feat: add edit session times functionality with modal for monitoring sessions

backend/routers/projects.py

@@ -20,7 +20,7 @@ import json
 import logging
 import io
 
-from backend.utils.timezone import utc_to_local, format_local_datetime
+from backend.utils.timezone import utc_to_local, format_local_datetime, local_to_utc
 
 from backend.database import get_db
 from fastapi import UploadFile, File
@@ -1800,6 +1800,23 @@ async def delete_session(
 
 VALID_PERIOD_TYPES = {"weekday_day", "weekday_night", "weekend_day", "weekend_night"}
 
+
+def _derive_period_type(dt: datetime) -> str:
+    is_weekend = dt.weekday() >= 5
+    is_night = dt.hour >= 22 or dt.hour < 7
+    if is_weekend:
+        return "weekend_night" if is_night else "weekend_day"
+    return "weekday_night" if is_night else "weekday_day"
+
+
+def _build_session_label(dt: datetime, location_name: str, period_type: str) -> str:
+    day_abbr = dt.strftime("%a")
+    date_str = f"{dt.month}/{dt.day}"
+    period_str = {"weekday_day": "Day", "weekday_night": "Night", "weekend_day": "Day", "weekend_night": "Night"}.get(period_type, "")
+    parts = [p for p in [location_name, f"{day_abbr} {date_str}", period_str] if p]
+    return " — ".join(parts)
+
+
 @router.patch("/{project_id}/sessions/{session_id}")
 async def patch_session(
     project_id: str,
@@ -1807,13 +1824,53 @@ async def patch_session(
     data: dict,
     db: Session = Depends(get_db),
 ):
-    """Update session_label and/or period_type on a monitoring session."""
+    """Update session fields: started_at, stopped_at, session_label, period_type."""
     session = db.query(MonitoringSession).filter_by(id=session_id).first()
     if not session:
         raise HTTPException(status_code=404, detail="Session not found")
     if session.project_id != project_id:
         raise HTTPException(status_code=403, detail="Session does not belong to this project")
 
+    times_changed = False
+
+    if "started_at" in data and data["started_at"]:
+        try:
+            local_dt = datetime.fromisoformat(data["started_at"])
+            session.started_at = local_to_utc(local_dt)
+            times_changed = True
+        except ValueError:
+            raise HTTPException(status_code=400, detail="Invalid started_at datetime format")
+
+    if "stopped_at" in data:
+        if data["stopped_at"]:
+            try:
+                local_dt = datetime.fromisoformat(data["stopped_at"])
+                session.stopped_at = local_to_utc(local_dt)
+                times_changed = True
+            except ValueError:
+                raise HTTPException(status_code=400, detail="Invalid stopped_at datetime format")
+        else:
+            session.stopped_at = None
+            times_changed = True
+
+    if times_changed and session.started_at and session.stopped_at:
+        delta = session.stopped_at - session.started_at
+        session.duration_seconds = max(0, int(delta.total_seconds()))
+    elif times_changed and not session.stopped_at:
+        session.duration_seconds = None
+
+    # Re-derive period_type and session_label from new started_at unless explicitly provided
+    if times_changed and session.started_at and "period_type" not in data:
+        local_start = utc_to_local(session.started_at)
+        session.period_type = _derive_period_type(local_start)
+
+    if times_changed and session.started_at and "session_label" not in data:
+        from backend.models import MonitoringLocation
+        location = db.query(MonitoringLocation).filter_by(id=session.location_id).first()
+        location_name = location.name if location else ""
+        local_start = utc_to_local(session.started_at)
+        session.session_label = _build_session_label(local_start, location_name, session.period_type or "")
+
     if "session_label" in data:
         session.session_label = str(data["session_label"]).strip() or None
     if "period_type" in data: