refac: DELETE /v1/user/{id}?expected_role_id=N, user.remove audit event, 409 target_role_not_found, GetAll returns its error, Own-scope visibility filter moved into repos, JSON tags removed from use-case types

internal/infrastructure/persistence/repositories/userRepository.go

@@ -52,6 +52,26 @@ func (u *UserRepository) Delete(id uint32) error {
 	return deleteOrNotFound(result, domainUser.ErrUserNotFound)
 }
 
+func (u *UserRepository) DeleteIfRole(id uint32, roleID uint32) error {
+	return u.db.Transaction(func(tx *gorm.DB) error {
+		result := tx.Where("id = ? AND role_id = ?", id, roleID).Delete(&entity.User{})
+		if result.Error != nil {
+			return result.Error
+		}
+		if result.RowsAffected > 0 {
+			return nil
+		}
+		var users int64
+		if err := tx.Model(&entity.User{}).Where("id = ?", id).Count(&users).Error; err != nil {
+			return err
+		}
+		if users == 0 {
+			return domainUser.ErrUserNotFound
+		}
+		return domainUser.ErrRoleChanged
+	})
+}
+
 func (u *UserRepository) GetAll() ([]domainUser.User, error) {
 	var users []entity.User
 	if err := u.db.Model(&entity.User{}).Find(&users).Error; err != nil {

internal/infrastructure/useCases/ReassignRoleMembers.go

@@ -34,7 +34,8 @@ func (u *ReassignRoleMembersUseCase) Reassign(ctx context.Context, command Reass
 	if err := u.checkSource(command.Caller, source); err != nil {
 		return 0, err
 	}
-	if err := u.checkTarget(command, source); err != nil {
+	target, err := u.checkTarget(command, source)
+	if err != nil {
 		return 0, err
 	}
 
@@ -42,6 +43,7 @@ func (u *ReassignRoleMembersUseCase) Reassign(ctx context.Context, command Reass
 	event.Target = roleTarget(source)
 	event.Params[audit.ParamFrom] = source.ID
 	event.Params[audit.ParamTo] = command.TargetID
+	event.Params[audit.ParamToName] = target.Name
 	event.Params[audit.ParamMoved] = 0
 	moved, err := u.roles.ReassignMembers(source.ID, command.TargetID)
 	if err != nil {
@@ -68,19 +70,22 @@ func (u *ReassignRoleMembersUseCase) checkSource(caller ContentCaller, source ro
 	return ensureCovered(caller, u.contentTypes, source)
 }
 
-func (u *ReassignRoleMembersUseCase) checkTarget(command ReassignRoleMembersCommand, source role.Role) error {
+func (u *ReassignRoleMembersUseCase) checkTarget(command ReassignRoleMembersCommand, source role.Role) (role.Role, error) {
 	if command.TargetID == 0 || command.TargetID == source.ID {
-		return role.ErrInvalidReassign
+		return role.Role{}, role.ErrInvalidReassign
 	}
 	target, err := u.roles.Get(command.TargetID)
 	if errors.Is(err, role.ErrRoleNotFound) {
-		return role.ErrInvalidReassign
+		return role.Role{}, role.ErrReassignTargetNotFound
 	}
 	if err != nil {
-		return err
+		return role.Role{}, err
 	}
 	if target.Locked {
-		return role.ErrInvalidReassign
+		return role.Role{}, role.ErrInvalidReassign
 	}
-	return ensureCovered(command.Caller, u.contentTypes, target)
+	if err := ensureCovered(command.Caller, u.contentTypes, target); err != nil {
+		return role.Role{}, err
+	}
+	return target, nil
 }

internal/infrastructure/useCases/RemoveUser.go

@@ -0,0 +1,79 @@
+package useCases
+
+import (
+	"RenewCMS/internal/domain/audit"
+	"RenewCMS/internal/domain/contenttype"
+	"RenewCMS/internal/domain/role"
+	"RenewCMS/internal/domain/user"
+	"context"
+	"errors"
+)
+
+type RemoveUserUseCase struct {
+	users        user.Repository
+	roles        role.Repository
+	contentTypes contenttype.Repository
+	recorder     audit.Recorder
+}
+
+type RemoveUserCommand struct {
+	Caller         ContentCaller
+	TargetID       uint32
+	ExpectedRoleID uint32
+}
+
+func NewRemoveUserUseCase(users user.Repository, roles role.Repository, contentTypes contenttype.Repository, recorder audit.Recorder) *RemoveUserUseCase {
+	return &RemoveUserUseCase{users: users, roles: roles, contentTypes: contentTypes, recorder: recorder}
+}
+
+func (u *RemoveUserUseCase) Remove(ctx context.Context, command RemoveUserCommand) error {
+	if command.ExpectedRoleID == 0 {
+		return role.ErrUnknownRole
+	}
+	target, err := u.users.Get(command.TargetID)
+	if err != nil {
+		return err
+	}
+	if err := u.check(command, target); err != nil {
+		return err
+	}
+	event := audit.NewEvent(audit.ActionUserRemove, audit.CategoryUsers)
+	event.Target = audit.NewTarget(audit.TargetUser, target.ID, target.Username)
+	if err := u.users.DeleteIfRole(target.ID, command.ExpectedRoleID); err != nil {
+		u.recordWriteFailure(ctx, event, err)
+		return err
+	}
+	u.recorder.Record(ctx, event)
+	return nil
+}
+
+func (u *RemoveUserUseCase) check(command RemoveUserCommand, target user.User) error {
+	if target.ID == command.Caller.UserID {
+		return role.ErrOwnRole
+	}
+	if target.RoleID != command.ExpectedRoleID {
+		return user.ErrRoleChanged
+	}
+	held, err := resolveRole(u.roles, target)
+	if errors.Is(err, role.ErrRoleNotFound) {
+		return nil
+	}
+	if err != nil {
+		return err
+	}
+	if held.Locked {
+		return role.ErrRoleLocked
+	}
+	typeKeys, err := allowedTypeKeys(u.contentTypes)
+	if err != nil {
+		return err
+	}
+	return ensureCoveredBy(command.Caller, typeKeys, held)
+}
+
+func (u *RemoveUserUseCase) recordWriteFailure(ctx context.Context, event audit.Event, err error) {
+	if errors.Is(err, user.ErrRoleChanged) || errors.Is(err, user.ErrUserNotFound) {
+		return
+	}
+	recordFailure(ctx, u.recorder, event, err)
+}