import logging
import os
import sys
import threading
import time
from collections import deque
from datetime import datetime, timedelta
from typing import Any, Dict, List, Optional, Tuple

import cv2
import numpy as np
import redis

logger = logging.getLogger(__name__)

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))


class LeavePostAlgorithm:
    STATE_WAITING = "WAITING"
    STATE_ON_DUTY = "ON_DUTY"
    STATE_LEAVING = "LEAVING"
    STATE_OFF_DUTY = "OFF_DUTY"
    STATE_NON_WORK_TIME = "NON_WORK_TIME"

    def __init__(
        self,
        confirm_on_duty_sec: int = 10,
        confirm_leave_sec: int = 10,
        cooldown_sec: int = 300,
        working_hours: Optional[List[Dict]] = None,
        target_class: Optional[str] = "person",
    ):
        self.confirm_on_duty_sec = confirm_on_duty_sec
        self.confirm_leave_sec = confirm_leave_sec
        self.cooldown_sec = cooldown_sec
        self.working_hours = working_hours or []
        self.target_class = target_class

        self.alert_cooldowns: Dict[str, datetime] = {}

        self.state: str = self.STATE_WAITING
        self.state_start_time: Optional[datetime] = None
        self.detection_history: deque = deque()

        self.alarm_sent: bool = False
        self.last_person_time: Optional[datetime] = None

    def _is_in_working_hours(self, dt: Optional[datetime] = None) -> bool:
        if not self.working_hours:
            return True
        
        import json
        
        working_hours = self.working_hours
        if isinstance(working_hours, str):
            try:
                working_hours = json.loads(working_hours)
            except:
                return True
        
        if not working_hours:
            return True
        
        dt = dt or datetime.now()
        current_minutes = dt.hour * 60 + dt.minute
        for period in working_hours:
            start_str = period["start"] if isinstance(period, dict) else period
            end_str = period["end"] if isinstance(period, dict) else period
            start_minutes = self._parse_time_to_minutes(start_str)
            end_minutes = self._parse_time_to_minutes(end_str)
            if start_minutes <= current_minutes < end_minutes:
                return True
        return False
    
    def _parse_time_to_minutes(self, time_str: str) -> int:
        """将时间字符串转换为分钟数"""
        if isinstance(time_str, int):
            return time_str
        try:
            parts = time_str.split(":")
            return int(parts[0]) * 60 + int(parts[1])
        except:
            return 0

    def _check_detection_in_roi(self, detection: Dict, roi_id: str) -> bool:
        matched_rois = detection.get("matched_rois", [])
        for roi in matched_rois:
            if roi.get("roi_id") == roi_id:
                return True
        return False

    def _check_target_class(self, detection: Dict, target_class: Optional[str]) -> bool:
        if not target_class:
            return True
        return detection.get("class") == target_class

    def _get_detection_window(self, current_time: datetime) -> List[bool]:
        detections = []
        while self.detection_history and (current_time - self.detection_history[0][0]).total_seconds() > max(self.confirm_on_duty_sec, self.confirm_leave_sec):
            self.detection_history.popleft()
        for _, has_person in self.detection_history:
            detections.append(has_person)
        return detections

    def _get_latest_bbox(self, tracks: List[Dict], roi_id: str) -> List[float]:
        for det in tracks:
            if self._check_detection_in_roi(det, roi_id):
                return det.get("bbox", [])
        return []

    def process(
        self,
        roi_id: str,
        camera_id: str,
        tracks: List[Dict],
        current_time: Optional[datetime] = None,
    ) -> List[Dict]:
        current_time = current_time or datetime.now()

        in_work = self._is_in_working_hours(current_time)
        alerts = []

        if not in_work:
            self.state = self.STATE_NON_WORK_TIME
            self.detection_history.clear()
            self.alarm_sent = False
            return []

        if self.state == self.STATE_NON_WORK_TIME:
            self.state = self.STATE_WAITING
            self.detection_history.clear()
            self.alarm_sent = False

        roi_has_person = False
        for det in tracks:
            if self._check_detection_in_roi(det, roi_id) and self._check_target_class(det, self.target_class):
                roi_has_person = True
                break

