import React from 'react';
import PropTypes from 'prop-types';
import ReactGA from 'react-ga';
import { Route } from 'react-router-dom';

import auth from '../../../auth.json';

class GoogleAnalytics extends React.Component {
	componentDidMount() {
		this.logPageChange(
			this.props.location.pathname,
			this.props.location.search
		);
	}

	componentDidUpdate({location: prevLocation}) {
		const { location: { pathname, search } } = this.props;
		const isDifferentPathname = pathname !== prevLocation.pathname;
		const isDifferentSearch = search !== prevLocation.search;

		if (isDifferentPathname || isDifferentSearch) {
			this.logPageChange(pathname, search);
		}
	}

	logPageChange(pathname, search = '') {
		const page = pathname + search;
		const { location } = window;
		ReactGA.set({
			page,
			location: `${location.origin}${page}`,
			...this.props.options
		});
		ReactGA.pageview(page);
	}

	render() {
		return null;
	}
}

GoogleAnalytics.propTypes = {
	location: PropTypes.shape({
		pathname: PropTypes.string,
		search: PropTypes.string,
	}).isRequired,
	options: PropTypes.object
}

const RouteTracker = () =>
	<Route component={GoogleAnalytics} />

const init = (options = {}) => {
	const env = auth.env || {};
	const isGAEnabled = !!env.REACT_APP_GA_TRACKING_ID;

	if (isGAEnabled) {
		ReactGA.initialize(
			env.REACT_APP_GA_TRACKING_ID, {
				debug: env.REACT_APP_GA_DEBUG === 'true',
				...options
			}
		)
	}

	return isGAEnabled;
}

export default {
	GoogleAnalytics,
	RouteTracker,
	init
}