mapping from multiple repeating elemnts

Summary

enrich nested payload with values .

Content

i have this complex mapping
i have this payload with 1 or more invoiceLine ,  each 1 or more child elements called  invoiceDistribution .

but i'm stuck doing the following logic :
for each line i will call db adapter which will generate a unique id for each line .
  for each distribution i will also call other db adapter that will generate unique id for each distribution .

so if i have 3 lines , each line has 4 distribution
then i will call generateLindId DB adapter : 3 times in total ;
and will call the generateDistId Db adapter : 4 * 3 = 12 times in total .


the problem is in the right side of the mapping , i pass the lines and distribution separately . that is for each distribution