File to custom IDOC or File to abap proxy

Hi there,

I would like to know best approach for the following scenario.

1) i have file coming from legacy system

2) On target side SAP , I have BAPI's available (Create, Save, Commit )(No standard IDOC available)

I can create Custom IDOC and call those BAPI's in Custom Function Module

or

I can use ABAP proxy and call BAPI's

What is the best way of doing this? and Is there any other way?

Thanks

Kumar