import { useState, useMemo, useRef, useEffect } from 'react';
import { useHealthStore } from '@/stores/health';
import { useAuthStore } from '@/stores/auth';
import { usePageData } from '@/hooks/usePageData';
import { trackPageView } from '@/services/analytics';
import * as appointmentApi from '@/services/appointment';
import * as followupApi from '@/services/followup';
import { listPendingSuggestions, type AiSuggestionItem } from '@/services/ai-analysis';
import { notificationService } from '@/services/notification';
import { listPatientAlerts } from '@/services/alert';

export interface ReminderItem {
  id: string;
  text: string;
  type: 'ai' | 'appointment' | 'followup';
  tag: string;
}

function buildSuggestionText(s: AiSuggestionItem): string {
  const riskMap: Record<string, string> = { high: '高风险', medium: '中风险', low: '低风险' };
  const typeMap: Record<string, string> = {
    vital_sign_anomaly: '体征异常',
    lab_result_anomaly: '化验异常',
    medication_adherence: '用药提醒',
    lifestyle: '生活建议',
  };
  const risk = riskMap[s.risk_level] || '';
  const type = typeMap[s.suggestion_type] || '健康建议';
  return `${type}：发现${risk}指标，建议关注`;
}

export function useHomeData() {
  const user = useAuthStore((s) => s.user);
  const currentPatient = useAuthStore((s) => s.currentPatient);
  const todaySummary = useHealthStore((s) => s.todaySummary);
  const loading = useHealthStore((s) => s.loading);
  const refreshToday = useHealthStore((s) => s.refreshToday);
  const [reminders, setReminders] = useState<ReminderItem[]>([]);
  const [unreadCount, setUnreadCount] = useState(0);
  const [remindersLoading, setRemindersLoading] = useState(false);
  const [alertCount, setAlertCount] = useState(0);

  const fetchData = async () => {
    const patientId = useAuthStore.getState().currentPatient?.id;
    if (!patientId) return;
    refreshToday();
    loadReminders(patientId);
    loadUnread();
    loadAlertCount(patientId);
    trackPageView('home');
  };

  const { trigger, refresh } = usePageData(fetchData, {
    throttleMs: 5000,
    enablePullDown: true,
    enabled: !!user,
  });

  // currentPatient 从 null 变为有值时重新触发加载
  // 解决 loadPatients 异步完成前 useDidShow 已触发 fetchData 并因 patientId 为空提前返回的问题
  const prevPatientRef = useRef<string | null>(null);
  useEffect(() => {
    const pid = currentPatient?.id ?? null;
    if (pid && pid !== prevPatientRef.current) {
      prevPatientRef.current = pid;
      trigger();
    }
  }, [currentPatient?.id, trigger]);

  const loadUnread = async () => {
    try {
      const res = await notificationService.getUnreadCount() as { data?: { count?: number } | number };
      const d = res.data;
      setUnreadCount(typeof d === 'object' && d ? (d.count ?? 0) : 0);
    } catch (err) { console.warn('[home] 获取未读消息数失败:', err); }
  };

  const loadReminders = async (patientId: string) => {
    setRemindersLoading(true);
    try {
      const items: ReminderItem[] = [];
      const [apptRes, taskRes, suggestRes] = await Promise.allSettled([
        appointmentApi.listAppointments(patientId, 1),
        followupApi.listTasks(patientId, 'pending'),
        listPendingSuggestions(),
      ]);

      if (suggestRes.status === 'fulfilled') {
        for (const s of suggestRes.value.slice(0, 1)) {
          items.push({ id: s.id, text: buildSuggestionText(s), type: 'ai', tag: 'AI 建议' });
        }
      }
      if (apptRes.status === 'fulfilled') {
        for (const a of apptRes.value.data.slice(0, 1)) {
          if (a.status === 'pending' || a.status === 'confirmed') {
            items.push({
              id: a.id,
              text: `${a.appointment_date} ${a.start_time} — ${a.doctor_name || '医护'} ${a.department || '门诊'}`,
              type: 'appointment',
              tag: '预约',
            });
          }
        }
      }
      if (taskRes.status === 'fulfilled') {
        for (const t of taskRes.value.data.slice(0, 1)) {
          items.push({
            id: t.id,
            text: `${t.follow_up_type} · 截止 ${t.planned_date}`,
            type: 'followup',
            tag: '随访',
          });
        }
      }
      setReminders(items.slice(0, 3));
    } catch (err) {
      console.warn('[home] 加载提醒列表失败:', err);
      setReminders([]);
    } finally {
      setRemindersLoading(false);
    }
  };

  const loadAlertCount = async (patientId: string) => {
    try {
      const res = await listPatientAlerts(patientId, { status: 'pending', page: 1, page_size: 1 });
      setAlertCount(res.total ?? 0);
    } catch {
      setAlertCount(0);
    }
  };

  const summary = todaySummary || {};
  const indicators = [!!summary.blood_pressure, !!summary.heart_rate, !!summary.blood_sugar, !!summary.weight];
  const completedCount = indicators.filter(Boolean).length;
  const progressPercent = Math.round((completedCount / 4) * 100);

  const indicatorCapsules = useMemo(() => [
    { label: '血压', done: !!summary.blood_pressure },
    { label: '心率', done: !!summary.heart_rate },
    { label: '血糖', done: !!summary.blood_sugar },
    { label: '体重', done: !!summary.weight },
  ], [summary.blood_pressure, summary.heart_rate, summary.blood_sugar, summary.weight]);

  const healthItems = useMemo(() => [
    { label: '血压', value: summary.blood_pressure ? `${summary.blood_pressure.systolic}/${summary.blood_pressure.diastolic}` : '—', unit: 'mmHg', status: summary.blood_pressure?.status, indicator: 'systolic_bp_morning' },
    { label: '心率', value: summary.heart_rate ? `${summary.heart_rate.value}` : '—', unit: 'bpm', status: summary.heart_rate?.status, indicator: 'heart_rate' },
    { label: '血糖', value: summary.blood_sugar ? `${summary.blood_sugar.value}` : '—', unit: 'mmol/L', status: summary.blood_sugar?.status, indicator: 'blood_sugar' },
    { label: '体重', value: summary.weight ? `${summary.weight.value}` : '—', unit: 'kg', status: summary.weight?.status, indicator: 'weight' },
  ], [summary.blood_pressure, summary.heart_rate, summary.blood_sugar, summary.weight]);

  const hour = new Date().getHours();
  const greeting = hour < 12 ? '上午好' : hour < 18 ? '下午好' : '晚上好';
  const displayName = user?.display_name || currentPatient?.name || user?.username || (user?.phone ? `${user.phone.slice(-4)}` : '') || '用户';

  return {
    user,
    currentPatient,
    todaySummary: summary,
    loading,
    reminders,
    unreadCount,
    remindersLoading,
    alertCount,
    indicatorCapsules,
    healthItems,
    completedCount,
    progressPercent,
    greeting,
    displayName,
    trigger,
    refresh,
  };
}