Tiny program to log to file active application and window

I need a tiny program (or shell script if possible) that will run in the background and do 2 things: 1) Log to file the current active application and window each time this changes (time, name of application and name of window). For help on how to do that, see [login to view URL] 2) If the computer have been idle (no mouse movement or keys pressed) for 1 minute, log this (time and "idle").