feat: add maintenance module for message deletion and related utilities

feat: implement tests for maintenance functions and dashboard interactions
feat: add timezone and country tests for thctime module

tests/test_maintenance.py

@@ -0,0 +1,88 @@
+from datetime import datetime, timezone
+
+import maintenance
+
+
+class DummyResponse:
+    def __init__(self, headers=None, payload=None):
+        self.headers = headers or {}
+        self._payload = payload
+
+    def json(self):
+        if self._payload is None:
+            raise ValueError("no json")
+        return self._payload
+
+
+def test_parse_float():
+    assert maintenance.parse_float("1.5") == 1.5
+    assert maintenance.parse_float(2) == 2.0
+    assert maintenance.parse_float(None) is None
+    assert maintenance.parse_float("nope") is None
+
+
+def test_parse_message_timestamp_and_build_delete_entry():
+    msg = {"id": "42", "timestamp": "2026-01-01T10:00:00Z"}
+    parsed = maintenance.parse_message_timestamp(msg)
+    assert parsed == datetime(2026, 1, 1, 10, 0, 0)
+
+    entry = maintenance.build_delete_entry(msg)
+    assert entry["id"] == "42"
+    assert entry["timestamp"] == parsed
+
+
+def test_should_delete_message():
+    ts = int(datetime(2026, 1, 1, 10, 0, 0, tzinfo=timezone.utc).timestamp())
+    message = {
+        "timestamp": "2026-01-01T10:00:00Z",
+        "webhook_id": "w",
+        "author": {"id": "a"},
+    }
+
+    assert maintenance.should_delete_message(
+        message,
+        webhook_id="w",
+        author_id="a",
+        cutoff=ts,
+    )
+    assert not maintenance.should_delete_message(
+        message,
+        webhook_id="x",
+        author_id="a",
+        cutoff=ts,
+    )
+
+
+def test_get_rate_limit_retry_after_header_priority():
+    response = DummyResponse(
+        headers={
+            "Retry-After": "2.5",
+            "X-RateLimit-Reset-After": "10",
+        },
+        payload={"retry_after": "20"},
+    )
+    assert maintenance.get_rate_limit_retry_after(response) == 2.5
+
+
+def test_get_rate_limit_retry_after_json_fallback():
+    response = DummyResponse(payload={"retry_after": "3"})
+    assert maintenance.get_rate_limit_retry_after(response) == 3.0
+
+
+def test_get_bucket_exhausted_delay():
+    response = DummyResponse(
+        headers={
+            "X-RateLimit-Remaining": "0",
+            "X-RateLimit-Reset-After": "1.25",
+        }
+    )
+    assert maintenance.get_bucket_exhausted_delay(response) == 1.25
+
+    response_not_exhausted = DummyResponse(
+        headers={
+            "X-RateLimit-Remaining": "1",
+            "X-RateLimit-Reset-After": "1.25",
+        }
+    )
+    assert maintenance.get_bucket_exhausted_delay(
+        response_not_exhausted) is None