/// @file
/// @ingroup common_render
/*************************************************************************
 * Copyright (c) 2011 AT&T Intellectual Property 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors: Details at https://graphviz.org
 *************************************************************************/

#include <common/render.h>
#include <common/htmltable.h>
#include <errno.h>
#include <gvc/gvc.h>
#include <xdot/xdot.h>
#include <cgraph/agxbuf.h>
#include <cgraph/gv_ctype.h>
#include <cgraph/gv_math.h>
#include <limits.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <util/alloc.h>
#include <util/exit.h>
#include <util/gv_fopen.h>
#include <util/startswith.h>
#include <util/strcasecmp.h>
#include <util/streq.h>

static char *usageFmt =
    "Usage: %s [-Vv?] [-(GNE)name=val] [-(KTlso)<val>] <dot files>\n";

static char *genericItems = "\n\
 -V          - Print version and exit\n\
 -v          - Enable verbose mode \n\
 -Gname=val  - Set graph attribute 'name' to 'val'\n\
 -Nname=val  - Set node attribute 'name' to 'val'\n\
 -Ename=val  - Set edge attribute 'name' to 'val'\n\
 -Tv         - Set output format to 'v'\n\
 -Kv         - Set layout engine to 'v' (overrides default based on command name)\n\
 -lv         - Use external library 'v'\n\
 -ofile      - Write output to 'file'\n\
 -O          - Automatically generate an output filename based on the input filename with a .'format' appended. (Causes all -ofile options to be ignored.) \n\
 -P          - Internally generate a graph of the current plugins. \n\
 -q[l]       - Set level of message suppression (=1)\n\
 -s[v]       - Scale input by 'v' (=72)\n\
 -y          - Invert y coordinate in output\n";

static char *neatoFlags =
    "(additional options for neato)    [-x] [-n<v>]\n";
static char *neatoItems = "\n\
 -n[v]       - No layout mode 'v' (=1)\n\
 -x          - Reduce graph\n";

static char *fdpFlags =
    "(additional options for fdp)      [-L(gO)] [-L(nUCT)<val>]\n";
static char *fdpItems = "\n\
 -Lg         - Don't use grid\n\
 -LO         - Use old attractive force\n\
 -Ln<i>      - Set number of iterations to i\n\
 -LU<i>      - Set unscaled factor to i\n\
 -LC<v>      - Set overlap expansion factor to v\n\
 -LT[*]<v>   - Set temperature (temperature factor) to v\n";

static char *configFlags = "(additional options for config)  [-cv]\n";
static char *configItems = "\n\
 -c          - Configure plugins (Writes $prefix/lib/graphviz/config \n\
               with available plugin information.  Needs write privilege.)\n\
 -?          - Print usage and exit\n";

/* Print usage information. If GvExitOnUsage is set, exit with
 * given exval, else return exval+1.
 *
 * @param argv0 Command name to use in usage message
 */
int dotneato_usage(const char *argv0, int exval) {
    FILE *outs;

    if (exval > 0)
	outs = stderr;
    else
	outs = stdout;

    fprintf(outs, usageFmt, argv0);
    fputs(neatoFlags, outs);
    fputs(fdpFlags, outs);
    fputs(configFlags, outs);
    fputs(genericItems, outs);
    fputs(neatoItems, outs);
    fputs(fdpItems, outs);
    fputs(configItems, outs);

    if (GvExitOnUsage && exval >= 0)
	graphviz_exit(exval);
    return exval + 1;
}

/* Look for flag parameter. idx is index of current argument.
 * We assume argv[*idx] has the form "-x..." If there are characters 
 * after the x, return
 * these, else if there are more arguments, return the next one,
 * else return NULL.
 */
static char *getFlagOpt(int argc, char **argv, int *idx)
{
    int i = *idx;
    char *arg = argv[i];

    if (arg[2])
	return arg + 2;
    if (i < argc - 1) {
	i++;
	arg = argv[i];
	if (*arg && *arg != '-') {
	    *idx = i;
	    return arg;
	}
    }
    return 0;
}

