[Feature] Search for Permissions, Prep Compound / Structure to be extended, Prep Template overwrites (#347)

Co-authored-by: Tim Lorsbach <tim@lorsba.ch>
Reviewed-on: enviPath/enviPy#347

epapi/v1/dal.py

@@ -41,6 +41,24 @@ def get_package_for_read(user, package_uuid: UUID):
     return package
 
 
+def get_package_for_write(user, package_uuid: UUID):
+    """
+    Get package by UUID with permission check.
+    """
+
+    # FIXME: update package manager with custom exceptions to avoid manual checks here
+    try:
+        package = Package.objects.get(uuid=package_uuid)
+    except Package.DoesNotExist:
+        raise EPAPINotFoundError(f"Package with UUID {package_uuid} not found")
+
+    # FIXME: optimize package manager to exclusively work with UUIDs
+    if not user or user.is_anonymous or not PackageManager.writable(user, package):
+        raise EPAPIPermissionDeniedError("Insufficient permissions to access this package.")
+
+    return package
+
+
 def get_scenario_for_read(user, scenario_uuid: UUID):
     """Get scenario by UUID with read permission check."""
     try: