<?php
namespace QWSpeedCache\Rest;

defined( 'ABSPATH' ) || exit;

/**
 * REST API: purge cache and read safe configuration.
 */
class Controller {

	const NS = 'qw-speed-cache/v1';

	/** Max purge calls per user per window. */
	const PURGE_MAX = 10;

	/** Window length in seconds. */
	const PURGE_WINDOW = 60;

	public function __construct() {
		add_action( 'rest_api_init', array( $this, 'register' ) );
	}

	public function register() {
		register_rest_route(
			self::NS,
			'/purge',
			array(
				'methods'             => 'POST',
				'callback'            => array( $this, 'purge' ),
				'permission_callback' => array( $this, 'can_manage' ),
			)
		);
		register_rest_route(
			self::NS,
			'/status',
			array(
				'methods'             => 'GET',
				'callback'            => array( $this, 'status' ),
				'permission_callback' => array( $this, 'can_manage' ),
			)
		);
		register_rest_route(
			self::NS,
			'/health',
			array(
				'methods'             => 'GET',
				'callback'            => array( $this, 'health' ),
				'permission_callback' => array( $this, 'can_manage' ),
			)
		);
		register_rest_route(
			self::NS,
			'/settings',
			array(
				'methods'             => 'GET',
				'callback'            => array( $this, 'settings' ),
				'permission_callback' => array( $this, 'can_manage' ),
			)
		);
	}

	public function can_manage() {
		return current_user_can( 'manage_options' );
	}

	/**
	 * Rate-limit key for current user.
	 *
	 * @return string
	 */
	public static function purge_rate_key() {
		$uid = function_exists( 'get_current_user_id' ) ? (int) get_current_user_id() : 0;
		return 'qwsc_rest_purge_' . $uid;
	}

	/**
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response|\WP_Error
	 */
	public function purge( $request ) {
		$key   = self::purge_rate_key();
		$count = (int) get_transient( $key );
		if ( ! \QWSpeedCache\Admin\ActionGuard::rate_limit_allows( $count, self::PURGE_MAX, self::PURGE_WINDOW ) ) {
			return new \WP_Error(
				'qwsc_rate_limited',
				'Too many purge requests. Try again in a minute.',
				array( 'status' => 429 )
			);
		}
		set_transient( $key, $count + 1, self::PURGE_WINDOW );

		// Use the same page, memory and CDN purge path as the toolbar.
		// Do not return success when the filesystem purge failed.
		$result = \QWSpeedCache\Cache\Purge::purge_all();
		if ( is_wp_error( $result ) ) {
			return new \WP_Error( 'qwsc_purge_failed', $result->get_error_message(), array( 'status' => 500 ) );
		}
		return rest_ensure_response(
			array(
				'success' => true,
				'message' => 'Cache purged',
			)
		);
	}

	/**
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response
	 */
	public function status( $request ) {
		return rest_ensure_response( \QWSpeedCache\Stats\Metrics::snapshot() );
	}

	/**
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response
	 */
	public function settings( $request ) {
		$all    = \QWSpeedCache\Plugin::instance()->get_all_settings();
		$schema = \QWSpeedCache\Settings\Schema::all();
		$out    = array();
		foreach ( $all as $k => $v ) {
			if ( ! empty( $schema[ $k ]['secret'] ) ) {
				continue;
			}
			$out[ $k ] = $v;
		}
		return rest_ensure_response( $out );
	}

	/**
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response
	 */
	public function health( $request ) {
		return rest_ensure_response( \QWSpeedCache\Stats\Metrics::health() );
	}
}