( function ( mw, $ ) {

	/**
	 * @private
	 *
	 * Gets the title of a local page from an href given some configuration.
	 *
	 * @param {String} href
	 * @param {mw.Map} config
	 * @return {String|undefined}
	 */
	function getTitle( href, config ) {
		var linkHref,
			matches,
			queryLength,
			titleRegex = new RegExp( mw.RegExp.escape( config.get( 'wgArticlePath' ) )
				.replace( '\\$1', '(.+)' ) );

		// Skip every URI that mw.Uri cannot parse
		try {
			linkHref = new mw.Uri( href );
		} catch ( e ) {
			return undefined;
		}

		// External links
		if ( linkHref.host !== location.hostname ) {
			return undefined;
		}

		queryLength = Object.keys( linkHref.query ).length;

		// No query params (pretty URL)
		if ( !queryLength ) {
			matches = titleRegex.exec( linkHref.path );
			return matches ? decodeURIComponent( matches[ 1 ] ) : undefined;
		} else if ( queryLength === 1 && linkHref.query.hasOwnProperty( 'title' ) ) {
			// URL is not pretty, but only has a `title` parameter
			return linkHref.query.title;
		}

		return undefined;
	}

	/**
	 * Processes and returns link elements (or "`<a>`s") that are eligible for
	 * previews in a given container.
	 *
	 * An `<a>` is eligible for a preview if:
	 *
	 * * It has an href and a title, i.e. `<a href="/wiki/Foo" title="Foo" />`.
	 * * It doesn't have any blacklisted CSS classes.
	 * * Its href is a valid URI of a page on the local wiki.
	 *
	 * If an `<a>` is eligible, then the title of the page on the local wiki is
	 * stored in the `data-previews-page-title` attribute for later reuse.
	 *
	 * @param {jQuery} $container
	 * @param {String[]} blacklist If an `<a>` has one or more of these CSS
	 *  classes, then it will be ignored.
	 * @param {mw.Map} config
	 *
	 * @return {jQuery}
	 */
	mw.popups.processLinks = function ( $container, blacklist, config ) {
		var contentNamespaces;

		contentNamespaces = config.get( 'wgContentNamespaces' );

		return $container
			.find( 'a[href][title]:not(' + blacklist.join( ', ' ) + ')' )
			.filter( function () {
				var title,
					titleText = getTitle( this.href, config );

				if ( !titleText ) {
					return false;
				}
				// Is titleText in a content namespace?
				title = mw.Title.newFromText( titleText );
				if ( title && ( $.inArray( title.namespace, contentNamespaces ) >= 0 ) ) {
					$( this ).data( 'page-previews-title', titleText );

					return true;
				}
			} );
	};

}( mediaWiki, jQuery ) );