/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*  GMime
 *  Copyright (C) 1999-2020 Jeffrey Stedfast
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2.1
 *  of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
 *  02110-1301, USA.
 */


#include <stdio.h>
#include <stdlib.h>
#include <iconv.h>

enum {
	ISO_UNSUPPORTED          = 0,
	
	/* iso-8859-1 */
	ISO_DASH_UINT_DASH_UINT_LOWER  = (1 << 0),
	ISO_DASH_UINT_DASH_UINT        = (1 << 1),
	ISO_UINT_DASH_UINT             = (1 << 2),
	ISO_UINT_UINT                  = (1 << 3),
	ISO_UNDER_UINT_DASH_UINT       = (1 << 4),
	NO_ISO_UINT_DASH_UINT          = (1 << 5),
	
	/* iso-10646-1 */
	/*ISO_DASH_UINT_DASH_UINT_LOWER  = (1 << 0),*/
	/*ISO_DASH_UINT_DASH_UINT        = (1 << 1),*/
	/*ISO_UINT_DASH_UINT             = (1 << 2),*/
	ISO_DASH_UINT_LOWER            = (1 << 3),
	ISO_DASH_UINT                  = (1 << 4),
	ISO_UINT                       = (1 << 5),
	UCS4                           = (1 << 6),
	
	/* iso-2022-jp */
	ISO_DASH_UINT_DASH_STR_LOWER   = (1 << 0),
	ISO_DASH_UINT_DASH_STR         = (1 << 1),
	ISO_UINT_DASH_STR              = (1 << 2),

	/* shift-jis */
	SHIFT_DASH_JIS                 = (1 << 0),
	SHIFT_UNDERSCORE_JIS           = (1 << 1),
	SJIS                           = (1 << 2),
	SHIFT_JISX0213                 = (1 << 3),
};


typedef struct {
	char *charset;
	char *format;
	int id;
} CharInfo;


static CharInfo iso8859_tests[] = {
	{ "iso-8859-1",  "iso-%u-%u", ISO_DASH_UINT_DASH_UINT_LOWER },
	{ "ISO-8859-1",  "ISO-%u-%u", ISO_DASH_UINT_DASH_UINT },
	{ "ISO8859-1",   "ISO%u-%u",  ISO_UINT_DASH_UINT },
	{ "ISO88591",    "ISO%u%u",   ISO_UINT_UINT },
	{ "ISO_8859-1",  "ISO_%u-%u", ISO_UNDER_UINT_DASH_UINT },
	{ "8859-1",      "%u-%u",     NO_ISO_UINT_DASH_UINT },
};

static int num_iso8859_tests = sizeof (iso8859_tests) / sizeof (CharInfo);

static CharInfo iso2022_tests[] = {
	{ "iso-2022-jp", "iso-%u-%s", ISO_DASH_UINT_DASH_STR_LOWER },
	{ "ISO-2022-JP", "ISO-%u-%s", ISO_DASH_UINT_DASH_STR },
	{ "ISO2022-JP",  "ISO%u-%s",  ISO_UINT_DASH_STR },
};

static int num_iso2022_tests = sizeof (iso2022_tests) / sizeof (CharInfo);

static CharInfo shiftjis_tests[] = {
	{ "shift-jis",      "shift-jis",      SHIFT_DASH_JIS },
	{ "shift_jis",      "shift_jis",      SHIFT_UNDERSCORE_JIS },
	{ "sjis",           "sjis",           SJIS },
	{ "shift_jisx0213", "shift_jisx0213", SHIFT_JISX0213 },
};

static int num_shiftjis_tests = sizeof (shiftjis_tests) / sizeof (CharInfo);

static CharInfo iso10646_tests[] = {
	{ "iso-10646-1", "iso-%u-%u",  ISO_DASH_UINT_DASH_UINT_LOWER },
	{ "ISO-10646-1", "ISO-%u-%u",  ISO_DASH_UINT_DASH_UINT },
	{ "ISO10646-1",  "ISO%u-%u",   ISO_UINT_DASH_UINT },
	{ "iso-10646",   "iso-%u",     ISO_DASH_UINT_LOWER },
	{ "ISO-10646",   "ISO-%u",     ISO_DASH_UINT },
	{ "ISO10646",    "ISO%u",      ISO_UINT },
	{ "UCS-4BE",     "UCS-4BE",    UCS4 },
};

static int num_iso10646_tests = sizeof (iso10646_tests) / sizeof (CharInfo);


int main (int argc, char **argv)
{
	unsigned int iso8859, iso2022, iso10646, shiftjis;
	CharInfo *info;
	iconv_t cd;
	FILE *fp;
	int i;
	
