config.ts

/**
 * Reads the `PUBLIC_*` env vars Vite bundles into client-side JS (ADR-0030) and fails loudly,
 * not silently, if any are missing — a misconfigured deploy should show an error banner, never
 * a sign-in button that quietly points at `undefined`.
 */
import type { AuthConfig } from './auth';

/** Only the fields this module reads — deliberately not the full Astro/Vite `ImportMetaEnv`
 * (which also carries `BASE_URL`/`MODE`/`DEV`/`PROD`/etc.), so a test can pass a plain object
 * with just these five keys instead of satisfying Astro's whole env shape. */
export interface EnvSource {
  readonly PUBLIC_COGNITO_DOMAIN?: string;
  readonly PUBLIC_COGNITO_CLIENT_ID?: string;
  readonly PUBLIC_REDIRECT_URI?: string;
  readonly PUBLIC_LOGOUT_URI?: string;
  readonly PUBLIC_API_BASE_URL?: string;
}

export class ConfigError extends Error {}

function required(value: string | undefined, name: string): string {
  if (!value || !value.trim()) {
    throw new ConfigError(`missing required env var ${name} — check web/.env.example`);
  }
  return value;
}

export function loadAuthConfig(env: EnvSource = import.meta.env): AuthConfig {
  return {
    domain: required(env.PUBLIC_COGNITO_DOMAIN, 'PUBLIC_COGNITO_DOMAIN'),
    clientId: required(env.PUBLIC_COGNITO_CLIENT_ID, 'PUBLIC_COGNITO_CLIENT_ID'),
    redirectUri: required(env.PUBLIC_REDIRECT_URI, 'PUBLIC_REDIRECT_URI'),
    logoutUri: required(env.PUBLIC_LOGOUT_URI, 'PUBLIC_LOGOUT_URI'),
  };
}

export function loadApiBaseUrl(env: EnvSource = import.meta.env): string {
  return required(env.PUBLIC_API_BASE_URL, 'PUBLIC_API_BASE_URL').replace(/\/+$/, '');
}