{ lib, cfg, models, allPhones }:

if cfg.intercomPrefix == null then []
else lib.concatLists (lib.mapAttrsToList (key: phone:
  let m = models.${phone.model}; in
  lib.optional m.hasProvisioning {
    extension        = "${cfg.intercomPrefix}${phone.extension}";
    endpoint         = "${key}-intercom";
    phoneKey         = key;
    target           = phone.extension;
    displayName      = "Intercom ${phone.displayName}";
    password         = phone.password;
    endpointTemplate = m.endpointTemplate;
    maxContacts      = m.maxContacts;
  }
) allPhones)