import { RequestMethod, ValidationPipe, VersioningType } from '@nestjs/common';
import { NestExpressApplication } from '@nestjs/platform-express';
import helmet from 'helmet';
import cookieParser from 'cookie-parser';

export function configureApp(app: NestExpressApplication): void {
  // Trust the single reverse-proxy hop (K8s ingress) so req.ip reflects the
  // real client IP from X-Forwarded-For — required for per-client throttling
  // to work correctly rather than rate-limiting all traffic together.
  app.set('trust proxy', 1);
  app.use(helmet());
  app.use(cookieParser());

  app.enableCors({
    origin: process.env.FRONTEND_ORIGIN ?? 'http://localhost:3000',
    credentials: true,
  });

  app.setGlobalPrefix('api', {
    exclude: [
      { path: 'health', method: RequestMethod.GET },
      { path: 'health/ready', method: RequestMethod.GET },
    ],
  });
  app.enableVersioning({ type: VersioningType.URI, defaultVersion: '1' });

  app.useGlobalPipes(
    new ValidationPipe({
      whitelist: true,
      forbidNonWhitelisted: true,
      transform: true,
    }),
  );
}