Fixes an unlikely bug with JTAC laser code allocation (#1477)

* Fixes an unlikely bug with JTAC laser code allocation, allows for future allocation of codes to a/c with TGPs

* Fixing typing issues

* Changelog

changelog.md

@@ -49,6 +49,7 @@ Saves from 4.0.0 are compatible with 4.1.0.
 * **[Mission Generation]** Prevent the creation of a transfer order with 0 units for a rare situtation when a point was captured.
 * **[Mission Generation]** Planned transfers which will be impossible after a base capture will no longer prevent the mission result submit.
 * **[Mission Generation]** Fix occasional KeyError preventing mission generation when all units of the same type in a convoy were killed.
+* **[Mission Generation]** Fixed a potential bug with laser code generation where it would generate invalid codes.  
 * **[UI]** Statistics window tick marks are now always integers.
 * **[UI]** Statistics window now shows the correct info for the turn
 * **[UI]** Toggling custom loadout for an aircraft with no preset loadouts no longer breaks the flight.

game/operation/operation.py

@@ -29,6 +29,7 @@ from gen.environmentgen import EnvironmentGenerator
 from gen.forcedoptionsgen import ForcedOptionsGenerator
 from gen.groundobjectsgen import GroundObjectsGenerator
 from gen.kneeboard import KneeboardGenerator
+from gen.lasercoderegistry import LaserCodeRegistry
 from gen.naming import namegen
 from gen.radios import RadioFrequency, RadioRegistry
 from gen.tacan import TacanRegistry
@@ -50,6 +51,7 @@ class Operation:
     groundobjectgen: GroundObjectsGenerator
     radio_registry: RadioRegistry
     tacan_registry: TacanRegistry
+    laser_code_registry: LaserCodeRegistry
     game: Game
     trigger_radius = TRIGGER_RADIUS_MEDIUM
     is_quick = None
@@ -192,6 +194,10 @@ class Operation:
         for frequency in unique_map_frequencies:
             cls.radio_registry.reserve(frequency)
 
+    @classmethod
+    def create_laser_code_registry(cls) -> None:
+        cls.laser_code_registry = LaserCodeRegistry()
+
     @classmethod
     def assign_channels_to_flights(
         cls, flights: List[FlightData], air_support: AirSupport
@@ -282,6 +288,7 @@ class Operation:
         cls.air_support = AirSupport()
         cls.create_unit_map()
         cls.create_radio_registries()
+        cls.create_laser_code_registry()
         # Set mission time and weather conditions.
         EnvironmentGenerator(cls.current_mission, cls.game.conditions).generate()
         cls._generate_ground_units()
@@ -399,6 +406,7 @@ class Operation:
                 cls.unit_map,
                 cls.radio_registry,
                 cls.air_support,
+                cls.laser_code_registry,
             )
             ground_conflict_gen.generate()
 

gen/armor.py

@@ -44,6 +44,7 @@ from .airsupport import AirSupport, JtacInfo
 from .callsigns import callsign_for_support_unit
 from .conflictgen import Conflict
 from .ground_forces.combat_stance import CombatStance
+from .lasercoderegistry import LaserCodeRegistry
 from .naming import namegen
 from .radios import MHz, RadioFrequency, RadioRegistry
 
@@ -81,6 +82,7 @@ class GroundConflictGenerator:
         unit_map: UnitMap,
         radio_registry: RadioRegistry,
         air_support: AirSupport,
+        laser_code_registry: LaserCodeRegistry,
     ) -> None:
         self.mission = mission
         self.conflict = conflict
@@ -92,6 +94,7 @@ class GroundConflictGenerator:
         self.unit_map = unit_map
         self.radio_registry = radio_registry
         self.air_support = air_support
+        self.laser_code_registry = laser_code_registry
 
     def generate(self) -> None:
         position = Conflict.frontline_position(
@@ -140,7 +143,7 @@ class GroundConflictGenerator:
         # Add JTAC
         if self.game.blue.faction.has_jtac:
             n = "JTAC" + str(self.conflict.blue_cp.id) + str(self.conflict.red_cp.id)
-            code = 1688 - len(self.air_support.jtacs)
+            code: int = self.laser_code_registry.get_next_laser_code()
             freq = self.radio_registry.alloc_uhf()
 
             utype = self.game.blue.faction.jtac_unit

gen/lasercoderegistry.py

@@ -0,0 +1,37 @@
+from collections import deque
+from typing import Iterator
+
+
+class OutOfLaserCodesError(RuntimeError):
+    def __init__(self) -> None:
+        super().__init__(
+            f"All JTAC laser codes have been allocated.  No available codes."
+        )
+
+
+class LaserCodeRegistry:
+    def __init__(self) -> None:
+        self.allocated_codes: set[int] = set()
+        self.allocator: Iterator[int] = LaserCodeRegistry.__laser_code_generator()
+
+    def get_next_laser_code(self) -> int:
+        try:
+            while (code := next(self.allocator)) in self.allocated_codes:
+                pass
+            self.allocated_codes.add(code)
+            return code
+        except StopIteration:
+            raise OutOfLaserCodesError
+
+    @staticmethod
+    def __laser_code_generator() -> Iterator[int]:
+        # Valid laser codes are as follows
+        # First digit is always 1
+        # Second digit is 5-7
+        # Third and fourth digits are 1 - 8
+        # We iterate backward (reversed()) so that 1687 follows 1688
+        q = deque(int(oct(code)[2:]) + 11 for code in reversed(range(0o1500, 0o2000)))
+
+        # We start with the default of 1688 and wrap around when we reach the end
+        q.rotate(-q.index(1688))
+        return iter(q)