/* Partial implementation of real basename.
 * Skip over any trailing slashes or backslashes; then
 * find next (back)slash moving left; return string to the right.
 * If no next slash is found, return the whole string.
 */
static char *dotneato_basename(char *pathname) {
    char* ret;
    char* s = pathname;
    if (*s == '\0') return pathname; /* empty string */
#ifdef _WIN32
    /* On Windows, executables, by convention, end in ".exe". Thus,
     * this may be part of the path name and must be removed for
     * matching to work.
     */
    {
	char* dotp = strrchr (s, '.');
	if (dotp && !strcasecmp(dotp+1,"exe")) *dotp = '\0';
    }
#endif
    while (*s) s++;
    s--;
    /* skip over trailing slashes, nulling out as we go */
    while (s > pathname && (*s == '/' || *s == '\\'))
	*s-- = '\0';
    if (s == pathname) ret = pathname;
    else {
	while (s > pathname && *s != '/' && *s != '\\') s--;
	if (*s == '/' || *s == '\\') ret = s+1;
	else ret = pathname;
    }
#ifdef _WIN32
    /* On Windows, names are case-insensitive, so make name lower-case
     */
    gv_tolower_str(ret);
#endif
    return ret;
}

static void use_library(GVC_t *gvc, const char *name)
{
    static size_t cnt = 0;
    if (name) {
	const size_t old_nmemb = cnt == 0 ? cnt : cnt + 1;
	Lib = gv_recalloc(Lib, old_nmemb, cnt + 2, sizeof(const char *));
	Lib[cnt++] = name;
	Lib[cnt] = NULL;
    }
    gvc->common.lib = Lib;
}

static void global_def(char *dcl, int kind) {
    char *p;
    char *rhs = "true";
    agxbuf xb = {0};

    attrsym_t *sym;
    if ((p = strchr(dcl, '='))) {
        agxbput_n(&xb, dcl, (size_t)(p - dcl));
        rhs = p+1;
    }
    else
	agxbput(&xb, dcl);
    sym = agattr(NULL, kind, agxbuse(&xb), rhs);
    sym->fixed = 1;
    agxbfree(&xb);
}

static int gvg_init(GVC_t *gvc, graph_t *g, char *fn, int gidx)
{
    GVG_t *gvg = gv_alloc(sizeof(GVG_t));
    if (!gvc->gvgs) 
	gvc->gvgs = gvg;
    else
	gvc->gvg->next = gvg;
    gvc->gvg = gvg;
    gvg->gvc = gvc;
    gvg->g = g;
    gvg->input_filename = fn;
    gvg->graph_index = gidx;
    return 0;
}

static graph_t *P_graph;

graph_t *gvPluginsGraph(GVC_t *gvc)
{
    gvg_init(gvc, P_graph, "<internal>", 0);
    return P_graph;
}

/* Scan argv[] for allowed flags.
 * Return 0 on success; v+1 if calling function should call exit(v).
 * If -c is set, config file is created and we exit. 
 */
int dotneato_args_initialize(GVC_t * gvc, int argc, char **argv)
{
    char c, *rest, *layout;
    const char *val;
    int i, v;
    int Kflag = 0;

    /* establish if we are running in a CGI environment */
    HTTPServerEnVar = getenv("SERVER_NAME");

    // test `$GV_FILE_PATH`, a legacy knob, is not set
    if (getenv("GV_FILE_PATH") != NULL) {
        fprintf(stderr, "$GV_FILE_PATH environment variable set; exiting\n"
                        "\n"
                        "This sandboxing mechanism is no longer supported\n");
        graphviz_exit(EXIT_FAILURE);
    }

    gvc->common.cmdname = dotneato_basename(argv[0]);
    if (gvc->common.verbose) {
        fprintf(stderr, "%s - %s version %s (%s)\n",
	    gvc->common.cmdname, gvc->common.info[0],
	    gvc->common.info[1], gvc->common.info[2]);
    }

    /* configure for available plugins */
    /* needs to know if "dot -c" is set (gvc->common.config) */
    /* must happen before trying to select any plugins */
    if (gvc->common.config) {
        gvconfig(gvc, gvc->common.config);
	graphviz_exit(0);
    }

