/*
    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 <stdio.h>		/* need sprintf() */
#include <aghdr.h>

#ifdef DMALLOC
#include "dmalloc.h"
#endif

#define EMPTY(s)		((s == 0) || (s)[0] == '\0')

typedef void iochan_t;

static void ioput(Agraph_t *g, iochan_t *ofile, char *str)
{
	AGDISC(g,io)->putstr(ofile, str);
}

static void write_body(Agraph_t *g, iochan_t *ofile);
static int Level;
static unsigned char Attrs_not_written_flag;
static Agsym_t *Tailport,*Headport;

static void indent(Agraph_t *g, iochan_t *ofile)
{
	int		i;
	for (i = Level; i > 0; i--) 
		ioput(g, ofile, "\t");
}

/*
 * canonicalize a string for printing.
 * must agree with strings in scan.l
 */
char *agcanonstr(char *arg, char *buf)
{
	char	*s,*p;
	int		cnt = 0;
	int		needs_quotes = FALSE;
	int		maybe_num = (isdigit(arg[0]) || (arg[0] == '.'));
	static const char *tokenlist[]	/* must agree with scan.l */
		= {"node","edge","strict","graph","digraph","subgraph", NIL(char*)};
	const char	**tok;

	if (EMPTY(arg)) return "\"\"";
	s = arg; p = buf;
	*p++ = '\"';
	while (*s) {
		if (*s == '\"') { *p++ = '\\'; needs_quotes = TRUE; }
		else if (*s == '\\') {*p++ = *s++; needs_quotes = TRUE;}
		else {
			if (!isalnum(*s) && ((*s != '_'))) needs_quotes = TRUE;
			else if (maybe_num && (!isdigit(*s) && (*s != '.')))
				needs_quotes = TRUE;
		}
		*p++ = *s++;
		cnt++;
		if (cnt >= MAX_OUTPUTLINE) {
			*p++ = '\\';
			*p++ = '\n';
			needs_quotes = TRUE;
			cnt = 0;
		}
	}
	*p++ = '\"'; *p = '\0';
	if (needs_quotes) return buf;

	/* Use quotes to protect tokens (example, a node named "node") */
	/* It would be great if it were easier to use flex here. */
	for (tok = tokenlist; *tok; tok++) if (streq(*tok,arg)) return buf;
	return arg;
}

static void write_canonstr(Agraph_t *g, iochan_t *ofile, char *str)
{
	static char		*buf;
	static long		bufsiz;
	char			*p;
	long			len;

	len = strlen(str) + 10;
	if (len > bufsiz) {
		bufsiz = len;
		if (buf == NIL(char*)) buf = malloc((unsigned)bufsiz);
		else buf = realloc(buf,(unsigned)bufsiz);
	}
	p = agcanonstr(str,buf);
	ioput(g, ofile, p);
}

static void write_dict(Agraph_t *g, iochan_t *ofile, char *name, Dict_t *dict)
{
	int		cnt = 0;
	Dict_t	*view;
	Agsym_t	*sym,*psym;

	view = dtview(dict,NIL(Dict_t*));
	for (sym = (Agsym_t*)dtfirst(dict); sym; sym = (Agsym_t*)dtnext(dict,sym)) {
		if (EMPTY(sym->defval)) {	/* try to skip empty str (default) */
			if (view == NIL(Dict_t*)) continue;	/* no parent */
			psym = (Agsym_t*)dtsearch(view,sym);
			assert(psym);
			if (EMPTY(psym->defval)) continue;	/* also empty in parent */
		}
		if (cnt++ == 0) { 
			indent(g,ofile); 
			ioput(g, ofile, name);
			ioput(g, ofile, " [");
			Level++;
		}
		else { 
			ioput(g, ofile, ",\n");
			indent(g,ofile);
		}
		write_canonstr(g, ofile, sym->name);
		ioput(g, ofile, "=");
		write_canonstr(g, ofile, sym->defval);
	}
	if (cnt > 0) {
		Level--;
		if (cnt > 1) {ioput(g, ofile, "\n"); indent(g,ofile);}
		ioput(g, ofile, "];\n");
	}
	dtview(dict,view);			/* restore previous view */
}

static void write_dicts(Agraph_t *g, iochan_t *ofile)
{
	Agdatadict_t	*def;
	if ((def = agdatadict(g))) {
		write_dict(g, ofile, "graph", def->dict.g);
		write_dict(g, ofile, "node", def->dict.n);
		write_dict(g, ofile, "edge", def->dict.e);
	}
}

static void write_hdr(Agraph_t *g, iochan_t *ofile, int top)
{
	char	*name,*sep,*kind,*strict;

