Its just a mig-19 no match even for our early 1970’s aircraft.
Self-developed? What a huge laugh. I can't think of a single technological development or product that China makes/builds that isn't essentially ripped-off technology from someone else.. At least they use to actually do some form of licensing from other nations for their weapons systems (mostly Russia), but now - they unabashedly copy everyone else.
There more recent "designs" for fighters look and operate strikingly like the Eurofighter Typhoon with a drop or two of US F-16. Their missiles that this plane carries are copied from Israel's Python system.