fix: restore Hong Kong CoWIN reference curve

src/data_collection/country_networks.py

@@ -1214,20 +1214,28 @@ def build_country_network_snapshot(city: str, raw: Dict[str, Any]) -> Dict[str,
     }
     airport_primary_today_obs = ((raw.get("metar") or {}).get("today_obs") or [])
     if airport_primary.get("source_code") == "cowin_obs":
-        try:
-            from src.database.runtime_state import OfficialIntradayObservationRepository
-            repo = OfficialIntradayObservationRepository()
-            local_now = datetime.now(timezone.utc) + timedelta(seconds=city_offset or 0)
-            local_date_str = local_now.strftime("%Y-%m-%d")
-            points = repo.load_points(
-                source_code="cowin_obs",
-                station_code=airport_primary.get("station_code") or "6087",
-                target_date=local_date_str,
-            )
-            if points:
-                airport_primary_today_obs = [{"time": p["time"], "temp": p["temp"]} for p in points]
-        except Exception:
-            pass
+        live_points = raw.get("cowin_today_obs") or []
+        if live_points:
+            airport_primary_today_obs = [
+                {"time": p["time"], "temp": p["temp"]}
+                for p in live_points
+                if isinstance(p, dict) and p.get("time") and p.get("temp") is not None
+            ]
+        if not airport_primary_today_obs:
+            try:
+                from src.database.runtime_state import OfficialIntradayObservationRepository
+                repo = OfficialIntradayObservationRepository()
+                local_now = datetime.now(timezone.utc) + timedelta(seconds=city_offset or 0)
+                local_date_str = local_now.strftime("%Y-%m-%d")
+                points = repo.load_points(
+                    source_code="cowin_obs",
+                    station_code=airport_primary.get("station_code") or "6087",
+                    target_date=local_date_str,
+                )
+                if points:
+                    airport_primary_today_obs = [{"time": p["time"], "temp": p["temp"]} for p in points]
+            except Exception:
+                pass
 
     return {
         "provider_code": provider.provider_code,

src/data_collection/cowin_sources.py

@@ -11,6 +11,7 @@ import os
 import time
 from datetime import datetime, timedelta, timezone
 from typing import Any, Dict, Optional
+from urllib.parse import urlencode
 
 import requests
 from loguru import logger
@@ -21,6 +22,16 @@ COWIN_BASE_URL = os.getenv("COWIN_BASE_URL", "").strip() or "https://cowin.hku.h
 COWIN_SERIES_URL = f"{COWIN_BASE_URL}/API/data/CoWIN/series"
 COWIN_STATION_ID = int(os.getenv("COWIN_HK_STATION_ID", "6087"))
 COWIN_STATION_LABEL = os.getenv("COWIN_HK_STATION_LABEL", "").strip() or "保良局陳守仁小學 1min (CoWIN)"
+COWIN_HK_UTC_OFFSET_SECONDS = 8 * 60 * 60
+
+
+def _cowin_tls_fallback_enabled() -> bool:
+    raw = os.getenv("COWIN_ALLOW_INSECURE_TLS_FALLBACK", "1").strip().lower()
+    return raw not in {"0", "false", "no", "off"}
+
+
+def _is_tls_certificate_error(exc: Exception) -> bool:
+    return "CERTIFICATE_VERIFY_FAILED" in str(exc).upper()
 
 
 def _cowin_obs_time_to_iso(value: Any) -> Optional[str]:
@@ -32,22 +43,52 @@ def _cowin_obs_time_to_iso(value: Any) -> Optional[str]:
     except (ValueError, TypeError):
         return None
     if dt.tzinfo is None:
-        dt = dt.replace(tzinfo=timezone.utc)
-    else:
-        dt = dt.astimezone(timezone.utc)
-    return dt.isoformat().replace("+00:00", "Z")
+        dt = dt.replace(tzinfo=timezone(timedelta(seconds=COWIN_HK_UTC_OFFSET_SECONDS)))
+    return dt.isoformat()
 
 
 class CowinSourceMixin:
 
