import { Controller, Get, Header } from '@nestjs/common';

@Controller('example')
export class ExampleController {
  @Get('static')
  @Header('Content-Type', 'application/json')
  @Header('Cache-Control', 'no-cache')
  getStatic() {
    return { message: 'Static headers' };
  }
}

Content-Type: application/json
Cache-Control: no-cache

@Get('dynamic')
@Header('X-Request-Time', (req) => Date.now().toString())
getDynamic() {
  return { message: 'Dynamic headers' };
}

import { Response } from 'express';

@Get('manual')
getManual(@Res() res: Response) {
  res.set('X-Custom-Header', 'value');
  res.send({ data: 'Manual headers' });
}

@Get('order')
@Header('A', '1')
@Header('B', '2')
getOrder() {
  return {};
}

@Get('override')
@Header('Content-Type', 'text/plain')
getOverride() {
  return 'Plain text response';
}

@Get('service-data')
@Header('X-Version', (req, res, next) => {
  const appVersion = req.app.get('APP_VERSION');
  return appVersion;
})
getServiceData() {
  return { version: '1.0.0' };
}

import { Injectable, NestInterceptor, ExecutionContext, CallHandler } from '@nestjs/common';

@Injectable()
export class HeadersInterceptor implements NestInterceptor {
  intercept(context: ExecutionContext, next: CallHandler) {
    const response = context.switchToHttp().getResponse();
    response.setHeader('X-Powered-By', 'NestJS');
    return next.handle();
  }
}

@Get('secure')
@Header('Content-Security-Policy', "default-src 'self'")
@Header('X-Content-Type-Options', 'nosniff')
getSecure() {
  return { data: 'Secure headers' };
}

@Get('conditional')
@Header('X-Conditional', (req) => req.query.debug ? 'true' : 'false')
getConditional() {
  return { debugMode: !!req.query.debug };
}