<?php
/**
 * REST API: WP_REST_Post_Statuses_Controller class
 *
 * @package WordPress
 * @subpackage REST_API
 * @since 4.7.0
 */

/**
 * Core class used to access post statuses via the REST API.
 *
 * @since 4.7.0
 *
 * @see WP_REST_Controller
 */
class WP_REST_Post_Statuses_Controller extends WP_REST_Controller {

	/**
	 * Constructor.
	 *
	 * @since 4.7.0
	 */
	public function __construct() {
		$this->namespace = 'wp/v2';
		$this->rest_base = 'statuses';
	}

	/**
	 * 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_items' ),
				'permission_callback' => array( $this, 'get_items_permissions_check' ),
				'args'                => $this->get_collection_params(),
			),
			'schema' => array( $this, 'get_public_item_schema' ),
		) );

		register_rest_route( $this->namespace, '/' . $this->rest_base . '/(?P<status>[\w-]+)', array(
			'args' => array(
				'status' => array(
					'description' => __( 'An alphanumeric identifier for the status.' ),
					'type'        => 'string',
				),
			),
			array(
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => array( $this, 'get_item' ),
				'permission_callback' => array( $this, 'get_item_permissions_check' ),
				'args'                => array(
					'context' => $this->get_context_param( array( 'default' => 'view' ) ),
				),
			),
			'schema' => array( $this, 'get_public_item_schema' ),
		) );
	}

	/**
	 * Checks whether a given request has permission to read post statuses.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_Error|bool True if the request has read access, WP_Error object otherwise.
	 */
	public function get_items_permissions_check( $request ) {
		if ( 'edit' === $request['context'] ) {
			$types = get_post_types( array( 'show_in_rest' => true ), 'objects' );

			foreach ( $types as $type ) {
				if ( current_user_can( $type->cap->edit_posts ) ) {
					return true;
				}
			}
			return new WP_Error( 'rest_cannot_view', __( 'Sorry, you are not allowed to edit posts in this post type.' ), array( 'status' => rest_authorization_required_code() ) );
		}

		return true;
	}

	/**
	 * Retrieves all post statuses, depending on user context.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_Error|WP_REST_Response Response object on success, or WP_Error object on failure.
	 */
	public function get_items( $request ) {
		$data = array();
		$statuses = get_post_stati( array( 'internal' => false ), 'object' );
		$statuses['trash'] = get_post_status_object( 'trash' );

		foreach ( $statuses as $slug => $obj ) {
			$ret = $this->check_read_permission( $obj );

			if ( ! $ret ) {
				continue;
			}

			$status = $this->prepare_item_for_response( $obj, $request );
			$data[ $obj->name ] = $this->prepare_response_for_collection( $status );
		}

		return rest_ensure_response( $data );
	}

	/**
	 * Checks if a given request has access to read a post status.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_Error|bool True if the request has read access for the item, WP_Error object otherwise.
	 */
	public function get_item_permissions_check( $request ) {
		$status = get_post_status_object( $request['status'] );

		if ( empty( $status ) ) {
			return new WP_Error( 'rest_status_invalid', __( 'Invalid status.' ), array( 'status' => 404 ) );
		}

		$check = $this->check_read_permission( $status );

		if ( ! $check ) {
			return new WP_Error( 'rest_cannot_read_status', __( 'Cannot view status.' ), array( 'status' => rest_authorization_required_code() ) );
		}

		return true;
	}

	/**
	 * Checks whether a given post status should be visible.
	 *
	 * @since 4.7.0
	 *
	 * @param object $status Post status.
	 * @return bool True if the post status is visible, otherwise false.
	 */
	protected function check_read_permission( $status ) {
		if ( true === $status->public ) {
			return true;
		}

		if ( false === $status->internal || 'trash' === $status->name ) {
			$types = get_post_types( array( 'show_in_rest' => true ), 'objects' );

			foreach ( $types as $type ) {
				if ( current_user_can( $type->cap->edit_posts ) ) {
					return true;
				}
			}
		}

		return false;
	}

	/**
	 * Retrieves a specific post status.
	 *
	 * @since 4.7.0
	 *
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_Error|WP_REST_Response Response object on success, or WP_Error object on failure.
	 */
	public function get_item( $request ) {
		$obj = get_post_status_object( $request['status'] );

		if ( empty( $obj ) ) {
			return new WP_Error( 'rest_status_invalid', __( 'Invalid status.' ), array( 'status' => 404 ) );
		}