	if (!(fp = fopen ("iconv-detect.h", "w")))
		return EXIT_FAILURE;
	
	fprintf (fp, "/* This is an auto-generated header, DO NOT EDIT! */\n\n");
	
	iso8859 = ISO_UNSUPPORTED;
	info = iso8859_tests;
	/*printf ("#define DEFAULT_ISO_FORMAT(iso,codepage)\t");*/
	for (i = 0; i < num_iso8859_tests; i++) {
		cd = iconv_open (info[i].charset, "UTF-8");
		if (cd != (iconv_t) -1) {
			iconv_close (cd);
			/*printf ("(\"%s\", (iso), (codepage))\n", info[i].format);*/
			fprintf (stderr, "System prefers %s\n", info[i].charset);
			iso8859 = info[i].id;
			break;
		}
	}
	
	if (iso8859 == ISO_UNSUPPORTED) {
		fprintf (stderr, "System doesn't support any ISO-8859-1 formats\n");
		fprintf (fp, "#define ICONV_ISO_INT_FORMAT \"%s\"\n", info[0].format);
#ifdef CONFIGURE_IN
		return EXIT_FAILURE;
#endif
	} else {
		fprintf (fp, "#define ICONV_ISO_INT_FORMAT \"%s\"\n", info[i].format);
	}
	
	iso2022 = ISO_UNSUPPORTED;
	info = iso2022_tests;
	/*printf ("#define ISO_2022_FORMAT(iso,codepage)\t");*/
	for (i = 0; i < num_iso2022_tests; i++) {
		cd = iconv_open (info[i].charset, "UTF-8");
		if (cd != (iconv_t) -1) {
			iconv_close (cd);
			/*printf ("(\"%s\", (iso), (codepage))\n", info[i].format);*/
			fprintf (stderr, "System prefers %s\n", info[i].charset);
			iso2022 = info[i].id;
			break;
		}
	}
	
	if (iso2022 == ISO_UNSUPPORTED) {
		fprintf (stderr, "System doesn't support any ISO-2022 formats\n");
		fprintf (fp, "#define ICONV_ISO_STR_FORMAT \"%s\"\n", info[0].format);
#ifdef CONFIGURE_IN
		return EXIT_FAILURE;
#endif
	} else {
		fprintf (fp, "#define ICONV_ISO_STR_FORMAT \"%s\"\n", info[i].format);
	}
	
	shiftjis = ISO_UNSUPPORTED;
	info = shiftjis_tests;
	/*printf ("#define ISO_2022_FORMAT(iso,codepage)\t");*/
	for (i = 0; i < num_shiftjis_tests; i++) {
		cd = iconv_open (info[i].charset, "UTF-8");
		if (cd != (iconv_t) -1) {
			iconv_close (cd);
			/*printf ("(\"%s\", (iso), (codepage))\n", info[i].format);*/
			fprintf (stderr, "System prefers %s\n", info[i].charset);
			shiftjis = info[i].id;
			break;
		}
	}
	
	if (shiftjis == ISO_UNSUPPORTED) {
		fprintf (stderr, "System doesn't support any SHIFT-JIS aliases\n");
		fprintf (fp, "#define ICONV_SHIFT_JIS \"%s\"\n", info[0].format);
#ifdef CONFIGURE_IN
		return EXIT_FAILURE;
#endif
	} else {
		fprintf (fp, "#define ICONV_SHIFT_JIS \"%s\"\n", info[i].format);
	}
	
	iso10646 = ISO_UNSUPPORTED;
	info = iso10646_tests;
	/*printf ("#define ISO_10646_FORMAT(iso,codepage)\t");*/
	for (i = 0; i < num_iso10646_tests; i++) {
		cd = iconv_open (info[i].charset, "UTF-8");
		if (cd != (iconv_t) -1) {
			iconv_close (cd);
			/*if (info[i].id < ISO_DASH_UINT_LOWER)
				printf ("(\"%s\", (iso), (codepage))\n", info[i].format);
			else
			printf ("(\"%s\", (iso))\n", info[i].format);*/
			fprintf (stderr, "System prefers %s\n", info[i].charset);
			iso10646 = info[i].id;
			break;
		}
	}
	
	/* we don't need a printf format for iso-10646 because there is only 1 */
	if (iso10646 == ISO_UNSUPPORTED) {
		fprintf (stderr, "System doesn't support any ISO-10646-1 formats\n");
		fprintf (fp, "#define ICONV_10646 \"%s\"\n", info[0].charset);
#ifdef CONFIGURE_IN
		return EXIT_FAILURE;
#endif
	} else {
		fprintf (fp, "#define ICONV_10646 \"%s\"\n", info[i].charset);
	}
	
	fclose (fp);
	
	return EXIT_SUCCESS;
}
