Fix merge conflict

Author: nabramow

app/backend/src/couchers/i18n/locales/en.json

@@ -73,6 +73,7 @@
     "event_in_past": "The event must be in the future.",
     "event_not_an_organizer": "That user is not an organizer.",
     "event_not_found": "Event not found.",
+    "event_timezone_not_found": "Could not find a timezone for the event location.",
     "event_too_far_in_future": "The event needs to start within the next year.",
     "event_too_long": "Events cannot last longer than 7 days.",
     "event_transfer_permission_denied": "You're not allowed to transfer that event.",
@@ -111,6 +112,7 @@
     "invalid_delivery_method": "Invalid delivery method.",
     "invalid_email": "Invalid email.",
     "invalid_endpoint": "Invalid push notification endpoint.",
+    "invalid_event_start_end_datetime": "Invalid event start or end date and time.",
     "invalid_guide_location": "You need to either supply an address and location or neither for a guide.",
     "invalid_host_request_status": "You can't set the host request status to that.",
     "invalid_public_trip_status": "You can't set the public trip status to that.",
@@ -134,6 +136,7 @@
     "missing_discussion_content": "Missing discussion content.",
     "missing_discussion_title": "Missing discussion title.",
     "missing_event_address_or_location": "Missing event address or location.",
+    "missing_event_start_end_datetime": "Missing event start or end date and time.",
     "missing_event_content": "Missing event content.",
     "missing_event_title": "Missing event title.",
     "missing_page_address": "Missing page address.",

app/backend/src/couchers/migrations/versions/0172_add_event_timezone_column.py

@@ -0,0 +1,47 @@
+"""Add event timezone column
+
+Revision ID: 0172
+Revises: 0171
+Create Date: 2026-07-02 13:47:21.368662
+
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "0172"
+down_revision = "0171"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column("event_occurrences", sa.Column("timezone", sa.String(), nullable=True))
+
+    op.execute(
+        """
+        UPDATE event_occurrences
+        SET timezone = (
+            SELECT tzid
+            FROM timezone_areas
+            WHERE ST_Contains(timezone_areas.geom, event_occurrences.geom)
+            LIMIT 1
+        )
+        WHERE event_occurrences.geom IS NOT NULL
+        """
+    )
+
+    op.execute(
+        """
+        UPDATE event_occurrences
+        SET timezone = 'Etc/UTC'
+        WHERE timezone IS NULL
+        """
+    )
+
+    op.alter_column("event_occurrences", "timezone", nullable=False)
+
+
+def downgrade() -> None:
+    op.drop_column("event_occurrences", "timezone")

app/backend/src/couchers/models/events.py

@@ -134,7 +134,8 @@ class EventOccurrence(Base, kw_only=True):
     # The physical address string. Legacy online events have been migrated to put the link in here.
     address: Mapped[str] = mapped_column(String)
 
-    timezone = "Etc/UTC"
+    # IANA timezone identifier of the event
+    timezone: Mapped[str] = mapped_column(String)
 
     # time during which the event takes place; this is a range type (instead of separate start+end times) which
     # simplifies database constraints, etc

app/backend/src/couchers/servicers/events.py

@@ -1,11 +1,13 @@
 import logging
 from datetime import datetime, timedelta
 from typing import Any, cast
+from zoneinfo import ZoneInfo
 
 import grpc
+from geoalchemy2 import WKBElement
 from google.protobuf import empty_pb2
 from psycopg.types.range import TimestamptzRange
-from sqlalchemy import Select, select
+from sqlalchemy import Select, func, select
 from sqlalchemy.orm import Session
 from sqlalchemy.sql import and_, func, or_, update
 
@@ -32,6 +34,7 @@
     User,
 )
 from couchers.models.notifications import NotificationTopicAction
+from couchers.models.static import TimezoneArea
 from couchers.moderation.utils import create_moderation
 from couchers.notifications.notify import notify
 from couchers.proto import events_pb2, events_pb2_grpc, notification_data_pb2
@@ -44,11 +47,11 @@
 from couchers.utils import (
     Timestamp_from_datetime,
     create_coordinate,
+    datetime_to_iso8601_local,
     dt_from_millis,
     millis_from_dt,
     not_none,
     now,
-    to_aware_datetime,
 )
 
 logger = logging.getLogger(__name__)
@@ -220,6 +223,60 @@ def _get_event_and_occurrence_one_or_none(
     return result._tuple() if result else None
 
