Umbraco multiple hostnames, get correct url for a page, based on the domain of the current page.

PublishedContentWrappedExtensions.cs

public static class PublishedContentWrappedExtensions
{
	public static string GetContextAwareUrl(this PublishedContentWrapped content)
	{
		var urls = new List<string>();

		urls.Add(UmbracoContext.Current.RoutingContext.UrlProvider.GetUrl(content.Id));
		urls.AddRange(UmbracoContext.Current.RoutingContext.UrlProvider.GetOtherUrls(content.Id));

		var url = urls.FirstOrDefault(x => x.Contains(UmbracoContext.Current.HttpContext.Request.Url.Host));

		if (url != null)
			return url;

		return content.Url;
	}
}