<?php

declare(strict_types=1);

namespace Llamly\Free\Auth;

final class WellKnown
{
	public static function registerHooks(): void
	{
		add_filter('query_vars', [self::class, 'queryVars']);
		add_action('init', [self::class, 'addRewriteRules'], 1);
		add_action('template_redirect', [self::class, 'dispatch'], 0);
	}

	public static function queryVars(array $vars): array
	{
		$vars[] = 'llamly_well_known';
		return $vars;
	}

	public static function addRewriteRules(): void
	{
		add_rewrite_rule('^\.well-known/oauth-authorization-server/?$', 'index.php?llamly_well_known=authorization-server', 'top');
		add_rewrite_rule('^\.well-known/oauth-protected-resource/?$', 'index.php?llamly_well_known=protected-resource', 'top');
	}

	public static function dispatch(): void
	{
		$type = (string) get_query_var('llamly_well_known');
		if ($type === '') {
			return;
		}
		$issuer = untrailingslashit(home_url('/'));
		if ($type === 'authorization-server') {
			$metadata = [
				'issuer' => $issuer,
				'authorization_endpoint' => rest_url('llamly/v1/oauth/authorize'),
				'token_endpoint' => rest_url('llamly/v1/oauth/token'),
				'registration_endpoint' => rest_url('llamly/v1/oauth/register'),
				'revocation_endpoint' => rest_url('llamly/v1/oauth/revoke'),
				'response_types_supported' => ['code'],
				'grant_types_supported' => ['authorization_code', 'refresh_token'],
				'token_endpoint_auth_methods_supported' => ['none'],
				'code_challenge_methods_supported' => ['S256'],
				'authorization_response_iss_parameter_supported' => true,
				'scopes_supported' => ['llamly.read', 'llamly.write'],
			];
		} elseif ($type === 'protected-resource') {
			$metadata = [
				'resource' => untrailingslashit(rest_url('llamly/v1/endpoint')),
				'authorization_servers' => [$issuer],
				'bearer_methods_supported' => ['header'],
				'scopes_supported' => ['llamly.read', 'llamly.write'],
				'resource_name' => 'Llamly MCP endpoint',
			];
		} else {
			return;
		}
		nocache_headers();
		header('Content-Type: application/json; charset=utf-8');
		header('Cache-Control: public, max-age=300');
		echo wp_json_encode($metadata, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
		exit;
	}
}