/*
 * array.c -- manipulate dynamic arrays
 *
 * Copyright (c) 2011, 2012, David Demelier <markand@malikania.fr>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "array.h"

#define OFFSET(x)	(arr->unit * (x))

static int	grow(struct array *);

int
array_init(struct array *arr, size_t unit)
{
	if (unit == 0)
		return -1;

	arr->unit	= unit;
	arr->size	= OFFSET(arr->bsize);

	/* Set defaults if needed */
	arr->bsize	= (arr->bsize <= 0) ? ARRAY_DEFAULT_BSIZE : arr->bsize;
	arr->malloc	= (arr->malloc == NULL) ? &malloc : arr->malloc;
	arr->realloc	= (arr->realloc == NULL) ? &realloc : arr->realloc;

	if ((arr->data = arr->malloc(arr->size)) == NULL)
		return -1;

	if (arr->flags & ARRAY_CLEARBITS)
		memset(arr->data, 0, arr->size);

	return 0;
}

/*
 * Valid options that can be set for an array :
 * l -> optional array block size of type int
 * m -> malloc function that must matches void * (*malloc)(size_t)
 * r -> realloc function that must matches void * (*realloc)(void *, size_t)
 * f -> array flags of type int
 */

void
array_set(struct array *arr, const char *fmt, ...)
{
	va_list ap;
	const char *p;

	va_start(ap, fmt);
	for (p = fmt; *p != '\0'; ++p)
		switch (*p) {
		case 'l':
			arr->bsize = va_arg(ap, int);
			break;
		case 'm':
			arr->malloc = va_arg(ap, void *(*)(size_t));
			break;
		case 'r':
			arr->realloc = va_arg(ap, void *(*)(void *, size_t));
			break;
		case 'f':
			arr->flags = va_arg(ap, int);
			break;
		default:
			break;
		}
}

/*
 * Add to the head of array. NOTE: this may be very slow when adding a lot
 * of object (about 100000). If you need to add a lot of data please consider
 * using linked list instead.
 */

int
array_push(struct array *arr, const void *data)
{
	if (grow(arr) < 0)
		return -1;

	memmove((char *)arr->data + arr->unit, arr->data, OFFSET(arr->length++));
	memcpy((char *)arr->data, data, arr->unit);

	return 0;
}

/*
 * Insert the data at the specified index. The function returns -1 on
 * allocation failure or when the index is outof bounds otherwise 0 is returned.
 */

int
array_insert(struct array *arr, const void *data, int index)
{
	if (index < 0)
		return array_push(arr, data);
	if (index >= arr->length)
		return array_append(arr, data);

	/* Good place */
	memmove((char *)arr->data + OFFSET(index + 1),
	    (char *)arr->data + OFFSET(index), OFFSET(arr->length++ - index));
	memcpy((char *)arr->data + OFFSET(index), data, arr->unit);

	return 0;
}

/*
 * Append the data to the end of array.
 */

int
array_append(struct array *arr, const void *data)
{
	if (grow(arr) < 0)
		return -1;

	memcpy((char *)arr->data + OFFSET(arr->length++), data, arr->unit);

	return 0;
}

/*
 * Remove the array's head.
 */

void
array_pop(struct array *arr)
{
	array_iremove(arr, 0);
}

/*
 * Remove the array's tail.
 */

void
array_unqueue(struct array *arr)
{
	array_iremove(arr, arr->length - 1);
}

/*
 * Remove the data at the specified index. Bounds are checked.
 */

void
array_iremove(struct array *arr, int index)
{
	if (arr->length > 0 && index >= 0 && index < arr->length) {
		if (arr->flags & ARRAY_FASTREMOVE)
			memmove((char *)arr->data + OFFSET(index),
			    (char *)arr->data + OFFSET(--arr->length),
			    arr->unit);
		else
			memmove((char *)arr->data + OFFSET(index),
			    (char *)arr->data + OFFSET(index + 1),
			    OFFSET(arr->length-- - index - 1));
	}

	if (arr->flags & ARRAY_CLEARBITS)
		memset((char *)arr->data + OFFSET(arr->length), 0, arr->unit);
}

/*
 * Remove the object referenced by the `data' argument. Useful when you
 * don't know the index.
 */

void
array_premove(struct array *arr, const void *data)
{
	void *elm;
	int i;

	for (i = 0; i < arr->length; ++i) {
		elm = (char *)arr->data + OFFSET(i);

		if (memcmp(elm, data, arr->unit) == 0) {
			array_iremove(arr, i);
			break;
		}
	}
}

