This module recalculates VAT amounts of each Drupal Commerce Line-items that has product discount attached as a component.
Calculation triggers on rules event "Calculating the sell price of a product".
Default rule (Calculate VAT on discount) is generated with weight 5 so that this event updates currently calculated prices.
Idea is to subtract the VAT amount with same ratio as the line item price.
New component is being added to line-item price as a positive value, so that the order total calculation is not being messed up.