export interface ServiceUrls {
	keyvalue: string;
	stream: string;
	vector: string;
	aigateway: string;
	catalyst: string;
	otel: string;
	sandbox: string;
	email: string;
}

/**
 * Resolve the region from the provided value or AGENTUITY_REGION environment variable.
 * Throws an error if no region can be resolved.
 */
export function resolveRegion(region?: string): string {
	const resolved = region ?? process.env.AGENTUITY_REGION;
	if (!resolved) {
		throw new Error(
			'Region is required but not provided. Set the AGENTUITY_REGION environment variable or pass region as a parameter.'
		);
	}
	return resolved;
}

/**
 * Get service URLs from environment variables with fallback defaults.
 * Throws an error if region cannot be resolved (neither passed as parameter nor set via AGENTUITY_REGION).
 */
export function getServiceUrls(region?: string): ServiceUrls {
	const resolvedRegion = resolveRegion(region);
	const transportUrl =
		process.env.AGENTUITY_TRANSPORT_URL || buildRegionalURL(resolvedRegion, 'catalyst');

	return {
		keyvalue: process.env.AGENTUITY_KEYVALUE_URL || transportUrl,
		stream: process.env.AGENTUITY_STREAM_URL || buildRegionalURL(resolvedRegion, 'streams'),
		vector: process.env.AGENTUITY_VECTOR_URL || transportUrl,
		aigateway:
			process.env.AGENTUITY_AIGATEWAY_URL || buildRegionalURL(resolvedRegion, 'aigateway'),
		catalyst: process.env.AGENTUITY_CATALYST_URL || transportUrl,
		otel: process.env.AGENTUITY_OTLP_URL || buildRegionalURL(resolvedRegion, 'otel'),
		sandbox: process.env.AGENTUITY_SANDBOX_URL || transportUrl,
		email: process.env.AGENTUITY_EMAIL_URL || transportUrl,
	};
}

function getDomainSuffix(region?: string) {
	if (region === 'local' || region === 'l') {
		return 'agentuity.io';
	}
	return 'agentuity.cloud';
}

function buildRegionalURL(region?: string, hostname?: string) {
	const suffix = getDomainSuffix(region);
	if (suffix === 'agentuity.io') {
		return `https://${hostname}.${suffix}`;
	}
	return `https://${hostname}-${region}.${suffix}`;
}