 
+def _check_location(location: events_pb2.EventLocation | None, context: CouchersContext) -> tuple[WKBElement, str]:
+    # As protobuf parses a missing value as 0.0, this is not a permitted event coordinate value
+    if not location or not location.address:
+        context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "missing_event_address_or_location")
+    if location.lat == 0 and location.lng == 0:
+        # No events allowed on Null Island
+        context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "invalid_coordinate")
+
+    geom = create_coordinate(location.lat, location.lng)
+    return (geom, location.address)
+
+
+def _check_timezone_at(geom: WKBElement, context: CouchersContext, session: Session) -> ZoneInfo:
+    timezone_id = session.execute(
+        select(TimezoneArea.tzid).where(func.ST_Contains(TimezoneArea.geom, func.ST_PointOnSurface(geom))).limit(1)
+    ).scalar_one_or_none()
+    if not timezone_id:
+        context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "event_timezone_not_found")
+
+    return ZoneInfo(timezone_id)
+
+
+def _check_iso8601_local_datetime(value: str, timezone: ZoneInfo, context: CouchersContext) -> datetime:
+    if not value:
+        context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "missing_event_start_end_datetime")
+
+    try:
+        naive_datetime = datetime.fromisoformat(value)
+    except ValueError:
+        context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "invalid_event_start_end_datetime")
+
+    if naive_datetime.tzinfo is not None:
+        # Expected a local datetime, otherwise we have two sources of timezones.
+        context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "invalid_event_start_end_datetime")
+
+    return naive_datetime.replace(tzinfo=timezone).replace(second=0, microsecond=0)
+
+
+def _update_datetime(
+    new_iso8601_local: str | None,
+    new_timezone: ZoneInfo,
+    old_datetime: datetime,
+    old_timezone: ZoneInfo,
+    context: CouchersContext,
+) -> datetime:
+    if new_iso8601_local is None and new_timezone != old_timezone:
+        # Local time wasn't updated, but the timezone changed so the effective datetime/timestamp may have changed.
+        new_iso8601_local = datetime_to_iso8601_local(old_datetime.astimezone(old_timezone))
+    if new_iso8601_local is None:
+        return old_datetime  # No change
+    # New effective datetime/timestamp
+    return _check_iso8601_local_datetime(new_iso8601_local, new_timezone, context)
+
+
 def _check_occurrence_time_validity(start_time: datetime, end_time: datetime, context: CouchersContext) -> None:
     if start_time < now():
         context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "event_in_past")
@@ -394,20 +451,11 @@ def CreateEvent(
         if not request.content:
             context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "missing_event_content")
 
-        # As protobuf parses a missing value as 0.0, this is not a permitted event coordinate value
-        if not (
-            request.HasField("location") and request.location.address and request.location.lat and request.location.lng
-        ):
-            context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "missing_event_address_or_location")
-        if request.location.lat == 0 and request.location.lng == 0:
-            context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "invalid_coordinate")
-        geom = create_coordinate(request.location.lat, request.location.lng)
-        address = request.location.address
-
-        start_time = to_aware_datetime(request.start_time)
-        end_time = to_aware_datetime(request.end_time)
-
-        _check_occurrence_time_validity(start_time, end_time, context)
+        geom, address = _check_location(request.location if request.HasField("location") else None, context)
+        timezone = _check_timezone_at(geom, context, session)
+        start_datetime = _check_iso8601_local_datetime(request.start_datetime_iso8601_local, timezone, context)
+        end_datetime = _check_iso8601_local_datetime(request.end_datetime_iso8601_local, timezone, context)
+        _check_occurrence_time_validity(start_datetime, end_datetime, context)
 
