#include <stdio.h>
#include <stdlib.h>
#include "stack.h"

void stackPush(struct stack_st* s, int val){

  if (s->len == 0 || s->arr == NULL){

    // Peame küsima mälu
    s->size = 1;
    //printf("yeet: %d\n", *(s->arr));
    s->arr = (int*) malloc(s->size * sizeof(int));

    // Kontrollime, et mälu allokeermisel ei tekinud probleeme
    if (s->arr == NULL) {
	    printf("Mälu otsas\n");
        return;
    }
    s->arr[s->len++] = val;

  } // s->len == 0 end

  else if (s->len == s->size){
    int tmp_size = 2 * s->size;
    int* tmp_arr = realloc(s->arr, tmp_size);

    // Kontrollime, kas saime mälu juurde
    if (tmp_arr == NULL) {
	    printf("Mäluala suurendamine Erroris\n");
        return;
    }

    s->size = tmp_size;
    s->arr = tmp_arr;

    s->arr[s->len] = val;
    s->len++;
    return;
  }
  else {
    s->arr[s->len++] = val;
  }
}


int stackPop(struct stack_st *s){
  int x = s->arr[--s->len];
  int tmp_size = s->size / 2;

  // Kui vaja s-> mälu suurust kahandada
  if (s->len < tmp_size){
     int* tmp_arr = realloc(s->arr, tmp_size);

     if (!tmp_arr){
         printf("No good, malu otsas");
         return 0;
     }

  s->size = tmp_size;
  s->arr = tmp_arr;
  }

  if (s->len == 0)
      stackFree(s);

  return x;
}

void stackFree(struct stack_st *s){
  free(s->arr); 
  s->arr = NULL;
}


int stackIsEmpty(struct stack_st *s) {
    return !(s->len > 0);
}


int stackPeek(struct stack_st *s){
	// To avoid funking up the s->len
	if (stackIsEmpty(s)) return 0;
	else if (s->len == 1) return s->arr[1];
	else{
		int x = stackPop(s);
		stackPush(s, x);
		return x;
	}
}


void stackPrint(struct stack_st *s){
	while(1){
		if(stackIsEmpty(s))
			break;

		int x = stackPop(s);
		printf("%d\n", x);
	}
	return;
}