Construindo a espinha dorsal da
próxima geração da web.

import { Injectable, CanActivate, ExecutionContext } from '@nestjs/common';
import { Reflector } from '@nestjs/core';
import { JwtService } from '@nestjs/jwt';

@Injectable()
export class AuthGuard implements CanActivate {
  constructor(
    private readonly jwtService: JwtService,
    private readonly reflector: Reflector,
  ) {}

  async canActivate(context: ExecutionContext): Promise<boolean> {
    const isPublic = this.reflector.get<boolean>(
      'isPublic',
      context.getHandler()
    );

    if (isPublic) return true;

    const request = context.switchToHttp().getRequest();
    const token = this.extractTokenFromHeader(request);

    if (!token) throw new UnauthorizedException();

    try {
      const payload = await this.jwtService.verifyAsync(token, {
        secret: process.env.JWT_SECRET,
      });
      request['user'] = payload;
    } catch {
      throw new UnauthorizedException();
    }
    
    return true;
  }
}

package com.peixoto.enterprise.services;

import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service
public class OrderService {

    private final OrderRepository orderRepository;
    private final PaymentGateway paymentGateway;

    public OrderService(OrderRepository repo, PaymentGateway payment) {
        this.orderRepository = repo;
        this.paymentGateway = payment;
    }

    @Transactional
    public OrderDto createOrder(CreateOrderRequest req) {
        // 1. Validate Inventory
        validateStock(req.getItems());

        // 2. Process Payment
        PaymentResult payment = paymentGateway.process(req.getTotal());
        
        if (!payment.isAuthorized()) {
            throw new PaymentDeclinedException("Funds insufficient");
        }

        // 3. Persist Order
        Order order = new Order(req);
        order.setStatus(OrderStatus.CONFIRMED);
        
        return OrderMapper.toDto(orderRepository.save(order));
    }
}

version: '3.8'

services:
  api_core:
    build: .
    ports:
      - "3000:3000"
    environment:
      - DATABASE_URL=postgresql://user:pass@db:5432/main
      - REDIS_HOST=cache
    depends_on:
      - db
      - cache

  db:
    image: postgres:15-alpine
    volumes:
      - postgres_data:/var/lib/postgresql/data
    environment:
      POSTGRES_DB: main
      POSTGRES_USER: user
      POSTGRES_PASSWORD: pass

  cache:
    image: redis:7-alpine
    ports:
      - "6379:6379"