import { analyzeHRVData, fetchHRVWithStatus } from '@/utils/health';
import AsyncStorage from '@/utils/kvStore';
import { logger } from '@/utils/logger';
import { convertHrvToStressIndex, getStressLevelInfo, StressLevel } from '@/utils/stress';
import { NativeEventEmitter, NativeModules } from 'react-native';
import { sendHRVStressNotification } from './hrvNotificationService';

const { HealthKitManager } = NativeModules;

const HRV_EVENT_NAME = 'hrvUpdate';
const HRV_NOTIFICATION_STATE_KEY = '@hrv_stress_notification_state';
const MIN_NOTIFICATION_INTERVAL_HOURS = 2;

interface HrvEventData {
  timestamp: number;
  type: 'hrv_data_updated' | string;
}

interface NotificationState {
  lastSentAt: number;
  lastStressLevel: StressLevel;
}

class HRVMonitorService {
  private eventEmitter: NativeEventEmitter | null = null;
  private eventSubscription: any = null;
  private isInitialized = false;
  private lastProcessedTime = 0;
  private debounceDelay = 3000;

  async initialize(): Promise<boolean> {
    if (this.isInitialized) {
      logger.info('[HRVMonitor] Already initialized');
      return true;
    }

    try {
      this.eventEmitter = new NativeEventEmitter(HealthKitManager);
      this.eventSubscription = this.eventEmitter.addListener(
        HRV_EVENT_NAME,
        this.handleHRVUpdate.bind(this)
      );

      if (HealthKitManager.startHRVObserver) {
        await HealthKitManager.startHRVObserver();
      } else {
        logger.warn('[HRVMonitor] Native startHRVObserver not available');
        return false;
      }

      this.isInitialized = true;
      logger.info('[HRVMonitor] Initialized successfully');
      return true;
    } catch (error) {
      logger.error('[HRVMonitor] Initialization failed:', error);
      return false;
    }
  }

  async stop(): Promise<void> {
    if (!this.isInitialized) return;

    try {
      if (this.eventSubscription) {
        this.eventSubscription.remove();
        this.eventSubscription = null;
      }

      if (HealthKitManager.stopHRVObserver) {
        await HealthKitManager.stopHRVObserver();
      }

      this.isInitialized = false;
      logger.info('[HRVMonitor] Stopped successfully');
    } catch (error) {
      logger.error('[HRVMonitor] Failed to stop:', error);
    }
  }

  private async handleHRVUpdate(event: HrvEventData): Promise<void> {
    logger.info('[HRVMonitor] HRV data updated:', event);

    const now = Date.now();
    if (now - this.lastProcessedTime < this.debounceDelay) {
      logger.info('[HRVMonitor] Debouncing HRV update');
      return;
    }
    this.lastProcessedTime = now;

    try {
      const canNotify = await this.canSendNotification(now);
      if (!canNotify) {
        logger.info('[HRVMonitor] Notification recently sent, skipping');
        return;
      }

      const { hrvData, message } = await fetchHRVWithStatus(new Date());
      if (!hrvData) {
        logger.warn('[HRVMonitor] No HRV data available for analysis');
        return;
      }

      const analysis = analyzeHRVData(hrvData);
      const stressIndex = convertHrvToStressIndex(hrvData.value);
      if (stressIndex == null) {
        logger.warn('[HRVMonitor] Unable to derive stress index from HRV value:', hrvData.value);
        return;
      }

      const stressInfo = getStressLevelInfo(stressIndex);
      await sendHRVStressNotification({
        hrvValue: Math.round(hrvData.value),
        stressIndex,
        stressLevel: stressInfo.level,
        recordedAt: hrvData.recordedAt,
        interpretation: analysis.interpretation,
        recommendations: analysis.recommendations,
        dataSource: analysis.dataSource,
        message,
      });

      await this.markNotificationSent(now, stressInfo.level);
    } catch (error) {
      logger.error('[HRVMonitor] Failed to process HRV update:', error);
    }
  }

  private async canSendNotification(now: number): Promise<boolean> {
    try {
      const stored = await AsyncStorage.getItem(HRV_NOTIFICATION_STATE_KEY);
      if (!stored) {
        return true;
      }

      const state: NotificationState = JSON.parse(stored);
      const elapsed = now - state.lastSentAt;
      const minIntervalMs = MIN_NOTIFICATION_INTERVAL_HOURS * 60 * 60 * 1000;

      // 只检查最小间隔时间（2小时），不再限制每天只能发送一次
      if (elapsed < minIntervalMs) {
        const hoursLeft = ((minIntervalMs - elapsed) / (1000 * 60 * 60)).toFixed(1);
        logger.info(`[HRVMonitor] Cooldown active, ${hoursLeft}h remaining`);
        return false;
      }

      return true;
    } catch (error) {
      logger.warn('[HRVMonitor] Failed to read notification state:', error);
      return true;
    }
  }

  private async markNotificationSent(timestamp: number, level: StressLevel): Promise<void> {
    try {
      const state: NotificationState = {
        lastSentAt: timestamp,
        lastStressLevel: level,
      };
      await AsyncStorage.setItem(HRV_NOTIFICATION_STATE_KEY, JSON.stringify(state));
    } catch (error) {
      logger.warn('[HRVMonitor] Failed to persist notification state:', error);
    }
  }
}

export const hrvMonitorService = new HRVMonitorService();