import { getDb } from '../../utils/db'

export default defineEventHandler(async (event) => {
  const db = getDb()
  const query = getQuery(event)
  
  const type = query.type as string || 'short-term'
  const period = query.period as string || '24h'
  
  // 기간/간격 계산
  let intervalClause = ''
  let groupFormat = ''
  
  if (period === '1h') {
    intervalClause = `'-1 hours'`
    groupFormat = '%Y-%m-%d %H:%M'  // 분 단위
  } else if (period === '6h') {
    intervalClause = `'-6 hours'`
    groupFormat = '%Y-%m-%d %H:00' // 시간 단위
  } else if (period === '12h') {
    intervalClause = `'-12 hours'`
    groupFormat = '%Y-%m-%d %H:00'
  } else if (period === '24h') {
    intervalClause = `'-24 hours'`
    groupFormat = '%Y-%m-%d %H:00'
  } else if (period === '7d') {
    intervalClause = `'-7 days'`
    groupFormat = '%Y-%m-%d'  // 일 단위
  } else if (period === '30d') {
    intervalClause = `'-30 days'`
    groupFormat = '%Y-%m-%d'
  } else {
    intervalClause = `'-24 hours'`
    groupFormat = '%Y-%m-%d %H:00'
  }
  
  // 시간대별 집계
  const rows = db.prepare(`
    SELECT 
      strftime('${groupFormat}', detected_at) as time_slot,
      SUM(CASE WHEN level = 'warning' THEN 1 ELSE 0 END) as warning,
      SUM(CASE WHEN level = 'danger' THEN 1 ELSE 0 END) as danger
    FROM anomaly_logs
    WHERE detect_type = ?
      AND detected_at >= datetime('now', ${intervalClause}, 'localtime')
    GROUP BY time_slot
    ORDER BY time_slot ASC
  `).all(type) as any[]
  
  // 시간 포맷 변환
  const data = rows.map(r => ({
    time: formatTimeLabel(r.time_slot, period),
    warning: r.warning,
    danger: r.danger
  }))
  
  return {
    data,
    type,
    period,
    timestamp: new Date().toISOString()
  }
})

function formatTimeLabel(timeSlot: string, period: string): string {
  if (!timeSlot) return ''
  
  if (period === '7d' || period === '30d') {
    // 일 단위: MM/DD
    const parts = timeSlot.split('-')
    return `${parts[1]}/${parts[2]}`
  } else {
    // 시간 단위: HH:MM
    const parts = timeSlot.split(' ')
    if (parts.length === 2) {
      return parts[1].substring(0, 5)
    }
    return timeSlot.substring(11, 16)
  }
}