import threading
import collections
from enum import Enum, auto
from typing import Callable
from gco import GCO
from vs_types import GroupConfig
from vs_log_macros import VSC_INFO


class State(Enum):
    CREATED = auto()
    LOADED = auto()
    RUNNING = auto()
    STOPPING = auto()
    STOPPED = auto()
    FAILED = auto()

class GCOWrapper:
    def __init__(self, gco_cfg: GroupConfig):
        self.m_cfg = gco_cfg
        self._gco = None
        self._state = State.CREATED
        self._log_queue = collections.deque(maxlen=1000)
        self._log_subscribers = set()
        self._lock = threading.Lock()
        self._push_callback: Callable = lambda t,d,s: None
        
    def set_push_callback(self, callback: Callable):
        self._push_callback = callback
        
    def _log(self, msg: str):
        with self._lock:
            VSC_INFO("-", msg)
            self._log_queue.append(msg)
            for sub in self._log_subscribers:
                try:
                    sub(msg)
                except Exception:
                    pass
        # 原有 push callback
        self._push_callback("LOG", msg.encode(), self._state)
        
    def get_logs(self, last_n=50):
        with self._lock:
            return list(self._log_queue)[-last_n:]

    def subscribe_logs(self, callback: Callable):
        with self._lock:
            self._log_subscribers.add(callback)

    def unsubscribe_logs(self, callback: Callable):
        with self._lock:
            self._log_subscribers.discard(callback)

    def _transition(self, from_state, to_state):
        if self._state != from_state:
            raise Exception(f"invalid transition {self._state} -> {to_state}")
        print(f"[STATE] {self._state.name} -> {to_state.name}")
        self._state = to_state

    def load(self):
        self._transition(State.CREATED, State.LOADED)

    def start(self):
        self._transition(State.LOADED, State.RUNNING)
        try:
            self._gco = GCO(self.m_cfg, logger=self._log)
            self._gco.start()  # 真正的 start 工作
        except Exception:
            self._state = State.FAILED
            raise

    def stop(self):
        self._transition(State.RUNNING, State.STOPPING)
        try:
            self._gco.stop()  # 原逻辑 stop
        finally:
            self._transition(State.STOPPING, State.STOPPED)