Reduce fuel for fast-forwarded player flights.

This only has an effect for aircraft for which we have fuel consumption
data, but that's fine.

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/1681

game/ato/flight.py

@@ -1,12 +1,13 @@
 from __future__ import annotations
 
 from datetime import datetime, timedelta
-from typing import Any, Optional, List, TYPE_CHECKING
+from typing import Any, List, Optional, TYPE_CHECKING
+
+from dcs.planes import C_101CC, C_101EB, Su_33
 
 from gen.flights.loadouts import Loadout
-
 from .flightroster import FlightRoster
-from .flightstate import Uninitialized, FlightState
+from .flightstate import FlightState, Uninitialized
 
 if TYPE_CHECKING:
     from game.dcs.aircrafttype import AircraftType
@@ -122,6 +123,18 @@ class Flight:
         self.roster.clear()
         self.squadron.claim_inventory(-self.count)
 
+    def max_takeoff_fuel(self) -> Optional[float]:
+        # Special case so Su 33 and C101 can take off
+        unit_type = self.unit_type.dcs_unit_type
+        if unit_type == Su_33:
+            if self.flight_type.is_air_to_air:
+                return Su_33.fuel_max / 2.2
+            else:
+                return Su_33.fuel_max * 0.8
+        elif unit_type in {C_101EB, C_101CC}:
+            return unit_type.fuel_max * 0.5
+        return None
+
     def __repr__(self) -> str:
         if self.custom_name:
             return f"{self.custom_name} {self.count} x {self.unit_type}"

game/ato/flightstate/flightstate.py

@@ -37,3 +37,9 @@ class FlightState(ABC):
 
     def a2a_commit_region(self) -> Optional[ThreatPoly]:
         return None
+
+    def estimate_fuel(self) -> float:
+        """Returns the estimated remaining fuel **in kilograms**."""
+        if (max_takeoff_fuel := self.flight.max_takeoff_fuel()) is not None:
+            return max_takeoff_fuel
+        return self.flight.unit_type.dcs_unit_type.fuel_max

game/ato/flightstate/inflight.py

@@ -11,7 +11,7 @@ from game.ato.flightstate.flightstate import FlightState
 from game.ato.flightwaypoint import FlightWaypoint
 from game.ato.flightwaypointtype import FlightWaypointType
 from game.ato.starttype import StartType
-from game.utils import Distance, Speed, meters
+from game.utils import Distance, LBS_TO_KG, Speed, meters, pairwise
 from gen.flights.flightplan import LoiterFlightPlan
 
 if TYPE_CHECKING:
@@ -83,6 +83,30 @@ class InFlight(FlightState):
             self.current_waypoint, self.next_waypoint
         )
 
+    def estimate_fuel_at_current_waypoint(self) -> float:
+        initial_fuel = super().estimate_fuel()
+        if self.flight.unit_type.fuel_consumption is None:
+            return initial_fuel
+        initial_fuel -= self.flight.unit_type.fuel_consumption.taxi * LBS_TO_KG
+        waypoints = self.flight.flight_plan.waypoints[: self.waypoint_index + 1]
+        for a, b in pairwise(waypoints[:-1]):
+            consumption = self.flight.flight_plan.fuel_consumption_between_points(a, b)
+            assert consumption is not None
+            initial_fuel -= consumption * LBS_TO_KG
+        return initial_fuel
+
+    def estimate_fuel(self) -> float:
+        initial_fuel = self.estimate_fuel_at_current_waypoint()
+        ppm = self.flight.flight_plan.fuel_rate_to_between_points(
+            self.current_waypoint, self.next_waypoint
+        )
+        if ppm is None:
+            return initial_fuel
+        position = self.estimate_position()
+        distance = meters(self.current_waypoint.position.distance_to_point(position))
+        consumption = distance.nautical_miles * ppm * LBS_TO_KG
+        return initial_fuel - consumption
+
     def next_waypoint_state(self) -> FlightState:
         from game.ato.flightstate.loiter import Loiter
         from game.ato.flightstate.racetrack import RaceTrack

game/ato/flightstate/loiter.py

@@ -29,6 +29,10 @@ class Loiter(InFlight):
     def estimate_speed(self) -> Speed:
         return self.flight.unit_type.preferred_patrol_speed(self.estimate_altitude()[0])
 
+    def estimate_fuel(self) -> float:
+        # TODO: Estimate loiter consumption per minute?
+        return self.estimate_fuel_at_current_waypoint()
+
     def next_waypoint_state(self) -> FlightState:
         # Do not automatically advance to the next waypoint. Just proceed from the
         # current one with the normal flying state.

game/ato/flightstate/racetrack.py

@@ -40,6 +40,10 @@ class RaceTrack(InFlight):
     def estimate_speed(self) -> Speed:
         return self.flight.unit_type.preferred_patrol_speed(self.estimate_altitude()[0])
 
+    def estimate_fuel(self) -> float:
+        # TODO: Estimate loiter consumption per minute?
+        return self.estimate_fuel_at_current_waypoint()
+
     def travel_time_between_waypoints(self) -> timedelta:
         return self.patrol_duration
 

game/ato/flightstate/takeoff.py

@@ -7,6 +7,7 @@ from typing import TYPE_CHECKING
 from .flightstate import FlightState
 from .inflight import InFlight
 from ..starttype import StartType
+from ...utils import LBS_TO_KG
 
 if TYPE_CHECKING:
     from game.ato.flight import Flight
@@ -33,6 +34,12 @@ class Takeoff(FlightState):
     def spawn_type(self) -> StartType:
         return StartType.RUNWAY
 
+    def estimate_fuel(self) -> float:
+        initial_fuel = super().estimate_fuel()
+        if self.flight.unit_type.fuel_consumption is None:
+            return initial_fuel
+        return initial_fuel - self.flight.unit_type.fuel_consumption.taxi * LBS_TO_KG
+
     def should_halt_sim(self, enemy_aircraft_coverage: AircraftEngagementZones) -> bool:
         if (
             self.flight.client_count > 0