[Context] Implement LionContext

Need to append a Text to all bot replies to ask people to !vote
- Implement LionContext
- Implement Callback handler to enable Modules intercept cmdClient.Context.Utils() (attr calls)

bot/LionContext.py

@@ -0,0 +1,48 @@
+import datetime
+
+import discord
+from cmdClient import Context
+from cmdClient.logger import log
+
+reply_callbacks: list = [] # TODO Extend to all cmdClient.Context.Utils to give flexibility to modules
+
+class LionContext(Context):
+    """
+    Subclass to allow easy attachment of custom hooks and structure to contexts.
+    """
+
+    def __init__(self, client, **kwargs):
+        super().__init__(client, **kwargs)
+    
+    @classmethod
+    def util(self, util_func):
+        """
+        Decorator to make a utility function available as a Context instance method
+        """
+        log('added util_function: ' + util_func.__name__)
+
+        def util_fun_wrapper(*args, **kwargs):
+            [args, kwargs] = self.util_pre(util_func, *args, **kwargs)            
+            return util_func(*args, **kwargs)
+
+        util_fun_wrapper.__name__ = util_func.__name__      # Hack
+
+        super().util(util_fun_wrapper)
+
+    @classmethod
+    def util_pre(self, util_func, *args, **kwargs):
+
+        if util_func.__name__ == 'reply':
+            for cb in reply_callbacks:
+                [args, kwargs] = cb(util_func, *args, **kwargs)    # Nesting handlers. Note: args and kwargs are mutable
+                
+        return [args, kwargs]
+
+
+def register_reply_callback(func):
+    reply_callbacks.append(func)
+
+def unregister_reply_callback(func):
+    reply_callbacks.remove(func)
+
+