chat.py

"""
Interactive CLI client for the LocalStack Agent.
Prompts to resume the last session or start a new one, then enters a REPL loop.
"""
import sys
import uuid

import httpx

BASE_URL = "http://localhost:8000"


def get_last_session() -> str | None:
    """Fetch the most recent session ID from the server. Returns None if none exist or server is down."""
    try:
        resp = httpx.get(f"{BASE_URL}/sessions", timeout=5.0)
        sessions = resp.json()
        return sessions[0] if sessions else None
    except httpx.ConnectError:
        return None


def resolve_session() -> str:
    """Prompt user to resume last session or start a new one. Returns the session ID to use."""
    last = get_last_session()
    if last:
        answer = input(f"Resume session {last}? (y/n): ").strip().lower()
        if answer == "y":
            return last
    return str(uuid.uuid4())


def chat(session_id: str, message: str) -> str:
    """Send a message to the agent and return the response text."""
    resp = httpx.post(
        f"{BASE_URL}/chat",
        json={"session_id": session_id, "message": message},
        timeout=180.0,
    )
    resp.raise_for_status()
    return resp.json()["message"]


def main() -> None:
    """Entry point — resolve session, print session ID, run REPL loop."""
    try:
        session_id = resolve_session()
    except httpx.ConnectError:
        print(f"Error: could not connect to {BASE_URL}. Is the server running?")
        sys.exit(1)

    print(f"Session: {session_id}\n")

    while True:
        try:
            user_input = input("You: ").strip()
        except (EOFError, KeyboardInterrupt):
            print()
            break

        if user_input.lower() in ("quit", "exit"):
            break

        if not user_input:
            continue

        try:
            response = chat(session_id, user_input)
            print(f"Agent: {response}\n")
        except httpx.ConnectError:
            print(f"Error: lost connection to {BASE_URL}.")
            break
        except httpx.HTTPStatusError as e:
            print(f"Error: server returned {e.response.status_code}")


if __name__ == "__main__":
    main()