<?php
/**
 * REST API Endpoints
 *
 * @package User_ID
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class User_ID_REST_API extends WP_REST_Controller {

	/**
	 * Constructor.
	 */
	public function __construct() {
		$this->namespace = 'user-id/v1';
		$this->rest_base = 'inspect';
		
		add_action( 'rest_api_init', array( $this, 'register_routes' ) );
	}

	/**
	 * Register the routes.
	 */
	public function register_routes() {
		register_rest_route(
			$this->namespace,
			'/' . $this->rest_base . '/(?P<id>[\d]+)',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_item' ),
					'permission_callback' => array( $this, 'get_item_permissions_check' ),
					'args'                => array(
						'id' => array(
							'description' => __( 'Unique identifier for the user.', 'user-id' ),
							'type'        => 'integer',
							'required'    => true,
						),
					),
				),
			)
		);
	}

	/**
	 * Check permissions.
	 *
	 * @param WP_REST_Request $request Request object.
	 * @return bool|WP_Error
	 */
	public function get_item_permissions_check( $request ) {
		if ( ! current_user_can( 'manage_options' ) ) {
			return new WP_Error( 'rest_forbidden', esc_html__( 'You do not have permission to inspect users.', 'user-id' ), array( 'status' => rest_authorization_required_code() ) );
		}
		return true;
	}

	/**
	 * Get one item.
	 *
	 * @param WP_REST_Request $request Request object.
	 * @return WP_REST_Response|WP_Error
	 */
	public function get_item( $request ) {
		$user_id = (int) $request['id'];
		$user    = get_userdata( $user_id );

		if ( ! $user ) {
			return new WP_Error( 'rest_user_invalid_id', esc_html__( 'Invalid user ID.', 'user-id' ), array( 'status' => 404 ) );
		}

		$roles = ! empty( $user->roles ) ? $user->roles : array();
		$caps  = ! empty( $user->allcaps ) ? array_keys( array_filter( $user->allcaps ) ) : array();

		/**
		 * Filter user_meta keys to be returned via API.
		 */
		$allowed_keys = apply_filters( 'user_id_rest_meta_keys', array() );
		$all_meta = get_user_meta( $user->ID );
		$filtered_meta = array();

		if ( ! empty( $allowed_keys ) ) {
			foreach ( $allowed_keys as $key ) {
				if ( isset( $all_meta[ $key ] ) ) {
					$filtered_meta[ $key ] = maybe_unserialize( $all_meta[ $key ][0] );
				}
			}
		}

		$data = array(
			'id'           => $user->ID,
			'username'     => $user->user_login,
			'email'        => $user->user_email,
			'roles'        => $roles,
			'capabilities' => $caps,
			'registered'   => $user->user_registered,
			'meta'         => $filtered_meta,
		);

		return rest_ensure_response( $data );
	}
}

new User_ID_REST_API();