feat: Add mediafile_download_policy

src/elody/policies/authorization/mediafile_download_policy.py

@@ -0,0 +1,70 @@
+import re as regex
+
+from elody.policies.permission_handler import (
+    get_permissions,
+    handle_single_item_request,
+)
+from flask import Request  # pyright: ignore
+from flask_restful import abort  # pyright: ignore
+from inuits_policy_based_auth import BaseAuthorizationPolicy  # pyright: ignore
+from inuits_policy_based_auth.contexts.policy_context import (  # pyright: ignore
+    PolicyContext,
+)
+from inuits_policy_based_auth.contexts.user_context import (  # pyright: ignore
+    UserContext,
+)
+from storage.storagemanager import StorageManager  # pyright: ignore
+
+
+class MediafileDownloadPolicy(BaseAuthorizationPolicy):
+    def authorize(
+        self, policy_context: PolicyContext, user_context: UserContext, request_context
+    ):
+        request: Request = request_context.http_request
+        if not regex.match(r"^/mediafiles/(.+)/download$", request.path):
+            return policy_context
+
+        view_args = request.view_args or {}
+        collection = view_args.get("collection", request.path.split("/")[-3])
+        id = view_args.get("id")
+        item = (
+            StorageManager()
+            .get_db_engine()
+            .get_item_from_collection_by_id(collection, id)
+        )
+        if not item:
+            abort(
+                404,
+                message=f"Item with id {id} doesn't exist in collection {collection}",
+            )
+
+        for role in user_context.x_tenant.roles:
+            permissions = get_permissions(role, user_context)
+            if not permissions:
+                continue
+
+            rules = [
+                GetRequestRules,
+            ]
+            access_verdict = None
+            for rule in rules:
+                access_verdict = rule().apply(item, user_context, request, permissions)
+                if access_verdict != None:
+                    policy_context.access_verdict = access_verdict
+                    if not policy_context.access_verdict:
+                        return policy_context
+
+            if policy_context.access_verdict:
+                return policy_context
+
+        return policy_context
+
+
+class GetRequestRules:
+    def apply(
+        self, item, user_context: UserContext, request: Request, permissions
+    ) -> bool | None:
+        if request.method != "GET":
+            return None
+
+        return handle_single_item_request(user_context, item, permissions, "read")