Dedup purchase requests.

Since the theater commander runs once per campaign action, missions that
do not have aircraft available may be checked more than once a turn.
Without deduping requests this can lead to cases where the AI buys
dozens of tankers on turn 0.

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/1470

game/commander/tasks/compound/protectairspace.py

@@ -9,4 +9,4 @@ class ProtectAirSpace(CompoundTask[TheaterState]):
     def each_valid_method(self, state: TheaterState) -> Iterator[Method[TheaterState]]:
         for cp, needed in state.barcaps_needed.items():
             if needed > 0:
-                yield [PlanBarcap(cp)]
+                yield [PlanBarcap(cp, needed)]

game/commander/tasks/packageplanningtask.py

@@ -74,6 +74,27 @@ class PackagePlanningTask(TheaterCommanderTask, Generic[MissionTargetT]):
     def asap(self) -> bool:
         return False
 
+    @property
+    def purchase_multiplier(self) -> int:
+        """The multiplier for aircraft quantity when missions could not be fulfilled.
+
+        For missions that do not schedule in rounds like BARCAPs do, this should be one
+        to ensure that the we only purchase enough aircraft to plan the mission once.
+
+        For missions that repeat within the same turn, however, we may need to buy for
+        the same mission more than once. If three rounds of BARCAP still need to be
+        fulfilled, this would return 3, and we'd triplicate the purchase order.
+
+        There is a small misbehavior here that's not symptomatic for our current mission
+        planning: multi-round, multi-flight packages will only purchase multiple sets of
+        aircraft for whatever is unavailable for the *first* failed package. For
+        example, if we extend this to CAS and have no CAS aircraft but enough TARCAP
+        aircraft for one round, we'll order CAS for every round but will not order any
+        TARCAP aircraft, since we can't know that TARCAP aircraft are needed until we
+        attempt to plan the second mission *without returning the first round aircraft*.
+        """
+        return 1
+
     def fulfill_mission(self, state: TheaterState) -> bool:
         self.propose_flights()
         fulfiller = PackageFulfiller(
@@ -83,7 +104,9 @@ class PackagePlanningTask(TheaterCommanderTask, Generic[MissionTargetT]):
             state.context.settings,
         )
         self.package = fulfiller.plan_mission(
-            ProposedMission(self.target, self.flights), state.context.tracer
+            ProposedMission(self.target, self.flights),
+            self.purchase_multiplier,
+            state.context.tracer,
         )
         return self.package is not None
 

game/commander/tasks/primitive/barcap.py

@@ -10,6 +10,8 @@ from gen.flights.flight import FlightType
 
 @dataclass
 class PlanBarcap(PackagePlanningTask[ControlPoint]):
+    max_orders: int
+
     def preconditions_met(self, state: TheaterState) -> bool:
         if not state.barcaps_needed[self.target]:
             return False
@@ -20,3 +22,7 @@ class PlanBarcap(PackagePlanningTask[ControlPoint]):
 
     def propose_flights(self) -> None:
         self.propose_flight(FlightType.BARCAP, 2)
+
+    @property
+    def purchase_multiplier(self) -> int:
+        return self.max_orders