Split purchase budget based on investment ratio.

The AI purchaser will aim to have a 50/50 ground/air investment mix.
This allows it to overspend on one category if significant losses were
taken the previous turn.

The total purchase amount is still limited, so if the bases are full
when only 10% of the investment is in ground units, the full budget for
the turn will still go to air.

game/procurement.py

@@ -8,14 +8,13 @@ from typing import Iterator, List, Optional, TYPE_CHECKING, Tuple, Type
 from dcs.unittype import FlyingType, VehicleType
 
 from game import db
+from game.data.groundunitclass import GroundUnitClass
 from game.factions.faction import Faction
 from game.theater import ControlPoint, MissionTarget
 from game.utils import Distance
 from gen.flights.ai_flight_planner_db import aircraft_for_task
 from gen.flights.closestairfields import ObjectiveDistanceCache
 from gen.flights.flight import FlightType
-from game.data.groundunitclass import GroundUnitClass
-
 
 if TYPE_CHECKING:
     from game import Game
@@ -46,10 +45,7 @@ class ProcurementAi:
         manage_runways: bool,
         manage_front_line: bool,
         manage_aircraft: bool,
-        front_line_budget_share: float,
     ) -> None:
-        if front_line_budget_share > 1.0:
-            raise ValueError
 
         self.game = game
         self.is_player = for_player
@@ -58,14 +54,34 @@ class ProcurementAi:
         self.manage_runways = manage_runways
         self.manage_front_line = manage_front_line
         self.manage_aircraft = manage_aircraft
-        self.front_line_budget_share = front_line_budget_share
         self.threat_zones = self.game.threat_zone_for(not self.is_player)
 
+    def calculate_ground_unit_budget_share(self) -> float:
+        armor_investment = 0
+        aircraft_investment = 0
+        for cp in self.owned_points:
+            cp_ground_units = cp.allocated_ground_units(self.game.transfers)
+            armor_investment += cp_ground_units.total_value
+            cp_aircraft = cp.allocated_aircraft(self.game)
+            aircraft_investment += cp_aircraft.total_value
+
+        total_investment = aircraft_investment + armor_investment
+        if total_investment == 0:
+            # Turn 0 or all units were destroyed. Either way, split 50/50.
+            return 0.5
+
+        # the more planes we have, the more ground units we want and vice versa
+        ground_unit_share = aircraft_investment / total_investment
+        if ground_unit_share > 1.0:
+            raise ValueError
+
+        return ground_unit_share
+
     def spend_budget(self, budget: float) -> float:
         if self.manage_runways:
             budget = self.repair_runways(budget)
         if self.manage_front_line:
-            armor_budget = math.ceil(budget * self.front_line_budget_share)
+            armor_budget = budget * self.calculate_ground_unit_budget_share()
             budget -= armor_budget
             budget += self.reinforce_front_line(armor_budget)