How to intercept and forward GRPC call based on content of message

Question

I want to be able to forward a RPC call to a different implementation based on the content of a message.

I've research GRPC interceptors but the website doesn't have a good explanation on this. I can't seem to find good documentation on the subject

My proto file looks like:

message RPCParameters {
  enum DataSource {
    DS1 = 0;
    DS2 = 1;
    ...
    DS100 = 99;
  }
  int32 param1 = 1;
  ...
  DataSource datasource = 10;
}
...
...

message Result {
...
}

service MyService {
  rpc func1(RPCParameters) returns (Something) {}
  ....
  rpc func100(RPCParameters) returns (Something) {}
}

Now in my code I want to conditionally implement the functions based on the datasource value

Currently I am doing a conditional check in each function

i.e.:

MyServiceImplementation

implementation func1(params: Params) {
  switch on params.datasource {
     case DS1 => implementation 1
     case DS2 => implementation 2
     ..
     case DS100 => implementation 100
  }
}

implementation func2(params: Params) {
  switch on params.datasource {
     case DS1 => implementation 1
     case DS2 => implementation 2
     ..
     case DS100 => implementation 100
  }
}
...
implementation func100(params: Params) {
  switch on params.datasource {
     case DS1 => implementation 1
     case DS2 => implementation 2
     ..
     case DS100 => implementation 100
  }
}

So basically this is very cumbersome and error prone - i need to add a bunch of boiler plate to each function

I'm wondering if i can instead create different implementors and then through middle ware forward the RPC call to the correct version which should perform the logic.