import asyncio
import threading
import time
from collections import deque
from typing import Any, Callable, Dict, List, Optional, Tuple

import cv2
import numpy as np


class StreamReader:
    def __init__(
        self,
        camera_id: str,
        rtsp_url: str,
        buffer_size: int = 2,
        reconnect_delay: float = 3.0,
        timeout: float = 10.0,
    ):
        self.camera_id = camera_id
        self.rtsp_url = rtsp_url
        self.buffer_size = buffer_size
        self.reconnect_delay = reconnect_delay
        self.timeout = timeout

        self.cap = None
        self.running = False
        self.thread: Optional[threading.Thread] = None
        self.frame_buffer: deque = deque(maxlen=buffer_size)
        self.lock = threading.Lock()
        self.fps = 0.0
        self.last_frame_time = time.time()
        self.frame_count = 0

    def _reader_loop(self):
        while self.running:
            with self.lock:
                if self.cap is None or not self.cap.isOpened():
                    self._connect()
                    if self.cap is None:
                        time.sleep(self.reconnect_delay)
                        continue

            ret = False
            frame = None
            with self.lock:
                if self.cap is not None and self.cap.isOpened():
                    ret, frame = self.cap.read()

            if ret and frame is not None:
                self.frame_buffer.append(frame)
                self.frame_count += 1
                current_time = time.time()

                if current_time - self.last_frame_time >= 1.0:
                    self.fps = self.frame_count / (current_time - self.last_frame_time)
                    self.frame_count = 0
                    self.last_frame_time = current_time
            else:
                time.sleep(0.1)

    def _connect(self):
        if self.cap is not None:
            try:
                self.cap.release()
            except Exception:
                pass
            self.cap = None

        try:
            self.cap = cv2.VideoCapture(self.rtsp_url, cv2.CAP_FFMPEG)
            if self.cap.isOpened():
                self.cap.set(cv2.CAP_PROP_BUFFERSIZE, 1)
                print(f"[{self.camera_id}] RTSP连接成功: {self.rtsp_url[:50]}...")
            else:
                print(f"[{self.camera_id}] 无法打开视频流")
                self.cap = None
        except Exception as e:
            print(f"[{self.camera_id}] 连接失败: {e}")
            self.cap = None

    def start(self):
        if self.running:
            return

        self.running = True
        self.thread = threading.Thread(target=self._reader_loop, daemon=True)
        self.thread.start()

    def stop(self):
        if not self.running:
            return

        self.running = False

        if self.thread is not None:
            self.thread.join(timeout=5.0)
            if self.thread.is_alive():
                print(f"[{self.camera_id}] 警告: 线程未能在5秒内结束")

        with self.lock:
            if self.cap is not None:
                try:
                    self.cap.release()
                except Exception:
                    pass
                self.cap = None

        self.frame_buffer.clear()

    def read(self) -> Tuple[bool, Optional[np.ndarray]]:
        if len(self.frame_buffer) > 0:
            return True, self.frame_buffer.popleft()
        return False, None

    def get_frame(self) -> Optional[np.ndarray]:
        if len(self.frame_buffer) > 0:
            return self.frame_buffer[-1]
        return None

    def is_connected(self) -> bool:
        with self.lock:
            return self.cap is not None and self.cap.isOpened()

    def get_info(self) -> Dict[str, Any]:
        return {
            "camera_id": self.camera_id,
            "running": self.running,
            "connected": self.is_connected(),
            "fps": self.fps,
            "buffer_size": len(self.frame_buffer),
            "buffer_max": self.buffer_size,
        }


class StreamManager:
    def __init__(self, buffer_size: int = 2, reconnect_delay: float = 3.0):
        self.streams: Dict[str, StreamReader] = {}
        self.buffer_size = buffer_size
        self.reconnect_delay = reconnect_delay

    def add_stream(
        self,
        camera_id: str,
        rtsp_url: str,
        buffer_size: Optional[int] = None,
    ) -> StreamReader:
        if camera_id in self.streams:
            self.remove_stream(camera_id)

        stream = StreamReader(
            camera_id=camera_id,
            rtsp_url=rtsp_url,
            buffer_size=buffer_size or self.buffer_size,
            reconnect_delay=self.reconnect_delay,
        )
        stream.start()
        self.streams[camera_id] = stream
        return stream

    def remove_stream(self, camera_id: str):
        if camera_id in self.streams:
            self.streams[camera_id].stop()
            del self.streams[camera_id]

    def get_stream(self, camera_id: str) -> Optional[StreamReader]:
        return self.streams.get(camera_id)

    def read(self, camera_id: str) -> Tuple[bool, Optional[np.ndarray]]:
        stream = self.get_stream(camera_id)
        if stream is None:
            return False, None
        return stream.read()

    def get_frame(self, camera_id: str) -> Optional[np.ndarray]:
        stream = self.get_stream(camera_id)
        if stream is None:
            return None
        return stream.get_frame()

    def stop_all(self):
        for camera_id in list(self.streams.keys()):
            self.remove_stream(camera_id)

    def get_all_info(self) -> List[Dict[str, Any]]:
        return [stream.get_info() for stream in self.streams.values()]

    def __contains__(self, camera_id: str) -> bool:
        return camera_id in self.streams

    def __len__(self) -> int:
        return len(self.streams)