Headphone stand, automatic audio switcher

We need:
prototype pcb board
3x mini-jack socket
3x two-position momentary switch (sorry, I designed it many months ago and I bought the switches in a local store. I don't know the model)

Hello
It is a headphone stand mounted in the vesa 100x100 standard on the back of the LCD monitor. The handle has 3 mini-jack sockets. One connector is for connecting the sound input (for example a computer), two outputs are for connecting headphones and speakers separately. By taking off the headphones, we will automatically switch to them.

https://www.youtube.com/watch?v=0LSzmXr9iBQ