    /* feed the globals */
    Verbose = gvc->common.verbose > UCHAR_MAX
      ? UCHAR_MAX
      : (unsigned char)gvc->common.verbose;

    size_t nfiles = 0;
    for (i = 1; i < argc; i++)
	if (argv[i] && argv[i][0] != '-')
	    nfiles++;
    gvc->input_filenames = gv_calloc(nfiles + 1, sizeof(char *));
    nfiles = 0;
    for (i = 1; i < argc; i++) {
	if (argv[i] &&
	    (startswith(argv[i], "-V") || strcmp(argv[i], "--version") == 0)) {
	    fprintf(stderr, "%s - %s version %s (%s)\n",
	            gvc->common.cmdname, gvc->common.info[0],
	            gvc->common.info[1], gvc->common.info[2]);
	    if (GvExitOnUsage) graphviz_exit(0);
	    return 1;
	} else if (argv[i] &&
	    (startswith(argv[i], "-?") || strcmp(argv[i], "--help") == 0)) {
	    return dotneato_usage(argv[0], 0);
	} else if (argv[i] && startswith(argv[i], "--filepath=")) {
	    free(Gvfilepath);
	    Gvfilepath = gv_strdup(argv[i] + strlen("--filepath="));
	} else if (argv[i] && argv[i][0] == '-') {
	    rest = &argv[i][2];
	    switch (c = argv[i][1]) {
	    case 'G':
		if (*rest)
		    global_def(rest, AGRAPH);
		else {
		    fprintf(stderr, "Missing argument for -G flag\n");
		    return dotneato_usage(argv[0], 1);
		}
		break;
	    case 'N':
		if (*rest)
		    global_def(rest, AGNODE);
		else {
		    fprintf(stderr, "Missing argument for -N flag\n");
		    return dotneato_usage(argv[0], 1);
		}
		break;
	    case 'E':
		if (*rest)
		    global_def(rest, AGEDGE);
		else {
		    fprintf(stderr, "Missing argument for -E flag\n");
		    return dotneato_usage(argv[0], 1);
		}
		break;
	    case 'T':
		val = getFlagOpt(argc, argv, &i);
		if (!val) {
		    fprintf(stderr, "Missing argument for -T flag\n");
		    return dotneato_usage(argv[0], 1);
		}
		if (!gvjobs_output_langname(gvc, val)) {
		    /* TODO: Detect empty results from gvplugin_list() and prompt to configure with '-c' */
		    char *fmts;
		    fprintf(stderr, "Format: \"%s\" not recognized.", val);
		    fmts = gvplugin_list(gvc, API_device, val);
		    if (strlen(fmts) > 1) {
			fprintf(stderr, " Use one of:%s\n", fmts);
		    } else {
			/* Q: Should 'dot -c' be suggested generally or only when val = "dot"? */
			fprintf(stderr, " No formats found.\nPerhaps \"dot -c\" needs to be run (with installer's privileges) to register the plugins?\n");
		    }
		    if (GvExitOnUsage) graphviz_exit(1);
		    return(2);
		}
		break;
	    case 'K':
		val = getFlagOpt(argc, argv, &i);
		if (!val) {
                    fprintf(stderr, "Missing argument for -K flag\n");
                    return dotneato_usage(argv[0], 1);
                }
                v = gvlayout_select(gvc, val);
                if (v == NO_SUPPORT) {
	            fprintf(stderr, "There is no layout engine support for \"%s\"\n", val);
                    if (streq(val, "dot")) {
                        fprintf(stderr, "Perhaps \"dot -c\" needs to be run (with installer's privileges) to register the plugins?\n");
                    }
		    else {
			/* TODO: Detect empty results from gvplugin_list() and prompt to configure with '-c' */
			/* fprintf(stderr, "Use one of:%s\n", gvplugin_list(gvc, API_layout, val)); */
			char *lyts;
			lyts = gvplugin_list(gvc, API_layout, val);
			if (strlen(lyts) > 1) {
			    fprintf(stderr, " Use one of:%s\n", lyts);
			} else {
			    /* Q: Should 'dot -c' be suggested generally or only when val = "dot"? */
			    fprintf(stderr, " No layouts found.\nPerhaps \"dot -c\" needs to be run (with installer's privileges) to register the plugins?\n");
			}
		    }
		    if (GvExitOnUsage) graphviz_exit(1);
		    return(2);
                }
		Kflag = 1;
		break;
	    case 'P':
		P_graph = gvplugin_graph(gvc);
		break;
	    case 'l':
		val = getFlagOpt(argc, argv, &i);
		if (!val) {
		    fprintf(stderr, "Missing argument for -l flag\n");
		    return dotneato_usage(argv[0], 1);
		}
		use_library(gvc, val);
		break;
	    case 'o':
		val = getFlagOpt(argc, argv, &i);
		if (!val) {
		    fprintf(stderr, "Missing argument for -o flag\n");
		    return dotneato_usage(argv[0], 1);
		}
		if (! gvc->common.auto_outfile_names)
		    gvjobs_output_filename(gvc, val);
		break;
	    case 'q':
		if (*rest) {
		    v = atoi(rest);
		    if (v <= 0) {
			fprintf(stderr,
				"Invalid parameter \"%s\" for -q flag - ignored\n",
				rest);
		    } else if (v == 1)
			agseterr(AGERR);
		    else
			agseterr(AGMAX);
		} else
		    agseterr(AGERR);
		break;
	    case 's':
		if (*rest) {
		    PSinputscale = atof(rest);
		    if (PSinputscale < 0) {
			fprintf(stderr,
				"Invalid parameter \"%s\" for -s flag\n",
				rest);
			return dotneato_usage(argv[0], 1);
		    }
		    else if (is_exactly_zero(PSinputscale))
			PSinputscale = POINTS_PER_INCH;
		} else
		    PSinputscale = POINTS_PER_INCH;
		break;
	    case 'x':
		Reduce = true;
		break;
	    case 'y':
		Y_invert = true;
		break;
	    default:
		agerrorf("%s: option -%c unrecognized\n\n", gvc->common.cmdname,
			c);
		return dotneato_usage(argv[0], 1);
	    }
	} else if (argv[i])
	    gvc->input_filenames[nfiles++] = argv[i];
    }

