Trigger to check for the role of an agent

Hi,

The Problem I am having there is no permission for a role to only change the state of the ticket. I can either allow an agent to be able to close a ticket and be able to reply on tickets or an agent can not close a ticket and can not reply on a ticket.
I would like to be able to either have a separated permission field or
I would like to add a Trigger that can check on an update on a ticket and check if the update was done by a specific role.

So my proposal would be that triggers can check on the Owner of the Ticket (Or any other way to view the last active user) and check upon this object for usefull informations. For example the trigger can check like the Article object and on this object the sender variable (which is the role of the sender in this case)


OR
To be able to edit a roles permissons to enable/disable them from editing the state of the ticket but also allowing them to being able to reply to tickets.

But now I could check for the role of the agent and modify accordingly.