From fd49a272ae8c23dbf393e9f975c7945f1ad85e9a Mon Sep 17 00:00:00 2001
From: Richard Chien <richardchienthebest@gmail.com>
Date: Mon, 25 Jun 2018 22:49:15 +0800
Subject: [PATCH] Add CommandGroup class

---
 none/command.py         | 18 ++++++++++++++++++
 none/plugins/weather.py |  9 +++++----
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/none/command.py b/none/command.py
index c433d4df..0227d9cc 100644
--- a/none/command.py
+++ b/none/command.py
@@ -106,6 +106,24 @@ def on_command(name: Union[str, Tuple[str]], *,
     return deco
 
 
+class CommandGroup:
+    __slots__ = ('basename', 'permission')
+
+    def __init__(self, name: Union[str, Tuple[str]], permission: int = None):
+        self.basename = name if isinstance(name, tuple) else (name,)
+        self.permission = permission
+
+    def command(self, name: Union[str, Tuple[str]], *,
+                aliases: Iterable = None, permission: int = None) -> Callable:
+        name = self.basename + (name if isinstance(name, tuple) else (name,))
+        kwargs = {}
+        if aliases is not None:
+            kwargs['aliases'] = aliases
+        if permission is not None:
+            kwargs['permission'] = permission
+        return on_command(name, **kwargs)
+
+
 def _find_command(name: Union[str, Tuple[str]]) -> Optional[Command]:
     cmd_name = name if isinstance(name, tuple) else (name,)
 
diff --git a/none/plugins/weather.py b/none/plugins/weather.py
index bbb71f83..2ca82b62 100644
--- a/none/plugins/weather.py
+++ b/none/plugins/weather.py
@@ -1,9 +1,11 @@
 import none
-from none.command import Session
+from none.command import Session, CommandGroup
 from none.expressions import weather as expr
 
+w = CommandGroup('weather')
 
-@none.on_command(('weather', 'weather'), aliases=('天气', '天气预报'))
+
+@w.command('weather', aliases=('天气', '天气预报'))
 async def weather(session: Session):
     city = session.require_arg('city', prompt_expr=expr.WHICH_CITY)
     await session.send_expr(expr.REPORT, city=city)
@@ -15,7 +17,6 @@ async def _(session: Session):
         session.args[session.current_key] = session.current_arg.strip()
 
 
-@none.on_command(('weather', 'suggestion'),
-                 aliases=('生活指数', '生活建议', '生活提示'))
+@w.command('suggestion', aliases=('生活指数', '生活建议', '生活提示'))
 async def suggestion(session: Session):
     await session.send('suggestion')