import { NextRequest, NextResponse } from 'next/server'
import { unsubscribeByUserId } from '@/lib/marketing/preference'
import { publicAppOrigin, verifyUnsubscribeToken } from '@/lib/marketing/unsubscribe-token'

export const dynamic = 'force-dynamic'

function tokenFromRequest(request: NextRequest, bodyToken?: string | null): string | null {
  return (
    request.nextUrl.searchParams.get('token') ||
    bodyToken ||
    null
  )
}

async function applyUnsubscribe(request: NextRequest, token: string | null) {
  const payload = token ? verifyUnsubscribeToken(token) : null
  if (!payload) {
    return NextResponse.json({ ok: false }, { status: 400 })
  }
  const forwarded = request.headers.get('x-forwarded-for')
  const ip = forwarded?.split(',')[0]?.trim() || request.headers.get('x-real-ip')
  await unsubscribeByUserId({
    userId: payload.userId,
    source: 'unsubscribe-one-click',
    meta: { ip, userAgent: request.headers.get('user-agent') },
  })
  return new NextResponse('OK', { status: 200 })
}

export async function POST(request: NextRequest) {
  let bodyToken: string | null = null
  const contentType = request.headers.get('content-type') || ''
  try {
    if (contentType.includes('application/x-www-form-urlencoded')) {
      const form = await request.formData()
      bodyToken = String(form.get('token') || '')
    } else if (contentType.includes('application/json')) {
      const json = await request.json().catch(() => null)
      bodyToken = json?.token ? String(json.token) : null
    }
  } catch {
    bodyToken = null
  }
  return applyUnsubscribe(request, tokenFromRequest(request, bodyToken))
}

export async function GET(request: NextRequest) {
  const token = request.nextUrl.searchParams.get('token') || ''
  const origin = publicAppOrigin() || request.nextUrl.origin
  const url = new URL('/unsubscribe', origin)
  if (token) url.searchParams.set('token', token)
  return NextResponse.redirect(url, 303)
}