Add logic for specification of ground_units in campaign yaml file

Resolves #22

game/campaignloader/campaign.py

@@ -19,6 +19,7 @@ from game.theater.iadsnetwork.iadsnetwork import IadsNetwork
 from game.theater.theaterloader import TheaterLoader
 from game.version import CAMPAIGN_FORMAT_VERSION
 from .campaignairwingconfig import CampaignAirWingConfig
+from .campaigngroundconfig import TgoConfig
 from .mizcampaignloader import MizCampaignLoader
 
 PERF_FRIENDLY = 0
@@ -137,6 +138,13 @@ class Campaign:
             return CampaignAirWingConfig({})
         return CampaignAirWingConfig.from_campaign_data(squadron_data, theater)
 
+    def load_ground_forces_config(self) -> TgoConfig:
+        ground_forces = self.data.get("ground_forces", {})
+        if not ground_forces:
+            logging.warning(f"Campaign {self.name} does not define any squadrons")
+            return TgoConfig({})
+        return TgoConfig.from_campaign_data(ground_forces)
+
     @property
     def is_out_of_date(self) -> bool:
         """Returns True if this campaign is not up to date with the latest format.

game/campaignloader/campaigngroundconfig.py

@@ -0,0 +1,25 @@
+from __future__ import annotations
+
+from collections import defaultdict
+from dataclasses import dataclass
+from typing import Iterator, Optional
+
+from game.armedforces.forcegroup import ForceGroup
+
+
+@dataclass(frozen=True)
+class TgoConfig:
+    by_original_name: dict[str, ForceGroup]
+
+    def __iter__(self) -> Iterator[str]:
+        return self.by_original_name.__iter__()
+
+    def __getitem__(self, name: str) -> Optional[ForceGroup]:
+        return self.by_original_name.get(name)
+
+    @classmethod
+    def from_campaign_data(cls, data: dict[str, str]) -> TgoConfig:
+        by_original_name: dict[str, ForceGroup] = defaultdict()
+        for tgo_name, force_group in data.items():
+            by_original_name[tgo_name] = ForceGroup.from_preset_group(force_group)
+        return TgoConfig(by_original_name)