Change default music folder (#225)

* Get default music folder via xdg-user-dirs

* Add a test

core/handle.py

@@ -14,7 +14,7 @@ default_conf = { 'spotify-downloader':
                  { 'manual'                 : False,
                    'no-metadata'            : False,
                    'avconv'                 : False,
-                   'folder'                 : os.path.join(sys.path[0], 'Music'),
+                   'folder'                 : internals.get_music_dir(),
                    'overwrite'              : 'prompt',
                    'input-ext'              : '.m4a',
                    'output-ext'             : '.mp3',

core/internals.py

@@ -141,3 +141,27 @@ def get_splits(url):
     else:
         splits = url.split(':')
     return splits
+
+
+# a hacky way to user's localized music directory
+# (thanks @linusg, issue #203)
+def get_music_dir():
+    home = os.path.expanduser('~')
+
+    # On Linux, the localized folder names are the actual ones.
+    # It's a freedesktop standard though.
+    if sys.platform.startswith('linux'):
+        for file_item in ('.config/user-dirs.dirs', 'user-dirs.dirs'):
+            path = os.path.join(home, file_item)
+            if os.path.isfile(path):
+                with open(path, 'r') as f:
+                    for line in f:
+                        if line.startswith('XDG_MUSIC_DIR'):
+                            return os.path.expandvars(line.strip().split('=')[1].strip('"'))
+
+    # On both Windows and macOS, the localized folder names you see in
+    # Explorer and Finder are actually in English on the file system.
+    # So, defaulting to C:\Users\<user>\Music or /Users/<user>/Music
+    # respectively is sufficient.
+    # On Linux, default to /home/<user>/Music if the above method failed.
+    return os.path.join(home, 'Music')