import { NextResponse } from 'next/server'
import { FrappeError, METHODS, frappeCall, registrationEnabled } from '@/lib/lukenya-api'

// The browser posts the form here; this route forwards it to Frappe. The backend
// re-validates everything and decides the price, so nothing here is trusted for money.

const ALLOWED = [
  'event_edition', 'race_category', 'residency', 'first_name', 'last_name', 'id_number',
  'date_of_birth', 'gender', 'nationality', 'email', 'phone', 'whatsapp', 'shirt_size',
  'emergency_contact_name', 'emergency_contact_phone', 'guardian_name', 'guardian_phone',
  'indemnity_accepted', 'communication_consent', 'preferred_payment', 'emergency_contact_relationship',
  'support_request', 'consents',
] as const

const REQUIRED = [
  'race_category', 'first_name', 'last_name', 'email', 'phone',
  'emergency_contact_name', 'emergency_contact_phone',
] as const

export async function POST(req: Request) {
  if (!registrationEnabled()) {
    return NextResponse.json({ error: 'Online registration is not open yet.' }, { status: 403 })
  }

  let body: Record<string, unknown>
  try {
    body = await req.json()
  } catch {
    return NextResponse.json({ error: 'The form data could not be read.' }, { status: 400 })
  }

  const payload: Record<string, unknown> = {}
  for (const key of ALLOWED) {
    const value = body[key]
    if (value === undefined || value === null) continue
    payload[key] = typeof value === 'string' ? value.trim().slice(0, key === 'support_request' ? 1000 : 500) : value
  }
  payload.event_edition = payload.event_edition || process.env.FRAPPE_EDITION

  const missing = REQUIRED.filter((k) => !payload[k])
  if (!payload.event_edition) missing.unshift('race edition' as never)
  if (payload.indemnity_accepted !== true) missing.push('indemnity acceptance' as never)
  if (missing.length) {
    return NextResponse.json({ error: `Please complete: ${missing.join(', ').replace(/_/g, ' ')}.` }, { status: 400 })
  }

  try {
    const result = await frappeCall<{
      registration: string
      amount_due: number
      currency: string
      payment_token?: string
    }>(METHODS.createRegistration, { args: { payload }, post: true })
    return NextResponse.json({
      registration: result.registration,
      amount_due: result.amount_due,
      currency: result.currency,
      payment_token: result.payment_token,
    })
  } catch (err) {
    const status = err instanceof FrappeError && err.status < 500 ? 400 : 502
    return NextResponse.json({ error: (err as Error).message }, { status })
  }
}