/**
 * WordPress dependencies
 */
import { addQueryArgs } from '@safe-wordpress/url';

export function addFreeTracker( link: string ): string {
	return addQueryArgs( link, {
		utm_source: 'nelio-ab-testing',
		utm_medium: 'plugin',
		utm_campaign: 'free',
	} );
}

export function isExternalLink( link: string ): boolean {
	// Internal link.
	if ( ! /^[a-z]+:\/\//.test( link ) ) {
		return false;
	}

	link = link.replace( /^https?:\/\//, 'http://' );
	const currentDomain = document.location.href
		.replace( /^https?:\/\//, '' )
		.replace( /\/.*$/, '' );
	if ( 0 === link.indexOf( 'http://' + currentDomain ) ) {
		return false;
	}

	return true;
}

export function disableExternalLinks(): void {
	Array.from( document.querySelectorAll( 'a' ) ).forEach( ( link ) => {
		const href = link.getAttribute( 'href' ) || '';
		if ( ! isExternalLink( href ) ) {
			return;
		}

		link.classList.add( 'nab-disabled-link' );
		link.addEventListener( 'click', ( ev ) => ev.preventDefault() );
	} );
}

export function addParamToLocalLinks(
	paramName: string,
	paramValue?: number | string | boolean
): void {
	Array.from( document.querySelectorAll( 'a' ) ).forEach( ( link ) => {
		const href = link.getAttribute( 'href' ) || '';
		if ( isExternalLink( href ) ) {
			return;
		}

		// HACK. Remove fragment stuff when this pull request is finally merged: https://github.com/WordPress/gutenberg/pull/16656
		const cleanUrl = href.replace( /#.*$/, '' );
		const fragment = href.replace( /^[^#]*/, '' );
		const finalUrl =
			addQueryArgs( cleanUrl, { [ paramName ]: paramValue ?? '' } ) +
			fragment;

		link.setAttribute( 'href', finalUrl );
	} );
}