feat: iam dependencies

IAM endpoints now use dependencies to perform most initial database get requests.

Issue #6

src/iam/dependencies.py

@@ -1,5 +1,5 @@
 """
-Router dependencies for <this module>
+Router dependencies for the IAM module
 
 Classes:
  - List: Description
@@ -8,4 +8,49 @@ Classes:
 Functions:
  - List: Description
  - Functions: Description
-"""
+"""
+from typing import Annotated, Optional
+
+from fastapi import Depends, Query
+
+from src.database import db_dependency
+
+from src.iam.models import Group
+from src.iam.exceptions import GroupNotFoundException, PermNotFoundException
+from src.iam.schemas import GroupIDMixin, PermIDMixin
+
+
+def get_group_model_query(db: db_dependency, group_id: Annotated[int, Query(gt=0)]) -> type[Group]:
+	group_model = db.get(Group, group_id)
+	if group_model is None:
+		raise GroupNotFoundException(group_id)
+
+	return group_model
+
+group_model_query_dependency = Annotated[type[Group], Depends(get_group_model_query)]
+
+
+def get_group_model_body(db: db_dependency, request_model: Optional[GroupIDMixin] = None) -> type[Group]:
+	group_id = getattr(request_model, "group_id", None)
+	if group_id is None:
+		raise GroupNotFoundException()
+	group_model = db.get(Group, group_id)
+	if group_model is None:
+		raise GroupNotFoundException(group_id)
+
+	return group_model
+
+group_model_body_dependency = Annotated[type[Group], Depends(get_group_model_body)]
+
+
+def get_perm_model_body(db: db_dependency, request_model: Optional[PermIDMixin] = None) -> type[Group]:
+	perm_id = getattr(request_model, "permission_id", None)
+	if perm_id is None:
+		raise PermNotFoundException
+	group_model = db.get(Group, perm_id)
+	if group_model is None:
+		raise PermNotFoundException(perm_id)
+
+	return group_model
+
+perm_model_body_dependency = Annotated[type[Group], Depends(get_perm_model_body)]