    /* if no -K, use cmd name to set layout type */
    if (!Kflag) {
	layout = gvc->common.cmdname;
	if (streq(layout, "dot_static")
	    || streq(layout, "dot_builtins")
	    || streq(layout, "lt-dot")
	    || streq(layout, "lt-dot_builtins")
	    || streq(layout, "")   /* when run as a process from Gvedit on Windows */
	)
            layout = "dot";
	i = gvlayout_select(gvc, layout);
	if (i == NO_SUPPORT) {
	    fprintf(stderr, "There is no layout engine support for \"%s\"\n", layout);
            if (streq(layout, "dot")) {
		fprintf(stderr, "Perhaps \"dot -c\" needs to be run (with installer's privileges) to register the plugins?\n");
	    } else {
		/* TODO: Detect empty results from gvplugin_list() and prompt to configure with '-c' */
		/* fprintf(stderr, "Use one of:%s\n", gvplugin_list(gvc, API_layout, "")); */
		char *lyts;
		lyts = gvplugin_list(gvc, API_layout, "");
		if (strlen(lyts) > 1) {
                    fprintf(stderr, " Use one of:%s\n", lyts);
		} else {
		    /* Q: Should 'dot -c' be suggested generally or only when val = "dot"? */
		    fprintf(stderr, " No layouts found.\nPerhaps \"dot -c\" needs to be run (with installer's privileges) to register the plugins?\n");
		}
	    }

	    if (GvExitOnUsage) graphviz_exit(1);
	    return 2;
	}
    }

    /* if no -Txxx, then set default format */
    if (!gvc->jobs || !gvc->jobs->output_langname) {
	if (!gvjobs_output_langname(gvc, "dot")) {
		fprintf(stderr,
			"Unable to find even the default \"-Tdot\" renderer.  Has the config\nfile been generated by running \"dot -c\" with installer's privileges?\n");
			return 2;
	}
    }

    /* set persistent attributes here (if not already set from command line options) */
    if (!agattr(NULL, AGNODE, "label", 0))
	agattr(NULL, AGNODE, "label", NODENAME_ESC);
    return 0;
}

