/*
 *  gpxreader
 *  read GPX files
 *
 *  Copyright (C) 2006, 2007 Nils Faerber <nils.faerber@kernelconcepts.de>
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */


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

#include <glib.h>
#include <math.h>

#include "mappix.h"

#include "geo-tools.h"

#define BUFFSIZE        8192


/* oh well ... we have to remember in which tag we are... */
#define CurrentIsTrackMask		(guint)0x000000ff
#define CurrentIsTrack			(guint)1 << 0
#define CurrentIsTrackName		(guint)1 << 1
#define CurrentIsTrackType		(guint)1 << 2
#define CurrentIsTrackShow		(guint)1 << 3
#define CurrentIsTrackpointMask		(guint)0x0000ff00
#define CurrentIsTrackpoint		(guint)1 << 8
#define CurrentIsTrackpointEle		(guint)1 << 9
#define CurrentIsTrackpointNRSAT	(guint)1 << 10
#define CurrentIsTrackpointHDOP		(guint)1 << 11
#define CurrentIsTrackpointPDOP		(guint)1 << 12
#define CurrentIsWaypointMask		(guint)0x00ff0000
#define CurrentIsWaypoint		(guint)1 << 16
#define CurrentIsWaypointEle		(guint)1 << 17
#define CurrentIsWaypointName		(guint)1 << 18

/* for passing data around the callbacks */
typedef struct {
	mapwin *Mapper;
	guint current;
	GList *track;
	GList *waypoints;
	trackdata *tdata;
	waypoint *wpt;
	gchar *fname;
	gchar *tname;
	gboolean show;
	tracktype type;
} udt;


void finish_track(udt *ltdata)
{
track_head *new_track;

	if (ltdata->track != NULL) {
		/* done reading the track */
		new_track = (track_head *)malloc(sizeof(track_head));
		new_track->xmax = -1;
		new_track->ymax = -1;
		new_track->xmin = WORLD_SIZE_UNITS;
		new_track->ymin = WORLD_SIZE_UNITS;
		new_track->track = g_list_reverse(ltdata->track);
		new_track->show = ltdata->show;
		new_track->type = ltdata->type;
		if (ltdata->tname != NULL)
			new_track->name = g_strdup(ltdata->tname);
		else
			new_track->name = g_path_get_basename(ltdata->fname);
		// fprintf(stderr,"track '%s' has bbox latmin=%lf longmin=%lf latmax=%lf longmax=%lf\n", new_track->name, new_track->latmin, new_track->longmin, new_track->latmax, new_track->longmax);
		track_add_new_to_main(ltdata->Mapper, new_track);
	}
}


static void XMLCALL
startElement(void *userData, const char *name, const char **atts)
{
udt *ud = (udt *)userData;
gdouble rlat, rlong;
	
