more refactors

internal/db/role.go

@@ -33,70 +33,28 @@ type RolePermission struct {
 	Permission   *Permission `bun:"rel:belongs-to,join:permission_id=id"`
 }
 
+func (r Role) isSystem() bool {
+	return r.IsSystem
+}
+
 // GetRoleByName queries the database for a role matching the given name
 // Returns nil, nil if no role is found
 func GetRoleByName(ctx context.Context, tx bun.Tx, name roles.Role) (*Role, error) {
 	if name == "" {
 		return nil, errors.New("name cannot be empty")
 	}
-
-	role := new(Role)
-	err := tx.NewSelect().
-		Model(role).
-		Where("name = ?", name).
-		Limit(1).
-		Scan(ctx)
-	if err != nil {
-		if err == sql.ErrNoRows {
-			return nil, nil
-		}
-		return nil, errors.Wrap(err, "tx.NewSelect")
-	}
-	return role, nil
+	return GetByField[Role](tx, "name", name).GetFirst(ctx)
 }
 
 // GetRoleByID queries the database for a role matching the given ID
 // Returns nil, nil if no role is found
 func GetRoleByID(ctx context.Context, tx bun.Tx, id int) (*Role, error) {
-	if id <= 0 {
-		return nil, errors.New("id must be positive")
-	}
-
-	role := new(Role)
-	err := tx.NewSelect().
-		Model(role).
-		Where("id = ?", id).
-		Limit(1).
-		Scan(ctx)
-	if err != nil {
-		if err == sql.ErrNoRows {
-			return nil, nil
-		}
-		return nil, errors.Wrap(err, "tx.NewSelect")
-	}
-	return role, nil
+	return GetByID[Role](tx, id).GetFirst(ctx)
 }
 
 // GetRoleWithPermissions loads a role and all its permissions
 func GetRoleWithPermissions(ctx context.Context, tx bun.Tx, id int) (*Role, error) {
-	if id <= 0 {
-		return nil, errors.New("id must be positive")
-	}
-
-	role := new(Role)
-	err := tx.NewSelect().
-		Model(role).
-		Where("id = ?", id).
-		Relation("Permissions").
-		Limit(1).
-		Scan(ctx)
-	if err != nil {
-		if err == sql.ErrNoRows {
-			return nil, nil
-		}
-		return nil, errors.Wrap(err, "tx.NewSelect")
-	}
-	return role, nil
+	return GetByID[Role](tx, id).Relation("Permissions").GetFirst(ctx)
 }
 
 // ListAllRoles returns all roles
@@ -155,28 +113,7 @@ func DeleteRole(ctx context.Context, tx bun.Tx, id int) error {
 	if id <= 0 {
 		return errors.New("id must be positive")
 	}
-
-	// Check if role is system role
-	role, err := GetRoleByID(ctx, tx, id)
-	if err != nil {
-		return errors.Wrap(err, "GetRoleByID")
-	}
-	if role == nil {
-		return errors.New("role not found")
-	}
-	if role.IsSystem {
-		return errors.New("cannot delete system role")
-	}
-
-	_, err = tx.NewDelete().
-		Model((*Role)(nil)).
-		Where("id = ?", id).
-		Exec(ctx)
-	if err != nil {
-		return errors.Wrap(err, "tx.NewDelete")
-	}
-
-	return nil
+	return DeleteWithProtection[Role](ctx, tx, id)
 }
 
 // AddPermissionToRole grants a permission to a role