<?php

declare(strict_types=1);

namespace LinkCheckup\Features\Settings;

use LinkCheckup\Shared\Rest\RestRoutes;
use LinkCheckup\Shared\Settings\SettingsStore;
use WP_Error;
use WP_REST_Request;

final class SettingsFeature {

	private const ROUTE                  = '/settings';
	private const INVALID_PARAMETER_CODE = 'rest_invalid_param';
	private const BAD_REQUEST_STATUS     = 400;

	public function __construct(
		private readonly RestRoutes $routes,
		private readonly SettingsStore $settings_store,
		private readonly SettingsChange $settings_change
	) {
	}

	public function register(): void {
		add_action( 'rest_api_init', array( $this, 'add_routes' ) );
	}

	public function add_routes(): void {
		$this->routes->add( self::ROUTE, 'GET', $this->read_settings( ... ) );
		$this->routes->add(
			self::ROUTE,
			'POST',
			$this->change_settings( ... )
		);
	}

	/** @return array<string, mixed> */
	public function read_settings(): array {
		return $this->settings_store->load()->to_array();
	}

	/**
	 * @param WP_REST_Request<array<string, mixed>> $settings_request
	 * @return array<string, mixed>|WP_Error
	 */
	public function change_settings(
		WP_REST_Request $settings_request
	): array|WP_Error {
		$changes = (array) $settings_request->get_json_params();

		try {
			$changed = $this->settings_change->apply(
				$this->settings_store->load(),
				$changes
			);
		} catch ( InvalidSettingValue $invalid_value ) {
			return new WP_Error(
				self::INVALID_PARAMETER_CODE,
				$invalid_value->refusal->message(),
				array( 'status' => self::BAD_REQUEST_STATUS )
			);
		}

		$this->settings_store->save( $changed );

		return $changed->to_array();
	}
}