'use client'

import { useEffect, useRef, useState } from 'react'
import { useTranslations } from 'next-intl'
import { Link } from '@/i18n/navigation'

const ERROR_KEYS = ['invalidLink', 'expiredLink'] as const

export function ActivateClient({ hash }: { hash: string }) {
  const t = useTranslations('Activate')
  // Sin hash el error se sabe YA, al renderizar (y 'invalidLink' es justo el
  // errorKey por defecto): se deriva del prop en vez de ponerlo con setState
  // dentro del efecto, que encadena un render de más.
  const [state, setState] = useState<'loading' | 'ok' | 'error'>(hash ? 'loading' : 'error')
  const [errorKey, setErrorKey] = useState<string>('invalidLink')
  const ran = useRef(false)

  useEffect(() => {
    if (!hash || ran.current) return // evita doble POST en StrictMode
    ran.current = true
    fetch('/api/auth/activate', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ hash }),
    })
      .then((r) => r.json())
      .then((d: { success?: boolean; error?: string }) => {
        if (d.success) setState('ok')
        else {
          setErrorKey((ERROR_KEYS as readonly string[]).includes(d.error ?? '') ? d.error! : 'invalidLink')
          setState('error')
        }
      })
      .catch(() => setState('error'))
  }, [hash])

  return (
    <div className="centered">
      {state === 'loading' && <p>{t('activating')}</p>}
      {state === 'ok' && (
        <>
          <span className="ok-form-response">{t('success')}</span>
          <p style={{ marginTop: 16 }}>
            <Link href="/log-in">{t('goLogin')}</Link>
          </p>
        </>
      )}
      {state === 'error' && <span className="red-form-response">{t(errorKey)}</span>}
    </div>
  )
}
