Converting PHP site to Multilingual Site

We need our site converted from PHP to Multilingual Site, we need the integration bellow: Based on our discussion with our api provider in order to integrate their api then the senario will be that each time an entry of any content in the site then that word will be tracked and its relevant translated version will be stored in the database by the api. Then there is a need to call the API as many times as the language you want in the [login to view URL] example you want it to be in 5 languages , then the particular phrase needs to be passed 5 times for 5 languages and then each translated text needs to be stored in database. You need to have language flags in the front end from which the user will be able to choose the desired language they want to see the site in. The implementation of this API is equivalent to converting the existing work from php into a multilingual site. Static text labels will also be translated and for that it has to be manual process as the API doesn't do this feature. Currently we are using a 3rd party forum, we will need this to be changed to accommodate the API and so would like an original created non 3rd party forum integrated in this platform. Future problem:Initially the API will call us 5 languages, When that changes to 30 or more languages, this site needs to be able to adapt and not require rebuilds. Please read and price accordingly. Project must be completed within 1 month.