/*
 *		edges.c
 *	a part of libbubulle from tTh
 */

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

#include   "bubulles.h"
#include   "edges.h"

/* --------------------------------------------------------------------- */
EdgeList * alloc_edgelist(char *name, int sz, int flags)
{
EdgeList	*elptr;
AnEdge		*array;

#if DEBUG_LEVEL
fprintf(stderr, ">>> %s ( '%s'  %d  0x%X )\n", __func__, name, sz, flags);
#endif

if (NULL==(elptr = calloc(1, sizeof(EdgeList)))) {
	fprintf(stderr, "no mem available in %s\n", __func__);
	return NULL;
	}
memset(elptr, 0, sizeof(EdgeList));

if (NULL==(array = calloc(sz, sizeof(Bubulle)))) {
	fprintf(stderr, "no mem available in %s\n", __func__);
	free(elptr);
	return NULL;
	}
elptr->edges = array;

if ( (NULL != name) && (strlen(name) < SZ_BUBULLE_TEXT) )
	strcpy(elptr->name, name);
else
	strcpy(elptr->name, "noname");

elptr->magic = 0x55555555;
elptr->size  = sz;
elptr->flags = flags;

return elptr;
}
/* --------------------------------------------------------------------- */
int free_edgelist(EdgeList *list, int k)
{
#if DEBUG_LEVEL
fprintf(stderr, ">>> %s ( %p  0x%X )\n", __func__, list, k);
#endif

if (k) {
	fprintf(stderr, "%s: k must be 0, was %d\n", __func__, k);
	return k;
	}

free(list->edges);

memset(list, 0, sizeof(EdgeList));
free(list);

return 0;
}
/* --------------------------------------------------------------------- */
/*
 *	with this func, you can search for duplicates, but 
 *	it is going to be SLOW with huges object.
 */
static int is_edge_in_list(EdgeList *list, int p0, int p1)
{
int		idx, retval, place;

#if DEBUG_LEVEL
fprintf(stderr, ">>> %s ( %p  %d %d )\n", __func__, list, p0, p1);
#endif

retval = 0;	place = -1;

for (idx=0; idx < list->fidx; idx++) {
	if (	(list->edges[idx].A == p0) &&
		(list->edges[idx].B == p1) ) {
			retval = 1; place = idx; break; }

	if (	(list->edges[idx].A == p1) &&
		(list->edges[idx].B == p0) ){
			retval = 2; place = idx; break; }
	}

if (retval) fprintf(stderr, "  edge %d %d found at %d\n", p0, p1, idx);

return retval;
}
/* --------------------------------------------------------------------- */
/*
 *	we have two functions for adding an edge to a list
 *	the first one add unconditionnaly the edge to the
 *	(non full) list...
 */
int push_an_edge(EdgeList *list, int p0, int p1)
{
#if DEBUG_LEVEL
fprintf(stderr, ">>> %s ( %p  %d %d )\n", __func__, list, p0, p1);
#endif

if (list->fidx >= list->size) {
	fprintf(stderr, "%s: w're doomed and overflowed\n", __func__);
#if MUST_ABORT
	abort();
#endif
	return -1;
	}
list->edges[list->fidx].A = p0;
list->edges[list->fidx].B = p1;
list->fidx ++;
return 0;
}

/*
 *	and the second only insert an edge if it was missing
 *	from the currently know list.
 */
int push_a_missing_edge(EdgeList *list, int p0, int p1)
{
#if DEBUG_LEVEL
fprintf(stderr, ">>> %s ( %p  %d %d )\n", __func__, list, p0, p1);
#endif

if (list->fidx >= list->size) {
	fprintf(stderr, "%s: w're doomed and overflowed\n", __func__);
#if MUST_ABORT
	abort();
#endif
	return -1;
	}

if ( ! is_edge_in_list(list, p0, p1) ) {
	list->edges[list->fidx].A = p0;
	list->edges[list->fidx].B = p1;
	fprintf(stderr, "edge %d %d poked at %d\n", p0, p1, list->fidx);
	list->fidx ++;
	}
else	{
	fprintf(stderr, "    %s: drop edge %d %d\n", __func__, p0, p1);
	}
return 0;
}
/* --------------------------------------------------------------------- */
int  print_edgelist_desc(EdgeList *list, int k)
{

fprintf(stderr, "------- edgelist '%s' at %p\n", list->name, list);

if (k) {
	fprintf(stderr, "%s: k must be 0, was %d\n", __func__, k);
	return k;
	}

fprintf(stderr, "\tarray @             %p\n",       list->edges);
fprintf(stderr, "\tsize                %8d\n",      list->size);
fprintf(stderr, "\tnext free           %8d\n",      list->fidx);
fprintf(stderr, "\tmagic              0x%08lX\n",   list->magic);

return 0;
}
/* --------------------------------------------------------------------- */
/*
 *	/!\	the output format is subject to changes in
 *		a near futur.
 */
int  edges_to_data(char *fname, EdgeList *list, int k)
{
FILE		*fp;
int		idx, foo;

#if DEBUG_LEVEL
fprintf(stderr, ">>> %s ( '%s'  %p %d )\n", __func__, fname, list, k);
#endif

if (NULL==(fp=fopen(fname, "w"))) {
	perror(fname);
	return -1;
	}
for (idx=0; idx<list->fidx; idx++) {
	foo = fprintf(fp, "%d %d\n", list->edges[idx].A, list->edges[idx].B);
	/*
	 * error check
	 */
	if (foo < 0) {
		perror(fname);
		exit(1);		/* be violent ! */
		}
	}
fclose(fp);
return 0;
}
/* --------------------------------------------------------------------- */
int  print_the_edges(FILE *fp, EdgeList *list, int k)
{
int		idx;

#if DEBUG_LEVEL
fprintf(stderr, ">>> %s ( %p %d )\n", __func__, list, k);
#endif

if (k) {
	fprintf(stderr, "In %s, k must be 0, was %d\n", __func__, k);
	return k;
	}

fprintf(stderr, "    list.fidx = %d\n", list->fidx);

for (idx=0; idx<list->fidx; idx++) {
	fprintf(fp, "%6d\t\t%5d %5d\n", idx,
			list->edges[idx].A, list->edges[idx].B);
	}

return -1;
}
/* --------------------------------------------------------------------- */