feat(BE): approval_workflow, adjusment project_flocks, common, and migration

internal/common/service/common.relation.service.go

@@ -0,0 +1,41 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/gofiber/fiber/v2"
+)
+
+// RelationCheck describes a foreign-key style dependency that must exist before processing.
+type RelationCheck struct {
+	Name   string
+	ID     *uint
+	Exists func(context.Context, uint) (bool, error)
+}
+
+// EnsureRelations validates that each RelationCheck is satisfied, returning consistent Fiber errors.
+func EnsureRelations(ctx context.Context, checks ...RelationCheck) error {
+	for _, check := range checks {
+		if check.ID == nil {
+			continue
+		}
+
+		exists, err := check.Exists(ctx, *check.ID)
+		if err != nil {
+			return fiber.NewError(
+				fiber.StatusInternalServerError,
+				fmt.Sprintf("Failed to check %s", strings.ToLower(check.Name)),
+			)
+		}
+		if !exists {
+			return fiber.NewError(
+				fiber.StatusNotFound,
+				fmt.Sprintf("%s with id %d not found", check.Name, *check.ID),
+			)
+		}
+	}
+
+	return nil
+}