feat: implement CORS and externalize payments config

backend/.env.example

@@ -0,0 +1,7 @@
+DATABASE_URL=postgres://user:password@host:port/dbname?sslmode=disable
+PORT=8080
+DB_MAX_OPEN_CONNS=25
+DB_MAX_IDLE_CONNS=25
+DB_CONN_MAX_IDLE=15m
+MERCADOPAGO_BASE_URL=https://api.mercadopago.com
+MARKETPLACE_COMMISSION=2.5

backend/internal/config/config.go

@@ -9,24 +9,28 @@ import (
 
 // Config centralizes runtime configuration loaded from the environment.
 type Config struct {
-	AppName      string
-	Port         string
-	DatabaseURL  string
-	MaxOpenConns int
-	MaxIdleConns int
-	ConnMaxIdle  time.Duration
+	AppName               string
+	Port                  string
+	DatabaseURL           string
+	MaxOpenConns          int
+	MaxIdleConns          int
+	ConnMaxIdle           time.Duration
+	MercadoPagoBaseURL    string
+	MarketplaceCommission float64
 }
 
 // Load reads configuration from environment variables and applies sane defaults
 // for local development.
 func Load() Config {
 	cfg := Config{
-		AppName:      getEnv("APP_NAME", "saveinmed-performance-core"),
-		Port:         getEnv("PORT", "8080"),
-		DatabaseURL:  getEnv("DATABASE_URL", "postgres://postgres:postgres@localhost:5432/saveinmed?sslmode=disable"),
-		MaxOpenConns: getEnvInt("DB_MAX_OPEN_CONNS", 15),
-		MaxIdleConns: getEnvInt("DB_MAX_IDLE_CONNS", 5),
-		ConnMaxIdle:  getEnvDuration("DB_CONN_MAX_IDLE", 5*time.Minute),
+		AppName:               getEnv("APP_NAME", "saveinmed-performance-core"),
+		Port:                  getEnv("PORT", "8080"),
+		DatabaseURL:           getEnv("DATABASE_URL", "postgres://postgres:postgres@localhost:5432/saveinmed?sslmode=disable"),
+		MaxOpenConns:          getEnvInt("DB_MAX_OPEN_CONNS", 15),
+		MaxIdleConns:          getEnvInt("DB_MAX_IDLE_CONNS", 5),
+		ConnMaxIdle:           getEnvDuration("DB_CONN_MAX_IDLE", 5*time.Minute),
+		MercadoPagoBaseURL:    getEnv("MERCADOPAGO_BASE_URL", "https://api.mercadopago.com"),
+		MarketplaceCommission: getEnvFloat("MARKETPLACE_COMMISSION", 2.5),
 	}
 
 	return cfg
@@ -61,3 +65,12 @@ func getEnvDuration(key string, fallback time.Duration) time.Duration {
 	}
 	return fallback
 }
+
+func getEnvFloat(key string, fallback float64) float64 {
+	if value := os.Getenv(key); value != "" {
+		if parsed, err := strconv.ParseFloat(value, 64); err == nil {
+			return parsed
+		}
+	}
+	return fallback
+}

backend/internal/http/middleware/cors.go

@@ -0,0 +1,22 @@
+package middleware
+
+import "net/http"
+
+// CORS adds Cross-Origin Resource Sharing headers to the response.
+// For now, it allows all origins (*).
+func CORS(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Access-Control-Allow-Origin", "*")
+		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS, PATCH")
+		w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization")
+		w.Header().Set("Access-Control-Max-Age", "86400")
+
+		// Handle preflight requests
+		if r.Method == http.MethodOptions {
+			w.WriteHeader(http.StatusOK)
+			return
+		}
+
+		next.ServeHTTP(w, r)
+	})
+}

backend/internal/payments/mercadopago.go

@@ -14,10 +14,10 @@ type MercadoPagoGateway struct {
 	BaseURL               string
 }
 
-func NewMercadoPagoGateway() *MercadoPagoGateway {
+func NewMercadoPagoGateway(baseURL string, commission float64) *MercadoPagoGateway {
 	return &MercadoPagoGateway{
-		MarketplaceCommission: 2.5,
-		BaseURL:               "https://api.mercadopago.com",
+		MarketplaceCommission: commission,
+		BaseURL:               baseURL,
 	}
 }
 

backend/internal/server/server.go

@@ -36,7 +36,7 @@ func New(cfg config.Config) (*Server, error) {
 	db.SetConnMaxIdleTime(cfg.ConnMaxIdle)
 
 	repo := postgres.New(db)
-	gateway := payments.NewMercadoPagoGateway()
+	gateway := payments.NewMercadoPagoGateway(cfg.MercadoPagoBaseURL, cfg.MarketplaceCommission)
 	svc := usecase.NewService(repo, gateway)
 	h := handler.New(svc)
 
@@ -76,7 +76,7 @@ func (s *Server) Start(ctx context.Context) error {
 
 	srv := &http.Server{
 		Addr:              s.cfg.Addr(),
-		Handler:           s.mux,
+		Handler:           middleware.CORS(s.mux),
 		ReadHeaderTimeout: 5 * time.Second,
 	}
 

backoffice/.env.example

@@ -0,0 +1,3 @@
+DATABASE_URL=postgresql://user:password@host:port/dbname?schema=public
+JWT_SECRET=secret-key
+PORT=3000