     def _cowin_http_get(self, url: str) -> requests.Response:
         getter = getattr(self, "_http_get", None)
-        if callable(getter):
-            resp = getter(url)
+        try:
+            if callable(getter):
+                return getter(url)
+            resp = self.session.get(url, timeout=self.timeout)
+            resp.raise_for_status()
             return resp
-        resp = self.session.get(url, timeout=self.timeout)
-        resp.raise_for_status()
-        return resp
+        except Exception as exc:
+            if not _cowin_tls_fallback_enabled() or not _is_tls_certificate_error(exc):
+                raise
+            logger.warning(
+                "CoWIN TLS verification failed; retrying unverified HTTPS for public station data: {}",
+                exc,
+            )
+            requests.packages.urllib3.disable_warnings()  # type: ignore[attr-defined]
+            resp = requests.get(
+                url,
+                timeout=self.timeout,
+                verify=False,
+                headers={"User-Agent": getattr(self, "user_agent", "PolyWeather/1.0")},
+            )
+            resp.raise_for_status()
+            return resp
+
+    def _cowin_series_payload(self, params: Dict[str, Any]) -> Dict[str, Any]:
+        resp = self._cowin_http_get(COWIN_SERIES_URL + "?" + urlencode(params))
+        return resp.json() if resp.content else {}
+
+    @staticmethod
+    def _cowin_local_day_bounds(now_utc: Optional[datetime] = None) -> tuple[str, datetime, datetime]:
+        utc_now = now_utc or datetime.now(timezone.utc)
+        if utc_now.tzinfo is None:
+            utc_now = utc_now.replace(tzinfo=timezone.utc)
+        else:
+            utc_now = utc_now.astimezone(timezone.utc)
+        hk_tz = timezone(timedelta(seconds=COWIN_HK_UTC_OFFSET_SECONDS))
+        local_now = utc_now.astimezone(hk_tz)
+        local_start = local_now.replace(hour=0, minute=0, second=0, microsecond=0)
+        return local_now.strftime("%Y-%m-%d"), local_start, local_now
 
     def fetch_cowin_obs_current(
         self,
@@ -69,8 +110,9 @@ class CowinSourceMixin:
                 return cached["d"]
 
         try:
-            # Fetch last 10 minutes to get the latest reading
-            now = datetime.now(timezone.utc)
+            # CoWIN series API expects Hong Kong local timestamps.
+            hk_tz = timezone(timedelta(seconds=COWIN_HK_UTC_OFFSET_SECONDS))
+            now = datetime.now(timezone.utc).astimezone(hk_tz)
             end_dt = now.strftime("%Y-%m-%dT%H:%M:%S")
             start_dt = (now - timedelta(minutes=10)).strftime("%Y-%m-%dT%H:%M:%S")
 
@@ -80,10 +122,7 @@ class CowinSourceMixin:
                 "start_dt": start_dt,
                 "end_dt": end_dt,
             }
-            resp = self._cowin_http_get(COWIN_SERIES_URL + "?" + "&".join(
-                f"{k}={v}" for k, v in params.items()
-            ))
-            payload = resp.json() if resp.content else {}
+            payload = self._cowin_series_payload(params)
         except Exception as exc:
             logger.warning("CoWIN obs fetch failed city={} error={}", city_key, exc)
             with self._cowin_obs_cache_lock:
@@ -133,6 +172,74 @@ class CowinSourceMixin:
                            (time.perf_counter() - started) * 1000.0)
         return result
 