	Attrs_not_written_flag = AGATTRWF(g);
	strict = "";
	if (NOT(top) && agparent(g)) kind = "sub";
	else {
		if (g->desc.directed) kind = "di";
		else kind = "";
		if (agisstrict(g)) strict = "strict ";
		Tailport = agattr(g,AGEDGE,"tailport",NIL(char*));
		Headport = agattr(g,AGEDGE,"headport",NIL(char*));
	}
	name = agnameof(g);
	sep = " ";
	if (!name || name[0] == '_') sep = name = "";
	indent(g,ofile); 
	ioput(g,ofile,strict);
	ioput(g,ofile,kind);
	ioput(g,ofile,"graph ");
	if (name[0]) write_canonstr(g, ofile, name);
	ioput(g,ofile,sep);
	ioput(g,ofile,"{\n");
	Level++;
	write_dicts(g, ofile);
	AGATTRWF(g) = NOT(AGATTRWF(g));
}

static void write_trl(Agraph_t *g, iochan_t *ofile)
{
	NOTUSED(g);
	Level--;
	indent(g,ofile);
	ioput(g,ofile,"}\n");
}

static int irrelevant_subgraph(Agraph_t *g)
{
	int			i,n;
	Agattr_t	*sdata,*pdata;
	char		*name;

	name = agnameof(g);
	if (name && name[0] != LOCALNAMEPREFIX) return FALSE;
	if ((sdata = agattrrec(g)) && (pdata = agattrrec(agparent(g)))) {
		n = dtsize(sdata->dict);
		for (i = 0; i < n; i++)
			if (!sdata->str[i] && !pdata->str[i] 
			   && strcmp(sdata->str[i],pdata->str[i])) return FALSE;
	}
	return TRUE;
}

int node_in_subg(Agraph_t *g, Agnode_t *n)
{
	Agraph_t	*subg;

	for (subg = agfstsubg(g); subg; subg = agnxtsubg(subg)) {
		if (irrelevant_subgraph(subg)) continue;
		if (agsubnode(subg,n,FALSE)) return TRUE;
	}
	return FALSE;
}

static int has_no_edges(Agnode_t *n)
{
	return ((n->in == NIL(Agedge_t*)) && (n->out == NIL(Agedge_t*)));
}

static int has_no_predecessor_below(Agnode_t *n, unsigned long val)
{
	Agedge_t	*e;

	if (AGSEQ(n) < val) return FALSE;
	for (e = agfstin(n); e; e = agnxtin(e)) 
		if (AGSEQ(e->node) < val) return FALSE;
	return TRUE;
}

static int not_default_attrs(Agraph_t *g, Agnode_t *n)
{
	Agattr_t	*data;
	Agsym_t		*sym;
	
	NOTUSED(g);
	if ((data = agattrrec(n))) {
		for (sym = (Agsym_t*)dtfirst(data->dict); sym;
			sym = (Agsym_t*)dtnext(data->dict,sym)) {
				if (data->str[sym->id] != sym->defval) return TRUE;
		}
	}
	return FALSE;
}

static void write_subgs(Agraph_t *g, iochan_t *ofile)
{
	Agraph_t	*subg;

	for (subg = agfstsubg(g); subg; subg = agnxtsubg(subg)) {
		if (irrelevant_subgraph(subg)) continue;
		write_hdr(subg, ofile, FALSE);
		write_body(subg, ofile);
		write_trl(subg, ofile);
	}
}

static int write_edge_name(Agedge_t *e, iochan_t *ofile, int terminate)
{
	int			rv;
	char		*p;
	Agraph_t	*g;

	p = agnameof(e);
	g = agraphof(e);
	if (NOT(EMPTY(p))) {
		ioput(g, ofile, " [key=");
		write_canonstr(g, ofile, p);
		if (terminate) ioput(g, ofile, "]");
		rv = TRUE;
	}
	else rv = FALSE;
	return rv;
}


static void write_nondefault_attrs(void *obj, iochan_t *ofile, Dict_t *defdict)
{
	Agattr_t	*data;
	Agsym_t		*sym;
	Agraph_t	*g;
	int		cnt = 0;

