#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>

#include <unistd.h>
#include <sys/param.h>
#include <sys/stat.h>

/*  This program employs the open source GD graphics library to read and
    create PNG images.  GD is available from  http://www.libgd.org/

    Compile this program with:

	gcc -O -std=c99 -Wall -Werror -pedantic \
		-I/path/to/gd/includes -o makemap makemap.c
		/path/to/gd/library/libgd.a -lpng -lm

    Compiled and tested on:	Mac OS-X 10.5.4, with gcc v4.0.1
 */

#include "gd.h"

/*  makemap (v1.0)
    Copyright (C) 2008-, Chris McDonald

    Chris McDonald, chris@csse.uwa.edu.au
    School of Computer Science & Software Engineering
    The University of Western Australia,
    Crawley, Western Australia, 6009
    PH: +61 8 6488 2533, FAX: +61 8 6488 1089.

    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.,
    59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#define AUTHOR_NAME	"Chris McDonald"
#define AUTHOR_EMAIL	"chris@csse.uwa.edu.au"

#define	TILESQR		320
#define	MODE_FILE	0644
#define	MODE_DIR	0755

static	char		*argv0;
static	char		*tilefmt;

static	int		ncols	= 0;
static	int		nrows	= 0;

static void usage(int status)
{
    fprintf(stderr,
    "Usage: %s mapname.png latitude0 longitude0 latitude1 longitude1\n", argv0);

    fprintf(stderr, "\nPlease report any bugs to %s, %s\n",
                        AUTHOR_NAME, AUTHOR_EMAIL);
    exit(status);
}

static int make_tiles(const char *mapname, const char *filenm)
{
    FILE	*fp;

    fp	= fopen(filenm, "r");
    if(fp) {
	gdImagePtr	im_in;
	int		maxx, maxy;
	int		ndigits=1;
	char		fmt[MAXPATHLEN];

	im_in = gdImageCreateFromPng(fp);
	fclose(fp);

	maxx	= gdImageSX(im_in);
	maxy	= gdImageSY(im_in);
	printf("%s.png is %dx%d pixels\n", mapname, maxx, maxy);

	sprintf(fmt, "map-%s", mapname);
	mkdir(fmt, MODE_DIR); chmod(fmt, MODE_DIR);
	printf("mkdir \"%s\"\n", fmt);

	sprintf(fmt, "map-%s/tiles", mapname);
	mkdir(fmt, MODE_DIR); chmod(fmt, MODE_DIR);

	ncols	= maxx / TILESQR;
	nrows	= maxy / TILESQR;
	if(ncols >= 100 || nrows >= 100)	ndigits = 3;
	else if(ncols >= 10 || nrows >= 10)	ndigits = 2;

	sprintf(fmt, "map-%s/tiles/tile-%%0%dd-%%0%dd.png",
			mapname, ndigits, ndigits);
	tilefmt	= strdup( strchr(fmt, '/')+1 );

	ncols	= 0;
	nrows	= 0;
	for(int x=0 ; (x*TILESQR) < maxx ; ++x) {
	    int		w, h;

	    ++ncols;
	    nrows	= 0;
	    w	= maxx - (x*TILESQR);
	    if(w > TILESQR)
		w	= TILESQR;

	    for(int y=0 ; (y*TILESQR) < maxy ; ++y) {
		char		filenm[MAXPATHLEN];
		gdImagePtr	im_out;

		++nrows;
		sprintf(filenm, fmt, x,y);
		unlink(filenm);

		h	= maxy - (y*TILESQR);
		if(h > TILESQR)
		    h	= TILESQR;

		im_out	= gdImageCreateTrueColor(w, h);
		gdImageCopy(im_out, im_in, 0, 0, x*TILESQR, y*TILESQR, w, h);

		fp	= fopen(filenm, "w");
		if(fp) {
		    gdImagePng(im_out, fp);
		    fclose(fp);
		    chmod(filenm, MODE_FILE);
		}
	    }
	}
	printf("%dx%d tiles created\n", ncols, nrows);

