import os
from langchain_openai import ChatOpenAI
from langchain.tools import tool
from langgraph.checkpoint.memory import MemorySaver
from langgraph import create_agent
from langchain_core.messages import HumanMessage
from rich.console import Console

# LLM setup
llm = ChatOpenAI(
    model="openai/gpt-oss-20b:free",
    base_url="https://openrouter.ai/api/v1",
    api_key=os.getenv("OPENAI_API_KEY"),
    temperature=0.0,
)

# Console for rich output
console = Console()

# Dummy tool example: get_price (weather placeholder)
@tool
def get_price(*, city: str, date: str) -> str:
    """Return a mock weather price for a city and date."""
    return f"Weather in {city} on {date}: sunny 25°C"

# Memory and agent setup
memory = MemorySaver()

agent = create_agent(
    llm=llm,
    tools=[get_price],
    system_prompt="You are a helpful assistant that can call tools.",
    checkpointer=memory,
    interrupt_before=["tools"],
)

# Configuration for a single conversation thread
config = {"configurable": {"thread_id": "conversation-1"}}

# Helper to display tool calls nicely
def display_tool_call(tool_call):
    name = tool_call["name"]
    args = tool_call["args"]
    console.print(f"\n{name}({args})")
    console.print("Агент хочет вызвать утилиту", f"{name}({args})")

# Main interaction loop
def ask_and_run(user_input, config):
    for chunk in agent.stream(user_input, config=config, stream_mode=["messages", "updates"]):
        state = agent.get_state(config)
        chunk_type, chunk_data = chunk
        if chunk_type == "messages":
            # stream token output
            console.print(chunk_data, end="")
        if chunk_type == "updates":
            # tool calls
            for update in chunk_data:
                if update.get("type") == "tool_call":
                    tool_call = update["tool_call"]
                    display_tool_call(tool_call)
        if "__interrupt__" in chunk_data and state.next == ("tools",):
            # pause before tool
            answer = console.input("\nРазрешить? (Y/n): ")
            if answer.lower().strip() in ("", "y", "yes"):
                # resume
                ask_and_run(None, config)
            else:
                console.print("Отменено")
                break

if __name__ == "__main__":
    console.print("Добро пожаловать! Введите 'exit' для выхода.")
    while True:
        user_input = console.input("\nВы: ")
        if user_input.lower() == "exit":
            break
        ask_and_run({"messages": [{"role": "human", "content": user_input}]}, config)
        console.print("\n--- --- ---")