Allow in-line definitions of campaign factions.

A lot of campaigns want to define custom factions. This allows them to
do so without us having to fill the built-in factions list with a bunch
of campaign-specific factions. It also makes custom campaigns more
portable as they don't need to also distribute the custom faction files.

game/campaignloader/campaign.py

@@ -5,22 +5,24 @@ import logging
 from collections.abc import Iterator
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Any, Dict, Tuple
+from typing import Any, Dict, TYPE_CHECKING, Tuple
 
 import yaml
 from packaging.version import Version
 
 from game import persistence
 from game.profiling import logged_duration
-from game.theater import (
-    ConflictTheater,
-)
+from game.theater import ConflictTheater
 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 .factionrecommendation import FactionRecommendation
 from .mizcampaignloader import MizCampaignLoader
 
+if TYPE_CHECKING:
+    from game.factions.factions import Factions
+
 PERF_FRIENDLY = 0
 PERF_MEDIUM = 1
 PERF_HARD = 2
@@ -40,8 +42,8 @@ class Campaign:
     #: selecting a campaign that is not up to date.
     version: Tuple[int, int]
 
-    recommended_player_faction: str
-    recommended_enemy_faction: str
+    recommended_player_faction: FactionRecommendation
+    recommended_enemy_faction: FactionRecommendation
     recommended_start_date: datetime.date | None
     recommended_start_time: datetime.time | None
 
@@ -60,7 +62,6 @@ class Campaign:
         with path.open(encoding="utf-8") as campaign_file:
             data = yaml.safe_load(campaign_file)
 
-        sanitized_theater = data["theater"].replace(" ", "")
         version_field = data.get("version", "0")
         try:
             version = Version(version_field)
@@ -93,8 +94,12 @@ class Campaign:
             data.get("authors", "???"),
             data.get("description", ""),
             (version.major, version.minor),
-            data.get("recommended_player_faction", "USA 2005"),
-            data.get("recommended_enemy_faction", "Russia 1990"),
+            FactionRecommendation.from_field(
+                data.get("recommended_player_faction"), player=True
+            ),
+            FactionRecommendation.from_field(
+                data.get("recommended_enemy_faction"), player=False
+            ),
             start_date,
             start_time,
             data.get("recommended_player_money", DEFAULT_BUDGET),
@@ -163,6 +168,10 @@ class Campaign:
             return False
         return True
 
+    def register_campaign_specific_factions(self, factions: Factions) -> None:
+        self.recommended_player_faction.register_campaign_specific_faction(factions)
+        self.recommended_enemy_faction.register_campaign_specific_faction(factions)
+
     @staticmethod
     def iter_campaigns_in_dir(path: Path) -> Iterator[Path]:
         yield from path.glob("*.yaml")

game/campaignloader/factionrecommendation.py

@@ -0,0 +1,53 @@
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from typing import Any, TYPE_CHECKING
+
+from game.factions import Faction
+
+if TYPE_CHECKING:
+    from game.factions.factions import Factions
+
+
+class FactionRecommendation(ABC):
+    def __init__(self, name: str) -> None:
+        self.name = name
+
+    @abstractmethod
+    def register_campaign_specific_faction(self, factions: Factions) -> None:
+        ...
+
+    @abstractmethod
+    def get_faction(self, factions: Factions) -> Faction:
+        ...
+
+    @staticmethod
+    def from_field(
+        data: str | dict[str, Any] | None, player: bool
+    ) -> FactionRecommendation:
+        if data is None:
+            name = "USA 2005" if player else "Russia 1990"
+            return BuiltinFactionRecommendation(name)
+        if isinstance(data, str):
+            return BuiltinFactionRecommendation(data)
+        return CampaignDefinedFactionRecommendation(Faction.from_dict(data))
+
+
+class BuiltinFactionRecommendation(FactionRecommendation):
+    def register_campaign_specific_faction(self, factions: Factions) -> None:
+        pass
+
+    def get_faction(self, factions: Factions) -> Faction:
+        return factions.get_by_name(self.name)
+
+
+class CampaignDefinedFactionRecommendation(FactionRecommendation):
+    def __init__(self, faction: Faction) -> None:
+        super().__init__(faction.name)
+        self.faction = faction
+
+    def register_campaign_specific_faction(self, factions: Factions) -> None:
+        factions.add_campaign_defined(self.faction)
+
+    def get_faction(self, factions: Factions) -> Faction:
+        return self.faction