         if request.parent_community_id:
             parent_node = session.execute(
@@ -452,9 +500,9 @@ def create_occurrence(moderation_state_id: int) -> int:
                 content=request.content,
                 geom=geom,
                 address=address,
+                timezone=timezone.key,
                 photo_key=request.photo_key if request.photo_key != "" else None,
-                # timezone=timezone,
-                during=TimestamptzRange(start_time, end_time),
+                during=TimestamptzRange(start_datetime, end_datetime),
                 creator_user_id=context.user_id,
                 moderation_state_id=moderation_state_id,
             )
@@ -525,19 +573,12 @@ def ScheduleEvent(
     ) -> events_pb2.Event:
         if not request.content:
             context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "missing_event_content")
-        if not (
-            request.HasField("location") and request.location.address and request.location.lat and request.location.lng
-        ):
-            context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "missing_event_address_or_location")
-        if request.location.lat == 0 and request.location.lng == 0:
-            context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "invalid_coordinate")
-        geom = create_coordinate(request.location.lat, request.location.lng)
-        address = request.location.address
-
-        start_time = to_aware_datetime(request.start_time)
-        end_time = to_aware_datetime(request.end_time)
 
-        _check_occurrence_time_validity(start_time, end_time, context)
+        geom, address = _check_location(request.location if request.HasField("location") else None, context)
+        timezone = _check_timezone_at(geom, context, session)
+        start_datetime = _check_iso8601_local_datetime(request.start_datetime_iso8601_local, timezone, context)
+        end_datetime = _check_iso8601_local_datetime(request.end_datetime_iso8601_local, timezone, context)
+        _check_occurrence_time_validity(start_datetime, end_datetime, context)
 
         res = _get_event_and_occurrence_one_or_none(session, occurrence_id=request.event_id, context=context)
         if not res:
@@ -557,7 +598,7 @@ def ScheduleEvent(
         ):
             context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "photo_not_found")
 
-        during = TimestamptzRange(start_time, end_time)
+        during = TimestamptzRange(start_datetime, end_datetime)
 
         # && is the overlap operator for ranges
         if (
@@ -582,8 +623,8 @@ def create_occurrence(moderation_state_id: int) -> int:
                 content=request.content,
                 geom=geom,
                 address=address,
+                timezone=timezone.key,
                 photo_key=request.photo_key if request.photo_key != "" else None,
-                # timezone=timezone,
                 during=during,
                 creator_user_id=context.user_id,
                 moderation_state_id=moderation_state_id,
@@ -647,30 +688,45 @@ def UpdateEvent(
         if request.HasField("photo_key"):
             occurrence_update["photo_key"] = request.photo_key.value
 
+        old_timezone = ZoneInfo(occurrence.timezone)
+        timezone: ZoneInfo = old_timezone
         if request.HasField("location"):
             notify_updated.append(notification_data_pb2.EventUpdateItem.EVENT_UPDATE_ITEM_LOCATION)
-            if request.location.lat == 0 and request.location.lng == 0:
-                context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "invalid_coordinate")
-            occurrence_update["geom"] = create_coordinate(request.location.lat, request.location.lng)
-            occurrence_update["address"] = request.location.address
-
-        if request.HasField("start_time") or request.HasField("end_time"):
-            if request.update_all_future:
-                context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "event_cant_update_all_times")
-            if request.HasField("start_time"):
-                notify_updated.append(notification_data_pb2.EventUpdateItem.EVENT_UPDATE_ITEM_START_TIME)
-                start_time = to_aware_datetime(request.start_time)
-            else:
-                start_time = occurrence.start_time
-            if request.HasField("end_time"):
-                notify_updated.append(notification_data_pb2.EventUpdateItem.EVENT_UPDATE_ITEM_END_TIME)
-                end_time = to_aware_datetime(request.end_time)
-            else:
-                end_time = occurrence.end_time
+            geom, address = _check_location(request.location, context)
+            timezone = _check_timezone_at(geom, context, session)
+            occurrence_update["geom"] = geom
+            occurrence_update["address"] = address
+            occurrence_update["timezone"] = timezone.key
+
+        if timezone != old_timezone and request.update_all_future:
+            # Not implemented: We'd need to change and recheck the datetimes on all existing occurrences
+            context.abort_with_error_code(grpc.StatusCode.INVALID_ARGUMENT, "event_cant_update_all_times")
+
+        # Determine the new start/end datetimes, which may have changed explicitly or because of a timezone change
+        start_datetime = _update_datetime(
+            request.start_datetime_iso8601_local.value if request.HasField("start_datetime_iso8601_local") else None,
+            timezone,
+            old_datetime=occurrence.start_time,
+            old_timezone=old_timezone,
+            context=context,
+        )
+        if start_datetime != occurrence.start_time:
+            notify_updated.append(notification_data_pb2.EventUpdateItem.EVENT_UPDATE_ITEM_START_TIME)
+
+        end_datetime = _update_datetime(
+            request.end_datetime_iso8601_local.value if request.HasField("end_datetime_iso8601_local") else None,
+            timezone,
+            old_datetime=occurrence.end_time,
+            old_timezone=old_timezone,
+            context=context,
+        )
+        if end_datetime != occurrence.end_time:
+            notify_updated.append(notification_data_pb2.EventUpdateItem.EVENT_UPDATE_ITEM_END_TIME)
 
