Admin API for reported events (#8217)

Add an admin API to read entries of table `event_reports`. API: `GET /_synapse/admin/v1/event_reports`

docs/admin_api/event_reports.rst

@@ -0,0 +1,129 @@
+Show reported events
+====================
+
+This API returns information about reported events.
+
+The api is::
+
+    GET /_synapse/admin/v1/event_reports?from=0&limit=10
+
+To use it, you will need to authenticate by providing an ``access_token`` for a
+server admin: see `README.rst <README.rst>`_.
+
+It returns a JSON body like the following:
+
+.. code:: jsonc
+
+    {
+        "event_reports": [
+            {
+                "content": {
+                    "reason": "foo",
+                    "score": -100
+                },
+                "event_id": "$bNUFCwGzWca1meCGkjp-zwslF-GfVcXukvRLI1_FaVY",
+                "event_json": {
+                    "auth_events": [
+                        "$YK4arsKKcc0LRoe700pS8DSjOvUT4NDv0HfInlMFw2M",
+                        "$oggsNXxzPFRE3y53SUNd7nsj69-QzKv03a1RucHu-ws"
+                    ],
+                    "content": {
+                        "body": "matrix.org: This Week in Matrix",
+                        "format": "org.matrix.custom.html",
+                        "formatted_body": "<strong>matrix.org</strong>:<br><a href=\"https://matrix.org/blog/\"><strong>This Week in Matrix</strong></a>",
+                        "msgtype": "m.notice"
+                    },
+                    "depth": 546,
+                    "hashes": {
+                        "sha256": "xK1//xnmvHJIOvbgXlkI8eEqdvoMmihVDJ9J4SNlsAw"
+                    },
+                    "origin": "matrix.org",
+                    "origin_server_ts": 1592291711430,
+                    "prev_events": [
+                        "$YK4arsKKcc0LRoe700pS8DSjOvUT4NDv0HfInlMFw2M"
+                    ],
+                    "prev_state": [],
+                    "room_id": "!ERAgBpSOcCCuTJqQPk:matrix.org",
+                    "sender": "@foobar:matrix.org",
+                    "signatures": {
+                        "matrix.org": {
+                            "ed25519:a_JaEG": "cs+OUKW/iHx5pEidbWxh0UiNNHwe46Ai9LwNz+Ah16aWDNszVIe2gaAcVZfvNsBhakQTew51tlKmL2kspXk/Dg"
+                        }
+                    },
+                    "type": "m.room.message",
+                    "unsigned": {
+                        "age_ts": 1592291711430,
+                    }
+                },
+                "id": 2,
+                "reason": "foo",
+                "received_ts": 1570897107409,
+                "room_alias": "#alias1:matrix.org",
+                "room_id": "!ERAgBpSOcCCuTJqQPk:matrix.org",
+                "sender": "@foobar:matrix.org",
+                "user_id": "@foo:matrix.org"
+            },
+            {
+                "content": {
+                    "reason": "bar",
+                    "score": -100
+                },
+                "event_id": "$3IcdZsDaN_En-S1DF4EMCy3v4gNRKeOJs8W5qTOKj4I",
+                "event_json": {
+                    // hidden items
+                    // see above
+                },
+                "id": 3,
+                "reason": "bar",
+                "received_ts": 1598889612059,
+                "room_alias": "#alias2:matrix.org",
+                "room_id": "!eGvUQuTCkHGVwNMOjv:matrix.org",
+                "sender": "@foobar:matrix.org",
+                "user_id": "@bar:matrix.org"
+            }
+        ],
+        "next_token": 2,
+        "total": 4
+    }
+
+To paginate, check for ``next_token`` and if present, call the endpoint again
+with ``from`` set to the value of ``next_token``. This will return a new page.
+
+If the endpoint does not return a ``next_token`` then there are no more
+reports to paginate through.
+
+**URL parameters:**
+
+- ``limit``: integer - Is optional but is used for pagination,
+  denoting the maximum number of items to return in this call. Defaults to ``100``.
+- ``from``: integer - Is optional but used for pagination,
+  denoting the offset in the returned results. This should be treated as an opaque value and
+  not explicitly set to anything other than the return value of ``next_token`` from a previous call.
+  Defaults to ``0``.
+- ``dir``: string - Direction of event report order. Whether to fetch the most recent first (``b``) or the
+  oldest first (``f``). Defaults to ``b``.
+- ``user_id``: string - Is optional and filters to only return users with user IDs that contain this value.
+  This is the user who reported the event and wrote the reason.
+- ``room_id``: string - Is optional and filters to only return rooms with room IDs that contain this value.
+
+**Response**
+
+The following fields are returned in the JSON response body:
+
+- ``id``: integer - ID of event report.
+- ``received_ts``: integer - The timestamp (in milliseconds since the unix epoch) when this report was sent.
+- ``room_id``: string - The ID of the room in which the event being reported is located.
+- ``event_id``: string - The ID of the reported event.
+- ``user_id``: string - This is the user who reported the event and wrote the reason.
+- ``reason``: string - Comment made by the ``user_id`` in this report. May be blank.
+- ``content``: object - Content of reported event.
+
+  - ``reason``: string - Comment made by the ``user_id`` in this report. May be blank.
+  - ``score``: integer - Content is reported based upon a negative score, where -100 is "most offensive" and 0 is "inoffensive".
+
+- ``sender``: string - This is the ID of the user who sent the original message/event that was reported.
+- ``room_alias``: string - The alias of the room. ``null`` if the room does not have a canonical alias set.
+- ``event_json``: object - Details of the original event that was reported.
+- ``next_token``: integer - Indication for pagination. See above.
+- ``total``: integer - Total number of event reports related to the query (``user_id`` and ``room_id``).
+