Don't expect quality code. This is what you get if you leave a student with Ben Eater's 8-bit computer series as only previous experience and they learned VHDL by copy-pasting StackOverflow and other random examples from shady, full of ads, websites.
Even though it has some differences, the original architecture was inspired by Ben Eater's 8-bit computer which itself is inspired by the SAP-1 (Simple-As-Possible) architecture described in Digital Computer Electronics by Albert Paul Malvino and Jerald A. Brown
Red signals are hardcoded, black ones can be controlled by control signals.
It plays Bad Apple : Source Video (YouTube)
