/* reverse.c
 * last revised at 2, Feb. 1994
 *
 * Copyright (C) 1994, All rights reserved.
 * written by Gyudong Kim(chilly@eleceng.adelaide.edu.au)
 *
 */
#include "findhier.h"

extern struct branch *trees;

extern int topspecified;
extern int interactive;
extern char *targ, *top;
extern FILE *OUTPUT;

static struct names *parents;

static void add_parent(name)
char *name;
{
	struct names *tmp;

	for (tmp=parents;tmp!=NULL;tmp=tmp->next) {
		if (tmp->name == name) return;
	}
	tmp = (struct names *)myalloc(sizeof(struct names),"add_parent");
	tmp->name = name;
	tmp->next = parents;
	parents = tmp;
}

static int look_parent(parent,name)
struct branch *parent;
char *name;
{
	struct branch *tmpb;
	int found = 0;

	if (parent->name == name) return(1);
	if (parent->offspring == NULL) return(0);
	push(parent->name);
	for (tmpb=parent->offspring;tmpb!=NULL;tmpb=tmpb->next) {
		if (check(tmpb->name)) continue;
		if (look_parent(tmpb,name)) {
			add_parent(parent->name);	
			found = 1;
		}
	}
	pop();
	return(found);
}

static struct branch *look_top(bran,mytop)
struct branch *bran;
char *mytop;
{
	struct branch *tmpb;
	struct branch *result;

	if (bran->name == mytop) return(bran);
	if (bran->offspring == NULL) return((struct branch *)NULL);
	push(bran->name);
	for(tmpb=bran->offspring;tmpb!=NULL;tmpb=tmpb->next) {
		if ((result = look_top(tmpb,mytop)) == NULL) continue;
		pop();
		return(result);
	}
	pop();
	return((struct branch *)NULL);
}

struct branch *find_top(mytop)
char *mytop;
{
	struct branch *tmp;
	static struct branch *result;

	for(tmp=trees;tmp!=NULL;tmp=tmp->next) {
		result = look_top(tmp,mytop);
		if (result!=NULL) return(result);
	}
#ifdef __OLD__
	if (!interactive) {
		warning("Cell |%s| not found.\n",mytop);
		exit(-1);
	}
#endif /* __OLD__ */
	warning("Cell |%s| not found.\n",mytop);
	return((struct branch *)NULL);
}

int reverse()
{
	struct branch *tmp,*tmpb;
	struct names *tmpn;

	if (topspecified) {
		tmpb = find_top(top);
		if (tmpb==NULL) return(1);
		if (look_parent(tmpb,targ)) add_parent(tmpb->name);
	} else {
		for(tmp=trees;tmp!=NULL;tmp=tmp->next) {
			if (look_parent(tmp,targ)) add_parent(tmp->name);
		}
	}
	for(tmpn=parents;tmpn!=NULL;tmpn=tmpn->next)
		(void)fprintf(OUTPUT,"%s\n",tmpn->name);
	freelink(&parents);
	return(0);
}
/* reverse.c */