[Enhancement] Swappable Packages (#216)

Co-authored-by: Tim Lorsbach <tim@lorsba.ch>
Reviewed-on: enviPath/enviPy#216
Reviewed-by: liambrydon <lbry121@aucklanduni.ac.nz>
Reviewed-by: Tobias O <tobias.olenyi@envipath.com>

epdb/logic.py

@@ -1,39 +1,40 @@
-import re
-import logging
 import json
-from typing import Union, List, Optional, Set, Dict, Any
+import logging
+import re
+from typing import Any, Dict, List, Optional, Set, Union
 from uuid import UUID
 
 import nh3
+from django.conf import settings as s
 from django.contrib.auth import get_user_model
 from django.db import transaction
-from django.conf import settings as s
 from pydantic import ValidationError
 
 from epdb.models import (
-    User,
-    Package,
-    UserPackagePermission,
-    GroupPackagePermission,
-    Permission,
-    Group,
-    Setting,
-    EPModel,
-    UserSettingPermission,
-    Rule,
-    Pathway,
-    Node,
-    Edge,
     Compound,
-    Reaction,
     CompoundStructure,
+    Edge,
     EnzymeLink,
+    EPModel,
+    Group,
+    GroupPackagePermission,
+    Node,
+    Pathway,
+    Permission,
+    Reaction,
+    Rule,
+    Setting,
+    User,
+    UserPackagePermission,
+    UserSettingPermission,
 )
 from utilities.chem import FormatConverter
-from utilities.misc import PackageImporter, PackageExporter
+from utilities.misc import PackageExporter, PackageImporter
 
 logger = logging.getLogger(__name__)
 
+Package = s.GET_PACKAGE_MODEL()
+
 
 class EPDBURLParser:
     UUID_PATTERN = r"[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}"
@@ -583,25 +584,27 @@ class PackageManager(object):
     def import_legacy_package(
         data: dict, owner: User, keep_ids=False, add_import_timestamp=True, trust_reviewed=False
     ):
-        from uuid import UUID, uuid4
-        from datetime import datetime
         from collections import defaultdict
+        from datetime import datetime
+        from uuid import UUID, uuid4
+
+        from envipy_additional_information import AdditionalInformationConverter
+
         from .models import (
-            Package,
             Compound,
             CompoundStructure,
-            SimpleRule,
-            SimpleAmbitRule,
+            Edge,
+            Node,
+            Package,
             ParallelRule,
+            Pathway,
+            Reaction,
+            Scenario,
             SequentialRule,
             SequentialRuleOrdering,
-            Reaction,
-            Pathway,
-            Node,
-            Edge,
-            Scenario,
+            SimpleAmbitRule,
+            SimpleRule,
         )
-        from envipy_additional_information import AdditionalInformationConverter
 
         pack = Package()
         pack.uuid = UUID(data["id"].split("/")[-1]) if keep_ids else uuid4()