If we start with HERE, see their API first. We need search (address->coordinates), routing and reverse search (coordinates->address).
Pure Maps uses REST API to communicate with the servers. So, check their REST API and see if you can get trucks support if you use it.
Docs are at https://developer.here.com/documentation
Routing at https://developer.here.com/documentation/routing/dev_guide/topics/request-a-simple-route.html
If routing seems OK, then let's start with search. Its API at https://developer.here.com/documentation/geocoder/dev_guide/topics/what-is.html
That API we will translate to code in https://github.com/rinigus/pure-maps/tree/master/geocoders , so Pure Maps will understand it