export const dynamic = 'force-dynamic'
import { NextResponse } from 'next/server'
import { Agent } from 'undici'

const ORGP_BASE = 'https://transport.orgp.spb.ru'

// ORGP TLS chain fails default verification in Node — match curl -k behaviour.
const insecureAgent = new Agent({ connect: { rejectUnauthorized: false } })

export async function GET(req: Request) {
  const { searchParams } = new URL(req.url)
  const stopId = searchParams.get('stopId')
  if (!stopId || !/^\d+$/.test(stopId)) {
    return NextResponse.json({ error: 'stopId required (digits)' }, { status: 400 })
  }

  const body = new URLSearchParams({
    sEcho: '1',
    iColumns: '5',
    sColumns: 'index,routeNumber,timeToArrive,parkNumber,wheelchair',
    iDisplayStart: '0',
    iDisplayLength: '-1',
    sNames: 'index,routeNumber,timeToArrive,parkNumber,wheelchair',
  })

  try {
    const upstream = await fetch(
      `${ORGP_BASE}/Portal/transport/stop/${encodeURIComponent(stopId)}/arriving`,
      {
        method: 'POST',
        headers: {
          'X-Requested-With': 'XMLHttpRequest',
          'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
          'Accept': 'application/json, text/javascript, */*; q=0.01',
        },
        body: body.toString(),
        cache: 'no-store',
        // @ts-ignore — undici dispatcher option at runtime
        dispatcher: insecureAgent,
      }
    )

    if (!upstream.ok) {
      return NextResponse.json(
        { error: `upstream_${upstream.status}`, arrivals: [] },
        { status: 502 }
      )
    }

    const data = await upstream.json()
    const arrivals = Array.isArray(data?.aaData)
      ? data.aaData.map((row: any[]) => ({
          route: String(row[1] ?? ''),
          minutes: Number(row[2] ?? 0),
          park: String(row[3] ?? ''),
          wheelchair: Boolean(row[4]),
        }))
      : []

    return NextResponse.json({
      stopId,
      arrivals,
      fetchedAt: new Date().toISOString(),
    })
  } catch (e: any) {
    return NextResponse.json(
      { error: e?.message || 'fetch_failed', arrivals: [] },
      { status: 502 }
    )
  }
}