changed relationshipt to wekrefs

orm/relations.py

@@ -1,20 +1,49 @@
+import pprint
+import string
+import uuid
+from random import choices
 from typing import TYPE_CHECKING
+from weakref import proxy
+
+from sqlalchemy import text
+
+from orm.fields import ForeignKey
 
 if TYPE_CHECKING:  # pragma no cover
     from orm.models import Model
 
 
+def get_table_alias():
+    return ''.join(choices(string.ascii_uppercase, k=2)) + uuid.uuid4().hex[:4]
+
+
+def get_relation_config(relation_type: str, table_name: str, field: ForeignKey):
+    alias = get_table_alias()
+    config = {'type': relation_type,
+              'table_alias': alias,
+              'source_table': table_name if relation_type == 'primary' else field.to.__tablename__,
+              'target_table': field.to.__tablename__ if relation_type == 'primary' else table_name
+              }
+    return config
+
+
 class RelationshipManager:
 
     def __init__(self):
         self._relations = dict()
 
-    def add_relation_type(self, relations_key, reverse_key):
+    def add_relation_type(self, relations_key: str, reverse_key: str, field: ForeignKey, table_name: str):
         print(relations_key, reverse_key)
         if relations_key not in self._relations:
-            self._relations[relations_key] = {'type': 'primary'}
+            self._relations[relations_key] = get_relation_config('primary', table_name, field)
         if reverse_key not in self._relations:
-            self._relations[reverse_key] = {'type': 'reverse'}
+            self._relations[reverse_key] = get_relation_config('reverse', table_name, field)
+
+    def deregister(self, model: 'Model'):
+        for rel_type in self._relations.keys():
+            if model.__class__.__name__.lower() in rel_type.lower():
+                if model._orm_id in self._relations[rel_type]:
+                    del self._relations[rel_type][model._orm_id]
 
     def add_relation(self, parent_name: str, child_name: str, parent: 'Model', child: 'Model', virtual: bool = False):
         parent_id = parent._orm_id
@@ -22,9 +51,10 @@ class RelationshipManager:
         if virtual:
             child_name, parent_name = parent_name, child_name
             child_id, parent_id = parent_id, child_id
-            child, parent = parent, child
-        self._relations[parent_name.title() + '_' + child_name + 's'].setdefault(parent_id, []).append(
-            child)
+            child, parent = parent, proxy(child)
+        else:
+            child = proxy(child)
+        self._relations[parent_name.title() + '_' + child_name + 's'].setdefault(parent_id, []).append(child)
         self._relations[child_name.title() + '_' + parent_name].setdefault(child_id, []).append(parent)
 
     def contains(self, relations_key: str, object: 'Model'):
@@ -40,7 +70,7 @@ class RelationshipManager:
                 return self._relations[relations_key][object._orm_id]
 
     def __str__(self):  # pragma no cover
-        return ''.join(self._relations[rel].__str__() for rel in self._relations)
+        return pprint.pformat(self._relations, indent=4, width=1)
 
     def __repr__(self):  # pragma no cover
         return self.__str__()