improve timezone handling, fix lat/lon swapped bug

Author: NickCrews

findmydad/geofences.py

@@ -1,5 +1,6 @@
 import datetime
 import os
+import zoneinfo
 from typing import Literal, TypedDict
 
 import duckdb
@@ -11,6 +12,7 @@ class Geofence(TypedDict):
     schedule_start: datetime.time | None
     schedule_end: datetime.time | None
     description: str
+    timezone: zoneinfo.ZoneInfo
 
 
 class GeofenceManager:
@@ -30,8 +32,34 @@ def refresh_geofences(self):
                 schedule_stop::TIME as schedule_stop,
                 description,
                 ST_GeomFromGeoJSON(geojson) as geometry,
+                timezone::VARCHAR as timezone,
             FROM read_csv('{self.url}')
-            )"""
+            );
+            -- convert a timestamp to a time in the given timezone
+            CREATE OR REPLACE MACRO time_at(timestamp, timezone) AS (
+                strftime((timestamp AT TIME ZONE timezone), '%H:%M:%S')::TIME
+            );
+            CREATE MACRO violations(lat, lon, timestamp) AS TABLE
+                SELECT *, time_at(timestamp, timezone) AS time_at
+                FROM geofences
+                WHERE NOT ST_Contains(geometry, ST_Point(lon, lat))
+                AND (
+                    status = 'on'
+                    OR 
+                    (
+                        status = 'schedule'
+                        AND 
+                        CASE
+                            WHEN schedule_start IS NULL THEN TRUE
+                            WHEN schedule_stop IS NULL THEN TRUE
+                            WHEN schedule_start <= schedule_stop THEN
+                                time_at(timestamp, timezone) >= schedule_start AND time_at(timestamp, timezone) <= schedule_stop
+                            ELSE
+                                time_at(timestamp, timezone) >= schedule_start OR  time_at(timestamp, timezone) <= schedule_stop
+                        END
+                    )
+                );
+            """
         )
 
     def get_geofences(self) -> list[Geofence]:
@@ -43,31 +71,24 @@ def violations(
     ) -> list[Geofence]:
         """if the point is outside any geofence"""
         relation = self.conn.sql(
-            """
-            FROM geofences
-            WHERE NOT ST_Contains(geometry, ST_Point($lat, $lon))
-            AND (
-                status = 'on'
-                OR 
-                (
-                    status = 'schedule'
-                    AND 
-                    CASE
-                        WHEN schedule_start IS NULL THEN TRUE
-                        WHEN schedule_stop IS NULL THEN TRUE
-                        WHEN schedule_start <= schedule_stop THEN
-                            schedule_start <= $localtime AND $localtime <= schedule_stop
-                        ELSE
-                            schedule_start <= $localtime OR $localtime <= schedule_stop
-                    END
-                )
-            )
-            """,
-            params={"lat": lat, "lon": lon, "localtime": timestamp.time()},
+            "FROM violations($lat, $lon, $timestamp)",
+            params={"lat": lat, "lon": lon, "timestamp": timestamp},
         )
         return self._to_dicts(relation)
 
-    def _to_dicts(self, relation: duckdb.DuckDBPyRelation) -> list[Geofence]:
-        cols = ["id", "status", "schedule_start", "schedule_stop", "description"]
-        selection = relation.select(*cols)
-        return [Geofence(zip(cols, row)) for row in selection.fetchall()]
+    @staticmethod
+    def _to_dicts(relation: duckdb.DuckDBPyRelation) -> list[Geofence]:
+        cols = [
+            "id",
+            "status",
+            "schedule_start",
+            "schedule_stop",
+            "description",
+            "timezone",
+        ]
+        extra = [c for c in relation.columns if c not in cols]
+        cols = [*cols, *extra]
+        raw = [dict(zip(cols, row)) for row in relation.select(*cols).fetchall()]
+        for row in raw:
+            row["timezone"] = zoneinfo.ZoneInfo(row["timezone"])
+        return [Geofence(**row) for row in raw]

findmydad/main.py

@@ -45,8 +45,15 @@ def _google_maps_info(lat: float, lon: float) -> str:
 def summarize_violations(violations: list[Violation]) -> str:
     # there could be multiple violations that tie as the latest,
     # but here it doesn't matter which one we pick
-    violation = max(violations, key=lambda x: x["timestamp"])
-    return f"At {violation['timestamp']}, Dad was at {_google_maps_info(violation['lat'], violation['lon'])} "
+    latest_violation = max(violations, key=lambda x: x["timestamp"])
+    geofence_timezone = latest_violation["geofence"]["timezone"]
+    # print the timestamp without the timezone info
+    violation_timestamp_in_localtime = (
+        latest_violation["timestamp"]
+        .astimezone(geofence_timezone)
+        .strftime("%Y-%m-%d %H:%M:%S")
+    )
+    return f"At {violation_timestamp_in_localtime} ({geofence_timezone}), Dad was at {_google_maps_info(latest_violation['lat'], latest_violation['lon'])} "
 
 
 def main():

pyproject.toml

@@ -17,3 +17,7 @@ dev-dependencies = [
     "ruff",
     "dotenv",
 ]
+
+[build-system]
+requires = ["pdm-backend>=1.0.0"]
+build-backend = "pdm.backend"