import { AppServices } from './app-services';
import { NoopAnalyticsService } from './analytics/noop-analytics-service';
import { UmamiAnalyticsService } from './analytics/umami-analytics-service';
import { MemoryCacheService } from './cache/memory-cache-service';
import { RedisCacheService } from './cache/redis-cache-service';
import { GlitchtipErrorReportingService } from './errors/glitchtip-error-reporting-service';
import { NoopErrorReportingService } from './errors/noop-error-reporting-service';

let singleton: AppServices | undefined;

export function getAppServices(): AppServices {
  // In Next.js, module singletons are per-process (server) and per-tab (client).
  // This is good enough for a small service layer.
  if (singleton) return singleton;

  const umamiEnabled = Boolean(process.env.NEXT_PUBLIC_UMAMI_WEBSITE_ID);
  const sentryClientEnabled = Boolean(process.env.NEXT_PUBLIC_SENTRY_DSN);
  const sentryServerEnabled = Boolean(process.env.SENTRY_DSN);

  const analytics = umamiEnabled
    ? new UmamiAnalyticsService({ enabled: true })
    : new NoopAnalyticsService();

  // Enable GlitchTip/Sentry only when a DSN is present for the active runtime.
  const errors =
    typeof window === 'undefined'
      ? sentryServerEnabled
        ? new GlitchtipErrorReportingService({ enabled: true })
        : new NoopErrorReportingService()
      : sentryClientEnabled
        ? new GlitchtipErrorReportingService({ enabled: true })
        : new NoopErrorReportingService();

  const redisUrl = process.env.REDIS_URL;
  const cache = redisUrl
    ? new RedisCacheService({
        url: redisUrl,
        keyPrefix: process.env.REDIS_KEY_PREFIX ?? 'klz:',
      })
    : new MemoryCacheService();

  singleton = new AppServices(analytics, errors, cache);
  return singleton;
}