/*
    This software may only be used by you under license from AT&T Corp.
    ("AT&T").  A copy of AT&T's Source Code Agreement is available at
    AT&T's Internet website having the URL:
    <http://www.research.att.com/sw/tools/graphviz/license/source.html>
    If you received this software without first entering into a license
    with AT&T, you have an infringing copy of this software and cannot use
    it without violating AT&T's intellectual property rights.
*/
#pragma prototyped
                  
#include "dot.h"                  


/*
 * operations on the fast internal graph.
 */

static edge_t* ffe(node_t *u, elist uL, node_t *v, elist vL)
{
	int		i;
	edge_t	*e;

	if ((uL.size > 0) && (vL.size > 0)) {
		if (uL.size < vL.size) {
		for (i = 0; (e = uL.list[i]); i++)
			if (e->head == v) break;
		}
		else {
			for (i = 0; (e = vL.list[i]); i++)
				if (e->tail == u) break;
		}
	}
	else e = 0;
	return e;
}

edge_t* find_fast_edge(node_t *u,node_t *v)
{
	return ffe(u,ND_out(u),v,ND_in(v));
}

node_t* find_fast_node(graph_t *g, node_t *n)
{
	node_t		*v;
	for (v = GD_nlist(g); v; v = ND_next(v))
		if (v == n) break;
	return v;
}

edge_t* find_flat_edge(node_t *u, node_t *v)
{
	return ffe(u,ND_flat_out(u),v,ND_flat_in(v));
}

/* safe_list_append - append e to list L only if e not already a member */
void safe_list_append(edge_t *e, elist *L)
{
	int		i;

	for (i = 0; i < L->size; i++) if (e == L->list[i]) return;
	elist_append(e,(*L));
}

edge_t*
fast_edge(edge_t *e)
{
#ifdef DEBUG
	int		i;
	edge_t	*f;
	for (i = 0; (f = ND_out(e->tail).list[i]); i++) {
		if (e == f) {fprintf(stderr,"duplicate fast edge\n"); return;}
		assert (e->head != f->head);
	}
	for (i = 0; (f = ND_in(e->head).list[i]); i++) {
		if (e == f) {fprintf(stderr,"duplicate fast edge\n"); return;}
		assert (e->tail != f->tail);
	}
#endif
	elist_append(e,ND_out(e->tail));
	elist_append(e,ND_in(e->head));
	return e;
}

/* zapinlist - remove e from list and fill hole with last member of list */
void zapinlist(elist *L, edge_t *e)
{
	int	i;

	for (i = 0; i < L->size; i++) {
		if (L->list[i] == e) {
			L->size--;
			L->list[i] = L->list[L->size];
			L->list[L->size] = NULL;
			break;
		}
	}
}

/* disconnects e from graph */
void delete_fast_edge(edge_t *e)
{
	assert(e != NULL);
	zapinlist(&(ND_out(e->tail)),e);
	zapinlist(&(ND_in(e->head)),e);
}

void safe_delete_fast_edge(edge_t *e)
{
	int		i;
	edge_t	*f;

	assert(e != NULL);
	for (i = 0; (f = ND_out(e->tail).list[i]); i++)
		if (f == e) zapinlist(&(ND_out(e->tail)),e);
	for (i = 0; (f = ND_in(e->head).list[i]); i++)
		if (f == e) zapinlist(&(ND_in(e->head)),e);
}

void other_edge(edge_t *e)
{
	elist_append(e,ND_other(e->tail));
}

void safe_other_edge(edge_t *e)
{
	safe_list_append(e,&(ND_other(e->tail)));
}

void delete_other_edge(edge_t *e)
{
	assert(e != NULL);
	zapinlist(&(ND_other(e->tail)),e);
}

/* orig might be an input edge, reverse of an input edge, or virtual edge */
edge_t*
new_virtual_edge(node_t *u, node_t *v, edge_t *orig)
{
	edge_t		*e;

	e = NEW(edge_t);
	e->tail = u;
	e->head = v;
	ED_edge_type(e) = VIRTUAL;

	if (orig) {
		ED_count(e) = ED_count(orig);
		ED_xpenalty(e) = ED_xpenalty(orig);
		ED_weight(e) = ED_weight(orig);
		ED_minlen(e) = ED_minlen(orig);
		if (e->tail == orig->tail) ED_tail_port(e) = ED_tail_port(orig);
		else if (e->tail == orig->head) ED_tail_port(e) = ED_head_port(orig);
		if (e->head == orig->head) ED_head_port(e) = ED_head_port(orig);
		else if (e->head == orig->tail) ED_head_port(e) = ED_tail_port(orig);

		if (ED_to_virt(orig) == NULL) ED_to_virt(orig) = e;
		ED_to_orig(e) = orig;
	}
	else ED_minlen(e) = ED_count(e) = ED_xpenalty(e) = ED_weight(e) = 1;
	return e;
}

edge_t*
virtual_edge(node_t *u, node_t *v, edge_t *orig)
{
	return fast_edge(new_virtual_edge(u,v,orig));
}