/*
 * Swap the two elements referenced by index `i1' and `i2'. This function needs
 * to allocate data to swap elements thus if the functions fails it returns -1
 * otherwise 0 is returned.
 */

int
array_iswap(struct array *arr, int i1, int i2)
{
	void *tmp;

	/* Out of bounds */
	if (i1 >= arr->length || i1 < 0 || i2 >= arr->length || i2 < 0)
		return -1;

	if ((tmp = arr->malloc(arr->unit)) == NULL)
		return -1;

	memcpy((char *)tmp, (char *)arr->data + OFFSET(i1), arr->unit);
	memcpy((char *)arr->data + OFFSET(i1), (char *)arr->data + OFFSET(i2),
	    arr->unit);
	memcpy((char *)arr->data + OFFSET(i2), (char *)tmp, arr->unit);

	/*
	 * Clear bytes for safety you probably don't want a password or
	 * secure data to be left somewhere in the memory.
	 */

	if (arr->flags & ARRAY_CLEARBITS)
		memset(tmp, 0, arr->unit);
	free(tmp);

	return 0;
}

/*
 * Swap the two elements referenced by data `o1' and `o2'. This function
 * may be slow on large arrays since it must travel all the object
 * to find the indexes.
 */

int
array_pswap(struct array *arr, const void *o1, const void *o2)
{
	int found, i1, i2;

	for (i1 = found = 0; !found && i1 < arr->length; ++i1)
		found = memcmp((char *)arr->data + OFFSET(i1), o1, arr->unit) == 0;

	if (!found)
		return -1;

	for (i2 = found = 0; !found && i2 < arr->length; ++i2)
		found = memcmp((char *)arr->data + OFFSET(i2), o2, arr->unit) == 0;

	if (!found)
		return -1;

	return array_iswap(arr, --i1, --i2);
}

/*
 * Apply the function `fn' on each object and give the optional `udata'
 * argument to the function too.
 */

void
array_map(const struct array *arr, array_map_fn fn, void *udata)
{
	int i;

	for (i = 0; i < arr->length; ++i)
		fn((char *)arr->data + OFFSET(i), udata);
}

/*
 * Compare each object with the user supplied function. If the `fn' function
 * returns 1, 1 is returned and dst points to the correct object, dst should
 * be a pointer to a pointer of object, like (int **) for a array of int.
 */

int
array_find(const struct array *arr, array_cmp_fn fn, void *dst, void *u)
{
	int st, i;

	for (i = st = 0; i < arr->length && st != 1; ++i)
		st = fn((char *)arr->data + OFFSET(i), u);

	if (st && dst)
		*(char **)dst = (char *)arr->data + OFFSET(i - 1);

	return (st) ? i - 1 : -1;
}

void *
array_first(const struct array *arr)
{
	return arr->data;
}

void *
array_last(const struct array *arr)
{
	if (arr->length == 0)
		return array_first(arr);

	return (char *)arr->data + OFFSET(arr->length - 1);

}

void *
array_index(const struct array *arr, int idx)
{
	if (idx < 0)
		return array_first(arr);
	if (idx >= arr->length)
		return array_last(arr);

	return (char *)arr->data + OFFSET(idx);
}

/*
 * Erase every bytes and set the length to 0.
 */

void
array_clear(struct array *arr)
{
	if (arr->flags & ARRAY_CLEARBITS)
		memset(arr->data, 0, arr->size);

	arr->length = 0;
}

/*
 * Same as array_clear except it also free the array object.
 */

void
array_free(struct array *arr)
{
	array_clear(arr);
	free(arr->data);

	arr->data	= NULL;
	arr->size	= 0;
}

/*
 * Increate the array storage when it is full. If the buffer is fixed size
 * it returns -1 on full buffer otherwise 0 is returned if allocation
 * succeeded.
 */

static int
grow(struct array *arr)
{
	if ((arr->size / arr->unit) > (size_t)arr->length)
		return 0;

	if (!(arr->flags & ARRAY_FIXED)) {
		if ((arr->data = arr->realloc(arr->data, arr->size +
		    OFFSET(arr->bsize))) == NULL) {
			arr->size = arr->length = 0;
			return -1;
		}

		arr->size += OFFSET(arr->bsize);
	} else
		return -1;

	return 0;
}