Joomla. Component - Invoice manager. Paysera payment integration

I use Joomla, Hikashop and Invoice Manager components for invoices. Once order in Hikashop is created it is automatically creating invoice in IM. I need to create: 1. paysera payment plugin for Invoice Manager; 2. paysera notification integration; Documentation about payment gateway: [login to view URL] Documentation about notifications: [login to view URL] I need to have a list of all incoming notifications from paysera. I need to be able to search, filter this list. I need to be able to map all data coming from paysera to user, order, invoice, etc. For every order that comes from Hikashop in IM i need to automatically set "due date" - 5 days from invoice date. (To be set in "Hikashop - Invoice Manager plugin" config). After info about payment is received, Hikashop order status should be changed to "some order status", which is set in config.