import 'reflect-metadata';
import { ValidationPipe } from '@nestjs/common';
import { NestFactory } from '@nestjs/core';
import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
import { AppModule } from './app.module.js';
import { createRequestContextMiddleware } from './common/request-context.middleware.js';
import { MetricsService } from './common/metrics.service.js';

function requireEnv(name: string): string {
  const value = process.env[name];
  if (!value || value.trim() === '') {
    throw new Error(`Missing required env: ${name}`);
  }
  return value;
}

function validateEnv(): void {
  requireEnv('FABRIC_BACKEND_CENTER_DB_HOST');
  requireEnv('FABRIC_BACKEND_CENTER_DB_PORT');
  requireEnv('FABRIC_BACKEND_CENTER_DB_USER');
  requireEnv('FABRIC_BACKEND_CENTER_DB_PASSWORD');
  requireEnv('FABRIC_BACKEND_CENTER_DB_NAME');
  requireEnv('FABRIC_BACKEND_CENTER_JWT_ACCESS_SECRET');
  requireEnv('FABRIC_BACKEND_CENTER_JWT_REFRESH_SECRET');
}

async function bootstrap() {
  validateEnv();

  const app = await NestFactory.create(AppModule);
  const corsOrigins = (process.env.FABRIC_BACKEND_CENTER_CORS_ORIGINS ?? '')
    .split(',')
    .map((x) => x.trim())
    .filter(Boolean);

  app.enableCors({
    origin: (origin, callback) => {
      // no Origin header: curl/server-to-server/most desktop local calls
      if (!origin) return callback(null, true);

      // desktop/electron local file origin
      if (origin === 'null') return callback(null, true);

      // empty allowlist => allow all origins
      if (!corsOrigins.length) return callback(null, true);

      if (corsOrigins.includes(origin)) return callback(null, true);
      return callback(new Error('CORS origin not allowed'), false);
    },
    methods: ['GET', 'POST', 'PATCH', 'PUT', 'DELETE', 'OPTIONS'],
    allowedHeaders: ['Content-Type', 'Authorization', 'x-client-name', 'x-request-id', 'x-api-key'],
    credentials: false,
  });
  app.setGlobalPrefix('api');
  const metrics = app.get(MetricsService);
  app.use(createRequestContextMiddleware('center', metrics));
  app.useGlobalPipes(
    new ValidationPipe({
      whitelist: true,
      forbidNonWhitelisted: true,
      transform: true,
    }),
  );

  const swaggerConfig = new DocumentBuilder()
    .setTitle('Fabric Backend Center API')
    .setDescription('Identity Hub APIs for Fabric')
    .setVersion('1.0.0')
    .build();
  const swaggerDoc = SwaggerModule.createDocument(app, swaggerConfig);
  SwaggerModule.setup('docs', app, swaggerDoc);

  const port = process.env.FABRIC_BACKEND_CENTER_PORT ? Number(process.env.FABRIC_BACKEND_CENTER_PORT) : 7001;
  await app.listen(port);
  console.log(`Fabric.Backend.Center listening on :${port}`);
}

void bootstrap();