import { useState, useEffect } from 'react';
import { db, AttendanceRecord } from '../utils/db';
import { v4 as uuid } from 'uuid';

export function useAttendance() {
  const [todayRecords, setTodayRecords] = useState<AttendanceRecord[]>([]);

  useEffect(() => {
    const dayStart = new Date();
    dayStart.setHours(0,0,0,0);
    db.records
      .where('timestamp')
      .above(dayStart.getTime())
      .toArray()
      .then(setTodayRecords);
  }, []);

  const clockToggle = (teacherId: string) => {
    const recs = todayRecords.filter(r => r.teacherId === teacherId);
    const next: 'in' | 'out' = recs.pop()?.type === 'in' ? 'out' : 'in';
    const rec: AttendanceRecord = {
      id: uuid(),
      teacherId,
      timestamp: Date.now(),
      type: next
    };
    db.records.add(rec).then(() => setTodayRecords(prev => [...prev, rec]));
  };

  return { todayRecords, clockToggle };
}