	gdImageDestroy(im_in);
	return 0;
    }
    usage(1);
    return 1;
}


static int make_mapinfo_plist(const char *mapname,
			double lat0, double lon0, double lat1, double lon1)
{
    FILE	*fp;
    char	filenm[MAXPATHLEN];

    sprintf(filenm, "map-%s/mapinfo.plist", mapname);
    fp	= fopen(filenm, "w");
    if(fp == NULL)
	return(1);

    fprintf(fp,"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
    fprintf(fp,"<!DOCTYPE plist SYSTEM \"PropertyList-1.0.dtd\">\n");
    fprintf(fp,"<plist version=\"1.0\">\n");
    fprintf(fp,"<dict>\n");
	fprintf(fp,"\t<key>lat0</key>\n");
	    fprintf(fp,"\t\t<real>%lf</real>\n", lat0);
	fprintf(fp,"\t<key>lon0</key>\n");
	    fprintf(fp,"\t\t<real>%lf</real>\n", lon0);
	fprintf(fp,"\t<key>lat1</key>\n");
	    fprintf(fp,"\t\t<real>%lf</real>\n", lat1);
	fprintf(fp,"\t<key>lon1</key>\n");
	    fprintf(fp,"\t\t<real>%lf</real>\n", lon1);
    fprintf(fp,"</dict>\n");
    fprintf(fp,"</plist>\n");

    fclose(fp);
    chmod(filenm, MODE_FILE);
    return 0;
}

static int make_html(const char *mapname)
{
    FILE	*fp;
    char	filenm[MAXPATHLEN];

    sprintf(filenm, "map-%s/tiles.html", mapname);
    fp	= fopen(filenm, "w");
    if(fp == NULL)
	return(1);

    fprintf(fp,"<body>\n");
    fprintf(fp,"<html>\n");
    fprintf(fp,"<table bgcolor=\"red\" cellpadding=\"0\" cellspacing=\"2\">\n");

    char	*tdfmt	= calloc(1, strlen(tilefmt) + 32);

    sprintf(tdfmt, "\t<td><img src=\"%s\"></td>\n", tilefmt);
    for(int r=0 ; r<nrows ; ++r) {
	fprintf(fp,"<tr>\n");
	for(int c=0 ; c<ncols ; ++c)
	    fprintf(fp,tdfmt, c, r);
	fprintf(fp,"</tr>\n");
    }
    free(tdfmt);

    fprintf(fp,"</table>\n");
    fprintf(fp,"</html>\n");
    fprintf(fp,"</body>\n");

    fclose(fp);
    chmod(filenm, MODE_FILE);
    return 0;
}

static double check_double(const char *str)
{
    if(strspn(str, "-.0123456789") != strlen(str))
	usage(1);
    return atof(str);
}

#define	check_lat(x)	if(x <  -90.0 || x >  90.0) usage(1)
#define	check_lon(x)	if(x < -180.0 || x > 180.0) usage(2)

int main(int argc, char *argv[])
{
    double	lat0, lon0;
    double	lat1, lon1;
    char	*mapname, *dot;
    int		rtn;

    argv0	= (argv0 = strrchr(argv[0],'/')) ? argv0+1 : argv[0];
    if(argc != 6)
	usage(1);

    mapname	= (mapname = strrchr(argv[1],'/')) ? mapname+1 : argv[1];
    mapname	= strdup(mapname);
    dot		= strrchr(mapname, '.');
    if(dot == NULL || strcmp(dot, ".png") != 0)
	usage(1);
    *dot	= '\0';

    lat0	= check_double(argv[2]);	check_lat(lat0);
    lon0	= check_double(argv[3]);	check_lon(lon0);
    lat1	= check_double(argv[4]);	check_lat(lat1);
    lon1	= check_double(argv[5]);	check_lon(lon1);

    rtn	= make_tiles(mapname, argv[1]);
    if(rtn == 0)
	rtn	= make_mapinfo_plist(mapname, lat0, lon0, lat1, lon1);
    if(rtn == 0)
	rtn	= make_html(mapname);
    return rtn;
}