fix: correct time_detected logic, immutable sort pattern, add diagnose() test

app/services/diagnose.py

@@ -1,12 +1,16 @@
 """Frictionless diagnose service — NL time extraction + layered log search."""
 from __future__ import annotations
 
+import logging
 import re
 from datetime import datetime, timedelta, timezone
 from pathlib import Path
+from typing import Any
 
 from app.services.search import SearchResult, entries_in_window, search
 
+logger = logging.getLogger(__name__)
+
 try:
     from dateparser.search import search_dates as _search_dates  # type: ignore[import]
     _HAS_DATEPARSER = True
@@ -22,7 +26,11 @@ def parse_time_window(query: str) -> tuple[str | None, str | None, str]:
     the matched time phrase stripped. Falls back to last-60-min window.
     """
     if _HAS_DATEPARSER and _search_dates is not None:
-        results = _search_dates(query, languages=["en"], settings={"PREFER_DATES_FROM": "past"})
+        try:
+            results = _search_dates(query, languages=["en"], settings={"PREFER_DATES_FROM": "past"})
+        except Exception:
+            logger.warning("dateparser failed on query %r — falling back to 60-min window", query)
+            results = None
         if results:
             phrase, dt = results[0]
             if dt.tzinfo is None:
@@ -40,10 +48,10 @@ def diagnose(
     query: str,
     since: str | None = None,
     until: str | None = None,
-) -> dict:
+) -> dict[str, Any]:
     """Run layered log search with NL time extraction. Returns summary + entries."""
-    time_detected = since is not None or until is not None
-    if since is None or until is None:
+    time_detected = since is not None and until is not None
+    if not time_detected:
         parsed_since, parsed_until, keywords = parse_time_window(query)
         since = since or parsed_since
         until = until or parsed_until
@@ -55,14 +63,13 @@ def diagnose(
     window_hits = entries_in_window(db_path, since=since, until=until, limit=50)
 
     seen: set[str] = set()
-    combined: list[SearchResult] = []
+    merged: list[SearchResult] = []
     for r in keyword_hits + window_hits:
         if r.entry_id not in seen:
             seen.add(r.entry_id)
-            combined.append(r)
+            merged.append(r)
 
-    combined.sort(key=lambda r: (r.timestamp_iso or "\xff", r.sequence))
-    combined = combined[:200]
+    combined = sorted(merged, key=lambda r: (r.timestamp_iso or "\xff", r.sequence))[:200]
 
     by_severity: dict[str, int] = {"CRITICAL": 0, "ERROR": 0, "WARN": 0, "INFO": 0}
     by_source: dict[str, int] = {}

tests/test_services_diagnose.py

@@ -5,7 +5,7 @@ from datetime import datetime, timezone
 from unittest.mock import patch
 
 
-from app.services.diagnose import parse_time_window
+from app.services.diagnose import diagnose, parse_time_window
 
 
 def test_no_time_phrase_falls_back_to_last_60_min():
@@ -18,7 +18,7 @@ def test_no_time_phrase_falls_back_to_last_60_min():
     assert abs(diff - 3600) < 5
 
 
-def test_time_phrase_detected_produces_30min_window():
+def test_time_phrase_detected_produces_60min_window():
     dt = datetime(2026, 5, 11, 14, 0, tzinfo=timezone.utc)
     with patch("app.services.diagnose._HAS_DATEPARSER", True), \
          patch("app.services.diagnose._search_dates", return_value=[("around 2pm", dt)]):
@@ -37,7 +37,8 @@ def test_time_phrase_stripped_from_keywords():
 
 
 def test_no_dateparser_falls_back_to_60min():
-    with patch("app.services.diagnose._HAS_DATEPARSER", False):
+    with patch("app.services.diagnose._HAS_DATEPARSER", False), \
+         patch("app.services.diagnose._search_dates", None):
         since, until, keywords = parse_time_window("plex stopped playing audio")
     assert keywords == "plex stopped playing audio"
     diff = (datetime.fromisoformat(until) - datetime.fromisoformat(since)).total_seconds()
@@ -50,3 +51,13 @@ def test_keywords_cleaned_of_extra_spaces():
          patch("app.services.diagnose._search_dates", return_value=[("around 2pm", dt)]):
         _, _, keywords = parse_time_window("plex stopped audio around 2pm extra")
     assert "  " not in keywords
+
+
+def test_diagnose_with_explicit_window_sets_time_detected(tmp_path):
+    from app.ingest.pipeline import ensure_schema
+    db = tmp_path / "test.db"
+    ensure_schema(db)
+    result = diagnose(db, query="plex", since="2026-05-11T14:00:00+00:00", until="2026-05-11T15:00:00+00:00")
+    assert result["summary"]["time_detected"] is True
+    assert result["summary"]["total"] == 0  # empty DB
+    assert result["summary"]["window_start"] == "2026-05-11T14:00:00+00:00"