import { History, Location } from 'history'
import { debounce, inIframe } from './utils'

declare global {
	interface Window {
		_paq: any
	}
}

type PushArgs = ['trackPageView'] | ['trackEvent', ...Array<string | number>]
type PushType = (args: PushArgs) => void

const ua = window.navigator.userAgent
// https://chromium.googlesource.com/chromium/src.git/+/master/docs/ios/user_agent.md
const iOSSafari =
	(!!ua.match(/iPad/i) || !!ua.match(/iPhone/i)) &&
	!!ua.match(/WebKit/i) &&
	!ua.match(/CriOS/i)

export default class Tracker {
	push: PushType
	unlistenFromHistory: (() => void) | undefined
	previousPath: string | undefined

	constructor(
		pushFunction: PushType = args => {
			// There is an issue with the way Safari handle cookies in iframe, cf.
			// https://gist.github.com/iansltx/18caf551baaa60b79206. We could probably
			// do better but for now we don't track action of iOs Safari user in
			// iFrame -- to avoid errors in the number of visitors in our stats.
			if (!(iOSSafari && inIframe)) {
				window._paq.push(args)
			}
		}
	) {
		if (typeof window !== 'undefined') window._paq = window._paq || []
		this.push = debounce(200, pushFunction) as PushType
	}

	connectToHistory(history: History) {
		this.unlistenFromHistory = history.listen(loc => {
			this.track(loc)
		})

		return history
	}

	disconnectFromHistory() {
		if (this.unlistenFromHistory) {
			this.unlistenFromHistory()

			return true
		}
		return false
	}

	track(loc: Location) {
		const currentPath = loc.pathname + loc.search

		if (this.previousPath === currentPath) {
			return
		}
		this.push(['trackPageView'])
		this.previousPath = currentPath
	}
}

export const devTracker = new Tracker(
	console?.debug?.bind(console) ?? (() => {}) // eslint-disable-line no-console
)