Initial commit: Open sourcing all of the Maple Open Technologies code.

cloud/maplefile-backend/internal/domain/collection/state_validator.go

@@ -0,0 +1,37 @@
+// monorepo/cloud/backend/internal/maplefile/domain/collection/state_validator.go
+package collection
+
+import "errors"
+
+// StateTransition validates collection state transitions
+type StateTransition struct {
+	From string
+	To   string
+}
+
+// IsValidStateTransition checks if a state transition is allowed
+func IsValidStateTransition(from, to string) error {
+	validTransitions := map[StateTransition]bool{
+		// From active
+		{CollectionStateActive, CollectionStateDeleted}:  true,
+		{CollectionStateActive, CollectionStateArchived}: true,
+
+		// From deleted (cannot be restored nor archived)
+		{CollectionStateDeleted, CollectionStateActive}:   false,
+		{CollectionStateDeleted, CollectionStateArchived}: false,
+
+		// From archived (can only be restored to active)
+		{CollectionStateArchived, CollectionStateActive}: true,
+
+		// Same state transitions (no-op)
+		{CollectionStateActive, CollectionStateActive}:     true,
+		{CollectionStateDeleted, CollectionStateDeleted}:   true,
+		{CollectionStateArchived, CollectionStateArchived}: true,
+	}
+
+	if !validTransitions[StateTransition{from, to}] {
+		return errors.New("invalid state transition from " + from + " to " + to)
+	}
+
+	return nil
+}