// MUST be the very first import — see apps/portal-bff/src/observability/tracing.ts
// for the reasoning. Anything `import`ed above this line bypasses the
// OpenTelemetry auto-instrumentations and is silently un-traced.
import './observability/tracing';

import { ValidationPipe } from '@nestjs/common';
import { NestFactory } from '@nestjs/core';
import cookieParser from 'cookie-parser';
import { Logger } from 'nestjs-pino';
import { AppModule } from './app/app.module';
import { assertDatabaseUrl } from './config/check-database-url';
import { assertEntraConfig } from './config/check-entra-config';
import { assertSessionSecret } from './config/check-session-secret';

// Fail fast on a malformed DATABASE_URL (most often a special char in
// the password that needs URL-encoding) rather than letting Prisma
// surface a cryptic "invalid connection string" error mid-request.
assertDatabaseUrl();

// Same family of pre-flight check for the Entra app-registration env
// vars (per ADR-0009). Missing / placeholder values fail here rather
// than deep inside the first auth request.
assertEntraConfig();

// SESSION_SECRET signs the auth-flow cookies (pre-auth state +
// PKCE verifier today, session cookie next).
const sessionSecret = assertSessionSecret();

async function bootstrap() {
  // `bufferLogs: true` holds early-bootstrap log lines until the
  // Pino-based Logger is wired in below, so we don't lose anything
  // emitted before `app.useLogger()`.
  const app = await NestFactory.create(AppModule, { bufferLogs: true });
  app.useLogger(app.get(Logger));

  // CORS — minimal dev-time allowlist. The SPA running on
  // http://localhost:4200 issues fetches to the BFF and must be
  // able to send the W3C `traceparent` (and `tracestate`) headers
  // that `@opentelemetry/instrumentation-fetch` injects, so the BFF
  // can pick up the parent span id and emit child spans on the same
  // trace. The full security-grade allowlist (per-environment
  // origins, credentials policy, helmet stack, etc.) lands with the
  // phase-2 security ADR — for now this is the minimum needed for
  // end-to-end tracing.
  app.enableCors({
    origin: (process.env['CORS_ALLOWED_ORIGINS'] ?? 'http://localhost:4200')
      .split(',')
      .map((o) => o.trim())
      .filter(Boolean),
    allowedHeaders: ['Content-Type', 'Accept', 'Authorization', 'traceparent', 'tracestate'],
    credentials: true,
  });

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

  // Cookie parsing for the auth flow (per ADR-0009). The same
  // `SESSION_SECRET` will cover the post-login session cookie when
  // ADR-0010 storage lands; signed cookies are read from
  // `req.signedCookies`, unsigned from `req.cookies`.
  app.use(cookieParser(sessionSecret));

  // Phase-2 security ADRs will harden the above: helmet, real CORS
  // allowlist, CSRF protection, rate limiting, auth guards,
  // structured error filter.

  const globalPrefix = 'api';
  app.setGlobalPrefix(globalPrefix);
  const port = process.env['PORT'] ?? 3000;
  await app.listen(port);

  app
    .get(Logger)
    .log(`Application is running on: http://localhost:${port}/${globalPrefix}`, 'Bootstrap');
}

bootstrap();