Set up default currency accounts automatically (#72)

backend/product/auth/flow/service.go

@@ -31,8 +31,13 @@ type SignupFacts interface {
 	Ready(context.Context, bson.ObjectID) error
 }
 
+type CurrencyAccounts interface {
+	Ensure(context.Context, *customer.Account) error
+}
+
 type Service struct {
 	Facts         SignupFacts
+	Wallet        CurrencyAccounts
 	Accounts      account.DB
 	Customers     accountservice.AccountService
 	Tokens        verification.DB
@@ -110,6 +115,11 @@ func (s *Service) Signup(ctx context.Context, a *customer.Account, ip, key strin
 			return nil, err
 		}
 	}
+	if s.Wallet != nil {
+		if err := s.Wallet.Ensure(ctx, a); err != nil {
+			return nil, err
+		}
+	}
 	if raw != "" {
 		u, _ := url.Parse(s.ActivationURL)
 		q := u.Query()
@@ -148,6 +158,11 @@ func (s *Service) ResendActivation(ctx context.Context, email, ip, key string) e
 			return err
 		}
 	}
+	if s.Wallet != nil {
+		if err := s.Wallet.Ensure(ctx, a); err != nil {
+			return err
+		}
+	}
 	_, err = s.sendActivation(ctx, a, key)
 	return err
 }