Wrap game resource info from the server

Also add function to get the diff archive (for faster updating)

Download function soon, although I can't make sure that the download function will work properly (like pause, resume download etc.)

worthless/installer.py

@@ -7,27 +7,35 @@ from worthless import constants
 from worthless.launcher import Launcher
 
 
+def _read_version_from_game_file(globalgamemanagers: Path):
+    with globalgamemanagers.open("rb") as f:
+        data = f.read().decode("ascii", errors="ignore")
+    result = re.search(r"([1-9]+\.[0-9]+\.[0-9]+)_[\d]+_[\d]+", data)
+    if not result:
+        raise ValueError("Could not find version in game file")
+    return result.group(1)
+
+
 class Installer:
     def _read_version_from_config(self):
-        if self._config_file.exists():
+        if not self._config_file.exists():
             raise FileNotFoundError(f"Config file {self._config_file} not found")
         cfg = ConfigParser()
         cfg.read(str(self._config_file))
-        return cfg.get("miHoYo", "game_version")
+        return cfg.get("General", "game_version")
 
     # https://gitlab.com/KRypt0n_/an-anime-game-launcher/-/blob/main/src/ts/Game.ts#L26
-    def _read_version_from_game_file(self):
-        if self._overseas:
-            globalgamemanagers = self._gamedir.joinpath("./GenshinImpact_Data/globalgamemanagers")
+    def get_game_version(self):
+        if self._config_file.exists():
+            return self._read_version_from_config()
         else:
-            globalgamemanagers = self._gamedir.joinpath("./YuanShen_Data/globalgamemanagers")
-        if globalgamemanagers.exists():
-            with globalgamemanagers.open("rb") as f:
-                data = f.read().decode("ascii")
-            result = re.search(r"([1-9]+\.[0-9]+\.[0-9]+)_[\d]+_[\d]+", data)
-            if not result:
-                raise ValueError("Could not find version in game file")
-            return result.group(1)
+            if self._overseas:
+                globalgamemanagers = self._gamedir.joinpath("./GenshinImpact_Data/globalgamemanagers")
+            else:
+                globalgamemanagers = self._gamedir.joinpath("./YuanShen_Data/globalgamemanagers")
+            if not globalgamemanagers.exists():
+                return
+            return _read_version_from_game_file(globalgamemanagers)
 
     def __init__(self, gamedir: str | Path = Path.cwd(), overseas: bool = True, data_dir: str | Path = None):
         if isinstance(gamedir, str):
@@ -44,9 +52,24 @@ class Installer:
         self._config_file = config_file.resolve()
         self._version = None
         self._overseas = overseas
-        self._launcher = Launcher(self._gamedir, self._overseas)
-        if config_file.exists():
-            self._version = self._read_version_from_config()
-        elif gamedir.joinpath("./GenshinImpact_Data/globalgamemanagers").exists():
-            self._version = self._read_version_from_game_file()
+        self._launcher = Launcher(self._gamedir, overseas=self._overseas)
+        self._version = self.get_game_version()
 
+    async def get_game_diff_archive(self, from_version: str = None):
+        """Gets a diff archive from `from_version` to the latest one
+
+        If from_version is not specified, it will be taken from the game version.
+        """
+        if not from_version:
+            if self._version:
+                from_version = self._version
+            else:
+                from_version = self._version = self.get_game_version()
+        if not from_version:
+            raise ValueError("No game version found")
+        game_resource = await self._launcher.get_resource_info()
+        if not game_resource:
+            raise ValueError("Could not fetch game resource")
+        for v in game_resource.game.diffs:
+            if v.version == from_version:
+                return v