import { EmitterSubscription, Linking } from 'react-native';
import { router } from './router';

class DeepLinkImpl {
	private active = 0;
	private uriPrefix = '';
	private hasHandleInitialURL = false;
	private subscription: EmitterSubscription | null = null;

	activate(uriPrefix: string) {
		if (!uriPrefix) {
			throw new Error('must pass `uriPrefix` when activate router.');
		}
		if (this.active === 0) {
			this.uriPrefix = uriPrefix;
			if (!this.hasHandleInitialURL) {
				this.hasHandleInitialURL = true;
				Linking.getInitialURL()
					.then(url => {
						if (url) {
							console.info(`deeplink:${url}`);
							const path = url.replace(this.uriPrefix, '');
							return router.open(path);
						}
					})
					.catch(err => console.error('An error occurred', err));
			}
			this.subscription = Linking.addEventListener('url', this.handleLinking);
		}
		this.active++;
	}

	deactivate() {
		this.active--;
		if (this.active === 0) {
			if (this.subscription) {
				this.subscription.remove();
				this.subscription = null;
			} else {
				//@ts-ignore
				Linking.removeEventListener('url', this.handleLinking);
			}
		}

		if (this.active < 0) {
			this.active = 0;
		}
	}

	private handleLinking = (event: { url: string }) => {
		console.info(`deeplink:${event.url}`);
		let path = event.url.replace(this.uriPrefix, '');
		if (!path.startsWith('/')) {
			path = '/' + path;
		}
		router.open(path);
	};
}

export const DeepLink = new DeepLinkImpl();