We need a GWT composite that would integrate with
The composite should be self sustained, have toggle behavior between these two payment methods, and has to implement payment processing integration stack, including authorization (token acquisition for Yandex). Acquired token should be stored in memcache for the purpose of this project (it will stored in DB later after integration with the rest of the application).
A rough design is attached. Design is not as important as flawless payment processing. Payments will be accepted from users, they will specify amount in provided box, and click pay. Authorization can be implemented in two different steps, i.e. User clicks to link Yandex to this app first, and then processes the payment, as long as all the data entered by the use is preserved, and they don't have a need to reenter amount, etc...
Also, attached is the Billing component that was started but not finished (for reference)