refac: register only open while no verified acc exists, enforced by a use case rather than handler & sends verification email whose link uses the conf pub URL whose code expires after 2h

internal/infrastructure/useCases/CreateUser.go

@@ -2,7 +2,10 @@ package useCases
 
 import (
 	"RenewCMS/internal/domain/hash"
+	"RenewCMS/internal/domain/mail"
 	"RenewCMS/internal/domain/user"
+	"errors"
+	"fmt"
 	"time"
 
 	"github.com/google/uuid"
@@ -11,6 +14,8 @@ import (
 type CreateUserUseCase struct {
 	userRepository user.Repository
 	hasher         hash.Hasher
+	mailRepository mail.Repository
+	publicURL      string
 }
 
 type CreateUserCommand struct {
@@ -19,11 +24,20 @@ type CreateUserCommand struct {
 	Email    string
 }
 
-func NewCreateUserUseCase(userRepository user.Repository, hasher hash.Hasher) *CreateUserUseCase {
-	return &CreateUserUseCase{userRepository, hasher}
+type MailValidationData struct {
+	Host             string
+	VerificationCode string
+}
+
+func NewCreateUserUseCase(userRepository user.Repository, hasher hash.Hasher, mailRepository mail.Repository, publicURL string) *CreateUserUseCase {
+	return &CreateUserUseCase{userRepository, hasher, mailRepository, publicURL}
 }
 
 func (g *CreateUserUseCase) CreateUser(createUser CreateUserCommand) (user.User, error) {
+	if g.registrationClosed() {
+		return user.User{}, user.ErrRegistrationClosed
+	}
+
 	rawUuid := uuid.NewString()
 
 	hashedPassword, err := g.hasher.Hash(createUser.Password)
@@ -50,5 +64,26 @@ func (g *CreateUserUseCase) CreateUser(createUser CreateUserCommand) (user.User,
 	}
 
 	createdUser.VerificationCode = rawUuid
+
+	if err := g.mailRepository.Send(createdUser.Email, "mailValidation", MailValidationData{
+		Host:             g.publicURL,
+		VerificationCode: rawUuid,
+	}); err != nil {
+		sendErr := fmt.Errorf("failed to send verification email: %w", err)
+		if deleteErr := g.userRepository.Delete(createdUser.ID); deleteErr != nil {
+			return user.User{}, errors.Join(sendErr, deleteErr)
+		}
+		return user.User{}, sendErr
+	}
+
 	return createdUser, nil
 }
+
+func (g *CreateUserUseCase) registrationClosed() bool {
+	for _, existingUser := range g.userRepository.GetAll() {
+		if existingUser.IsVerified {
+			return true
+		}
+	}
+	return false
+}