void fast_node(graph_t *g, Agnode_t *n)
{

#ifdef DEBUG
	assert (find_fast_node(g,n) == NULL);
#endif
	ND_next(n) = GD_nlist(g);
	if (ND_next(n)) ND_next(n)->u.prev = n;
	GD_nlist(g) = n;
	ND_prev(n) = NULL;
	assert (n != ND_next(n));
}

void fast_nodeapp(node_t *u, node_t *v)
{
	assert (u != v);
	assert (ND_next(v) == NULL);
	ND_next(v) = ND_next(u);
	if (ND_next(u)) ND_next(u)->u.prev = v;
	ND_prev(v) = u;
	ND_next(u) = v;
}

void delete_fast_node(graph_t *g, node_t *n)
{
	assert(find_fast_node(g,n));
	if (ND_next(n)) ND_next(n)->u.prev = ND_prev(n);
	if (ND_prev(n)) ND_prev(n)->u.next = ND_next(n);
	else GD_nlist(g) = ND_next(n);
}

node_t* virtual_node(graph_t *g)
{
	node_t		*n;

	n = NEW(node_t);
	n->name = "virtual";
	n->graph = g;
	ND_node_type(n) = VIRTUAL;
	ND_lw_i(n) = ND_rw_i(n) = 1;
	ND_ht_i(n) = 1;
	ND_UF_size(n) = 1;
	alloc_elist(4,ND_in(n));
	alloc_elist(4,ND_out(n));
	fast_node(g,n);
	GD_n_nodes(g)++;
	return n;
}

void flat_edge(graph_t *g, edge_t *e)
{
	elist_append(e,ND_flat_out(e->tail));
	elist_append(e,ND_flat_in(e->head));
	GD_has_flat_edges(g->root) = GD_has_flat_edges(g) = TRUE;
}

void delete_flat_edge(edge_t *e)
{
	assert(e != NULL);
	if (ED_to_orig(e) && ED_to_virt(ED_to_orig(e)) == e)
		ED_to_virt(ED_to_orig(e)) = NULL;
	zapinlist(&(ND_flat_out(e->tail)),e);
	zapinlist(&(ND_flat_in(e->head)),e);
}

#ifdef DEBUG
static char*
NAME(node_t *n)
{
	static char buf[20];
	if (ND_node_type(n) == NORMAL) return n->name;
	sprintf(buf,"V%x",n);
	return buf;
}

void fastgr(graph_t *g)
{
	int			i,j;
	node_t		*n,*w;
	edge_t		*e,*f;

	for (n = GD_nlist(g); n; n = ND_next(n)) {
		fprintf(stderr,"%s %d: (",NAME(n), ND_rank(n));
		for (i = 0; e = ND_out(n).list[i]; i++) {
			fprintf(stderr," %s:%d",NAME(e->head),ED_count(e));
			w = e->head;
			if (g == g->root) {
				for (j = 0; f = ND_in(w).list[j]; j++) if (e == f) break;
				assert (f != NULL);
			}
		}
		fprintf(stderr," ) (");
		for (i = 0; e = ND_in(n).list[i]; i++) {
			fprintf(stderr," %s:%d",NAME(e->tail),ED_count(e));
			w = e->tail;
			if (g == g->root) {
				for (j = 0; f = ND_out(w).list[j]; j++) if (e == f) break;
				assert (f != NULL);
			}
		}
		fprintf(stderr," )\n");
	}
}
#endif

void merge_oneway(edge_t *e, edge_t *rep)
{
	if (rep == ED_to_virt(e)) {agerr(AGWARN, "merge_oneway glitch\n"); return;}
	assert(ED_to_virt(e) == NULL);
	ED_to_virt(e) = rep;
	basic_merge(e,rep);
}

void basic_merge(edge_t *e, edge_t *rep)
{
	if (ED_minlen(rep) < ED_minlen(e))
		ED_minlen(rep) = ED_minlen(e);
	while (rep) {
		ED_count(rep) += ED_count(e);
		ED_xpenalty(rep) += ED_xpenalty(e);
		ED_weight(rep) += ED_weight(e);
		rep = ED_to_virt(rep);
	}
}

static void unrep(edge_t *rep, edge_t *e)
{
	ED_count(rep) -= ED_count(e);
	ED_xpenalty(rep) -= ED_xpenalty(e);
	ED_weight(rep) -= ED_weight(e);
}

void unmerge_oneway(edge_t *e)
{
	edge_t	*rep,*nextrep;
	for (rep = ED_to_virt(e); rep; rep = nextrep) {
		unrep(rep,e);
		nextrep = ED_to_virt(rep);
		if (ED_count(rep) == 0) safe_delete_fast_edge(rep);	/* free(rep)? */

		/* unmerge from a virtual edge chain */
		while ((ED_edge_type(rep) == VIRTUAL)
		&& (ND_node_type(rep->head) == VIRTUAL)
		&& (ND_out(rep->head).size == 1)) {
			rep = ND_out(rep->head).list[0];
			unrep(rep,e);
		}
	}
	ED_to_virt(e) = NULL;
}

int is_fast_node(graph_t *g, node_t *v)
{
	node_t		*n;

	for (n = GD_nlist(g); n; n = ND_next(n))
		if (v == n) return TRUE;
	return FALSE;
}