feat: implement database handlerImplement a database api to manage nodes and relationships in a "graph databaselike" implemented in sqlite.closes #1

pkg/collection.go

@@ -0,0 +1,37 @@
+package synchronizator
+
+import "fmt"
+
+// Utility struct to represent a collection of nodes, it's a [Node] itself so all
+// the node's functionality is available.
+type Collection struct {
+	Node           // Underlaying node info
+	childs []*Node // Child nodes
+}
+
+// Internal RelationshipClass to handle the collection to node relationship
+type collection_relation struct{}
+
+func (collection *collection_relation) ToRelationship() (string, []byte, error) {
+	return "COLLECTION_HAS", nil, nil
+}
+
+func (collection *collection_relation) FromRelationship(_class string, metadata []byte) error {
+	if _class != "COLLECTION_HAS" {
+		return fmt.Errorf("invalid class %s", _class)
+	}
+	return nil
+}
+
+// Adds a new child to this collection. Use the underlaying node's AddRelation
+// method.
+func (collection *Collection) AddChild(node *Node) error {
+	_, err := collection.AddRelation(&collection_relation{}, node.Id)
+	if err != nil {
+		return err
+	}
+
+	collection.childs = append(collection.childs, node)
+
+	return nil
+}