        if self.state == self.STATE_WAITING:
            if roi_has_person:
                self.state = self.STATE_ON_DUTY
                self.state_start_time = current_time
                self.detection_history.clear()
                self.detection_history.append((current_time, True))
            else:
                pass

        elif self.state == self.STATE_ON_DUTY:
            self.detection_history.append((current_time, roi_has_person))
            if not roi_has_person:
                self.state = self.STATE_LEAVING
                self.state_start_time = current_time

        elif self.state == self.STATE_LEAVING:
            self.detection_history.append((current_time, roi_has_person))
            elapsed = (current_time - self.state_start_time).total_seconds()

            if roi_has_person:
                self.state = self.STATE_ON_DUTY
                self.state_start_time = current_time
            elif elapsed >= self.confirm_leave_sec:
                # 确认离岗后直接触发告警，不再进入 OFF_DUTY 二次等待
                self.state = self.STATE_OFF_DUTY
                self.state_start_time = current_time

                cooldown_key = f"{camera_id}_{roi_id}"
                now = datetime.now()
                if cooldown_key not in self.alert_cooldowns or (now - self.alert_cooldowns[cooldown_key]).total_seconds() > self.cooldown_sec:
                    bbox = self._get_latest_bbox(tracks, roi_id)
                    elapsed_minutes = int(elapsed / 60)
                    alerts.append({
                        "track_id": roi_id,
                        "camera_id": camera_id,
                        "bbox": bbox,
                        "duration_minutes": elapsed_minutes,
                        "alert_type": "leave_post",
                        "message": f"离岗 {elapsed_minutes} 分钟",
                    })
                    self.alert_cooldowns[cooldown_key] = now

        elif self.state == self.STATE_OFF_DUTY:
            # OFF_DUTY 状态：等待人员回岗或冷却后可再次告警
            if roi_has_person:
                self.state = self.STATE_ON_DUTY
                self.state_start_time = current_time
            else:
                elapsed = (current_time - self.state_start_time).total_seconds()
                cooldown_key = f"{camera_id}_{roi_id}"
                now = datetime.now()
                if cooldown_key in self.alert_cooldowns and (now - self.alert_cooldowns[cooldown_key]).total_seconds() > self.cooldown_sec:
                    bbox = self._get_latest_bbox(tracks, roi_id)
                    elapsed_minutes = int(elapsed / 60)
                    alerts.append({
                        "track_id": roi_id,
                        "camera_id": camera_id,
                        "bbox": bbox,
                        "duration_minutes": elapsed_minutes,
                        "alert_type": "leave_post",
                        "message": f"持续离岗 {elapsed_minutes} 分钟",
                    })
                    self.alert_cooldowns[cooldown_key] = now

        return alerts

    def reset(self):
        self.state = self.STATE_WAITING
        self.state_start_time = None
        self.detection_history.clear()
        self.alarm_sent = False
        self.last_person_time = None
        self.alert_cooldowns.clear()

    def get_state(self, roi_id: str) -> Dict[str, Any]:
        return {
            "state": self.state,
            "alarm_sent": self.alarm_sent,
            "last_person_time": self.last_person_time,
        }


class IntrusionAlgorithm:
    def __init__(
        self,
        cooldown_seconds: int = 120,
        confirm_seconds: int = 5,
        target_class: Optional[str] = None,
    ):
        self.cooldown_seconds = cooldown_seconds
        self.confirm_seconds = confirm_seconds
        self.target_class = target_class

        self.last_alert_time: Dict[str, datetime] = {}
        self.alert_triggered: Dict[str, bool] = {}
        self.detection_start: Dict[str, Optional[datetime]] = {}

    def _check_detection_in_roi(self, detection: Dict, roi_id: str) -> bool:
        matched_rois = detection.get("matched_rois", [])
        for roi in matched_rois:
            if roi.get("roi_id") == roi_id:
                return True
        return False

    def _check_target_class(self, detection: Dict, target_class: Optional[str]) -> bool:
        if not target_class:
            return True
        return detection.get("class") == target_class

    def _get_latest_bbox(self, tracks: List[Dict], roi_id: str) -> List[float]:
        for det in tracks:
            if self._check_detection_in_roi(det, roi_id):
                return det.get("bbox", [])
        return []

