import { NextRequest, NextResponse } from 'next/server'
import { prisma } from '@/lib/prisma'
import { withCors } from '@/lib/middleware'
import { Prisma } from '@prisma/client' // 为了 Prisma.sql / Prisma.join

async function handleTimeDistribution(req: NextRequest) {
  try {
    const pathSegments = req.nextUrl.pathname.split('/')
    const hostnameIndex = pathSegments.indexOf('hosts') + 1
    const hostname = pathSegments[hostnameIndex]

    if (!hostname) {
      return NextResponse.json({ error: '缺少主机名' }, { status: 400 })
    }

    const sp = req.nextUrl.searchParams
    const fromParam = sp.get('from') // ISO，如 2025-09-01T00:00:00Z
    const toParam = sp.get('to')     // ISO

    const whereParts: any[] = [Prisma.sql`"hostname" = ${hostname}`]
    if (fromParam) whereParts.push(Prisma.sql`"timestamp" >= ${new Date(fromParam)}`)
    if (toParam) whereParts.push(Prisma.sql`"timestamp" < ${new Date(toParam)}`)

    const rows = await prisma.$queryRaw<
      { ts: bigint | number; count: number }[]
    >(Prisma.sql`
      SELECT
        EXTRACT(EPOCH FROM date_trunc('hour', "timestamp"))::bigint AS ts,
        COUNT(*)::int AS count
      FROM "records"
      WHERE ${Prisma.join(whereParts, ' AND ')}
      GROUP BY 1
      ORDER BY 1
    `)

    // JSON 不支持 BigInt，转成 number（秒级时间戳安全）
    const distribution = rows.map(r => ({
      timestamp: Number(r.ts),
      count: r.count
    }))

    return NextResponse.json(
      { hostname, distribution },
    )
  } catch (error) {
    console.error('获取时间分布统计失败:', error)
    return NextResponse.json({ error: '获取时间分布统计失败' }, { status: 500 })
  }
}

export const GET = withCors(handleTimeDistribution)