from fastapi import APIRouter
from events.replay import ReplayController


router = APIRouter()

# in-memory demo store (later replace with session DB)
REPLAY_SESSIONS = {}


def get_session(journal_id):
    return REPLAY_SESSIONS.get(journal_id)


# -------------------------
# START REPLAY SESSION
# -------------------------
@router.post("/replay/start")
def start_replay(journal):

    session = ReplayController(journal)

    session_id = str(id(session))

    REPLAY_SESSIONS[session_id] = session

    return {
        "session_id": session_id,
        "event_count": len(session.timeline)
    }


# -------------------------
# STEP FORWARD
# -------------------------
@router.post("/replay/step")
def replay_step(session_id: str):

    session = get_session(session_id)

    event = session.step()

    return {
        "event": event,
        "index": session.index
    }


# -------------------------
# SEEK
# -------------------------
@router.post("/replay/seek")
def replay_seek(session_id: str, timestamp: float):

    session = get_session(session_id)

    event = session.seek(timestamp)

    return {
        "event": event,
        "index": session.index
    }


# -------------------------
# RESET
# -------------------------
@router.post("/replay/reset")
def replay_reset(session_id: str):

    session = get_session(session_id)

    event = session.reset()

    return {
        "event": event,
        "index": session.index
    }