    def process(
        self,
        roi_id: str,
        camera_id: str,
        tracks: List[Dict],
        current_time: Optional[datetime] = None,
    ) -> List[Dict]:
        current_time = current_time or datetime.now()
        key = f"{camera_id}_{roi_id}"

        roi_has_person = False
        for det in tracks:
            if self._check_detection_in_roi(det, roi_id) and self._check_target_class(det, self.target_class):
                roi_has_person = True
                break

        if not roi_has_person:
            self.detection_start.pop(key, None)
            self.alert_triggered[key] = False
            return []

        if self.alert_triggered.get(key, False):
            elapsed_since_alert = (current_time - self.last_alert_time.get(key, datetime.min)).total_seconds()
            if elapsed_since_alert < self.cooldown_seconds:
                return []
            self.alert_triggered[key] = False

        if self.detection_start.get(key) is None:
            self.detection_start[key] = current_time

        elapsed = (current_time - self.detection_start[key]).total_seconds()
        if elapsed < self.confirm_seconds:
            return []

        bbox = self._get_latest_bbox(tracks, roi_id)
        self.last_alert_time[key] = current_time
        self.alert_triggered[key] = True
        self.detection_start[key] = None

        return [{
            "roi_id": roi_id,
            "camera_id": camera_id,
            "bbox": bbox,
            "alert_type": "intrusion",
            "message": "检测到周界入侵",
        }]

    def reset(self):
        self.last_alert_time.clear()
        self.alert_triggered.clear()
        self.detection_start.clear()


class CrowdDetectionAlgorithm:
    """人群聚集检测算法"""

    def __init__(
        self,
        max_count: int = 10,
        cooldown_seconds: int = 300,
        target_class: Optional[str] = "person",
    ):
        self.max_count = max_count
        self.cooldown_seconds = cooldown_seconds
        self.target_class = target_class

        self.last_alert_time: Dict[str, datetime] = {}
        self.alert_triggered: Dict[str, bool] = {}

    def _check_detection_in_roi(self, detection: Dict, roi_id: str) -> bool:
        matched_rois = detection.get("matched_rois", [])
        for roi in matched_rois:
            if roi.get("roi_id") == roi_id:
                return True
        return False

    def _check_target_class(self, detection: Dict, target_class: Optional[str]) -> bool:
        if not target_class:
            return True
        return detection.get("class") == target_class

    def _get_bboxes(self, tracks: List[Dict], roi_id: str) -> List[List[float]]:
        bboxes = []
        for det in tracks:
            if self._check_detection_in_roi(det, roi_id) and self._check_target_class(det, self.target_class):
                bboxes.append(det.get("bbox", []))
        return bboxes

    def process(
        self,
        roi_id: str,
        camera_id: str,
        tracks: List[Dict],
        current_time: Optional[datetime] = None,
    ) -> List[Dict]:
        current_time = current_time or datetime.now()
        key = f"{camera_id}_{roi_id}"

        person_count = 0
        for det in tracks:
            if self._check_detection_in_roi(det, roi_id) and self._check_target_class(det, self.target_class):
                person_count += 1

        if person_count <= self.max_count:
            self.alert_triggered[key] = False
            return []

        if self.alert_triggered.get(key, False):
            elapsed_since_alert = (current_time - self.last_alert_time.get(key, datetime.min)).total_seconds()
            if elapsed_since_alert < self.cooldown_seconds:
                return []
            self.alert_triggered[key] = False

        bboxes = self._get_bboxes(tracks, roi_id)
        self.last_alert_time[key] = current_time
        self.alert_triggered[key] = True

        return [{
            "roi_id": roi_id,
            "camera_id": camera_id,
            "bbox": bboxes[0] if bboxes else [],
            "alert_type": "crowd_detection",
            "message": f"检测到人群聚集，当前人数: {person_count}",
            "count": person_count,
        }]

    def reset(self):
        self.last_alert_time.clear()
        self.alert_triggered.clear()


class AlgorithmManager:
    def __init__(self, working_hours: Optional[List[Dict]] = None):
        self.algorithms: Dict[str, Dict[str, Any]] = {}
        self.working_hours = working_hours or []
        self._update_lock = threading.Lock()
        self._registered_keys: set = set()  # 已注册的 (roi_id, bind_id, algo_type) 缓存

