#made by zombie
#02/01/21

#0-255 is internal registers and flags and etc
# program execcution starts at 256
#stack starts at 65535 FILO

#0  IP      #Instruction Pointer
#1	EAX
#2	EBX
#3	ECX
#4	EDX
#5	ESI
#6	EDI
#7	ESP     #stack pointer
#8	EBP
#9  FLAG    #Read-Only contains the flags


#list of opcodes
#0 interrupt
#1 reset
#2 debug info (nop)
#3 mov


import math
import numpy as np





class Zomcpu:
    def __init__(self, memorysize=None, debug=None):
        print('Processor Init')
        self._memorysize = memorysize
        self._memory = np.zeros(memorysize)
        self._debug = debug
        
    def reset(self):
        print('Processor Resetting')
        self._memory = np.zeros(self._memorysize) #clear memory
        
        self._memory[7] = self._memorysize - 1 #set stackpointer
        self._memory[0] = 256 #set instructiojn pointer
        
    def exec(self):
        Go = 1
        while Go: #change this to if not halt
            #fetch
            opcode = self._memory[int(self._memory[0])]
            address = self._memory[int(self._memory[0] + 1)]
            value = self._memory[int(self._memory[0] + 2)]
            
            if self._debug:
                print(f'Opcode: {opcode}\nAddress: {address}\nValue: {value}\nIP: {self._memory[0]}')

            if opcode == 0:
                Go = value
                if value == 0:
                    print('Processor Halted')

            elif opcode == 1: #reset
                self.reset()
            
            elif opcode == 2: #debug (nop if debug is not set)
                if self._debug:
                    print(f'Opcode: {opcode}\nAddress: {address}\nValue: {value}')
                
            elif opcode == 3: #mov
                self.write_memory(address, value)
                
            self._memory[0] += 3 #increment instruction pointer
            
    
    def set_memory(self, memory):
        self._memory = memory
    def write_memory(self, address, value):
        self._memory[int(address)] = value
    def read_memory(self):
        return self._memory
    def read_memory_address(self, address):
        return self._memory[address]
            
        
if __name__ == "__main__":
    cpu = Zomcpu(65536, True)
    cpu.reset()
    print(cpu.read_memory_address(7))
    
    #hard coded opcodes
    cpu.write_memory(256, 3)
    cpu.write_memory(257, 27)
    cpu.write_memory(258, 105)
    print(cpu.read_memory_address(27))
    cpu.exec()
    print(cpu.read_memory_address(27))