/* converts a graph attribute in inches to a pointf in points.
 * If only one number is given, it is used for both x and y.
 * Returns true if the attribute ends in '!'.
 */
static bool getdoubles2ptf(graph_t *g, char *name, pointf *result) {
    char *p;
    int i;
    double xf, yf;
    char c = '\0';
    bool rv = false;

    if ((p = agget(g, name))) {
	i = sscanf(p, "%lf,%lf%c", &xf, &yf, &c);
	if (i > 1 && xf > 0 && yf > 0) {
	    result->x = POINTS(xf);
	    result->y = POINTS(yf);
	    if (c == '!')
		rv = true;
	}
	else {
	    c = '\0';
	    i = sscanf(p, "%lf%c", &xf, &c);
	    if (i > 0 && xf > 0) {
		result->y = result->x = POINTS(xf);
		if (c == '!') rv = true;
	    }
	}
    }
    return rv;
}

void getdouble(graph_t * g, char *name, double *result)
{
    char *p;
    double f;

    if ((p = agget(g, name))) {
	if (sscanf(p, "%lf", &f) >= 1)
	    *result = f;
    }
}

graph_t *gvNextInputGraph(GVC_t *gvc)
{
    graph_t *g = NULL;
    static char *fn;
    static FILE *fp;
    static FILE *oldfp;
    static int gidx;

    while (!g) {
	if (!fp) {
    	    if (!(fn = gvc->input_filenames[0])) {
		if (gvc->fidx++ == 0)
		    fp = stdin;
	    }
	    else {
		while ((fn = gvc->input_filenames[gvc->fidx++]) && !(fp = gv_fopen(fn, "r")))  {
		    agerrorf("%s: can't open %s: %s\n", gvc->common.cmdname, fn, strerror(errno));
		    graphviz_errors++;
		}
	    }
	}
	if (fp == NULL)
	    break;
	if (oldfp != fp) {
	    agsetfile(fn ? fn : "<stdin>");
	    oldfp = fp;
	}
	g = agread(fp,NULL);
	if (g) {
	    gvg_init(gvc, g, fn, gidx++);
	    break;
	}
	if (fp != stdin)
	    fclose (fp);
	oldfp = fp = NULL;
	gidx = 0;
    }
    return g;
}

/* Check if the charset attribute is defined for the graph and, if
 * so, return the corresponding internal value. If undefined, return
 * CHAR_UTF8
 */
static unsigned char findCharset(graph_t *g) {
    char* p;

    p = late_nnstring(g,agfindgraphattr(g,"charset"),"utf-8");
    if (!strcasecmp(p,"latin-1")
	|| !strcasecmp(p,"latin1")
	|| !strcasecmp(p,"l1")
	|| !strcasecmp(p,"ISO-8859-1")
	|| !strcasecmp(p,"ISO_8859-1")
	|| !strcasecmp(p,"ISO8859-1")
	|| !strcasecmp(p,"ISO-IR-100"))
      return CHAR_LATIN1;
    if (!strcasecmp(p,"big-5")
	|| !strcasecmp(p,"big5")) 
      return CHAR_BIG5;
    if (!strcasecmp(p,"utf-8")
	|| !strcasecmp(p,"utf8"))
      return CHAR_UTF8;
    agwarningf("Unsupported charset \"%s\" - assuming utf-8\n", p);
    return CHAR_UTF8;
}

/// Checks "ratio" attribute, if any, and sets enum type.
static void setRatio(graph_t * g)
{
    char *p;
    double ratio;

    if ((p = agget(g, "ratio"))) {
	if (streq(p, "auto")) {
	    GD_drawing(g)->ratio_kind = R_AUTO;
	} else if (streq(p, "compress")) {
	    GD_drawing(g)->ratio_kind = R_COMPRESS;
	} else if (streq(p, "expand")) {
	    GD_drawing(g)->ratio_kind = R_EXPAND;
	} else if (streq(p, "fill")) {
	    GD_drawing(g)->ratio_kind = R_FILL;
	} else {
	    ratio = atof(p);
	    if (ratio > 0.0) {
		GD_drawing(g)->ratio_kind = R_VALUE;
		GD_drawing(g)->ratio = ratio;
	    }
	}
    }
}

void graph_init(graph_t * g, bool use_rankdir)
{
    char *p;
    double xf;
    static char *rankname[] = { "local", "global", "none", NULL };
    static int rankcode[] = { LOCAL, GLOBAL, NOCLUST, LOCAL };
    static char *fontnamenames[] = {"gd","ps","svg", NULL};
    static int fontnamecodes[] = {NATIVEFONTS,PSFONTS,SVGFONTS,-1};
    int rankdir;
    GD_drawing(g) = gv_alloc(sizeof(layout_t));