+    def fetch_cowin_obs_today_series(
+        self,
+        city: str,
+        use_fahrenheit: bool = False,
+        now_utc: Optional[datetime] = None,
+    ) -> list[Dict[str, Any]]:
+        started = time.perf_counter()
+        city_key = str(city or "").strip().lower()
+        if city_key != "hong kong":
+            return []
+
+        local_date_str, start_local, end_local = self._cowin_local_day_bounds(now_utc)
+        cache_key = f"cowin_obs_today:{city_key}:{use_fahrenheit}:{local_date_str}"
+        now_ts = time.time()
+        with self._cowin_obs_cache_lock:
+            cached = self._cowin_obs_cache.get(cache_key)
+            if cached and now_ts - cached["t"] < self.cowin_obs_cache_ttl_sec:
+                record_source_call("cowin_obs", "today_series", "cache_hit",
+                                   (time.perf_counter() - started) * 1000.0)
+                return cached["d"]
+
+        try:
+            payload = self._cowin_series_payload(
+                {
+                    "station_id": COWIN_STATION_ID,
+                    "element_id": "temp",
+                    "start_dt": start_local.strftime("%Y-%m-%dT%H:%M:%S"),
+                    "end_dt": end_local.strftime("%Y-%m-%dT%H:%M:%S"),
+                }
+            )
+        except Exception as exc:
+            logger.warning("CoWIN today series fetch failed city={} error={}", city_key, exc)
+            record_source_call("cowin_obs", "today_series", "error",
+                               (time.perf_counter() - started) * 1000.0)
+            return []
+
+        minutely = payload.get("minutely") if isinstance(payload, dict) else None
+        if not isinstance(minutely, list) or not minutely:
+            record_source_call("cowin_obs", "today_series", "no_data",
+                               (time.perf_counter() - started) * 1000.0)
+            return []
+
+        hk_tz = timezone(timedelta(seconds=COWIN_HK_UTC_OFFSET_SECONDS))
+        points_by_time: Dict[str, Dict[str, Any]] = {}
+        for row in minutely:
+            if not isinstance(row, dict):
+                continue
+            obs_iso = _cowin_obs_time_to_iso(row.get("obstime"))
+            if not obs_iso:
+                continue
+            try:
+                obs_dt = datetime.fromisoformat(obs_iso.replace("Z", "+00:00")).astimezone(hk_tz)
+                temp_c = float(row["value1"])
+            except (KeyError, ValueError, TypeError):
+                continue
+            if obs_dt.strftime("%Y-%m-%d") != local_date_str:
+                continue
+            temp = round(temp_c * 9 / 5 + 32, 1) if use_fahrenheit else round(temp_c, 1)
+            time_label = obs_dt.strftime("%H:%M")
+            points_by_time[time_label] = {"time": time_label, "temp": temp}
+
+        points = sorted(points_by_time.values(), key=lambda item: item["time"])
+        with self._cowin_obs_cache_lock:
+            self._cowin_obs_cache[cache_key] = {"d": points, "t": now_ts}
+        record_source_call("cowin_obs", "today_series", "success",
+                           (time.perf_counter() - started) * 1000.0)
+        return points
+
     def fetch_cowin_obs_official_nearby(
         self,
         city: str,

src/data_collection/weather_sources.py

@@ -1266,6 +1266,11 @@ class WeatherDataCollector(OpenMeteoCacheMixin, SettlementSourceMixin, MetarSour
             return
         results["cowin_obs_nearby"] = rows
         results["cowin_current"] = rows[0]
+        today_obs = self.fetch_cowin_obs_today_series(
+            city_lower, use_fahrenheit=use_fahrenheit
+        )
+        if today_obs:
+            results["cowin_today_obs"] = today_obs
         self._emit_temperature_patch_if_changed(
             city_lower,
             rows[0].get("temp"),

tests/test_country_networks.py

@@ -358,6 +358,49 @@ def test_hong_kong_cowin_primary_uses_station_6087_history(monkeypatch):
     ]
 
 
+def test_hong_kong_cowin_primary_prefers_live_intraday_series(monkeypatch):
+    from src.database import runtime_state
+
+    class FakeOfficialIntradayObservationRepository:
+        def load_points(self, *, source_code, station_code, target_date):
+            return [{"time": "09:00", "temp": 30.0}]
+
+    monkeypatch.setattr(
+        runtime_state,
+        "OfficialIntradayObservationRepository",
+        FakeOfficialIntradayObservationRepository,
+    )
+
+    snapshot = build_country_network_snapshot(
+        "hong kong",
+        {
+            "cowin_current": {
+                "temp": 31.3,
+                "obs_time": "2026-05-27T02:41:00Z",
+                "istNo": "6087",
+                "icao": "COWIN6087",
+                "station_label": "保良局陳守仁小學 1min (CoWIN)",
+            },
+            "cowin_today_obs": [
+                {"time": "10:40", "temp": 31.1},
+                {"time": "10:41", "temp": 31.3},
+            ],
+            "settlement_current": {
+                "station_code": "HKO",
+                "station_name": "HK Observatory",
+                "observation_time": "2026-05-27T10:40:00+08:00",
+                "current": {"temp": 31.2},
+            },
+        },
+    )
+
+    assert snapshot["airport_primary_current"]["source_code"] == "cowin_obs"
+    assert snapshot["airport_primary_today_obs"] == [
+        {"time": "10:40", "temp": 31.1},
+        {"time": "10:41", "temp": 31.3},
+    ]
+
+
 def test_moscow_provider_uses_realtime_metar_cluster_not_station_archive_rows():
     raw = {
         "metar": {

