import * as _cluster from 'node:cluster';
import * as os from 'node:os';
import { NestFactory } from '@nestjs/core';
import { ValidationPipe } from '@nestjs/common';
import { SwaggerModule, DocumentBuilder } from '@nestjs/swagger';
import { AppModule } from './app.module';

const cluster = _cluster as any; // Cast to 'any' bypasses the missing property errors
const isProduction = process.env.NODE_ENV === 'production';

// ---------------------------------------------------------------------------
// Clustering — fork one worker per CPU core in production
// ---------------------------------------------------------------------------

const WORKERS = isProduction
  ? Math.min(os.cpus().length, 4)  // cap at 4 workers to stay within DB pool
  : 1;                              // single process in dev

if (WORKERS > 1 && cluster.isPrimary) {
  console.log(`Primary ${process.pid} forking ${WORKERS} workers ...`);
  for (let i = 0; i < WORKERS; i++) {
    cluster.fork();
  }
  cluster.on('exit', (worker: any, code: number) => {
    console.warn(`Worker ${worker.process.pid} exited (code ${code}), restarting ...`);
    cluster.fork();
  });
} else {
  bootstrap();
}


// ---------------------------------------------------------------------------
// NestJS bootstrap
// ---------------------------------------------------------------------------

async function bootstrap() {
  const app = await NestFactory.create(AppModule, {
    logger: isProduction ? ['error', 'warn', 'log'] : ['error', 'warn', 'log', 'debug', 'verbose'],
  });

  app.setGlobalPrefix('api');

  // Request logging — only in development (too noisy / slow for prod)
  if (!isProduction) {
    app.use((req: any, _res: any, next: any) => {
      console.log(`[REQ] ${req.method} ${req.url} auth=${req.headers.authorization ? 'yes' : 'no'}`);
      next();
    });
  }

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

  // CORS — in production nginx handles this; accept all origins behind the proxy
  app.enableCors({
    origin: isProduction ? true : ['http://localhost', 'http://localhost:5173'],
    credentials: true,
  });

  // Swagger docs — available in all environments
  const config = new DocumentBuilder()
    .setTitle('HOA LedgerIQ API')
    .setDescription('API for the HOA LedgerIQ')
    .setVersion('2026.3.7')
    .addBearerAuth()
    .build();
  const document = SwaggerModule.createDocument(app, config);
  SwaggerModule.setup('api/docs', app, document);

  await app.listen(3000);
  console.log(`Backend worker ${process.pid} listening on port 3000`);
}