	if ((AGTYPE(obj) == AGINEDGE) || (AGTYPE(obj) == AGOUTEDGE)) {
		if (write_edge_name(obj, ofile, FALSE)) cnt++;
	}
	data = agattrrec(obj);
	g = agraphof(obj);
	if (data) for (sym = (Agsym_t*)dtfirst(defdict); sym;
		sym = (Agsym_t*)dtnext(defdict,sym)) {
			if ((AGTYPE(obj) == AGINEDGE) || (AGTYPE(obj) == AGOUTEDGE)) {
				if (Tailport && (sym->id == Tailport->id)) continue;
				if (Headport && (sym->id == Headport->id)) continue;
			}
			if (data->str[sym->id] != sym->defval) {
				if (cnt++ == 0) { 
					indent(g,ofile); 
					ioput(g, ofile, " [");
					Level++;
				}
				else { 
					ioput(g, ofile, ",\n");
					indent(g,ofile);
				}
				write_canonstr(g, ofile, sym->name);
				ioput(g, ofile, "=");
				write_canonstr(g, ofile, data->str[sym->id]);
			}
	}
	if (cnt > 0) {
	    ioput(g, ofile, "]");
	    Level--;
	}
	AGATTRWF((Agobj_t*)obj) = NOT(AGATTRWF((Agobj_t*)obj));
}

static void write_nodename(Agnode_t *n, iochan_t *ofile)
{
	char		*name, buf[20];
	Agraph_t	*g;

	name = agnameof(n);
	g = agraphof(n);
	if (name) write_canonstr(g, ofile, name);
	else {
	    sprintf(buf,"_%ld_SUSPECT",AGID(n));	/* could be deadly wrong */
	    ioput(g, ofile, buf);
	}
}

static int attrs_written(void *obj)
{
	return NOT(AGATTRWF((Agobj_t*)obj) == Attrs_not_written_flag);
}

static void write_node(Agnode_t *n, iochan_t *ofile, Dict_t *d)
{
	Agraph_t	*g;

	g = agraphof(n);
	indent(g, ofile);
	write_nodename(n, ofile);
	if (NOT(attrs_written(n)))
		write_nondefault_attrs(n, ofile, d);
	ioput(g, ofile, ";\n");
}

/* node must be written if it wasn't already emitted because of
 * a subgraph or one of its predecessors, and if it is a singleton
 * or has non-default attributes.
 */
static int write_node_test(Agraph_t *g, Agnode_t *n, unsigned long pred_id)
{
	if (NOT(node_in_subg(g,n)) && has_no_predecessor_below(n,pred_id)) {
		if (has_no_edges(n) || not_default_attrs(g,n))
			return TRUE;
	}
	return FALSE;
}

static void write_port(Agedge_t *e, iochan_t *ofile, char *name)
{
	char		*val;
	Agraph_t	*g;

	g = agraphof(e);
	val = agget(e,name);
	if (val[0]) {
		ioput(g, ofile, ":");
		write_canonstr(g, ofile, val);
	}
}

static int write_edge_test(Agraph_t *g, Agedge_t *e)
{
	Agraph_t	*subg;

	/* can use agedge() because we subverted the dict compar_f */
	for (subg = agfstsubg(g); subg; subg = agnxtsubg(subg)) {
		if (irrelevant_subgraph(subg)) continue;
		if (agsubedge(subg,e,FALSE)) return FALSE;
	}
	return TRUE;
}

static void write_edge(Agedge_t *e, iochan_t *ofile, Dict_t *d)
{
	Agnode_t	*t,*h;
	Agraph_t	*g;

	t = AGTAIL(e);
	h = AGHEAD(e);
	g = agraphof(t);
	indent(g,ofile);
	write_nodename(t, ofile);
	write_port(e, ofile, "tailport");
	ioput(g, ofile, (agisdirected(agraphof(t)) ? " -> " : " -- "));
	write_nodename(h, ofile);
	write_port(e, ofile, "headport");
	if (NOT(attrs_written(e)))
		write_nondefault_attrs(e, ofile, d);
	else
		write_edge_name(e, ofile, TRUE);
	ioput(g, ofile, ";\n");
}

static void write_body(Agraph_t *g, iochan_t *ofile)
{
	Agnode_t	*n;
	Agedge_t	*e;
	Agdatadict_t *dd;
	/* int			has_attr; */

	/* has_attr = (agattrrec(g) != NIL(Agattr_t*)); */
	write_subgs(g, ofile);
	dd = agdatadict(g);
	for (n = agfstnode(g); n; n = agnxtnode(n)) {
		if (write_node_test(g,n,AGSEQ(n)))
			write_node(n, ofile, dd->dict.n);
		for (e = agfstout(n); e; e = agnxtout(e)) {
			if (write_node_test(g,e->node,AGSEQ(n)))
				write_node(e->node, ofile, dd->dict.n);
			if (write_edge_test(g,e))
				write_edge(e, ofile, dd->dict.e);
		}
	}
}

int agwrite(Agraph_t *g, void *ofile)
{
	write_hdr(g, ofile, TRUE);
	write_body(g, ofile);
	write_trl(g, ofile);
	return AGDISC(g,io)->flush(ofile);
}