import { INestApplication, ValidationPipe, ValidationPipeOptions } from '@nestjs/common';
import { isValidationErrorDetailEnabled } from './bootstrap-security';

/**
 * The DTO validation contract itself, without the one option that depends on the environment.
 *
 * Exported so a spec can construct the real pipe from the same object production uses instead of
 * restating the options as literals. A restated copy is a mirror, and a mirror can drift: loosening
 * `whitelist` here would leave every spec that hardcoded `whitelist: true` still asserting the old
 * contract, green, while the running app no longer honours it. Reading one object makes production
 * and the specs unable to disagree — and turns those specs into a gate over this file.
 *
 * `disableErrorMessages` is deliberately NOT here: it is resolved from the environment at call time,
 * so it is not part of the contract a spec should reproduce.
 */
export const GLOBAL_VALIDATION_OPTIONS: ValidationPipeOptions = {
  whitelist: true,
  forbidNonWhitelisted: true,
  transform: true,
  transformOptions: { enableImplicitConversion: true },
};

/** Apply the HTTP prefix and DTO validation contract shared by production and e2e applications. */
export function applyGlobalValidation(app: INestApplication): void {
  app.setGlobalPrefix('api');
  app.useGlobalPipes(
    new ValidationPipe({
      ...GLOBAL_VALIDATION_OPTIONS,
      disableErrorMessages: !isValidationErrorDetailEnabled(process.env.VALIDATION_ERROR_DETAIL, process.env.NODE_ENV),
    }),
  );
}