#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
//#include <stdbool.h>
#include <assert.h>
#include "array.h"

void fill_array(Array *a);
void output_array(Array *a);
void shift_array(Array *a);
Array *average_adjacent(Array *a);

void fill_array(Array *a)
{
  for(int i = 0; i < a -> size; i++) {
     a->data[i] = (double)rand()/RAND_MAX*200.0-100.0;    //generate numbers betw. -100 and +100
  }
}

void output_array(Array *a)
{
  for(int i = 0; i < a -> size; i++) {
    printf("array[%i] = %.4f\n", i, a->data[i]);
  }
}

void shift_array(Array *a)
{
  double array_first_pos = a->data[0];
  //    printf("\narray1,pos0 = %f\n", a->data[0]);   //debug
    for (int i = 0 ; i < (a -> size)-1 ; i++)    {
	    a->data[i] = a->data[i+1];
    }
    a->data[(a->size)-1] = array_first_pos;
}

Array *average_adjacent(Array *a)
{
  Array *Array_2 = (Array *) malloc(sizeof(Array));
  if (Array_2 == NULL)
    printf("\nMalloc Error creating array!\n");
  Array_2 -> size = ((a->size)/2);
  Array_2 -> data = (double *) malloc(sizeof(double)*(Array_2->size));
  if ((Array_2 -> data) == NULL)
    printf("\nMalloc Error creating data!\n");

  //printf("\n\n A2 Size: %i\n\n", Array_2->size);  //debug
  for(int i =0 ; i < (Array_2->size) ; i++)
  {
    Array_2->data[i] = (((a->data[2*i])+(a->data[2*i+1]))/2);
  }

  return (Array_2);
}

int main(int argc, char *argv[])
{
  srand((double)time(NULL));
  
  //check if user input is valid
  if (argc != 2)
  {
    printf("\ninput value incorrect!\n");
    return 1;
  }

  Array *Array_1 = (Array *) malloc(sizeof(Array));
  if (Array_1 == NULL)
  {
    printf("\nMalloc Error creating array!\n");
    return 1;
  }
  Array_1 -> size = atoi(argv[1]);
  Array_1 -> data = (double *) malloc(sizeof(double)*(Array_1->size));
  if ((Array_1 -> data) == NULL)
  {
    printf("\nMalloc Error creating data!\n");
    return 1;
  }

  fill_array(Array_1);
  printf("\nArray 1\n");
  output_array(Array_1);
  shift_array(Array_1);
  printf("\nShift Array 1 left by 1\n");
  output_array (Array_1);
  Array *Array_2 = average_adjacent(Array_1);
  printf("\nArray 2 average\n");
  output_array(Array_2);

  //return mem to os
  free(Array_1 -> data);
  free(Array_1);
  free(Array_2 -> data);
  free(Array_2);

  return 0;
}