#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#ifndef instruktion
#include "instruktion.c"
#endif /* ifndef instruktion */
#ifndef code
#include "code.c"
#endif /* ifndef code */


//Comment to disable debug

#define DEBUG

unsigned int* programmSpeicher;

void copyToProgramm(unsigned int codeToCopy[]){
  programmSpeicher = codeToCopy;
}

// Stack
#define maxValues 1000

unsigned int stack[maxValues];
unsigned int current = 0;

void stackPush(unsigned int value) {
    if (current > (maxValues-1)) {
        fprintf(stderr, "stack overflow\n");
        exit(EXIT_FAILURE);
    }
    stack[current] = value;
    current++;
}

unsigned int stackPop(void) {
    if (current < 1) {
        fprintf(stderr, "stack underflow\n");
        exit(EXIT_FAILURE);
    }
    return stack[--current];
}

void version(void) {
    printf("Ninja Virtual Machine version %i (compiled %s, %s)\n", 0, __DATE__, __TIME__);
}

void help(void) {
    printf("usage: ./njvm [option] [option] ...\n\t--version\tshow version and exit\n\t--help\t\tshow this help and exit\n");
}

void useption(int argc, char *argv[]) {
    if (argc > 1) {
        if (strcmp(argv[1], "--version") == 0) {
            version();
        } else if (strcmp(argv[1], "--help") == 0) {
            help();
        } else {
            printf("unknown command line argument '%s', try './njvm --help'", argv[1]);
        }
    }
}
void printProgramm(){
  int i = 0;
  char c[10];
  while (programmSpeicher[i] != 0) 
  {
    switch (programmSpeicher[i] >> 24) {
      case PUSHC:
        strcpy(c,"pushc");
      break;
      case ADD:
        strcpy(c,"add");
      break;
      case SUB:
        strcpy(c,"sub");
      break;
      case MUL:
        strcpy(c,"mul");
      break;
      case DIV:
        strcpy(c,"div");
      break;
      case MOD:
        strcpy(c,"mod");
      break;
      case RDINT:
        strcpy(c,"rdint");
      break;
      case WRINT:
        strcpy(c,"wrint");
      break;
      case RDCHR:
        strcpy(c,"rdchr");
      break;
      case WRCHR:
        strcpy(c,"wrchr");
      break;
      default:
        strcpy(c,"halt");
      break;
    }
    IMMEDIATE(programmSpeicher[i])? printf("%03i:\t%s\t%i\n",i,c,IMMEDIATE(programmSpeicher[i])) : printf("%03i:\t%s\n",i,c);
       i++;
  }
  printf("%03i:\thalt\n",i);
}
void execute(void) {
    int i = 0;
    int intInput;
    int temp;
    char charInput;
    while (1) {

        switch (programmSpeicher[i] >> 24) {
            case HALT:
                  goto end;
                break;
            case PUSHC:
                  stackPush(IMMEDIATE(programmSpeicher[i]));
                break;
            case ADD:
                  stackPush(stackPop()+stackPop());
                break;
            case SUB:
                  temp = stackPop();
                  stackPush(stackPop() - temp);
                break;
            case MUL:
                  stackPush(stackPop()*stackPop());
                break;
            case DIV:
                  temp = stackPop();
                  stackPush(stackPop()/temp);
                break;
            case MOD:
                  temp = stackPop();
                  stackPush(stackPop()%temp);
                break;
            case RDINT:
                  scanf("%i",&intInput);
                  stackPush(intInput);
                break;
            case WRINT:
                  printf("%i",stackPop());
                break;
            case RDCHR:
                  scanf("%c",&charInput);
                  stackPush(charInput);
                break;
            case WRCHR:
                  printf("%c",stackPop());
                break;
        }
        i++;
    }
end:
  return;
}
#ifdef DEBUG

void printStack(void){
  if(current >= 0) return;
  printf("----\n");
  for (int i = 0; i < current; i++) {
    printf("|%i| \n",stack[i]);
  }
  printf("----\n");
}

void tests(void){
  printf("Runnig debug mode\n");
  copyToProgramm(code1);
  printProgramm();
  execute();
}

#endif /* ifdef DEBUG */

int main(int argc, char *argv[]) {
    #ifdef DEBUG
      tests();
    #endif /* ifdef DEBUG */
    if (argc > 1) useption(argc, argv);
    else {

//    Started
        printf("Ninja Virtual Machine started\n");

//    Stopped
        printf("Ninja Virtual Machine stopped\n");
        return 0;
    }
}