feat: change email, export my data, delete account (with data anonymization)

internal/infrastructure/useCases/DeleteOwnAccount.go

@@ -0,0 +1,199 @@
+package useCases
+
+import (
+	"RenewCMS/internal/domain/audit"
+	"RenewCMS/internal/domain/author"
+	"RenewCMS/internal/domain/hash"
+	"RenewCMS/internal/domain/image"
+	"RenewCMS/internal/domain/mail"
+	"RenewCMS/internal/domain/role"
+	"RenewCMS/internal/domain/user"
+	"context"
+	"errors"
+	"log"
+	"slices"
+	"time"
+)
+
+const accountDeletedTemplateName = "account-deleted"
+
+type MailAccountDeletedData struct {
+	Host string
+}
+
+type sessionRevoker interface {
+	Revoke(id string, expiresAt time.Time) error
+}
+
+type DeleteOwnAccountUseCase struct {
+	users          user.Repository
+	roles          role.Repository
+	hasher         hash.Hasher
+	eraser         user.Eraser
+	sessions       sessionRevoker
+	mailRepository mail.Repository
+	dispatcher     mail.Dispatcher
+	publicURL      string
+	recorder       audit.Recorder
+	authors        author.Repository
+	images         image.Repository
+	usage          *GetMediaUsageUseCase
+	avatars        mediaRemover
+}
+
+type DeleteOwnAccountCommand struct {
+	UserID           uint32
+	CurrentPassword  string
+	SessionID        string
+	SessionExpiresAt time.Time
+}
+
+func NewDeleteOwnAccountUseCase(users user.Repository, roles role.Repository, hasher hash.Hasher, eraser user.Eraser, sessions sessionRevoker, mailRepository mail.Repository, dispatcher mail.Dispatcher, publicURL string, recorder audit.Recorder, authors author.Repository, images image.Repository, usage *GetMediaUsageUseCase, storage image.Storage, variantFiles image.VariantFileRepository) *DeleteOwnAccountUseCase {
+	return &DeleteOwnAccountUseCase{users, roles, hasher, eraser, sessions, mailRepository, dispatcher, publicURL, recorder, authors, images, usage, newMediaRemover(images, storage, variantFiles)}
+}
+
+func (u *DeleteOwnAccountUseCase) Delete(ctx context.Context, command DeleteOwnAccountCommand) error {
+	account, err := u.users.Get(command.UserID)
+	if err != nil {
+		return err
+	}
+	event := audit.NewEvent(audit.ActionUserDeleteAccount, audit.CategoryUsers)
+	event.Target = userTarget(account)
+	event.Security = true
+
+	guard, err := u.check(account, command)
+	if err != nil {
+		recordFailure(ctx, u.recorder, event, err)
+		return err
+	}
+	avatar, err := u.removableAvatar(account)
+	if err != nil {
+		recordFailure(ctx, u.recorder, event, err)
+		return err
+	}
+	erasure := user.Erasure{UserID: account.ID, GuardRoleIDs: guard}
+	if avatar != nil {
+		erasure.AvatarImageID = &avatar.ID
+	}
+	if err := u.eraser.Erase(erasure); err != nil {
+		recordFailure(ctx, u.recorder, event, err)
+		return err
+	}
+	u.discardAvatar(avatar)
+	u.revoke(command)
+	u.notify(account)
+	u.recordSuccess(ctx, account)
+	return nil
+}
+
+func (u *DeleteOwnAccountUseCase) check(account user.User, command DeleteOwnAccountCommand) ([]uint32, error) {
+	if u.hasher.Compare(account.Password, command.CurrentPassword) != nil {
+		return nil, user.ErrWrongPassword
+	}
+	guard, label, err := u.guardedRoles(account)
+	if err != nil || len(guard) == 0 {
+		return nil, err
+	}
+	hasOther, err := u.hasOtherHolder(account.ID, guard)
+	if err != nil {
+		return nil, err
+	}
+	if !hasOther {
+		return nil, user.LastAdminError{Role: label}
+	}
+	return guard, nil
+}
+
+func (u *DeleteOwnAccountUseCase) guardedRoles(account user.User) ([]uint32, string, error) {
+	owner, err := builtInRole(u.roles, role.OwnerName)
+	if err != nil {
+		return nil, "", err
+	}
+	if account.RoleID == owner.ID {
+		return []uint32{owner.ID}, user.LastRoleOwner, nil
+	}
+	admin, err := builtInRole(u.roles, role.AdminName)
+	if err != nil {
+		return nil, "", err
+	}
+	if account.RoleID == admin.ID {
+		return []uint32{owner.ID, admin.ID}, user.LastRoleAdmin, nil
+	}
+	return nil, "", nil
+}
+
+func (u *DeleteOwnAccountUseCase) hasOtherHolder(exceptUserID uint32, roleIDs []uint32) (bool, error) {
+	everyone, err := u.users.GetAll()
+	if err != nil {
+		return false, err
+	}
+	for _, candidate := range everyone {
+		if candidate.ID != exceptUserID && candidate.IsVerified && slices.Contains(roleIDs, candidate.RoleID) {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+func (u *DeleteOwnAccountUseCase) removableAvatar(account user.User) (*image.Image, error) {
+	own, err := u.authors.GetByUserID(account.ID)
+	if errors.Is(err, author.ErrAuthorNotFound) || err == nil && own.AvatarID == nil {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	avatar, err := u.images.Get(*own.AvatarID)
+	if errors.Is(err, image.ErrImageNotFound) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	usages, err := u.usage.Usage(avatar.ID)
+	if err != nil {
+		return nil, err
+	}
+	for _, found := range usages {
+		if found.Type != UsageTypeAuthor || found.ID != own.ID {
+			return nil, nil
+		}
+	}
+	return &avatar, nil
+}
+
+func (u *DeleteOwnAccountUseCase) discardAvatar(avatar *image.Image) {
+	if avatar == nil {
+		return
+	}
+	if err := u.avatars.discardFiles(*avatar); err != nil {
+		log.Println("error when deleting the stored avatar of a deleted account:", err)
+	}
+}
+
+func (u *DeleteOwnAccountUseCase) revoke(command DeleteOwnAccountCommand) {
+	if command.SessionID == "" {
+		return
+	}
+	if err := u.sessions.Revoke(command.SessionID, command.SessionExpiresAt); err != nil {
+		log.Println("error when revoking the session of a deleted account:", err)
+	}
+}
+
+func (u *DeleteOwnAccountUseCase) notify(account user.User) {
+	address := account.Email
+	u.dispatcher.Dispatch(func() {
+		if err := u.mailRepository.Send(address, accountDeletedTemplateName, MailAccountDeletedData{Host: u.publicURL}); err != nil {
+			log.Println("error when Send-ing the account deleted mail:", err)
+		}
+	})
+}
+
+func (u *DeleteOwnAccountUseCase) recordSuccess(ctx context.Context, account user.User) {
+	event := audit.NewEvent(audit.ActionUserDeleteAccount, audit.CategoryUsers)
+	id := account.ID
+	event.Actor = audit.Actor{Type: audit.ActorUser, ID: &id, Name: user.DeletedUserName}
+	event.Target = audit.NewTarget(audit.TargetUser, account.ID, user.DeletedUserName)
+	event.Security = true
+	u.recorder.Record(ctx, event)
+}