/** A generic linked list
 *
 * Linked lists a used for several data structures in the code.
 *
 * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
 * @copyright 2017, Institute for Automation of Complex Power Systems, EONERC
 *********************************************************************************/

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

#include "list.h"
#include "utils.h"

/* Compare functions */
static int cmp_lookup(const void *a, const void *b) {
	const struct {
		char *name;
	} *obj = a;
		
	return strcmp(obj->name, b);
}

static int cmp_contains(const void *a, const void *b) {
	return a == b ? 0 : 1;
}

static int cmp_sort(const void *a, const void *b, void *thunk) {
	cmp_cb_t cmp = (cmp_cb_t) thunk;

	return cmp(*(void **) a, *(void **) b);
}

void list_init(struct list *l)
{
	assert(l->state == STATE_DESTROYED);

	pthread_mutex_init(&l->lock, NULL);

	l->length = 0;
	l->capacity = 0;
	l->array = NULL;

	l->state = STATE_INITIALIZED;
}

int list_destroy(struct list *l, dtor_cb_t destructor, bool release)
{
	pthread_mutex_lock(&l->lock);

	assert(l->state != STATE_DESTROYED);

	for (size_t i = 0; i < list_length(l); i++) {
		void *p = list_at(l, i);
		
		if (destructor)
			destructor(p);
		if (release)
			free(p);
	}
	
	free(l->array);
	
	l->array = NULL;

	l->length = -1;
	l->capacity = 0;

	pthread_mutex_unlock(&l->lock);
	pthread_mutex_destroy(&l->lock);
	
	l->state = STATE_DESTROYED;
	
	return 0;
}

void list_push(struct list *l, void *p)
{
	pthread_mutex_lock(&l->lock);

	assert(l->state == STATE_INITIALIZED);
	
	/* Resize array if out of capacity */
	if (l->length >= l->capacity) {
		l->capacity += LIST_CHUNKSIZE;
		l->array = realloc(l->array, l->capacity * sizeof(void *));
	}
	
	l->array[l->length] = p;
	l->length++;

	pthread_mutex_unlock(&l->lock);
}

void list_remove(struct list *l, void *p)
{
	int removed = 0;

	pthread_mutex_lock(&l->lock);

	assert(l->state == STATE_INITIALIZED);

	for (size_t i = 0; i < list_length(l); i++) {
		if (l->array[i] == p)
			removed++;
		else
			l->array[i - removed] = l->array[i];
	}
	
	l->length -= removed;

	pthread_mutex_unlock(&l->lock);
}

void * list_lookup(struct list *l, const char *name)
{
	return list_search(l, cmp_lookup, (void *) name);
}

int list_contains(struct list *l, void *p)
{	
	return list_count(l, cmp_contains, p);
}

int list_count(struct list *l, cmp_cb_t cmp, void *ctx)
{
	int c = 0;

	pthread_mutex_lock(&l->lock);

	assert(l->state == STATE_INITIALIZED);

	for (size_t i = 0; i < list_length(l); i++) {
		void *e = list_at(l, i);
		
		if (cmp(e, ctx) == 0)
			c++;
	}

	pthread_mutex_unlock(&l->lock);

	return c;
}

void * list_search(struct list *l, cmp_cb_t cmp, void *ctx)
{
	void *e;

	pthread_mutex_lock(&l->lock);

	assert(l->state == STATE_INITIALIZED);
	
	for (size_t i = 0; i < list_length(l); i++) {
		e = list_at(l, i);
		if (cmp(e, ctx) == 0)
			goto out;
	}
	
	e = NULL; /* not found */

out:	pthread_mutex_unlock(&l->lock);

	return e;
}

void list_sort(struct list *l, cmp_cb_t cmp)
{
	pthread_mutex_lock(&l->lock);

	assert(l->state == STATE_INITIALIZED);

	qsort_r(l->array, l->length, sizeof(void *), cmp_sort, (void *) cmp);

	pthread_mutex_unlock(&l->lock);
}