import { ref, computed } from 'vue'
import { useNostrFeed, type NostrFeedConfig } from './useNostrFeed'

export function useNostrFeedPreloader(config: NostrFeedConfig = {}) {
  const feed = useNostrFeed(config)
  
  // Preload state
  const isPreloading = ref(false)
  const isPreloaded = ref(false)
  const preloadError = ref<Error | null>(null)

  // Check if feed data is available in localStorage
  const hasStoredData = computed(() => {
    const storageKey = `nostr-feed-${config.feedType || 'all'}`
    const storedData = localStorage.getItem(storageKey)
    return storedData !== null
  })

  // Check if we should show loading (only if no cached data and actually loading)
  const shouldShowLoading = computed(() => {
    return (feed.isLoading.value || isPreloading.value) && feed.notes.value.length === 0
  })

  // Preload feed data
  const preloadFeed = async () => {
    if (isPreloaded.value || isPreloading.value) {
      return
    }

    try {
      isPreloading.value = true
      preloadError.value = null

      console.log('Preloading Nostr feed...')
      
      // Connect and load notes
      await feed.connectToFeed()
      await feed.loadNotes()
      
      // Subscribe to updates
      feed.subscribeToFeedUpdates()
      
      isPreloaded.value = true
      console.log('Nostr feed preloaded successfully')
      
    } catch (error) {
      console.error('Failed to preload Nostr feed:', error)
      preloadError.value = error instanceof Error ? error : new Error('Failed to preload feed')
    } finally {
      isPreloading.value = false
    }
  }

  // Reset preload state
  const resetPreload = () => {
    isPreloaded.value = false
    isPreloading.value = false
    preloadError.value = null
    feed.resetFeedState()
  }

  // Auto-preload if we have stored data
  const autoPreload = async () => {
    if (hasStoredData.value && !isPreloaded.value && !isPreloading.value) {
      await preloadFeed()
    }
  }

  return {
    // State
    isPreloading: computed(() => isPreloading.value),
    isPreloaded: computed(() => isPreloaded.value),
    preloadError: computed(() => preloadError.value),
    hasStoredData,
    shouldShowLoading,

    // Actions
    preloadFeed,
    resetPreload,
    autoPreload,

    // Expose feed methods
    ...feed
  }
}