拆分 analysis_service：剩余工具函数全部移至 analysis_utils.py

提取 _mgm_hourly_high/_dedupe_forecast_daily/_format_observation_time_local/_parse_local_hour/_parse_utc_datetime/_metar_is_current_local_day/_is_plausible_city_temp。统一 parse_utc_datetime 副本。analysis_service 2082→1966 行。

web/services/analysis_utils.py

@@ -6,6 +6,7 @@ Pure helpers: clock arithmetic, bucket labelling, signal packaging.
 from __future__ import annotations
 
 import re
+from datetime import datetime, timezone, timedelta
 from typing import Any, Dict, Optional
 
 from web.core import _sf
@@ -92,3 +93,114 @@ def add_signal(
             "summary_en": summary_en or summary,
         }
     )
+
+
+# ── Time / date helpers ────────────────────────────────────────────────
+
+def parse_utc_datetime(value: Any) -> Optional[datetime]:
+    raw = str(value or "").strip()
+    if not raw or "T" not in raw:
+        return None
+    try:
+        dt = datetime.fromisoformat(raw.replace("Z", "+00:00"))
+    except Exception:
+        return None
+    if dt.tzinfo is None:
+        dt = dt.replace(tzinfo=timezone.utc)
+    return dt.astimezone(timezone.utc)
+
+
+def format_observation_time_local(value: Any, utc_offset: int) -> str:
+    raw = str(value or "").strip()
+    if not raw:
+        return ""
+    if "T" in raw:
+        try:
+            dt = datetime.fromisoformat(raw.replace("Z", "+00:00"))
+            if dt.tzinfo is None:
+                dt = dt.replace(tzinfo=timezone.utc)
+            return dt.astimezone(timezone(timedelta(seconds=utc_offset))).strftime("%H:%M")
+        except Exception:
+            pass
+    import re
+    match = re.search(r"(\d{1,2}):(\d{2})", raw)
+    if match:
+        return f"{int(match.group(1)):02d}:{match.group(2)}"
+    return raw[:16]
+
+
+def parse_local_hour(local_time_str: Optional[str]) -> Optional[int]:
+    if not local_time_str:
+        return None
+    try:
+        parts = str(local_time_str).strip().split(":")
+        hour = int(parts[0])
+        if 0 <= hour <= 23:
+            return hour
+    except Exception:
+        pass
+    return None
+
+
+def metar_is_current_local_day(
+    metar: Dict[str, Any],
+    *,
+    local_date: str,
+    utc_offset: int,
+) -> bool:
+    if not isinstance(metar, dict) or not metar:
+        return False
+    if metar.get("stale_for_today") is True:
+        return False
+    observation_local_date = str(metar.get("observation_local_date") or "").strip()
+    if observation_local_date:
+        return observation_local_date == local_date
+    obs_dt = parse_utc_datetime(metar.get("observation_time"))
+    if obs_dt is None:
+        return True
+    local_dt = obs_dt.astimezone(timezone(timedelta(seconds=utc_offset)))
+    return local_dt.strftime("%Y-%m-%d") == local_date
+
+
+def is_plausible_city_temp(city: str, value: Any, unit: str = "°C") -> bool:
+    from src.data_collection.city_registry import CITY_REGISTRY
+
+    temp = _sf(value)
+    if temp is None:
+        return False
+    meta = CITY_REGISTRY.get(str(city or "").strip().lower(), {}) or {}
+    min_c = _sf(meta.get("min_plausible_metar_temp_c"))
+    if min_c is None:
+        return True
+    min_value = min_c * 9 / 5 + 32 if str(unit or "").upper().endswith("F") else min_c
+    return temp >= min_value
+
+
+def dedupe_forecast_daily(rows: Any) -> list:
+    if not isinstance(rows, list):
+        return []
+    seen = set()
+    out = []
+    for row in rows:
+        if not isinstance(row, dict):
+            continue
+        date = str(row.get("date") or "").strip()
+        if not date or date in seen:
+            continue
+        seen.add(date)
+        out.append(row)
+    return out
+
+
+def mgm_hourly_high(mgm: Dict[str, Any]) -> Optional[float]:
+    hourly = mgm.get("hourly") if isinstance(mgm, dict) else []
+    if not isinstance(hourly, list):
+        return None
+    values = []
+    for row in hourly:
+        if not isinstance(row, dict):
+            continue
+        value = _sf(row.get("temp"))
+        if value is not None:
+            values.append(value)
+    return max(values) if values else None