import uuid
from fastapi import FastAPI, HTTPException
import uvicorn

from environment.actions import ContextCorruptionAction, EpisodeObservation
from environment.env import ContextCorruptionEnv

app = FastAPI(title="ContextCorruption-Env")

# session_id -> env instance
_sessions: dict[str, ContextCorruptionEnv] = {}
_MAX_SESSIONS = 64


@app.post("/reset", response_model=EpisodeObservation)
def reset(session_id: str | None = None):
    if session_id is None:
        if len(_sessions) >= _MAX_SESSIONS:
            raise HTTPException(status_code=503, detail="Max concurrent sessions reached")
        session_id = str(uuid.uuid4())
    if session_id not in _sessions:
        _sessions[session_id] = ContextCorruptionEnv()
    obs = _sessions[session_id].reset()
    return obs


@app.post("/step/{session_id}", response_model=EpisodeObservation)
def step(session_id: str, action: ContextCorruptionAction):
    if session_id not in _sessions:
        raise HTTPException(status_code=404, detail="Session not found")
    obs = _sessions[session_id].step(action)
    if obs.episode_done:
        del _sessions[session_id]
    return obs


@app.get("/state/{session_id}")
def state(session_id: str):
    if session_id not in _sessions:
        raise HTTPException(status_code=404, detail="Session not found")
    return _sessions[session_id].state()


@app.delete("/session/{session_id}")
def close_session(session_id: str):
    _sessions.pop(session_id, None)
    return {"status": "closed"}


@app.get("/health")
def health():
    return {"status": "ok", "active_sessions": len(_sessions)}


if __name__ == "__main__":
    uvicorn.run("environment.server:app", host="0.0.0.0", port=8000, reload=False)