import { useIdle } from '@vueuse/core'
import { ref, onMounted, onUnmounted } from 'vue'

const SECONDS = 1000
const MINUTES = 60 * SECONDS

interface PollingOptions {
	interval?: number
	inactivityThreshold?: number
	pauseInBackground?: boolean
}

export function usePolling(
	fn: () => Promise<any> | void,
	options: PollingOptions = {}
) {
	const {
		interval = 30 * SECONDS,
		inactivityThreshold = 5 * MINUTES,
		pauseInBackground = true,
	} = options

	const { idle } = useIdle(inactivityThreshold)
	const isPolling = ref(true)
	const pollingId = ref<number | null>(null)

	const isTabActive = () => {
		return !pauseInBackground || document.visibilityState === 'visible'
	}

	// Stop polling permanently - cannot be resumed
	const stopPolling = () => {
		isPolling.value = false // Permanently set to false
		if (pollingId.value !== null) {
			clearTimeout(pollingId.value)
			pollingId.value = null
		}
	}

	// Pause polling temporarily - can be resumed
	const pausePolling = () => {
		if (pollingId.value !== null) {
			clearTimeout(pollingId.value)
			pollingId.value = null
		}
		// Note: We don't change isPolling.value here, just clear the timeout
	}

	// Start polling with intelligent checks
	const startPolling = () => {
		// Clear any existing polling timeout
		if (pollingId.value !== null) {
			clearTimeout(pollingId.value)
			pollingId.value = null
		}

		const poll = async () => {
			if (isPolling.value && isTabActive() && !idle.value) {
				try {
					await fn()
				} catch (error) {
					console.error('Polling error:', error)
				}
			}
			if (isPolling.value) {
				pollingId.value = window.setTimeout(poll, interval)
			}
		}
		poll()
	}

	const resumePolling = () => {
		if (isPolling.value) { startPolling() }
		else { console.warn('Cannot resume polling that was stopped') }
	}

	function updateVisibility() {
		if (document.visibilityState === 'visible') {
			if (isPolling.value) { startPolling() }
		} else if (pauseInBackground) {
			pausePolling()
		}
	}

	onMounted(() => {
		document.addEventListener('visibilitychange', updateVisibility)
		startPolling()
	})

	onUnmounted(() => {
		document.removeEventListener('visibilitychange', updateVisibility)
		stopPolling()
	})

	return {
		isPolling,
		pausePolling,
		resumePolling,
		startPolling,
		stopPolling
	}
}