Better handling of standard paths (#187)

src/internal.py

@@ -0,0 +1,22 @@
+import os
+
+app_id = "com.jeffser.Alpaca"
+
+in_flatpak = True if os.getenv("FLATPAK_ID") else False
+
+def get_xdg_home(env, default):
+    if in_flatpak:
+        return os.getenv(env)
+    else:
+        base = os.getenv(env) or os.path.expanduser(default)
+        path = os.path.join(base, app_id)
+        if not os.path.exists(path):
+            os.makedirs(path)
+        return path
+
+
+data_dir = get_xdg_home("XDG_DATA_HOME", "~/.local/share")
+config_dir = get_xdg_home("XDG_CONFIG_HOME", "~/.config")
+cache_dir = get_xdg_home("XDG_CACHE_HOME", "~/.cache")
+
+source_dir = os.path.abspath(os.path.dirname(__file__))