import { useState, useEffect } from 'react'

interface BeforeInstallPromptEvent extends Event {
  prompt: () => Promise<void>
  userChoice: Promise<{ outcome: 'accepted' | 'dismissed' }>
}

interface PWAInstall {
  canInstall: boolean      // Android/Chrome: native prompt available
  isIOS: boolean           // iOS Safari: must show manual instructions
  isInstalled: boolean     // Already running as installed PWA
  triggerInstall: () => Promise<void>
}

export function usePWAInstall(): PWAInstall {
  const [deferredPrompt, setDeferredPrompt] = useState<BeforeInstallPromptEvent | null>(null)
  const [isInstalled, setIsInstalled] = useState(false)

  const isIOS = /iPad|iPhone|iPod/.test(navigator.userAgent) && !(window as unknown as { MSStream?: unknown }).MSStream

  useEffect(() => {
    // Detect if already installed (standalone mode)
    const mq = window.matchMedia('(display-mode: standalone)')
    const iosStandalone = (navigator as unknown as { standalone?: boolean }).standalone === true
    if (mq.matches || iosStandalone) {
      setIsInstalled(true)
      return
    }

    const handler = (e: Event) => {
      e.preventDefault()
      setDeferredPrompt(e as BeforeInstallPromptEvent)
    }

    window.addEventListener('beforeinstallprompt', handler)

    window.addEventListener('appinstalled', () => {
      setIsInstalled(true)
      setDeferredPrompt(null)
    })

    return () => window.removeEventListener('beforeinstallprompt', handler)
  }, [])

  const triggerInstall = async () => {
    if (!deferredPrompt) return
    await deferredPrompt.prompt()
    const { outcome } = await deferredPrompt.userChoice
    if (outcome === 'accepted') {
      setIsInstalled(true)
      setDeferredPrompt(null)
    }
  }

  return {
    canInstall: !!deferredPrompt,
    isIOS,
    isInstalled,
    triggerInstall,
  }
}