Student solo pilot entering the downwind at a non-towered airport reported a NMAC when another aircraft entered downwind at the same position.

Narrative

I was the pilot in Aircraft X. I am a student pilot and I was soloing. I was returning from ZZZ and had descended into the traffic pattern altitude (1200 MSL) over 'The River and the Bridge' which is a visual marker that pilots use at WVI to describe 3 miles on the 45 for the left-downwind for runway 20. I then visually see a plane and hear; on the radio; a plane join the 45 entrance (the same thing I am doing) in front of me. I have; by this point; made my 10 mile radio call; my 5 mile radio call (over the river and the bridge); and now I call that I am going to follow Aircraft Z into the left downwind. Aircraft Z is around 1150; so I descend slightly to follow them and maintain separation.The other plane in question; Aircraft Y; has made no radio calls identifying themselves at this point. They (according to the radar) turned cross wind; with no radio call; and then turned downwind; cutting off the 45; again with the radio call. They were climbing into me; so I couldn't see them until the last few seconds. I tried initiating a right 360 to avoid them; but I quickly realized that they were climbing into me too quickly and I wouldn't have made it. So; I pulled up hard on the controls and dodged them; high by about 100 feet.I landed afterwards and immediately consulted with the owner of our flight school; my instructor; and another pilot who witnessed the event. I was pretty shaken up; but I knew to file a report immediately. I feet like it is important to mention that the aircraft; Aircraft Y; the aircraft who almost hit me; never made a single self-identifying radio call in any turn at an uncontrolled airport. They also made no evasive maneuvers to avoid me; they just stayed climbing in a straight line after turning into me. This can be confirmed by various recordings. - The river and the bridge call. The NEAR MISS call. I held the radio button down as a clutched the controls when stopping my right 360 and instead pulling back hard on the controls. You can hear this in the radio - Re-enter the pattern. Extend my downwind. Extend my base call for separation.Turning final call.Before; after; and in between all of these calls; there isn't a single aircraft identifying themselves as Aircraft Y and they never report their position; meaning I only had visual information to create separation. There were two questionable transmissions. The first is unintelligible; and the second sounds like 'Were turning left......... runway....... East....... Watsonville.' Even if this was them; there was no identifying information in tail number; no crosswind leg call; and no downwind leg call.