'use client'

import { useState } from 'react'
import { useTranslations } from 'next-intl'
import { Link } from '@/i18n/navigation'
import { Turnstile } from '@/components/Turnstile'

const ERROR_KEYS = [
  'missingFields',
  'passwordMismatch',
  'passwordTooLong',
  'invalidEmail',
  'emailExists',
  'recruiterNotFound',
  'captchaFailed',
] as const

/** Campo de contraseña con ojo para mostrar/ocultar. */
function PasswordInput({
  value,
  onChange,
  placeholder,
  ariaLabel,
  blockPaste,
}: {
  value: string
  onChange: (v: string) => void
  placeholder: string
  ariaLabel: string
  blockPaste?: boolean
}) {
  const [show, setShow] = useState(false)
  const noPaste = blockPaste ? (e: React.ClipboardEvent) => e.preventDefault() : undefined
  return (
    <>
      <input
        type={show ? 'text' : 'password'}
        maxLength={16}
        placeholder={placeholder}
        required
        value={value}
        onChange={(e) => onChange(e.target.value)}
        onPaste={noPaste}
        onCopy={noPaste}
        onCut={noPaste}
      />{' '}
      <span
        className={`far ${show ? 'fa-eye-slash' : 'fa-eye'} toggle-password`}
        role="button"
        tabIndex={0}
        aria-label={ariaLabel}
        onClick={() => setShow((s) => !s)}
      />
    </>
  )
}

export function RegisterForm() {
  const t = useTranslations('Register')
  const [form, setForm] = useState({ password: '', confPassword: '', email: '', confEmail: '', recruiter: '' })
  const [accepted, setAccepted] = useState(false)
  const [notUs, setNotUs] = useState(false)
  const [busy, setBusy] = useState(false)
  const [captcha, setCaptcha] = useState('')
  const [captchaKey, setCaptchaKey] = useState(0) // remonta el widget para pedir un token nuevo
  const [message, setMessage] = useState<{ ok: boolean; text: string } | null>(null)

  const canSubmit = accepted && notUs && !busy

  function upd(k: string, v: string) {
    setForm((f) => ({ ...f, [k]: v }))
  }

  /** Validación en cliente: muestra el error en rojo al instante, sin ir al servidor. */
  function clientError(): string | null {
    if (!form.password || !form.confPassword || !form.email || !form.confEmail) return 'missingFields'
    if (form.password !== form.confPassword) return 'passwordMismatch'
    if (form.password.length > 16) return 'passwordTooLong'
    if (form.email.trim() !== form.confEmail.trim()) return 'emailMismatch'
    return null
  }

  async function handleSubmit(e: React.FormEvent) {
    e.preventDefault()
    if (!canSubmit) return
    const err = clientError()
    if (err) {
      setMessage({ ok: false, text: t(err) })
      return
    }
    setBusy(true)
    setMessage(null)
    try {
      const res = await fetch('/api/auth/register', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'same-origin',
        body: JSON.stringify({ ...form, turnstileToken: captcha }),
      })
      const data: { success?: boolean; error?: string } = await res.json()
      if (data.success) {
        setMessage({ ok: true, text: t('success') })
      } else {
        const key = (ERROR_KEYS as readonly string[]).includes(data.error ?? '') ? data.error! : 'genericError'
        setMessage({ ok: false, text: t(key) })
        // El token de Turnstile es de un solo uso: resetear tras un fallo.
        setCaptcha('')
        setCaptchaKey((k) => k + 1)
      }
    } catch {
      setMessage({ ok: false, text: t('genericError') })
      setCaptcha('')
      setCaptchaKey((k) => k + 1)
    } finally {
      setBusy(false)
    }
  }

  const noPaste = (e: React.ClipboardEvent) => e.preventDefault()

  return (
    <>
      <form onSubmit={handleSubmit} acceptCharset="utf-8" noValidate>
        <table className="middle-center-table">
          <tbody>
            <tr>
              <td>
                <PasswordInput value={form.password} onChange={(v) => upd('password', v)} placeholder={t('password')} ariaLabel={t('showPassword')} />
              </td>
            </tr>
            <tr>
              <td>
                <PasswordInput value={form.confPassword} onChange={(v) => upd('confPassword', v)} placeholder={t('confPassword')} ariaLabel={t('showPassword')} blockPaste />
              </td>
            </tr>
            <tr>
              <td>
                <input type="email" maxLength={320} placeholder={t('email')} required value={form.email} onChange={(e) => upd('email', e.target.value)} />
              </td>
            </tr>
            <tr>
              <td>
                <input
                  type="email"
                  maxLength={320}
                  placeholder={t('confEmail')}
                  required
                  value={form.confEmail}
                  onChange={(e) => upd('confEmail', e.target.value)}
                  onPaste={noPaste}
                  onCopy={noPaste}
                  onCut={noPaste}
                />
              </td>
            </tr>
            <tr>
              <td>
                <hr />
              </td>
            </tr>
            <tr>
              <td className="second-brown">{t('recruiterOptional')}</td>
            </tr>
            <tr>
              <td>
                <input type="text" maxLength={12} placeholder={t('recruiter')} value={form.recruiter} onChange={(e) => upd('recruiter', e.target.value)} />
              </td>
            </tr>
            <tr>
              <td>
                <Turnstile key={captchaKey} onVerify={setCaptcha} />
              </td>
            </tr>
            <tr>
              <td className="lefted separate">
                <label>
                  <input type="checkbox" className="terms-check" checked={accepted} onChange={(e) => setAccepted(e.target.checked)} />{' '}
                  {t.rich('termsRich', {
                    terms: (c) => <Link href="/terms-and-conditions" target="_blank">{c}</Link>,
                    privacy: (c) => <Link href="/privacy-policy" target="_blank">{c}</Link>,
                  })}
                </label>
              </td>
            </tr>
            <tr>
              <td className="lefted separate">
                <label>
                  <input type="checkbox" className="terms-check" checked={notUs} onChange={(e) => setNotUs(e.target.checked)} /> {t('notUs')}
                </label>
              </td>
            </tr>
            <tr>
              <td>
                <button type="submit" className="create-button" disabled={!canSubmit}>
                  {busy ? t('creating') : t('submit')}
                </button>
              </td>
            </tr>
          </tbody>
        </table>
      </form>
      <hr />
      <div className="alert-message" style={{ display: message ? 'block' : 'none' }}>
        {message && <span className={message.ok ? 'ok-form-response' : 'red-form-response'}>{message.text}</span>}
      </div>
    </>
  )
}