Cleanup Lua plugin implementation.

* Move the UI code out of the plugin logic.
* Add types where needed.
* Move into game package.
* Improve error handling.
* Simplify settings behavior.
* Don't load disabled plugins.
* Remove knowledge of non-base plugins from game generation.

Fixes https://github.com/Khopa/dcs_liberation/issues/311

game/plugins/manager.py

@@ -0,0 +1,50 @@
+import json
+import logging
+from pathlib import Path
+from typing import Dict, List, Optional
+
+from game.settings import Settings
+from game.plugins.luaplugin import LuaPlugin
+
+
+class LuaPluginManager:
+    _plugins_loaded = False
+    _plugins: Dict[str, LuaPlugin] = {}
+
+    @classmethod
+    def _load_plugins(cls) -> None:
+        plugins_path = Path("resources/plugins")
+
+        path = plugins_path / "plugins.json"
+        if not path.exists():
+            raise RuntimeError(f"{path} does not exist. Cannot continue.")
+
+        logging.info(f"Reading plugins list from {path}")
+
+        data = json.loads(path.read_text())
+        for name in data:
+            plugin_path = plugins_path / name / "plugin.json"
+            if not plugin_path.exists():
+                raise RuntimeError(
+                    f"Invalid plugin configuration: required plugin {name} "
+                    f"does not exist at {plugin_path}")
+            logging.info(f"Loading plugin {name} from {plugin_path}")
+            plugin = LuaPlugin.from_json(name, plugin_path)
+            if plugin is not None:
+                cls._plugins[name] = plugin
+        cls._plugins_loaded = True
+
+    @classmethod
+    def _get_plugins(cls) -> Dict[str, LuaPlugin]:
+        if not cls._plugins_loaded:
+            cls._load_plugins()
+        return cls._plugins
+
+    @classmethod
+    def plugins(cls) -> List[LuaPlugin]:
+        return list(cls._get_plugins().values())
+
+    @classmethod
+    def load_settings(cls, settings: Settings) -> None:
+        for plugin in cls.plugins():
+            plugin.set_settings(settings)