New house: change old Indoor - Outdoor gate-lock opener /intercom . See picture:)

We have bought a new house with an wired interncom / gatelock opener. Today it works as follow: If somone rings the doorbell on the intercom, I can talk to them from the inside telephone and push a butten that sends a signal (BZZZZZ) to the gate so the people outside can open it.

I really want to use the old wires and connect a new one that has the possibility to be smart and automated. If someone uses the doorbell, I can have it show video on the phones and other screens if wanted. Also it must be possible to open the gate as today. It dosnt need to me really complicated, just simple automated/smart.

See pictures for the wires thats already installed and goes thru the house to the outside.