	if (strncmp(name, "trkpt", 5) == 0) {
		ud->tdata = (trackdata *)malloc(sizeof(trackdata));
		memset(ud->tdata, 0, sizeof(trackdata));
		if (ud->tdata != NULL) {
			ud->current |= CurrentIsTrackpoint;
			rlat = g_ascii_strtod (atts[1], NULL);
			rlong = g_ascii_strtod (atts[3], NULL);
			latlon2unit(rlat, rlong, ud->tdata->unitx, ud->tdata->unity);
			ud->tdata->selected = FALSE;
		}
		//fprintf(stderr,"lat=%lf long=%lf\n", tdata->latitude, tdata->longitude);
	} else if (strncmp(name, "trkseg", 6) == 0) {
		/* not yet supported */
	} else if (strncmp(name, "trk", 3) == 0) {
		// g_message("new track");
		ud->current |= CurrentIsTrack;
		if (ud->tname != NULL) {
			g_free(ud->tname);
			ud->tname = NULL;
		};
		ud->type = UNKNOWN;
		ud->show = FALSE;
	} else if (strncmp(name, "wpt", 3) == 0) {
		ud->wpt = (waypoint *)malloc(sizeof(waypoint));
		memset(ud->wpt, 0, sizeof(waypoint));
		if (ud->wpt != NULL) {
			ud->current |= CurrentIsWaypoint;
			rlat = g_ascii_strtod (atts[1], NULL);
			rlong = g_ascii_strtod (atts[3], NULL);
			latlon2unit(rlat, rlong, ud->wpt->unitx, ud->wpt->unity);
			ud->wpt->name = NULL;
		}
	} else {
		// fprintf(stderr,"xml unkn: '%s'\n", name);
		if (ud->current & CurrentIsTrackpoint) {
			//fprintf(stderr, "is trackpoint\n");
			if (strncmp(name, "ele", 3) == 0)
				ud->current |= CurrentIsTrackpointEle;
			if (strncmp(name, "sat", 3) == 0)
				ud->current |= CurrentIsTrackpointNRSAT;
			if (strncmp(name, "hdop", 4) == 0)
				ud->current |= CurrentIsTrackpointHDOP;
			if (strncmp(name, "pdop", 4) == 0)
				ud->current |= CurrentIsTrackpointPDOP;
		} else if (ud->current & CurrentIsWaypoint) {
			//fprintf(stderr, "is waypoint\n");
			if (strncmp(name, "name", 4) == 0)
				ud->current |= CurrentIsWaypointName;
			if (strncmp(name, "ele", 3) == 0)
				ud->current |= CurrentIsWaypointEle;
		} else if (ud->current & CurrentIsTrack) {
			//fprintf(stderr, "is track\n");
			if (strncmp(name, "name", 4) == 0) {
				ud->current |= CurrentIsTrackName;
				//fprintf(stderr,"name start\n");
			}
			if (strncmp(name, "type", 4) == 0) {
				ud->current |= CurrentIsTrackType;
				//fprintf(stderr,"type start\n");
			}
			if (strncmp(name, "show", 4) == 0) {
				ud->current |= CurrentIsTrackShow;
				//fprintf(stderr,"show start\n");
			}
		}
	}
}


static void XMLCALL
endElement(void *userData, const char *name)
{
udt *ud = (udt *)userData;
//mapwin *Mapper = (mapwin *)userData;
	
	//fprintf(stderr,"xml endelem: '%s'\n", name);

	/* trackpoints */
	if (strncmp(name, "trkpt", 5) == 0) {
		ud->current &= ~CurrentIsTrackpointMask;
		ud->track = g_list_prepend(ud->track, ud->tdata);
	} else if (strncmp(name, "trkseg", 6) == 0) {
	} else if (strncmp(name, "trk", 3) == 0) {
		finish_track(ud);
		ud->current = 0;
		ud->track = NULL;
		ud->current &= ~CurrentIsTrackMask;
	}

	if (ud->current & CurrentIsTrackName) {
		if (strncmp(name, "name", 4) == 0) {
			//fprintf(stderr, "bnamee 0x%04x ", ud->current);
			ud->current ^= CurrentIsTrackName;
			//fprintf(stderr, "anamee 0x%04x\n", ud->current);
		}
	}

	if (ud->current & CurrentIsTrackpoint) {
		if (strncmp(name, "ele", 3) == 0)
			ud->current ^= CurrentIsTrackpointEle;
	}

	/* waypoints */
	if (strncmp(name, "wpt", 3) == 0) {
		ud->current &= ~CurrentIsWaypointMask;
		//ud->Mapper->waypoints = g_list_prepend(ud->Mapper->waypoints, ud->wpt);
		ud->waypoints = g_list_prepend(ud->waypoints, ud->wpt);
	}
	if (ud->current & CurrentIsWaypoint) {
		if (strncmp(name, "name", 4) == 0)
			ud->current ^= CurrentIsWaypointName;
	}

	if (ud->current & CurrentIsTrack) {
		if (CurrentIsTrackType && strncmp(name, "type", 4) == 0)
			ud->current ^= CurrentIsTrackType;
		if (CurrentIsTrackShow && strncmp(name, "show", 4) == 0)
			ud->current ^= CurrentIsTrackShow;
	}
}


static void XMLCALL
CharData (void *userData, const XML_Char *s, int len)
{
udt *ud = (udt *)userData;
gchar *tmp;

