From 0d204e2d291365adb1a83bd477b278b3b470f1a4 Mon Sep 17 00:00:00 2001
From: Xingyao Wang <xingyao6@illinois.edu>
Date: Mon, 25 Mar 2024 11:13:17 -0500
Subject: [PATCH] add NullAction to potentially handle for chat scenario

---
 opendevin/action/__init__.py     |  3 ++-
 opendevin/action/base.py         |  9 +++++++++
 opendevin/controller/__init__.py | 10 +++++-----
 opendevin/server/session.py      |  4 ++++
 4 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/opendevin/action/__init__.py b/opendevin/action/__init__.py
index 450187202c0b..814842cac5eb 100644
--- a/opendevin/action/__init__.py
+++ b/opendevin/action/__init__.py
@@ -1,4 +1,4 @@
-from .base import Action
+from .base import Action, NullAction
 from .bash import CmdRunAction, CmdKillAction
 from .browse import BrowseURLAction
 from .fileop import FileReadAction, FileWriteAction
@@ -6,6 +6,7 @@
 
 __all__ = [
     "Action",
+    "NullAction",
     "CmdRunAction",
     "CmdKillAction",
     "BrowseURLAction",
diff --git a/opendevin/action/base.py b/opendevin/action/base.py
index d6dbc7890e04..4932a43f53e8 100644
--- a/opendevin/action/base.py
+++ b/opendevin/action/base.py
@@ -34,3 +34,12 @@ class NotExecutableAction(Action):
     @property
     def executable(self) -> bool:
         return False
+
+class NullAction(NotExecutableAction):
+    """An action that does nothing.
+    This is used when the agent need to receive user follow-up messages from the frontend.
+    """
+
+    @property
+    def message(self) -> str:
+        return "No action"
diff --git a/opendevin/controller/__init__.py b/opendevin/controller/__init__.py
index 28defaedccdf..9f71050f352c 100644
--- a/opendevin/controller/__init__.py
+++ b/opendevin/controller/__init__.py
@@ -5,6 +5,7 @@
 from opendevin.agent import Agent
 from opendevin.action import (
     Action,
+    NullAction,
     FileReadAction,
     FileWriteAction,
     AgentFinishAction,
@@ -18,10 +19,6 @@
 from .command_manager import CommandManager
 
 
-def print_callback(event):
-    print(event, flush=True)
-
-
 class AgentController:
     def __init__(
         self,
@@ -34,8 +31,8 @@ def __init__(
         self.max_iterations = max_iterations
         self.workdir = workdir
         self.command_manager = CommandManager(workdir)
-        self.state_updated_info: List[Tuple[Action, Observation]] = []
         self.callbacks = callbacks
+        self.state_updated_info: List[Tuple[Action, Observation]] = []
 
     def get_current_state(self) -> State:
         # update observations & actions
@@ -46,6 +43,9 @@ def get_current_state(self) -> State:
         self.state_updated_info = []
         return state
 
+    def add_observation(self, observation: Observation):
+        self.state_updated_info.append((NullAction(), observation))
+
     async def start_loop(self, task_instruction: str):
         try:
             self.agent.instruction = task_instruction
diff --git a/opendevin/server/session.py b/opendevin/server/session.py
index b8b54776a768..37c83a492732 100644
--- a/opendevin/server/session.py
+++ b/opendevin/server/session.py
@@ -20,6 +20,7 @@
 )
 from opendevin.observation import (
     Observation,
+    UserMessageObservation
 )
 
 # NOTE: this is a temporary solution - but hopefully we can use Action/Observation throughout the codebase
@@ -95,6 +96,9 @@ async def start_listening(self):
                 else:
                     if self.controller is None:
                         await self.send_error("No agent started. Please wait a second...")
+
+                    elif event["action"] == "chat":
+                        self.controller.add_observation(UserMessageObservation(event["message"]))
                     else:
                         # TODO: we only need to implement user message for now
                         # since even Devin does not support having the user taking other