-            _check_occurrence_time_validity(start_time, end_time, context)
+        if start_datetime != occurrence.start_time or end_datetime != occurrence.end_time:
+            _check_occurrence_time_validity(start_datetime, end_datetime, context)
 
-            during = TimestamptzRange(start_time, end_time)
+            during = TimestamptzRange(start_datetime, end_datetime)
 
             # && is the overlap operator for ranges
             if (
@@ -689,10 +745,6 @@ def UpdateEvent(
 
             occurrence_update["during"] = during
 
-        # TODO
-        # if request.HasField("timezone"):
-        #     occurrence_update["timezone"] = request.timezone
-
         # allow editing any event which hasn't ended more than 24 hours before now
         # when editing all future events, we edit all which have not yet ended
 

app/backend/src/couchers/utils.py

@@ -130,6 +130,14 @@ def to_timezone(value: Timestamp | datetime, timezone: tzinfo) -> datetime:
     return value.astimezone(timezone)
 
 
+def datetime_to_iso8601_local(value: datetime) -> str:
+    """
+    Gets a local ISO 8601 representation of a datetime, without timezone information.
+    This loses information and requires parsers to assume a timezone, so use with care.
+    """
+    return value.replace(tzinfo=None).isoformat()
+
+
 def now() -> datetime:
     return datetime.now(tz=UTC)
 

app/backend/src/tests/test_admin.py

@@ -38,7 +38,7 @@
     reporting_pb2,
     requests_pb2,
 )
-from couchers.utils import Timestamp_from_datetime, now, parse_date
+from couchers.utils import Timestamp_from_datetime, datetime_to_iso8601_local, now, parse_date
 from tests.fixtures.db import add_users_to_new_moderation_list, generate_user, make_friends
 from tests.fixtures.misc import EmailCollector, PushCollector
 from tests.fixtures.sessions import (
@@ -760,9 +760,8 @@ def test_DeleteEvent(db):
                     lat=0.1,
                     lng=0.2,
                 ),
-                start_time=Timestamp_from_datetime(start_time),
-                end_time=Timestamp_from_datetime(end_time),
-                timezone="UTC",
+                start_datetime_iso8601_local=datetime_to_iso8601_local(start_time),
+                end_datetime_iso8601_local=datetime_to_iso8601_local(end_time),
             )
         )
         event_id = res.event_id

app/backend/src/tests/test_communities.py

@@ -26,7 +26,7 @@
 )
 from couchers.proto import api_pb2, auth_pb2, communities_pb2, discussions_pb2, events_pb2, pages_pb2
 from couchers.tasks import enforce_community_memberships
-from couchers.utils import Timestamp_from_datetime, create_coordinate, create_polygon_lat_lng, now, to_multi
+from couchers.utils import create_coordinate, create_polygon_lat_lng, datetime_to_iso8601_local, now, to_multi
 from tests.fixtures.db import generate_user, get_user_id_and_token
 from tests.fixtures.misc import Moderator
 from tests.fixtures.sessions import (
@@ -215,9 +215,8 @@ def create_event(
                     lat=0.1,
                     lng=0.2,
                 ),
-                start_time=Timestamp_from_datetime(now() + start_td),
-                end_time=Timestamp_from_datetime(now() + start_td + timedelta(hours=2)),
-                timezone="UTC",
+                start_datetime_iso8601_local=datetime_to_iso8601_local(now() + start_td),
+                end_datetime_iso8601_local=datetime_to_iso8601_local(now() + start_td + timedelta(hours=2)),
             )
         )
         api.TransferEvent(