import cv2
import time
from datetime import datetime
import os
import uuid
from fastapi import APIRouter, HTTPException
from pydantic import BaseModel
from concurrent.futures import ThreadPoolExecutor
from threading import Lock, Timer
from app.core.config import settings

# -------------------- 配置 --------------------

executor = ThreadPoolExecutor(max_workers=4)
lock = Lock()

# 摄像头任务状态
cam_status = {}

router = APIRouter()


class TaskRequest(BaseModel):
    camera_id: str
    task_name: str


# -------------------- 录像函数 --------------------
def record_camera(camera_id: str, task_name: str, output_file: str):
    rtsp_url = settings.CAMERA_CONFIG[camera_id]
    cap = cv2.VideoCapture(rtsp_url)
    cap.set(cv2.CAP_PROP_BUFFERSIZE, 1)  # 减少延迟

    if not cap.isOpened():
        raise RuntimeError(f"无法连接摄像头 {camera_id}")

    frame_width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
    frame_height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
    fps = cap.get(cv2.CAP_PROP_FPS)
    if fps <= 0: fps = 25

    fourcc = cv2.VideoWriter_fourcc(*'mp4v')
    out = cv2.VideoWriter(output_file, fourcc, fps, (frame_width, frame_height))

    print(f"[{camera_id}] 任务 {task_name} 开始录制...")

    try:
        while True:
            ret, frame = cap.read()
            if not ret:
                print(f"[{camera_id}] 丢帧，停止录像")
                break
            out.write(frame)

            # 检查任务是否被标记停止
            with lock:
                status = cam_status.get(camera_id)
                if not status or status.get("stop_flag"):
                    break
            time.sleep(0.001)
    finally:
        cap.release()
        out.release()
        print(f"[{camera_id}] 任务 {task_name} 完成，文件: {output_file}")


def stop_task_internal(camera_id: str):
    with lock:
        status = cam_status.get(camera_id)
        if not status:
            return
        status["stop_flag"] = True
        status["timer"].cancel()


# -------------------- API接口 --------------------
@router.post("/start_task")
def start_task(req: TaskRequest):
    camera_id = req.camera_id
    task_name = req.task_name

    if camera_id not in settings.CAMERA_CONFIG:
        raise HTTPException(status_code=404, detail=f"摄像头 {camera_id} 未配置")

    with lock:
        if camera_id in cam_status:
            return {"status": "running", "task_name": cam_status[camera_id]["task_name"]}

        # 输出文件名
        now_time = datetime.now().strftime("%Y-%m-%d_%H-%M-%S")
        filename = f"{camera_id}_{task_name}_{now_time}.mp4"
        output_file = os.path.join(settings.OUTPUT_DIR, filename)

        # 记录状态
        stop_flag = False
        timer = Timer(settings.MAX_TASK_SECONDS, lambda: stop_task_internal(camera_id))
        timer.start()
        future = executor.submit(record_camera, camera_id, task_name, output_file)
        cam_status[camera_id] = {
            "task_name": task_name,
            "start_time": time.time(),
            "timer": timer,
            "future": future,
            "file": output_file,
            "stop_flag": stop_flag
        }

    return {"status": "started", "file": output_file}


@router.post("/stop_task")
def stop_task(req: TaskRequest):
    camera_id = req.camera_id
    task_name = req.task_name

    with lock:
        status = cam_status.get(camera_id)
        if not status:
            return {"status": "not_running"}

        if status["task_name"] != task_name:
            return {"status": "task_mismatch", "running_task": status["task_name"]}

        # 标记停止
        status["stop_flag"] = True
        status["timer"].cancel()

    return {"status": "stopped", "file": status["file"]}


@router.get("/status/{camera_id}")
def status(camera_id: str):
    with lock:
        status = cam_status.get(camera_id)
        if not status:
            return {"status": "idle"}
        return {
            "status": "running",
            "task_name": status["task_name"],
            "start_time": status["start_time"],
            "file": status["file"]
        }