Chat agent idle time

Summary

I need to build a report to show the idle time of a chat agent

Content

Hi, 

I'm trying to build a report that shows the agent idle time.

This is the time that the agent is online and available and not on any chat (Basically when the agent waiting for a chat but they are not on a chat)

I do not want to count the time that the agent in non-available status or the time that the agent on one chat but they can take more (This is not idle)

Lastly, I want to do it by hour interval if possible