		$data = $this->prepare_item_for_response( $obj, $request );

		return rest_ensure_response( $data );
	}

	/**
	 * Prepares a post status object for serialization.
	 *
	 * @since 4.7.0
	 *
	 * @param stdClass        $status  Post status data.
	 * @param WP_REST_Request $request Full details about the request.
	 * @return WP_REST_Response Post status data.
	 */
	public function prepare_item_for_response( $status, $request ) {

		$data = array(
			'name'         => $status->label,
			'private'      => (bool) $status->private,
			'protected'    => (bool) $status->protected,
			'public'       => (bool) $status->public,
			'queryable'    => (bool) $status->publicly_queryable,
			'show_in_list' => (bool) $status->show_in_admin_all_list,
			'slug'         => $status->name,
		);

		$context = ! empty( $request['context'] ) ? $request['context'] : 'view';
		$data = $this->add_additional_fields_to_object( $data, $request );
		$data = $this->filter_response_by_context( $data, $context );

		$response = rest_ensure_response( $data );

		if ( 'publish' === $status->name ) {
			$response->add_link( 'archives', rest_url( 'wp/v2/posts' ) );
		} else {
			$response->add_link( 'archives', add_query_arg( 'status', $status->name, rest_url( 'wp/v2/posts' ) ) );
		}

		/**
		 * Filters a status returned from the REST API.
		 *
		 * Allows modification of the status data right before it is returned.
		 *
		 * @since 4.7.0
		 *
		 * @param WP_REST_Response $response The response object.
		 * @param object           $status   The original status object.
		 * @param WP_REST_Request  $request  Request used to generate the response.
		 */
		return apply_filters( 'rest_prepare_status', $response, $status, $request );
	}

	/**
	 * Retrieves the post status' schema, conforming to JSON Schema.
	 *
	 * @since 4.7.0
	 *
	 * @return array Item schema data.
	 */
	public function get_item_schema() {
		$schema = array(
			'$schema'              => 'http://json-schema.org/draft-04/schema#',
			'title'                => 'status',
			'type'                 => 'object',
			'properties'           => array(
				'name'             => array(
					'description'  => __( 'The title for the status.' ),
					'type'         => 'string',
					'context'      => array( 'embed', 'view', 'edit' ),
					'readonly'     => true,
				),
				'private'          => array(
					'description'  => __( 'Whether posts with this status should be private.' ),
					'type'         => 'boolean',
					'context'      => array( 'edit' ),
					'readonly'     => true,
				),
				'protected'        => array(
					'description'  => __( 'Whether posts with this status should be protected.' ),
					'type'         => 'boolean',
					'context'      => array( 'edit' ),
					'readonly'     => true,
				),
				'public'           => array(
					'description'  => __( 'Whether posts of this status should be shown in the front end of the site.' ),
					'type'         => 'boolean',
					'context'      => array( 'view', 'edit' ),
					'readonly'     => true,
				),
				'queryable'        => array(
					'description'  => __( 'Whether posts with this status should be publicly-queryable.' ),
					'type'         => 'boolean',
					'context'      => array( 'view', 'edit' ),
					'readonly'     => true,
				),
				'show_in_list'     => array(
					'description'  => __( 'Whether to include posts in the edit listing for their post type.' ),
					'type'         => 'boolean',
					'context'      => array( 'edit' ),
					'readonly'     => true,
				),
				'slug'             => array(
					'description'  => __( 'An alphanumeric identifier for the status.' ),
					'type'         => 'string',
					'context'      => array( 'embed', 'view', 'edit' ),
					'readonly'     => true,
				),
			),
		);

		return $this->add_additional_fields_schema( $schema );
	}

	/**
	 * Retrieves the query params for collections.
	 *
	 * @since 4.7.0
	 *
	 * @return array Collection parameters.
	 */
	public function get_collection_params() {
		return array(
			'context' => $this->get_context_param( array( 'default' => 'view' ) ),
		);
	}

}