    /* reparseable input */
    if ((p = agget(g, "postaction"))) {   /* requires a graph wrapper for yyparse */
        agxbuf buf = {0};
        agxbprint(&buf, "%s { %s }", agisdirected(g) ? "digraph" : "graph", p);
        agmemconcat(g, agxbuse(&buf));
        agxbfree(&buf);
    }

    /* set this up fairly early in case any string sizes are needed */
    if ((p = agget(g, "fontpath")) || (p = getenv("DOTFONTPATH"))) {
	/* overide GDFONTPATH in local environment if dot
	 * wants its own */
#ifdef HAVE_SETENV
	setenv("GDFONTPATH", p, 1);
#else
	static agxbuf buf;
	agxbprint(&buf, "GDFONTPATH=%s", p);
	putenv(agxbuse(&buf));
#endif
    }

    GD_charset(g) = findCharset (g);

    if (!HTTPServerEnVar) {
	Gvimagepath = agget (g, "imagepath");
	if (!Gvimagepath) {
	    Gvimagepath = Gvfilepath;
	}
    }

    GD_drawing(g)->quantum =
	late_double(g, agfindgraphattr(g, "quantum"), 0.0, 0.0);

    /* setting rankdir=LR is only defined in dot,
     * but having it set causes shape code and others to use it. 
     * The result is confused output, so we turn it off unless requested.
     * This effective rankdir is stored in the bottom 2 bits of g->u.rankdir.
     * Sometimes, the code really needs the graph's rankdir, e.g., neato -n
     * with record shapes, so we store the real rankdir in the next 2 bits.
     */
    rankdir = RANKDIR_TB;
    if ((p = agget(g, "rankdir"))) {
	if (streq(p, "LR"))
	    rankdir = RANKDIR_LR;
	else if (streq(p, "BT"))
	    rankdir = RANKDIR_BT;
	else if (streq(p, "RL"))
	    rankdir = RANKDIR_RL;
    }
    if (use_rankdir)
	SET_RANKDIR (g, (rankdir << 2) | rankdir);
    else
	SET_RANKDIR(g, rankdir << 2);

    xf = late_double(g, agfindgraphattr(g, "nodesep"),
		DEFAULT_NODESEP, MIN_NODESEP);
    GD_nodesep(g) = POINTS(xf);

    p = late_string(g, agfindgraphattr(g, "ranksep"), NULL);
    if (p) {
	if (sscanf(p, "%lf", &xf) == 0)
	    xf = DEFAULT_RANKSEP;
	else {
	    if (xf < MIN_RANKSEP)
		xf = MIN_RANKSEP;
	}
	if (strstr(p, "equally"))
	    GD_exact_ranksep(g) = true;
    } else
	xf = DEFAULT_RANKSEP;
    GD_ranksep(g) = POINTS(xf);

    {
	int showboxes = late_int(g, agfindgraphattr(g, "showboxes"), 0, 0);
	if (showboxes > UCHAR_MAX) {
	    showboxes = UCHAR_MAX;
	}
	GD_showboxes(g) = (unsigned char)showboxes;
    }
    p = late_string(g, agfindgraphattr(g, "fontnames"), NULL);
    GD_fontnames(g) = maptoken(p, fontnamenames, fontnamecodes);

    setRatio(g);
    GD_drawing(g)->filled = getdoubles2ptf(g, "size", &GD_drawing(g)->size);
    getdoubles2ptf(g, "page", &GD_drawing(g)->page);

