feat(API): user invitations and emails

internal/infrastructure/useCases/CreateInvite.go

@@ -0,0 +1,128 @@
+package useCases
+
+import (
+	"RenewCMS/internal/domain/hash"
+	"RenewCMS/internal/domain/invite"
+	"RenewCMS/internal/domain/mail"
+	"RenewCMS/internal/domain/user"
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+const inviteTemplateName = "invitation"
+
+type CreateInviteUseCase struct {
+	userRepository   user.Repository
+	inviteRepository invite.Repository
+	hasher           hash.Hasher
+	mailRepository   mail.Repository
+	publicURL        string
+}
+
+type CreateInviteCommand struct {
+	Email     string
+	InvitedBy uint32
+}
+
+type MailInviteData struct {
+	Host             string
+	VerificationCode string
+	Email            string
+	InvitedBy        string
+}
+
+func (d MailInviteData) Subject() string {
+	inviter := strings.NewReplacer("\r", " ", "\n", " ").Replace(d.InvitedBy)
+	return inviter + " invited you to RenewCMS"
+}
+
+func NewCreateInviteUseCase(userRepository user.Repository, inviteRepository invite.Repository, hasher hash.Hasher, mailRepository mail.Repository, publicURL string) *CreateInviteUseCase {
+	return &CreateInviteUseCase{userRepository, inviteRepository, hasher, mailRepository, publicURL}
+}
+
+func (g *CreateInviteUseCase) CreateInvite(command CreateInviteCommand) (invite.Invite, error) {
+	email := strings.ToLower(command.Email)
+	now := time.Now()
+
+	inviter, err := g.userRepository.Get(command.InvitedBy)
+	if err != nil {
+		return invite.Invite{}, err
+	}
+
+	if g.emailHasAccount(email) {
+		return invite.Invite{}, invite.ErrEmailHasAccount
+	}
+
+	if err := g.discardOpenInvite(email, now); err != nil {
+		return invite.Invite{}, err
+	}
+
+	rawCode := uuid.NewString()
+	hashedCode, err := g.hasher.Hash(rawCode)
+	if err != nil {
+		return invite.Invite{}, err
+	}
+
+	createdInvite, err := g.inviteRepository.Create(invite.Invite{
+		Email:      email,
+		HashedCode: hashedCode,
+		ExpiresAt:  now.Add(invite.Lifetime),
+		InvitedBy:  command.InvitedBy,
+		CreatedAt:  now,
+	})
+	if err != nil {
+		return invite.Invite{}, err
+	}
+
+	if err := g.mailRepository.Send(email, inviteTemplateName, MailInviteData{
+		Host:             g.publicURL,
+		VerificationCode: rawCode,
+		Email:            email,
+		InvitedBy:        inviterName(inviter),
+	}); err != nil {
+		sendErr := fmt.Errorf("%w: %w", invite.ErrInviteEmailNotSent, err)
+		if deleteErr := g.inviteRepository.Delete(createdInvite.ID); deleteErr != nil {
+			return invite.Invite{}, errors.Join(sendErr, deleteErr)
+		}
+		return invite.Invite{}, sendErr
+	}
+
+	return createdInvite, nil
+}
+
+func (g *CreateInviteUseCase) emailHasAccount(email string) bool {
+	for _, existingUser := range g.userRepository.GetAll() {
+		if strings.EqualFold(existingUser.Email, email) {
+			return true
+		}
+	}
+	return false
+}
+
+func (g *CreateInviteUseCase) discardOpenInvite(email string, now time.Time) error {
+	for _, existing := range g.inviteRepository.GetAll() {
+		if existing.Email != email {
+			continue
+		}
+		switch existing.StatusAt(now) {
+		case invite.StatusPending:
+			return invite.ErrPendingInvite
+		case invite.StatusExpired:
+			if err := g.inviteRepository.Delete(existing.ID); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func inviterName(inviter user.User) string {
+	if inviter.DisplayName != "" {
+		return inviter.DisplayName
+	}
+	return inviter.Username
+}