import { NestFactory } from '@nestjs/core';
import { ValidationPipe } from '@nestjs/common';
import { SwaggerModule, DocumentBuilder } from '@nestjs/swagger';
import helmet from 'helmet';
import * as express from 'express';
import * as path from 'path';
import * as fs from 'fs';
import { AppModule } from './app.module';
import { AllExceptionsFilter } from './common/filters/all-exceptions.filter';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);

  app.use(helmet({ contentSecurityPolicy: false, crossOriginResourcePolicy: { policy: 'cross-origin' } }));

  // Global exception filter for error details
  app.useGlobalFilters(new AllExceptionsFilter());

  // Global prefix
  app.setGlobalPrefix('api/v1');

  // Uploaded media files (outside API prefix)
  const uploadsDir = path.join(process.cwd(), 'uploads');
  fs.mkdirSync(uploadsDir, { recursive: true });
  app.use(
    '/uploads',
    express.static(uploadsDir, {
      maxAge: '7d',
      fallthrough: true,
      index: false,
      dotfiles: 'deny',
      setHeaders: (res, filePath) => {
        res.setHeader('X-Content-Type-Options', 'nosniff');
        res.setHeader('Content-Security-Policy', "default-src 'none'; img-src 'self'; media-src 'self'; sandbox");
        if (/\.(html?|xhtml|svg|xml|js|mjs)$/i.test(filePath)) {
          res.setHeader('Content-Type', 'application/octet-stream');
          res.setHeader('Content-Disposition', 'attachment');
        }
      },
    }),
  );

  // CORS
  app.enableCors({
    origin: process.env.CORS_ORIGINS?.split(',') || ['http://localhost:3000'],
    credentials: true,
  });

  // Validation pipe
  app.useGlobalPipes(
    new ValidationPipe({
      whitelist: true,
      forbidNonWhitelisted: true,
      transform: true,
      transformOptions: {
        enableImplicitConversion: true,
      },
    }),
  );

  // Swagger (disabled in production)
  if (process.env.NODE_ENV !== 'production') {
    const config = new DocumentBuilder()
      .setTitle('SMHI API')
      .setDescription('SHEDAM Mental Health Initiative API')
      .setVersion('1.0')
      .addBearerAuth()
      .build();
    const document = SwaggerModule.createDocument(app, config);
    SwaggerModule.setup('api/docs', app, document);
  }

  const port = process.env.PORT || 3002;
  await app.listen(port);
  console.log(`API running on http://localhost:${port}`);
  if (process.env.NODE_ENV !== 'production') {
    console.log(`Swagger docs: http://localhost:${port}/api/docs`);
  }
}
bootstrap();