	/* string is not null terminated */
	tmp = (gchar *)malloc(2+len*sizeof(gchar));
	memcpy(tmp,s,len);
	tmp[len] = 0;
	// fprintf(stderr,"char-data: '%s'\n", tmp);

	/* track head */
	if (ud->current & CurrentIsTrackName) {
		if (ud->tname == NULL)
			ud->tname = g_strdup(tmp);
		else
			ud->tname = g_strconcat(ud->tname, tmp, NULL);
	}
	if (ud->current & CurrentIsTrackType) {
		//fprintf(stderr, "type = '%s'\n", tmp);
		gint val;
		sscanf(tmp, "%d", &val);
		ud->type = val;
	}
	if (ud->current & CurrentIsTrackShow) {
		//fprintf(stderr, "show = '%s'\n", tmp);
		if (len > 0 && g_ascii_strncasecmp("true", tmp, 4)==0 )
			ud->show = TRUE;
		else
			ud->show = FALSE;
	}

	/* trackpoints */
	if (ud->current & CurrentIsTrackpointEle) {
		sscanf(tmp, "%f", &ud->tdata->elevation);
	}
	if (ud->current & CurrentIsTrackpointNRSAT) {
		gint val;
		sscanf(tmp, "%d", &val);
		ud->tdata->nrsat = val;
	}
	if (ud->current & CurrentIsTrackpointHDOP) {
		sscanf(tmp, "%f", &ud->tdata->hdop);
	}
	if (ud->current & CurrentIsTrackpointPDOP) {
		sscanf(tmp, "%f", &ud->tdata->pdop);
	}

	/* waypoints */
	if (ud->current & CurrentIsWaypointName) {
		if (ud->wpt->name == NULL)
			ud->wpt->name = g_strdup(tmp);
		else
			ud->wpt->name = g_strconcat(ud->wpt->name, tmp, NULL);
	}
	if (ud->current & CurrentIsWaypointEle) {
		sscanf(tmp, "%f", &ud->wpt->elevation);
	}

	free(tmp);
}

#ifdef DEBUG_WP
void print_waypoints(gpointer data, gpointer user_data)
{
waypoint *wpnt = (waypoint *)data;

	if (data != NULL) {
		fprintf(stderr,"wpt: lat=%lf long=%lf name='%s'\n", wpnt->unitx, wpnt->unity, wpnt->name);
	}
}
#endif


gint gpxread(gchar *fname, mapwin *Mapper)
{
char buf[BUFFSIZE];
XML_Parser parser = XML_ParserCreate(NULL);
int done;
FILE *inpfile;
udt ldata;
// track_head *new_track;

	inpfile=fopen(fname, "r");
	if (inpfile == NULL)
		return -1;

	ldata.fname = fname;
	ldata.current = 0;
	ldata.Mapper = Mapper;
	ldata.track = NULL;
	ldata.tname = NULL;
	ldata.waypoints = NULL;
	XML_SetUserData(parser, &ldata);
	XML_SetElementHandler(parser, startElement, endElement);
	XML_SetCharacterDataHandler(parser, CharData);

	do {
		size_t len = fread(buf, 1, sizeof(buf), inpfile);
		done = len < sizeof(buf);
		if (XML_Parse(parser, buf, len, done) == XML_STATUS_ERROR) {
			fprintf(stderr, "%s at line %d\n", XML_ErrorString(XML_GetErrorCode(parser)), XML_GetCurrentLineNumber(parser));
			return -1;
		}
	} while (!done);

	XML_ParserFree (parser);
	fclose (inpfile);

	if (ldata.waypoints) {
		ldata.waypoints = g_list_reverse(ldata.waypoints);
		Mapper->waypoints = g_list_concat(Mapper->waypoints, ldata.waypoints);
	}
#ifdef DEBUG_WP
	if (Mapper->waypoints != NULL) {
		g_list_foreach(Mapper->waypoints, print_waypoints, NULL);
	}
#endif

return 0;
}