/**
 * Fetches active live sessions (camera + location sharing) and refreshes on an interval.
 * Only runs when the app is focused so we don't poll in the background.
 */

const POLL_MS = 1500

export function useLiveSessions() {
  const { data: sessions, refresh } = useAsyncData(
    'live-sessions',
    async () => {
      try {
        const result = await $fetch('/api/live')
        if (process.env.NODE_ENV === 'development') {
          console.log('[useLiveSessions] Fetched sessions:', result.map(s => ({
            id: s.id,
            label: s.label,
            hasStream: s.hasStream,
          })))
        }
        return result
      }
      catch (err) {
        const msg = err?.message ?? String(err)
        const status = err?.statusCode ?? err?.status
        console.error('[useLiveSessions] Failed to fetch sessions:', status ? `${status}: ${msg}` : msg)
        return []
      }
    },
    { default: () => [] },
  )

  const pollInterval = ref(null)

  function startPolling() {
    if (pollInterval.value) return
    refresh() // Fetch immediately so new sessions show without waiting for first interval
    pollInterval.value = setInterval(() => {
      refresh()
    }, POLL_MS)
  }

  function stopPolling() {
    if (pollInterval.value) {
      clearInterval(pollInterval.value)
      pollInterval.value = null
    }
  }

  onMounted(() => {
    if (typeof document === 'undefined') return
    const onFocus = () => startPolling()
    const onBlur = () => stopPolling()
    document.addEventListener('visibilitychange', () => {
      if (document.visibilityState === 'visible') {
        onFocus()
        refresh() // Fresh data when returning to tab
      }
      else onBlur()
    })
    if (document.visibilityState === 'visible') startPolling()
  })

  onBeforeUnmount(() => {
    stopPolling()
  })

  return { sessions, refresh, startPolling, stopPolling }
}