#include "list.h"
#include "util.h"
#include <string.h>
#include <stdio.h>

struct List_s {
  void **array;                 /* the array of elements */
  NUM len;                   /* the length of the array */
  NUM capacity;              /* the number of pre-allocated bytes
                                   for the array */
};

List *
new_list()
{
  void **array = MYALLOC(void*, LIST_INIT_AMOUNT);

  if (array == NULL) return NULL;

  for (NUM i = 0; i < LIST_INIT_AMOUNT; i++)
    *(array+i) = NULL;

  List *list = MYALLOC(List, 1);

  if (list == NULL) return NULL;

  list->array = array;
  list->len = 0;
  list->capacity = LIST_INIT_AMOUNT;

  return list;
}

H_ATTR
unsigned char
add_to_list(List *ls, void *element)
{
  if (!(ls->capacity)) {
    /* The capacity can be zero only when the list has been destroyed,
       in which case adding an element to that list is definitely an
       error. */
    eprintf("%s:%d, Adding an element to a destroyed list.\n",
            __FILE__, __LINE__);
  }

  (ls->len)++;

  if (ls->len >= ls->capacity) {
    NUM new_capacity = ((ls->capacity) * 3) >> 1;

    if (new_capacity < ls->capacity + LIST_INIT_AMOUNT)
      new_capacity = ls->capacity + LIST_INIT_AMOUNT;

    NUM max_diff = 1 << 20;
    if (new_capacity >= ls->capacity + max_diff)
      new_capacity = ls->capacity + max_diff;

    void **array = MYALLOC(void *, ls->capacity);

    if (array == NULL) {
      ls->len -= 1;
      return 1;
    }

    for (NUM i = 0; i < ls->capacity; i++)
      *(array+i) = *(ls->array+i);

    /* The new_capacity will not be zero, so upon failure it returns
       NULL. */
    ls->array = realloc(ls->array, sizeof(void*) * new_capacity);

    if (ls->array == NULL) {
      ls->len -= 1;
      free(array);
      return 1;
    }

    for (NUM i = 0; i < ls->capacity; i++)
      *(ls->array+i) = *(array+i);

    free(array);

    for (NUM i = ls->capacity; i < new_capacity; i++)
      *(ls->array+i) = NULL;

    ls->capacity = new_capacity;
  }

  *(ls->array+ls->len-1) = element;

  return 0;
}

H_ATTR
void *
pop_from_list(List *ls)
{
  if (!(ls->len)) return NULL;

  return *(ls->array+--(ls->len));
}

H_ATTR
void
map_list(List *ls, acter f)
{
  for (NUM i = 0; i < ls->len; i++)
    f(*(ls->array+i));
}

void
print_list(List *ls, printer prt)
{
  printf("printing a list with length = %lu and capacity = %lu\n",
         ls->len, ls->capacity);

  map_list(ls, (acter) prt);

  printf("printing terminated\n");
}

void *
copy_num(void *p)
{
  NUM *pointer = malloc(sizeof *pointer);

  if (pointer == NULL) return NULL;

  *pointer = *((NUM *) p);

  return pointer;
}

unsigned char
copy_list(List *dest, List *source, copyer copyf)
{
  unsigned char sign = 0;

  if ((sign = list_assure_size(dest, source->len)))
    return sign;

  dest->len = source->len;

  for (NUM i = 0; i < source->len; i++) {
    void *pointer = copyf(*(source->array+i));
    if (pointer == NULL) return 1;
    *(dest->array+i) = pointer;
  }

  return 0;
}

H_ATTR
void *
list_nth(List *ls, NUM n)
{
  return *(ls->array+n);
}

H_ATTR
NUM
list_length(List *ls)
{
  return ls->len;
}

unsigned char
list_assure_size(List *ls, NUM size)
{
  if (ls->capacity >= size) return 0;  /* we are good */

  void **array = MYALLOC(void *, ls->capacity);

  if (array == NULL) return 1;

  for (NUM i = 0; i < ls->capacity; i++)
    *(array+i) = *(ls->array+i);

  ls->array = realloc(ls->array, sizeof(void*) * size);

  if (ls->array == NULL) return 1;

  for (NUM i = 0; i < ls->capacity; i++)
    *(ls->array+i) = *(array+i);

  free(array);

  for (NUM i = ls->capacity; i < size; i++)
    *(ls->array+i) = NULL;

  ls->capacity = size;

  return 0;
}

unsigned char
list_set_length(List *ls, NUM len)
{
  if (ls->len >= len) return 0;

  NUM *array = MYALLOC(NUM, len - ls->len);

  if (array == NULL) return 1;

  for (NUM i = ls->len; i < len; i++) {
    *(array + i - ls->len) = -1;
    *(ls->array+i) = array + i - ls->len;
  }

  ls->len = len;

  return 0;
}

void *
list_to_array(List *ls, NUM element_bytes, NUM *num)
{
  /* We shall not use a void pointer here, since standard C does not
     allow doing arithmetic on void pointers.  So we use a char
     pointer here, since the size of char is 1. */
  char *array = malloc(element_bytes * ls->len);

  if (array == NULL) return NULL;

  *num = ls->len;

  for (NUM i = 0; i < *num; i++)
    memcpy(array+(element_bytes*i), *(ls->array+i), element_bytes);

  return array;
}

void
destroy_list(List *ls, unsigned char all_free_p)
{
  if (all_free_p == 1)
    for (NUM i = 0; i < ls->len; i++)
      free(*(ls->array+i));

  if (all_free_p == 2)
    free(*(ls->array));

  free(ls->array);
  free(ls);

  ls->len = (ls->capacity = 0);
}