        self.default_params = {
            "leave_post": {
                "confirm_on_duty_sec": 10,
                "confirm_leave_sec": 10,
                "cooldown_sec": 300,
                "target_class": "person",
            },
            "intrusion": {
                "cooldown_seconds": 120,
                "confirm_seconds": 5,
                "target_class": None,
            },
            "crowd_detection": {
                "max_count": 10,
                "cooldown_seconds": 300,
                "target_class": "person",
            },
        }
        
        self._pubsub = None
        self._pubsub_thread = None
        self._running = False
    
    def start_config_subscription(self):
        """启动配置变更订阅"""
        try:
            from config.settings import get_settings
            settings = get_settings()
            redis_client = redis.Redis(
                host=settings.redis.host,
                port=settings.redis.port,
                db=settings.redis.db,
                password=settings.redis.password,
                decode_responses=True,
            )
            
            self._pubsub = redis_client.pubsub()
            self._pubsub.subscribe("config_update")
            
            self._running = True
            self._pubsub_thread = threading.Thread(
                target=self._config_update_worker,
                name="ConfigUpdateSub",
                daemon=True
            )
            self._pubsub_thread.start()
            logger.info("已启动配置变更订阅")
        except Exception as e:
            logger.error(f"启动配置订阅失败: {e}")
    
    def _config_update_worker(self):
        """配置更新订阅工作线程"""
        try:
            for message in self._pubsub.listen():
                if not self._running:
                    break
                if message["type"] == "message":
                    try:
                        import json
                        data = json.loads(message["data"])
                        if data.get("type") == "roi":
                            roi_ids = data.get("ids", [])
                            if roi_ids:
                                for roi_id in roi_ids:
                                    self.reload_algorithm(roi_id)
                            else:
                                self.reload_all_algorithms()
                        elif data.get("type") == "bind":
                            bind_ids = data.get("ids", [])
                            if bind_ids:
                                for bind_id in bind_ids:
                                    self.reload_bind_algorithm(bind_id)
                            else:
                                self.reload_all_algorithms()
                    except Exception as e:
                        logger.error(f"处理配置更新消息失败: {e}")
        except Exception as e:
            logger.error(f"配置订阅线程异常: {e}")
    
    def stop_config_subscription(self):
        """停止配置变更订阅"""
        self._running = False
        if self._pubsub:
            self._pubsub.close()
        if self._pubsub_thread and self._pubsub_thread.is_alive():
            self._pubsub_thread.join(timeout=5)
        logger.info("配置订阅已停止")
    
    def load_bind_from_redis(self, bind_id: str) -> bool:
        """从Redis加载单个绑定配置的算法"""
        try:
            from core.config_sync import get_config_sync_manager
            config_manager = get_config_sync_manager()
            bind_config = config_manager.get_algo_bind_from_redis(bind_id)
            
            if not bind_config:
                return False
            
            with self._update_lock:
                roi_id = bind_config.get("roi_id")
                algo_code = bind_config.get("algo_code", "leave_post")
                params = bind_config.get("params", {})
                
                if roi_id not in self.algorithms:
                    self.algorithms[roi_id] = {}
                
                key = f"{roi_id}_{bind_id}"
                
