#include <stdlib.h>
#include <stdbool.h>

#include "track_list.h"

#define TRACK_LIST_START_CAPACITY 1

struct track_list
{
  int size;
  int capacity;
  int *starts;
  int *ends;
};

track_list *track_list_create()
{
  track_list *l = malloc(sizeof(track_list));
  if (l != NULL)
    {
      l->size = 0;
      l->capacity = TRACK_LIST_START_CAPACITY;
      l->starts = malloc(sizeof(int) * l->capacity);
      l->ends = malloc(sizeof(int) * l->capacity);

      if (l->starts == NULL || l->ends == NULL)
	{
	  free(l->starts);
	  free(l->ends);
	  free(l);
	  return NULL;
	}
    }
  return l;
}

void track_list_destroy(track_list *l)
{
  if (l != NULL)
    {
      free(l->starts);
      l->starts = NULL;
      free(l->ends);
      l->ends = NULL;
      free(l);
    }
}

int track_list_size(const track_list *l)
{
  if (l == NULL)
    {
      return 0;
    }
  else
    {
      return l->size;
    }
}

bool track_list_add(track_list *l, int start, int end)
{
  if (l == NULL)
    {
      return false;
    }

  if (l->size > 0 && start < l->ends[l->size - 1])
    {
      return false;
    }

  if (start > end)
    {
      return false;
    }

  if (l->size == l->capacity)
    {
      int *bigger_starts = malloc(sizeof(int) * l->capacity * 2);
      int *bigger_ends = malloc(sizeof(int) * l->capacity * 2);

      if (bigger_starts != NULL && bigger_ends != NULL)
	{
	  for (int i = 0; i < l->capacity; i++)
	    {
	      bigger_starts[i] = l->starts[i];
	      bigger_ends[i] = l->ends[i];
	    }
	  free(l->starts);
	  free(l->ends);
	  l->starts = bigger_starts;
	  l->ends = bigger_ends;
	  l->capacity *= 2;
	}
      else
	{
	  free(bigger_starts);
	  free(bigger_ends);
	}
    }

  if (l->size < l->capacity)
    {
      l->starts[l->size] = start;
      l->ends[l->size] = end;
      l->size++;
      
      return true;
    }
  else
    {
      return false;
    }
}

bool track_list_get(const track_list *l, int i, int *start, int *end)
{
  if (l == NULL || i < 0 || i >= l->size)
    {
      return false;
    }

  if (start != NULL)
    {
      *start = l->starts[i];
    }

  if (end != NULL)
    {
      *end = l->ends[i];
    }

  return true;
}