validation to be updated to null.

				 * Without this added protection a client could mistakenly

				 * delete all options that have invalid values from the

				 * database.

				 */

				if ( is_wp_error( rest_validate_value_from_schema( get_option( $args['option_name'], false ), $args['schema'] ) ) ) {

					return new WP_Error(

						'rest_invalid_stored_value', sprintf( __( 'The %s property has an invalid stored value, and cannot be updated to null.' ), $name ), array( 'status' => 500 )

					);

				}

				delete_option( $args['option_name'] );

			} else {

				update_option( $args['option_name'], $request[ $name ] );

			}

		}

		return $this->get_item( $request );

	}

	/**

	 * Retrieves all of the registered options for the Settings API.

	 *

	 * @since 4.7.0

	 *

	 * @return array Array of registered options.

	 */

	protected function get_registered_options() {

		$rest_options = array();

		foreach ( get_registered_settings() as $name => $args ) {

			if ( empty( $args['show_in_rest'] ) ) {

				continue;

			}

			$rest_args = array();

			if ( is_array( $args['show_in_rest'] ) ) {

				$rest_args = $args['show_in_rest'];

			}

			$defaults = array(

				'name'   => ! empty( $rest_args['name'] ) ? $rest_args['name'] : $name,

				'schema' => array(),

			);

			$rest_args = array_merge( $defaults, $rest_args );

			$default_schema = array(

				'type'        => empty( $args['type'] ) ? null : $args['type'],

				'description' => empty( $args['description'] ) ? '' : $args['description'],

				'default'     => isset( $args['default'] ) ? $args['default'] : null,

			);

			$rest_args['schema'] = array_merge( $default_schema, $rest_args['schema'] );

			$rest_args['option_name'] = $name;

			// Skip over settings that don't have a defined type in the schema.

			if ( empty( $rest_args['schema']['type'] ) ) {

				continue;

			}

			/*

			 * Whitelist the supported types for settings, as we don't want invalid types

			 * to be updated with arbitrary values that we can't do decent sanitizing for.

			 */

			if ( ! in_array( $rest_args['schema']['type'], array( 'number', 'integer', 'string', 'boolean', 'array', 'object' ), true ) ) {

				continue;

			}

			$rest_args['schema'] = $this->set_additional_properties_to_false( $rest_args['schema'] );

			$rest_options[ $rest_args['name'] ] = $rest_args;

		}

		return $rest_options;

	}

	/**

	 * Retrieves the site setting schema, conforming to JSON Schema.

	 *

	 * @since 4.7.0

	 *

	 * @return array Item schema data.

	 */

	public function get_item_schema() {

		$options = $this->get_registered_options();

		$schema = array(

			'$schema'    => 'http://json-schema.org/draft-04/schema#',

			'title'      => 'settings',

			'type'       => 'object',

			'properties' => array(),

		);

		foreach ( $options as $option_name => $option ) {

			$schema['properties'][ $option_name ] = $option['schema'];

			$schema['properties'][ $option_name ]['arg_options'] = array(

				'sanitize_callback' => array( $this, 'sanitize_callback' ),

			);

		}

		return $this->add_additional_fields_schema( $schema );

	}

	/**

	 * Custom sanitize callback used for all options to allow the use of 'null'.

	 *

	 * By default, the schema of settings will throw an error if a value is set to

	 * `null` as it's not a valid value for something like "type => string". We

	 * provide a wrapper sanitizer to whitelist the use of `null`.

	 *

	 * @since 4.7.0

	 *

	 * @param  mixed           $value   The value for the setting.

	 * @param  WP_REST_Request $request The request object.

	 * @param  string          $param   The parameter name.

	 * @return mixed|WP_Error

	 */

	public function sanitize_callback( $value, $request, $param ) {

		if ( is_null( $value ) ) {

			return $value;

		}

		return rest_parse_request_arg( $value, $request, $param );

	}

	/**

	 * Recursively add additionalProperties = false to all objects in a schema.

	 *

	 * This is need to restrict properties of objects in settings values to only

	 * registered items, as the REST API will allow additional properties by

	 * default.

	 *

	 * @since 4.9.0

	 *

	 * @param array $schema The schema array.

	 * @return array

	 */

	protected function set_additional_properties_to_false( $schema ) {

		switch ( $schema['type'] ) {

			case 'object':

				foreach ( $schema['properties'] as $key => $child_schema ) {

					$schema['properties'][ $key ] = $this->set_additional_properties_to_false( $child_schema );

				}

				$schema['additionalProperties'] = false;

				break;

			case 'array':

				$schema['items'] = $this->set_additional_properties_to_false( $schema['items'] );

				break;

		}

		return $schema;

	}

}