Change squadrons to operate out of a single base.

https://github.com/dcs-liberation/dcs_liberation/issues/1145

Currently this is fixed at the start of the campaign. The squadron
locations are defined by the campaign file.

Follow up work:

* Track aircraft ownership per-squadron rather than per-airbase.
* UI for relocating squadrons.
* Ferry missions for squadrons that are relocating.
* Auto-relocation (probably only for retreat handling).

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/1138

game/campaignloader/defaultsquadronassigner.py

@@ -0,0 +1,142 @@
+from __future__ import annotations
+
+import logging
+from typing import Optional, TYPE_CHECKING
+
+from game.squadrons import Squadron
+from game.squadrons.squadrondef import SquadronDef
+from game.squadrons.squadrondefloader import SquadronDefLoader
+from gen.flights.flight import FlightType
+from .campaignairwingconfig import CampaignAirWingConfig, SquadronConfig
+from .squadrondefgenerator import SquadronDefGenerator
+from ..dcs.aircrafttype import AircraftType
+from ..theater import ControlPoint
+
+if TYPE_CHECKING:
+    from game import Game
+    from game.coalition import Coalition
+
+
+class DefaultSquadronAssigner:
+    def __init__(
+        self, config: CampaignAirWingConfig, game: Game, coalition: Coalition
+    ) -> None:
+        self.config = config
+        self.game = game
+        self.coalition = coalition
+        self.air_wing = coalition.air_wing
+        self.squadron_defs = SquadronDefLoader(game, coalition).load()
+        self.squadron_def_generator = SquadronDefGenerator(self.coalition)
+
+    def claim_squadron_def(self, squadron: SquadronDef) -> None:
+        try:
+            self.squadron_defs[squadron.aircraft].remove(squadron)
+        except ValueError:
+            pass
+
+    def assign(self) -> None:
+        for control_point, squadron_configs in self.config.by_location.items():
+            if not control_point.is_friendly(self.coalition.player):
+                continue
+            for squadron_config in squadron_configs:
+                squadron_def = self.find_squadron_for(squadron_config, control_point)
+                if squadron_def is None:
+                    logging.info(
+                        f"{self.coalition.faction.name} has no aircraft compatible "
+                        f"with {squadron_config.primary} at {control_point}"
+                    )
+                    continue
+
+                self.claim_squadron_def(squadron_def)
+                squadron = Squadron.create_from(
+                    squadron_def, control_point, self.coalition, self.game
+                )
+                squadron.set_auto_assignable_mission_types(
+                    squadron_config.auto_assignable
+                )
+                self.air_wing.add_squadron(squadron)
+
+    def find_squadron_for(
+        self, config: SquadronConfig, control_point: ControlPoint
+    ) -> Optional[SquadronDef]:
+        for preferred_aircraft in config.aircraft:
+            squadron_def = self.find_preferred_squadron(
+                preferred_aircraft, config.primary, control_point
+            )
+            if squadron_def is not None:
+                return squadron_def
+
+        # If we didn't find any of the preferred types we should use any squadron
+        # compatible with the primary task.
+        squadron_def = self.find_squadron_for_task(config.primary, control_point)
+        if squadron_def is not None:
+            return squadron_def
+
+        # If we can't find any squadron matching the requirement, we should
+        # create one.
+        return self.squadron_def_generator.generate_for_task(
+            config.primary, control_point
+        )
+
+    def find_preferred_squadron(
+        self, preferred_aircraft: str, task: FlightType, control_point: ControlPoint
+    ) -> Optional[SquadronDef]:
+        # Attempt to find a squadron with the name in the request.
+        squadron_def = self.find_squadron_by_name(
+            preferred_aircraft, task, control_point
+        )
+        if squadron_def is not None:
+            return squadron_def
+
+        # If the name didn't match a squadron available to this coalition, try to find
+        # an aircraft with the matching name that meets the requirements.
+        try:
+            aircraft = AircraftType.named(preferred_aircraft)
+        except KeyError:
+            # No aircraft with this name.
+            return None
+
+        if aircraft not in self.coalition.faction.aircrafts:
+            return None
+
+        squadron_def = self.find_squadron_for_airframe(aircraft, task, control_point)
+        if squadron_def is not None:
+            return squadron_def
+
+        # No premade squadron available for this aircraft that meets the requirements,
+        # so generate one if possible.
+        return self.squadron_def_generator.generate_for_aircraft(aircraft)
+
+    @staticmethod
+    def squadron_compatible_with(
+        squadron: SquadronDef, task: FlightType, control_point: ControlPoint
+    ) -> bool:
+        return squadron.operates_from(control_point) and task in squadron.mission_types
+
+    def find_squadron_for_airframe(
+        self, aircraft: AircraftType, task: FlightType, control_point: ControlPoint
+    ) -> Optional[SquadronDef]:
+        for squadron in self.squadron_defs[aircraft]:
+            if self.squadron_compatible_with(squadron, task, control_point):
+                return squadron
+        return None
+
+    def find_squadron_by_name(
+        self, name: str, task: FlightType, control_point: ControlPoint
+    ) -> Optional[SquadronDef]:
+        for squadrons in self.squadron_defs.values():
+            for squadron in squadrons:
+                if squadron.name == name and self.squadron_compatible_with(
+                    squadron, task, control_point
+                ):
+                    return squadron
+        return None
+
+    def find_squadron_for_task(
+        self, task: FlightType, control_point: ControlPoint
+    ) -> Optional[SquadronDef]:
+        for squadrons in self.squadron_defs.values():
+            for squadron in squadrons:
+                if self.squadron_compatible_with(squadron, task, control_point):
+                    return squadron
+        return None