Estimate TOTs for packages.

We estimate the longest possible time from mission start to TOT for
all flights in a package and use that to set the TOT (plus any delay
used to stagger flights). This both cuts down on loiter time for
shorter flights and ensures that long flights will make it to the
target in time.

This is also used to compute the start time for the AI, so the
explicit delay option is no longer needed.

qt_ui/models.py

@@ -1,7 +1,6 @@
 """Qt data models for game objects."""
 import datetime
-from enum import auto, IntEnum
-from typing import Any, Callable, Dict, Iterator, TypeVar, Optional
+from typing import Any, Callable, Dict, Iterator, Optional, TypeVar
 
 from PySide2.QtCore import (
     QAbstractListModel,
@@ -15,6 +14,7 @@ from game import db
 from game.game import Game
 from gen.ato import AirTaskingOrder, Package
 from gen.flights.flight import Flight
+from gen.flights.traveltime import TotEstimator
 from qt_ui.uiconstants import AIRCRAFT_ICONS
 from theater.missiontarget import MissionTarget
 
@@ -119,15 +119,15 @@ class PackageModel(QAbstractListModel):
             return flight
         return None
 
-    @staticmethod
-    def text_for_flight(flight: Flight) -> str:
+    def text_for_flight(self, flight: Flight) -> str:
         """Returns the text that should be displayed for the flight."""
         task = flight.flight_type.name
         count = flight.count
         name = db.unit_type_name(flight.unit_type)
-        delay = flight.scheduled_in
+        estimator = TotEstimator(self.package)
+        delay = datetime.timedelta(seconds=estimator.mission_start_time(flight))
         origin = flight.from_cp.name
-        return f"[{task}] {count} x {name} from {origin} in {delay} minutes"
+        return f"[{task}] {count} x {name} from {origin} in {delay}"
 
     @staticmethod
     def icon_for_flight(flight: Flight) -> Optional[QIcon]: