import {
  Injectable,
  NestInterceptor,
  ExecutionContext,
  CallHandler,
} from '@nestjs/common';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';
import { ApiResponse } from '../interfaces/communication';
import { v4 as uuidv4 } from 'uuid';

@Injectable()
export class TransformInterceptor<T> implements NestInterceptor<T, ApiResponse<T>> {
  intercept(
    context: ExecutionContext,
    next: CallHandler,
  ): Observable<ApiResponse<T>> {
    const serviceName = process.env.SERVICE_NAME || 'unknown-service';
    
    return next.handle().pipe(
      map((data) => ({
        success: true,
        data,
        meta: {
          timestamp: Date.now(),
          traceId: uuidv4(),
          service: serviceName,
        },
      })),
    );
  }
}