/** نوتیف مرورگر بدون Firebase — ترجیحاً با gesture کاربر؛ بعد از لاگین هم تلاش می‌شود. */

export type BrowserNotifState =
  | 'unsupported'
  | 'needs-pwa'
  | 'default'
  | 'granted'
  | 'denied'

function isStandalonePwa() {
  if (typeof window === 'undefined') return false
  return (
    window.matchMedia('(display-mode: standalone)').matches ||
    Boolean((window.navigator as Navigator & { standalone?: boolean }).standalone)
  )
}

/** فقط دستگاه‌های واقعی اپل موبایل — نه مک با ترک‌پد */
function isAppleMobileDevice() {
  if (typeof navigator === 'undefined') return false
  const ua = navigator.userAgent || ''

  if (/iPhone|iPod/i.test(ua)) return true
  if (/iPad/i.test(ua)) return true

  const isTouchMac = navigator.platform === 'MacIntel' && navigator.maxTouchPoints > 1
  if (!isTouchMac) return false

  if (/CriOS|FxiOS|EdgiOS/i.test(ua)) return true
  if (/Chrome|Edg|Firefox|OPR/i.test(ua) && !/Mobile/i.test(ua)) return false

  return true
}

export function getBrowserNotificationState(): BrowserNotifState {
  if (typeof window === 'undefined') return 'unsupported'
  if (typeof window.isSecureContext === 'boolean' && !window.isSecureContext) {
    return 'unsupported'
  }

  const hasApi = 'Notification' in window

  if (isAppleMobileDevice() && !isStandalonePwa() && !hasApi) {
    return 'needs-pwa'
  }

  if (!hasApi) {
    return 'unsupported'
  }

  const permission = Notification.permission
  if (permission === 'granted') return 'granted'
  if (permission === 'denied') return 'denied'
  return 'default'
}

export function canRequestBrowserNotification() {
  return getBrowserNotificationState() === 'default'
}

export async function requestBrowserNotificationPermission(): Promise<BrowserNotifState> {
  const before = getBrowserNotificationState()
  if (before === 'granted' || before === 'denied' || before === 'unsupported' || before === 'needs-pwa') {
    return before
  }
  if (!('Notification' in window)) {
    return getBrowserNotificationState()
  }

  try {
    const result = await Notification.requestPermission()
    if (result === 'granted') return 'granted'
    if (result === 'denied') return 'denied'
    return 'default'
  } catch {
    return getBrowserNotificationState()
  }
}

/** لوگوی برند از کانفیگ؛ fallback به آیکون‌های PWA */
function resolveNotifIcon() {
  try {
    const avatar = String(
      (window as Window & { __APP_CONFIG__?: { user?: { avatar?: string } } }).__APP_CONFIG__?.user
        ?.avatar ?? '',
    ).trim()
    if (avatar) {
      return avatar
    }
  } catch {
    // ignore
  }

  try {
    return new URL('/192.png', window.location.origin).href
  } catch {
    try {
      return new URL('/favicon.png', window.location.origin).href
    } catch {
      return undefined
    }
  }
}

export type ShowBrowserNotificationOptions = {
  title: string
  body?: string
  tag?: string
  url?: string
}

/** نمایش نوتیف سیستم؛ ترجیح با Service Worker (معتبرتر روی Chrome/Android). */
export async function showBrowserNotification(options: ShowBrowserNotificationOptions): Promise<boolean> {
  if (getBrowserNotificationState() !== 'granted') {
    return false
  }

  const title = options.title || 'اعلان جدید'
  const body = options.body || ''
  const tag = options.tag || `app-notification-${Date.now()}`
  const url = options.url || '/appNotifications'
  const icon = resolveNotifIcon()

  try {
    if ('serviceWorker' in navigator) {
      const reg = await navigator.serviceWorker.ready
      if (reg?.showNotification) {
        await reg.showNotification(title, {
          body,
          tag,
          icon,
          badge: icon,
          data: { url },
          renotify: true,
        })
        return true
      }
    }
  } catch (error) {
    console.warn('SW showNotification failed, falling back', error)
  }

  try {
    const n = new Notification(title, {
      body,
      tag,
      icon,
      dir: 'rtl',
      lang: 'fa',
    })
    n.onclick = () => {
      window.focus()
      n.close()
      if (url) {
        void import('@/router').then((mod) => {
          mod.default.push(url).catch(() => undefined)
        })
      }
    }
    return true
  } catch (error) {
    console.warn('Notification constructor failed', error)
    return false
  }
}