sloppy work on passing all of the test and reimplementing most of the features from encode

orm/relations.py

@@ -0,0 +1,45 @@
+from typing import Dict, Union, List
+
+from sqlalchemy import text
+
+
+class Relationship:
+
+    def __init__(self, name: str, parent: 'Model', child: 'Model', fk_side: str = 'child'):
+        self.fk_side = fk_side
+        self.child = child
+        self.parent = parent
+        self.name = name
+
+
+class RelationshipManager:
+
+    def __init__(self, model: 'Model'):
+        self._orm_id: str = model._orm_id
+        self._relations: Dict[str, Union[Relationship, List[Relationship]]] = dict()
+
+    def __contains__(self, item):
+        return item in self._relations
+
+    def add_related(self, relation: Relationship):
+        if relation.fk_side == 'child' and relation.parent._orm_id == self._orm_id:
+            new_relation = Relationship(name=relation.parent.__class__.__name__.lower(),
+                                        child=relation.parent,
+                                        parent=relation.child,
+                                        fk_side='parent')
+            relation.child._orm_relationship_manager.add(new_relation)
+
+    def add(self, relation: Relationship):
+        if relation.name in self._relations:
+            self._relations[relation.name].append(relation)
+        else:
+            self._relations[relation.name] = [relation]
+        self.add_related(relation)
+
+    def get(self, name: str):
+        for rel, relations in self._relations.items():
+            if rel == name:
+                if relations and relations[0].fk_side == 'parent':
+                    return relations[0].child
+                else:
+                    return [rela.child for rela in relations]