                if algo_code == "leave_post":
                    algo_params = {
                        "confirm_on_duty_sec": params.get("confirm_on_duty_sec", 10),
                        "confirm_leave_sec": params.get("confirm_leave_sec", 10),
                        "cooldown_sec": params.get("cooldown_sec", 300),
                        "working_hours": params.get("working_hours", []),
                        "target_class": params.get("target_class", bind_config.get("target_class", "person")),
                    }
                    if key in self.algorithms.get(roi_id, {}) and "leave_post" in self.algorithms[roi_id].get(key, {}):
                        algo = self.algorithms[roi_id][key]["leave_post"]
                        algo.confirm_on_duty_sec = algo_params["confirm_on_duty_sec"]
                        algo.confirm_leave_sec = algo_params["confirm_leave_sec"]
                        algo.cooldown_sec = algo_params["cooldown_sec"]
                        algo.target_class = algo_params["target_class"]
                        if algo_params["working_hours"]:
                            algo.working_hours = algo_params["working_hours"]
                        logger.info(f"已热更新算法参数: {key}")
                    else:
                        self.algorithms[roi_id][key] = {}
                        self.algorithms[roi_id][key]["leave_post"] = LeavePostAlgorithm(
                            confirm_on_duty_sec=algo_params["confirm_on_duty_sec"],
                            confirm_leave_sec=algo_params["confirm_leave_sec"],
                            cooldown_sec=algo_params["cooldown_sec"],
                            working_hours=algo_params["working_hours"],
                            target_class=algo_params["target_class"],
                        )
                        logger.info(f"已从Redis加载算法: {key}")
                elif algo_code == "intrusion":
                    algo_params = {
                        "cooldown_seconds": params.get("cooldown_seconds", 120),
                        "confirm_seconds": params.get("confirm_seconds", 5),
                        "target_class": params.get("target_class", bind_config.get("target_class")),
                    }
                    self.algorithms[roi_id][key] = {}
                    self.algorithms[roi_id][key]["intrusion"] = IntrusionAlgorithm(
                        cooldown_seconds=algo_params["cooldown_seconds"],
                        confirm_seconds=algo_params["confirm_seconds"],
                        target_class=algo_params["target_class"],
                    )
                    logger.info(f"已从Redis加载算法: {key}")
            
            return True
        except Exception as e:
            logger.error(f"从Redis加载算法配置失败: {e}")
            return False
    
    def reload_bind_algorithm(self, bind_id: str) -> bool:
        """重新加载单个绑定的算法配置"""
        return self.load_bind_from_redis(bind_id)
    
    def reload_algorithm(self, roi_id: str) -> bool:
        """重新加载单个ROI的所有算法绑定配置"""
        try:
            from core.config_sync import get_config_sync_manager
            config_manager = get_config_sync_manager()
            bindings = config_manager.get_bindings_from_redis(roi_id)
            
            if not bindings:
                return False
            
            for bind in bindings:
                bind_id = bind.get("bind_id")
                self.reset_algorithm(roi_id, bind_id)
                self.load_bind_from_redis(bind_id)
            
            return True
        except Exception as e:
            logger.error(f"重新加载ROI算法配置失败: {e}")
            return False
    
    def reload_all_algorithms(self) -> int:
        """重新加载所有算法配置"""
        count = 0
        try:
            from core.config_sync import get_config_sync_manager
            config_manager = get_config_sync_manager()
            bindings = config_manager.get_bindings_from_redis("")
            
            for bind in bindings:
                bind_id = bind.get("bind_id")
                roi_id = bind.get("roi_id")
                self.reset_algorithm(roi_id, bind_id)
                if self.load_bind_from_redis(bind_id):
                    count += 1
            
            logger.info(f"已重新加载 {count} 个算法配置")
            return count
        except Exception as e:
            logger.error(f"重新加载所有算法配置失败: {e}")
            return count
    
    def register_algorithm(
        self,
        roi_id: str,
        bind_id: str,
        algorithm_type: str,
        params: Optional[Dict[str, Any]] = None,
    ):
        """注册算法（支持绑定ID），使用缓存避免每帧重复查询"""
        cache_key = (roi_id, bind_id, algorithm_type)

        # 快速路径：已注册直接返回
        if cache_key in self._registered_keys:
            return

        key = f"{roi_id}_{bind_id}"
        
        if roi_id not in self.algorithms:
            self.algorithms[roi_id] = {}
        
        if key not in self.algorithms[roi_id]:
            self.algorithms[roi_id][key] = {}
        
        algo_params = self.default_params.get(algorithm_type, {}).copy()
        if params:
            algo_params.update(params)