    GD_drawing(g)->centered = mapbool(agget(g, "center"));

    if ((p = agget(g, "rotate")))
	GD_drawing(g)->landscape = atoi(p) == 90;
    else if ((p = agget(g, "orientation")))
	GD_drawing(g)->landscape = p[0] == 'l' || p[0] == 'L';
    else if ((p = agget(g, "landscape")))
	GD_drawing(g)->landscape = mapbool(p);

    p = agget(g, "clusterrank");
    CL_type = maptoken(p, rankname, rankcode);
    p = agget(g, "concentrate");
    Concentrate = mapbool(p);
    State = GVBEGIN;
    EdgeLabelsDone = 0;

    GD_drawing(g)->dpi = 0.0;
    if (((p = agget(g, "dpi")) && p[0])
	|| ((p = agget(g, "resolution")) && p[0]))
	GD_drawing(g)->dpi = atof(p);

    do_graph_label(g);

    Initial_dist = MYHUGE;

    G_ordering = agfindgraphattr(g, "ordering");
    G_gradientangle = agfindgraphattr(g,"gradientangle");
    G_margin = agfindgraphattr(g, "margin");

    /* initialize nodes */
    N_height = agfindnodeattr(g, "height");
    N_width = agfindnodeattr(g, "width");
    N_shape = agfindnodeattr(g, "shape");
    N_color = agfindnodeattr(g, "color");
    N_fillcolor = agfindnodeattr(g, "fillcolor");
    N_style = agfindnodeattr(g, "style");
    N_fontsize = agfindnodeattr(g, "fontsize");
    N_fontname = agfindnodeattr(g, "fontname");
    N_fontcolor = agfindnodeattr(g, "fontcolor");
    N_label = agfindnodeattr(g, "label");
    if (!N_label)
	N_label = agattr(g, AGNODE, "label", NODENAME_ESC);
    N_xlabel = agfindnodeattr(g, "xlabel");
    N_showboxes = agfindnodeattr(g, "showboxes");
    N_penwidth = agfindnodeattr(g, "penwidth");
    N_ordering = agfindnodeattr(g, "ordering");
    /* attribs for polygon shapes */
    N_sides = agfindnodeattr(g, "sides");
    N_peripheries = agfindnodeattr(g, "peripheries");
    N_skew = agfindnodeattr(g, "skew");
    N_orientation = agfindnodeattr(g, "orientation");
    N_distortion = agfindnodeattr(g, "distortion");
    N_fixed = agfindnodeattr(g, "fixedsize");
    N_imagescale = agfindnodeattr(g, "imagescale");
    N_imagepos = agfindnodeattr(g, "imagepos");
    N_nojustify = agfindnodeattr(g, "nojustify");
    N_layer = agfindnodeattr(g, "layer");
    N_group = agfindnodeattr(g, "group");
    N_comment = agfindnodeattr(g, "comment");
    N_vertices = agfindnodeattr(g, "vertices");
    N_z = agfindnodeattr(g, "z");
    N_gradientangle = agfindnodeattr(g,"gradientangle");

    /* initialize edges */
    E_weight = agfindedgeattr(g, "weight");
    E_color = agfindedgeattr(g, "color");
    E_fillcolor = agfindedgeattr(g, "fillcolor");
    E_fontsize = agfindedgeattr(g, "fontsize");
    E_fontname = agfindedgeattr(g, "fontname");
    E_fontcolor = agfindedgeattr(g, "fontcolor");
    E_label = agfindedgeattr(g, "label");
    E_xlabel = agfindedgeattr(g, "xlabel");
    E_label_float = agfindedgeattr(g, "labelfloat");
    E_dir = agfindedgeattr(g, "dir");
    E_headlabel = agfindedgeattr(g, "headlabel");
    E_taillabel = agfindedgeattr(g, "taillabel");
    E_labelfontsize = agfindedgeattr(g, "labelfontsize");
    E_labelfontname = agfindedgeattr(g, "labelfontname");
    E_labelfontcolor = agfindedgeattr(g, "labelfontcolor");
    E_labeldistance = agfindedgeattr(g, "labeldistance");
    E_labelangle = agfindedgeattr(g, "labelangle");
    E_minlen = agfindedgeattr(g, "minlen");
    E_showboxes = agfindedgeattr(g, "showboxes");
    E_style = agfindedgeattr(g, "style");
    E_decorate = agfindedgeattr(g, "decorate");
    E_arrowsz = agfindedgeattr(g, "arrowsize");
    E_constr = agfindedgeattr(g, "constraint");
    E_layer = agfindedgeattr(g, "layer");
    E_comment = agfindedgeattr(g, "comment");
    E_tailclip = agfindedgeattr(g, "tailclip");
    E_headclip = agfindedgeattr(g, "headclip");
    E_penwidth = agfindedgeattr(g, "penwidth");

