How to log everything in 'when' part of Drools rule?

Question

I have to log everything that is responsible to fire a rule in Drools like objects, conditions etc.

I am able to get the objects by using AgendaEventListener and writing below code in the beforeActivationFired method of it.

@Override
public void beforeActivationFired(BeforeActivationFiredEvent event){
    event.getActivation().getObjects();
}

But how do I get the conditions and which methods are called on which object? Like I have an object that is used as a global variable which is used to validate values against values in cache i.e. in when part of the rules different methods on this global object(have hundreds of methods in it) are called.

Now I want to have information on what methods are called so that I can log the information before hand because after the execution the values in the cache might get change.

For example -

If in when part below condition is there then I wish to know the condition as well as the value of both the sides in the condition i.e. the value of $val as well as $cache.getCurrentTimestamp()(Please note that the method called on cache is not known beforehand).

$val : timestamp,
$val == $cache.getCurrentTimestamp()

How can I achieve this task?