#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "xcpu.h"

int main(int argc, char* argv[]){
  int i = 0;
  int k = 0;
  int status;
  int cycles;
  char code;
  FILE* file;
  struct xcpu_context c;

  c.memory = malloc(sizeof(unsigned char)*0xFFFF);  //Memory allocation of 0s, 65536
  c.pc=0;                                           //Program Counter = 0
  c.state=0x0000;                                   //State initiated to 0
  for(i=0;i<=15;i++){                               //All registers set to 0
    c.regs[i]=0x0000;
  }

  if(argc!=3){
    printf("Format is xsim cycles filename\n");
    exit(0);
  }

  if((file=fopen(argv[2], "r")) == NULL){
    printf("Unable to open File %s\n", argv[2]);
    exit(0);
  }

  cycles=atoi(argv[1]);

  if(cycles<0){
    printf("Cycles must be 0 and higher\n");
    exit(0);
  }

  while(fread(&code, sizeof(char), 1, file)){
    c.memory[k]=code;
    k++;
    if(k==0xFFFF){
      printf("ERROR: Out of memory\n");
      exit(0);
    }
  }

 //Cycle execution
  if(cycles == 0){
      while(status != 0){
        status = xcpu_execute(&c);
        if(status == 0){
          printf("MESSAGE: CPU has halted.\n");
          break;
        }
      }
  }

  else{
    for(k = 1; k <= cycles; k++){
        status = xcpu_execute(&c);
        if(status == 0){
          printf("MESSAGE: CPU has halted.\n");
          break;
        }
    }
    if(status==1) printf("WARNING: CPU has timed-out.\n");
  }
  return 0;
}