tests/test_cowin_sources.py

@@ -0,0 +1,87 @@
+import threading
+from datetime import datetime, timezone
+
+import httpx
+
+from src.data_collection import cowin_sources
+from src.data_collection.cowin_sources import CowinSourceMixin
+
+
+class _FakeResponse:
+    content = b"{}"
+
+    def __init__(self, payload):
+        self._payload = payload
+        self.text = "{}"
+
+    def json(self):
+        return self._payload
+
+    def raise_for_status(self):
+        return None
+
+
+class _FakeCowinCollector(CowinSourceMixin):
+    timeout = 2
+    cowin_obs_cache_ttl_sec = 0
+    _cowin_obs_cache = {}
+    _cowin_obs_cache_lock = threading.Lock()
+    user_agent = "test"
+
+    def _http_get(self, url):
+        raise httpx.ConnectError("[SSL: CERTIFICATE_VERIFY_FAILED] unable to get local issuer certificate")
+
+
+def test_cowin_current_retries_without_tls_verification_when_chain_is_incomplete(monkeypatch):
+    calls = []
+
+    def fake_get(url, **kwargs):
+        calls.append({"url": url, **kwargs})
+        return _FakeResponse(
+            {
+                "station": 6087,
+                "minutely": [
+                    {"obstime": "2026-05-28T07:59:00", "value1": 30.1},
+                    {"obstime": "2026-05-28T08:00:00", "value1": 30.0},
+                ],
+            }
+        )
+
+    monkeypatch.setattr(cowin_sources.requests, "get", fake_get)
+
+    current = _FakeCowinCollector().fetch_cowin_obs_current("hong kong")
+
+    assert current is not None
+    assert current["station_code"] == "6087"
+    assert current["current"]["temp"] == 30.0
+    assert current["obs_time"] == "2026-05-28T08:00:00+08:00"
+    assert calls
+    assert calls[0]["verify"] is False
+
+
+def test_cowin_today_series_returns_hong_kong_local_intraday_points(monkeypatch):
+    def fake_get(url, **kwargs):
+        return _FakeResponse(
+            {
+                "station": 6087,
+                "minutely": [
+                    {"obstime": "2026-05-27T23:59:00", "value1": 29.8},
+                    {"obstime": "2026-05-28T00:00:00", "value1": 29.9},
+                    {"obstime": "2026-05-28T07:58:00", "value1": 30.1},
+                    {"obstime": "2026-05-28T08:00:00", "value1": 30.0},
+                ],
+            }
+        )
+
+    monkeypatch.setattr(cowin_sources.requests, "get", fake_get)
+
+    points = _FakeCowinCollector().fetch_cowin_obs_today_series(
+        "hong kong",
+        now_utc=datetime(2026, 5, 28, 0, 5, tzinfo=timezone.utc),
+    )
+
+    assert points == [
+        {"time": "00:00", "temp": 29.9},
+        {"time": "07:58", "temp": 30.1},
+        {"time": "08:00", "temp": 30.0},
+    ]

tests/test_observation_time_sources.py

@@ -21,9 +21,9 @@ def test_aeroweb_obs_time_is_utc_aware():
     )
 
 
-def test_cowin_obs_time_uses_utc_window_when_timezone_is_missing():
-    assert _cowin_obs_time_to_iso("2026-05-27T01:15:00") == "2026-05-27T01:15:00Z"
-    assert _cowin_obs_time_to_iso("2026-05-27T09:15:00+08:00") == "2026-05-27T01:15:00Z"
+def test_cowin_obs_time_keeps_hong_kong_timezone_when_timezone_is_missing():
+    assert _cowin_obs_time_to_iso("2026-05-27T09:15:00") == "2026-05-27T09:15:00+08:00"
+    assert _cowin_obs_time_to_iso("2026-05-27T09:15:00+08:00") == "2026-05-27T09:15:00+08:00"
 
 
 def test_hko_one_minute_obs_time_keeps_hong_kong_timezone():