import { Alert } from 'antd'
import { Link } from 'react-router-dom'
import { useQuery } from '@tanstack/react-query'
import { useTranslation } from 'react-i18next'

import apiClient, { isEnvelope } from '../api/client'

interface LicenseStatus {
  license_key?: string
  status: string
  type?: string
  valid_until?: string
  expires_at?: string
  last_error?: string | null
}

// LicenseBanner shows up in AppLayout next to UpdateBanner.
// Three visible states:
//  - trial-expiring (≤14d remaining) → warning
//  - expired / invalid → error
//  - last verify failed → warning (transient)
// Everything else stays silent.
export default function LicenseBanner() {
  const { t } = useTranslation()

  const { data: s } = useQuery({
    queryKey: ['license', 'status'],
    queryFn: async () => {
      const r = await apiClient.get('/license/status')
      return isEnvelope(r.data) ? (r.data.data as LicenseStatus) : null
    },
    refetchInterval: 5 * 60 * 1000,
  })

  if (!s) return null

  const expiry = s.valid_until || s.expires_at
  const days = expiry ? Math.ceil((new Date(expiry).getTime() - Date.now()) / 86_400_000) : null
  const isTrial = s.type === 'trial' || !s.license_key

  if (s.status === 'expired' || s.status === 'invalid') {
    return (
      <Alert
        type="error"
        showIcon
        banner
        message={
          <>
            {t('licenseBanner.expired')}{' '}
            <Link to="/license">{t('licenseBanner.cta')}</Link>
          </>
        }
      />
    )
  }

  if (isTrial && days !== null && days <= 14) {
    return (
      <Alert
        type={days <= 3 ? 'error' : 'warning'}
        showIcon
        banner
        message={
          <>
            {t('licenseBanner.trialExpiring', { days })}{' '}
            <Link to="/license">{t('licenseBanner.cta')}</Link>
          </>
        }
      />
    )
  }

  if (s.last_error) {
    return (
      <Alert
        type="warning"
        showIcon
        banner
        message={
          <>
            {t('licenseBanner.verifyFailed')}: {s.last_error}{' '}
            <Link to="/license">{t('licenseBanner.openPage')}</Link>
          </>
        }
        closable
      />
    )
  }

  return null
}