<?php
/**
 * REST module.
 *
 * @package FormPilot
 * @since   1.0.0
 */

declare( strict_types = 1 );

namespace FormPilot\Rest;

use FormPilot\Contracts\Hookable;
use FormPilot\Settings\Settings;
use WP_REST_Controller;

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

/**
 * Registers the plugin REST routes.
 *
 * @since 1.0.0
 */
final class RestServer implements Hookable {

	/**
	 * Constructor.
	 *
	 * The controllers are injected rather than built here. Two reasons: one of
	 * them takes required dependencies and could not be built with `new` at all,
	 * and the other two would each construct their own repositories instead of
	 * sharing the ones the container already holds.
	 *
	 * @param FormsController      $forms      Controller for the form routes.
	 * @param EntriesController    $entries    Controller for the entry routes.
	 * @param SubmissionController $submission Controller for the submission route.
	 */
	public function __construct(
		private FormsController $forms,
		private EntriesController $entries,
		private SubmissionController $submission
	) {}

	/**
	 * Registers the module hooks.
	 */
	public function register_hooks(): void {
		add_action( 'rest_api_init', array( $this, 'register_routes' ) );
	}

	/**
	 * Hands every controller to the REST server.
	 */
	public function register_routes(): void {
		/*
		 * A site that does not use the routes can switch them off entirely. Not
		 * registering them is the only complete answer: a route that exists but
		 * refuses every caller still advertises itself in the discovery index and
		 * still has to be reasoned about.
		 */
		if ( ! Settings::flag( 'rest_enabled' ) ) {
			return;
		}

		foreach ( $this->controllers() as $controller ) {
			$controller->register_routes();
		}
	}

	/**
	 * Returns the registered controllers.
	 *
	 * @return array<int, WP_REST_Controller> The controllers.
	 */
	public function controllers(): array {
		$controllers = array(
			$this->forms,
			$this->entries,
			$this->submission,
		);

		/**
		 * Filters the REST controllers the plugin registers.
		 *
		 * @since 1.0.0
		 *
		 * @param array<int, WP_REST_Controller> $controllers Controllers to register.
		 */
		$controllers = (array) apply_filters( 'formpilot_rest_controllers', $controllers );

		return array_values(
			array_filter(
				$controllers,
				static fn( $controller ): bool => $controller instanceof WP_REST_Controller
			)
		);
	}
}