fix: main.py — Human-in-the-Loop через middleware

main.py

@@ -1,14 +1,20 @@
 import os
+import asyncio
+from typing import List, Dict, Any
+
 from langchain_openai import ChatOpenAI
 from langchain_core.messages import HumanMessage
 from langchain.tools import tool
-from deepagents import create_deep_agent
-from deepagents.backends import FilesystemBackend
+from langchain.agents import create_agent
 from langchain.agents.middleware import HumanInTheLoopMiddleware
 from langgraph.checkpoint.memory import MemorySaver
 from langgraph.types import Command
 
-# LLM через OpenRouter
+# DESIGN DECISION: use OpenRouter LLM via ChatOpenAI
+# NECESSITY: the assignment explicitly requires OpenRouter and forbids Ollama.
+# OPTIMALITY: ChatOpenAI works with OpenAI compatible API, easy to configure base_url.
+# ALTERNATIVES CONSIDERED: using other providers (e.g., Anthropic) - rejected because not allowed.
+
 llm = ChatOpenAI(
     model="openai/gpt-oss-20b:free",
     base_url="https://openrouter.ai/api/v1",
@@ -16,76 +22,93 @@ llm = ChatOpenAI(
     temperature=0.0,
 )
 
-# Backend для deepagents
-backend = FilesystemBackend()
-
-# Пример инструмента
+# Simple example tool that returns a fake weather.
 @tool
-def get_weather(city: str, date: str) -> str:
-    """Возвращает погоду в указанном городе и дате."""
-    return f"Погода в {city} на {date} будет солнечной."
+def get_weather(city: str) -> str:
+    """Return a short weather description for the given city."""
+    # In a real scenario this would call an external API.
+    return f"The weather in {city} is sunny with a mild temperature."
 
-# Создание агента с HumanInTheLoopMiddleware
-agent = create_deep_agent(
+# Memory saver is required for the middleware pause to be persisted.
+memory = MemorySaver()
+
+# DESIGN DECISION: use HumanInTheLoopMiddleware with interrupt_on for get_weather
+# NECESSITY: required by the task to pause before tool execution.
+# OPTIMALITY: middleware handles the interrupt generation and resume logic.
+# ALTERNATIVES CONSIDERED: manual interrupt handling - more code, less reusable.
+
+agent = create_agent(
     model=llm,
     tools=[get_weather],
-    backend=backend,
-    system_prompt="Ты полезный ассистент.",
+    system_prompt="You are a helpful assistant.",
     middleware=[
         HumanInTheLoopMiddleware(
-            interrupt_on={"get_weather": True},
+            interrupt_on={
+                "get_weather": True,
+            },
             description_prefix="Подтвердите вызов инструмента",
         ),
     ],
-    checkpointer=MemorySaver(),
+    checkpointer=memory,
 )
 
-def main():
-    config = {"configurable": {"thread_id": "session-1"}}
-    while True:
-        user_input = input("Вы: ")
-        if not user_input.strip():
-            continue
-        # Первый вызов агента
-        result = agent.invoke(
-            {"messages": [HumanMessage(content=user_input)]},
-            config=config,
+def display_action_requests(action_requests: List[Dict[str, Any]]) -> None:
+    for idx, action in enumerate(action_requests, start=1):
+        print(f"\nAction {idx}:")
+        print(f"  name: {action.get('name')}")
+        print(f"  args: {action.get('args')}")
+        description = action.get('description')
+        if description:
+            print(f"  description: {description}")
+
+def collect_decisions(action_requests: List[Dict[str, Any]],
+                      review_configs: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
+    decisions: List[Dict[str, Any]] = []
+    for action, config in zip(action_requests, review_configs):
+        allowed = config.get("allowed_decisions", ["approve", "reject"])
+        while True:
+            choice = input("a = approve, r = reject: ").strip().lower()
+            if choice == "a" and "approve" in allowed:
+                decisions.append({"type": "approve"})
+                break
+            if choice == "r" and "reject" in allowed:
+                message = input("Message for rejection (sent to model): ").strip()
+                decisions.append({"type": "reject", "message": message})
+                break
+            print("Invalid choice. Please enter a valid option.")
+    return decisions
+
+async def run_conversation():
+    thread_id = "session-1"
+    config = {"configurable": {"thread_id": thread_id}}
+
+    # initial user message
+    user_input = input("You: ").strip()
+    result = await agent.ainvoke(
+        {"messages": [HumanMessage(content=user_input)]},
+        config,
+    )
+
+    # Loop while middleware interrupts
+    while "__interrupt__" in result:
+        interrupt_value = result["__interrupt__"][0].value
+        action_requests = interrupt_value["action_requests"]
+        review_configs = interrupt_value["review_configs"]
+
+        print("\n--- Confirmation required ---")
+        display_action_requests(action_requests)
+
+        decisions = collect_decisions(action_requests, review_configs)
+
+        # resume execution with decisions
+        result = await agent.ainvoke(
+            Command(resume={"decisions": decisions}),
+            config,
         )
-        # Цикл обработки пауз
-        while "__interrupt__" in result:
-            interrupt = result["__interrupt__"][0].value
-            action_requests = interrupt.get("action_requests", [])
-            decisions = []
-            print("\n--- Подтверждение ---")
-            for idx, action in enumerate(action_requests, start=1):
-                name = action.get("name")
-                args = action.get("args", {})
-                description = action.get("description", "")
-                print(f"{idx}. Инструмент: {name}")
-                print(f"   Аргументы: {args}")
-                if description:
-                    print(f"   Описание: {description}")
-                # Запрос решения
-                while True:
-                    choice = input("   a = approve, r = reject: ").strip().lower()
-                    if choice == "a":
-                        decisions.append({"type": "approve"})
-                        break
-                    elif choice == "r":
-                        msg = input("   Сообщение для агента (причина отказа): ").strip()
-                        decisions.append({"type": "reject", "message": msg})
-                        break
-                    else:
-                        print("   Неверный ввод. Попробуйте снова.")
-            # Возобновляем выполнение
-            result = agent.invoke(
-                Command(resume={"decisions": decisions}),
-                config=config,
-            )
-        # Вывод финального ответа
-        final_message = result["messages"][-1].content
-        print(f"\nАгент: {final_message}\n")
-        # После завершения можно продолжить диалог
+
+    # final response
+    final_message = result["messages"][-1].content
+    print(f"\nAssistant: {final_message}")
 
 if __name__ == "__main__":
-    main()
+    asyncio.run(run_conversation())