import uuid

SESSIONS = {}

def create_session(query: str) -> str:
    sid = uuid.uuid4().hex
    SESSIONS[sid] = {
        "original_query": query,
        "round": 0,
        "history_candidates": [],
        "user_feedback": []
    }
    return sid

def get_session(sid: str):
    return SESSIONS.get(sid)

def update_session_add_candidates(sid: str, candidates: list):
    s = SESSIONS[sid]
    s["round"] += 1
    s["history_candidates"].extend(candidates)

def log_user_choice(sid: str, choice: str):
    SESSIONS[sid]["user_feedback"].append(
        {"round": SESSIONS[sid]["round"], "choice": choice}
    )