#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <string.h>
#include "numbers.h"
#include "bintree.h"

unsigned int RANDOM_SEED = 0;

// TODO: getDuplicate und createNumbers implementieren
/*  *   * Erzeugen eines Arrays mit der vom Nutzer eingegebenen Anzahl an Zufallszahlen.
 * Sicherstellen, dass beim Befüllen keine Duplikate entstehen.
 * Duplizieren eines zufälligen Eintrags im Array.
 * in `getDuplicate()`: Sortieren des Arrays und Erkennen der doppelten Zahl durch Vergleich benachbarter Elemente. */

// Returns len random numbers between 1 and 2x len in random order which are all different, except for two entries.
// Returns NULL on errors. Use your implementation of the binary search tree to check for possible duplicates while
// creating random numbers.

unsigned int setSeed(seed)
{
  RANDOM_SEED = seed;
}

unsigned int createchecknumber(unsigned int len, unsigned int *numbers)
{
  for (unsigned int i = 0; i < len; i++)
  {
    unsigned int same = 0;

    do
    {
      unsigned int value = 0;
      value = (rand() % (len * 2) + 1);

      same = 0;

      for (unsigned int j = 0; j < i; j++)
      {
        if (numbers[j] == value)
        {
          same = 1;
          break;
        }
      }

      if (same == 0)
      {
        numbers[i] = value;
      }

    } while (same == 1);
  }
}

unsigned int *createNumbers(unsigned int len)
{
  if (RANDOM_SEED == 0)
  {
    srand(time(NULL));
  }
  else
  {
    srand(RANDOM_SEED);
  }

  unsigned int *numbers = malloc(sizeof(unsigned int) * len);
  if (numbers == NULL)
  {
    return NULL;
  }

  createchecknumber(len, numbers);

  unsigned int i = 0;
  unsigned int j = 0;

  do
  {
    i = 0;
    j = 0;

    i = rand() % len;
    j = rand() % len;

  } while (i == j);

  numbers[i] = numbers[j];
}

unsigned int *sortnumbers(unsigned int numbers[], unsigned int len)
{
  for (unsigned int j = 0; j < len - 1; j++)
  {
    for (unsigned int i = 0; i < len - 1 - j; i++)
    {
      unsigned int temp = 0;
      if (numbers[i] > numbers[i + 1])
      {
        temp = numbers[i];
        numbers[i] = numbers[i + 1];
        numbers[i + 1] = temp;
      }
    }
  }
  return numbers;
}

// Returns only the only number in numbers which is present twice. Returns zero on errors.
unsigned int getDuplicate(const unsigned int numbers[], unsigned int len)
{
  sortnumbers(numbers, len);

  for (unsigned i = 0; i < len - 1; i++)
  {
    if (numbers[i] == numbers[i+1])
    {
      return numbers[i];
    }
  }
  return 0;
}