        if algorithm_type == "leave_post":
            roi_working_hours = algo_params.get("working_hours") or self.working_hours
            self.algorithms[roi_id][key]["leave_post"] = LeavePostAlgorithm(
                confirm_on_duty_sec=algo_params.get("confirm_on_duty_sec", 10),
                confirm_leave_sec=algo_params.get("confirm_leave_sec", 10),
                cooldown_sec=algo_params.get("cooldown_sec", 300),
                working_hours=roi_working_hours,
                target_class=algo_params.get("target_class", "person"),
            )
        elif algorithm_type == "intrusion":
            self.algorithms[roi_id][key]["intrusion"] = IntrusionAlgorithm(
                cooldown_seconds=algo_params.get("cooldown_seconds", 120),
                confirm_seconds=algo_params.get("confirm_seconds", 5),
                target_class=algo_params.get("target_class"),
            )
        elif algorithm_type == "crowd_detection":
            from algorithms import CrowdDetectionAlgorithm
            self.algorithms[roi_id][key]["crowd_detection"] = CrowdDetectionAlgorithm(
                max_count=algo_params.get("max_count", 10),
                cooldown_seconds=algo_params.get("cooldown_seconds", 300),
                target_class=algo_params.get("target_class", "person"),
            )

        self._registered_keys.add(cache_key)
    
    def process(
        self,
        roi_id: str,
        bind_id: str,
        camera_id: str,
        algorithm_type: str,
        tracks: List[Dict],
        current_time: Optional[datetime] = None,
    ) -> List[Dict]:
        """处理检测结果（支持绑定ID）"""
        key = f"{roi_id}_{bind_id}"
        algo = self.algorithms.get(roi_id, {}).get(key, {}).get(algorithm_type)
        if algo is None:
            return []
        return algo.process(roi_id, camera_id, tracks, current_time)

    def update_roi_params(
        self,
        roi_id: str,
        bind_id: str,
        algorithm_type: str,
        params: Dict[str, Any],
    ):
        """更新算法参数（支持绑定ID）"""
        key = f"{roi_id}_{bind_id}"
        if roi_id in self.algorithms and key in self.algorithms[roi_id] and algorithm_type in self.algorithms[roi_id][key]:
            algo = self.algorithms[roi_id][key][algorithm_type]
            for param_key, value in params.items():
                if hasattr(algo, param_key):
                    setattr(algo, param_key, value)
    
    def reset_algorithm(self, roi_id: str, bind_id: Optional[str] = None):
        """重置算法状态（支持绑定ID）"""
        if roi_id not in self.algorithms:
            return

        if bind_id:
            key = f"{roi_id}_{bind_id}"
            if key in self.algorithms[roi_id]:
                for algo in self.algorithms[roi_id][key].values():
                    algo.reset()
                # 清除注册缓存
                self._registered_keys = {
                    k for k in self._registered_keys
                    if not (k[0] == roi_id and k[1] == bind_id)
                }
        else:
            for key in self.algorithms[roi_id]:
                for algo in self.algorithms[roi_id][key].values():
                    algo.reset()
            # 清除该 roi 的所有注册缓存
            self._registered_keys = {
                k for k in self._registered_keys if k[0] != roi_id
            }
    
    def reset_all(self):
        """重置所有算法"""
        for roi_algorithms in self.algorithms.values():
            for bind_algorithms in roi_algorithms.values():
                for algo in bind_algorithms.values():
                    algo.reset()
    
    def remove_roi(self, roi_id: str):
        """移除ROI的所有算法"""
        if roi_id in self.algorithms:
            for key in list(self.algorithms[roi_id].keys()):
                self.reset_algorithm(roi_id, key.split("_")[-1] if "_" in key else None)
            del self.algorithms[roi_id]
    
    def remove_bind(self, roi_id: str, bind_id: str):
        """移除绑定的算法"""
        key = f"{roi_id}_{bind_id}"
        if roi_id in self.algorithms and key in self.algorithms[roi_id]:
            for algo in self.algorithms[roi_id][key].values():
                algo.reset()
            del self.algorithms[roi_id][key]
    
    def get_status(self, roi_id: str) -> Dict[str, Any]:
        """获取算法状态"""
        status = {}
        if roi_id in self.algorithms:
            for key, bind_algorithms in self.algorithms[roi_id].items():
                bind_id = key.split("_", 1)[-1] if "_" in key else ""
                for algo_type, algo in bind_algorithms.items():
                    if algo_type == "leave_post":
                        status[f"{algo_type}_{bind_id}"] = {
                            "state": getattr(algo, "state", "WAITING"),
                            "alarm_sent": getattr(algo, "alarm_sent", False),
                        }
                    else:
                        status[f"{algo_type}_{bind_id}"] = {
                            "detection_count": len(getattr(algo, "detection_start", {})),
                        }
        return status