    /* background */
    GD_drawing(g)->xdots = init_xdot (g);

    /* initialize id, if any */
    if ((p = agget(g, "id")) && *p)
	GD_drawing(g)->id = strdup_and_subst_obj(p, g);
}

void graph_cleanup(graph_t *g)
{
    if (GD_drawing(g) && GD_drawing(g)->xdots)
	freeXDot(GD_drawing(g)->xdots);
    if (GD_drawing(g))
	free (GD_drawing(g)->id);
    free(GD_drawing(g));
    GD_drawing(g) = NULL;
    free_label(GD_label(g));
    //FIX HERE , STILL SHALLOW
    //memset(&(g->u), 0, sizeof(Agraphinfo_t));
    agclean(g, AGRAPH,"Agraphinfo_t");
}

/// Given an internal charset value, return a canonical string representation.
char*
charsetToStr (int c)
{
   char* s;

   switch (c) {
   case CHAR_UTF8 :
	s = "UTF-8";
	break;
   case CHAR_LATIN1 :
	s = "ISO-8859-1";
	break;
   case CHAR_BIG5 :
	s = "BIG-5";
	break;
   default :
	agerrorf("Unsupported charset value %d\n", c);
	s = "UTF-8";
	break;
   }
   return s;
}

/// Set characteristics of graph label if it exists.
void do_graph_label(graph_t * sg)
{
    char *str, *pos, *just;
    int pos_ix;

    /* it would be nice to allow multiple graph labels in the future */
    if ((str = agget(sg, "label")) && *str != '\0') {
	char pos_flag;
	pointf dimen;

	GD_has_labels(sg->root) |= GRAPH_LABEL;

	GD_label(sg) = make_label(sg, str, aghtmlstr(str) ? LT_HTML : LT_NONE,
	    late_double(sg, agfindgraphattr(sg, "fontsize"),
			DEFAULT_FONTSIZE, MIN_FONTSIZE),
	    late_nnstring(sg, agfindgraphattr(sg, "fontname"),
			DEFAULT_FONTNAME),
	    late_nnstring(sg, agfindgraphattr(sg, "fontcolor"),
			DEFAULT_COLOR));

	/* set label position */
	pos = agget(sg, "labelloc");
	if (sg != agroot(sg)) {
	    if (pos && pos[0] == 'b')
		pos_flag = LABEL_AT_BOTTOM;
	    else
		pos_flag = LABEL_AT_TOP;
	} else {
	    if (pos && pos[0] == 't')
		pos_flag = LABEL_AT_TOP;
	    else
		pos_flag = LABEL_AT_BOTTOM;
	}
	just = agget(sg, "labeljust");
	if (just) {
	    if (just[0] == 'l')
		pos_flag |= LABEL_AT_LEFT;
	    else if (just[0] == 'r')
		pos_flag |= LABEL_AT_RIGHT;
	}
	GD_label_pos(sg) = pos_flag;

	if (sg == agroot(sg))
	    return;

	/* Set border information for cluster labels to allow space
	 */
	dimen = GD_label(sg)->dimen;
	PAD(dimen);
	if (!GD_flip(agroot(sg))) {
	    if (GD_label_pos(sg) & LABEL_AT_TOP)
		pos_ix = TOP_IX;
	    else
		pos_ix = BOTTOM_IX;
	    GD_border(sg)[pos_ix] = dimen;
	} else {
	    /* when rotated, the labels will be restored to TOP or BOTTOM  */
	    if (GD_label_pos(sg) & LABEL_AT_TOP)
		pos_ix = RIGHT_IX;
	    else
		pos_ix = LEFT_IX;
	    GD_border(sg)[pos_ix].x = dimen.y;
	    GD_border(sg)[pos_ix].y = dimen.x;
	}
    }
}