To angulate, there is a plugin called angular-translate that is great and is very fast for what it intend to do.
But there are easy modes yes, in addition to these plugins, there is a specification called i18n that aims to standardize this part of translations. You can find some of this here and there is also another project maintained by Mozilla , which is basically a framework called l20n that keeps localization in hand locators and translators, it can be used in any type of project.
Automatic updating and switching between files can be done by these frameworks, but you'll still need to translate your website into parts. It is also possible to use google translator to generate an instant translation, the work is minimal, but the result is not so good either ...