/*  Audacious
 *  Copyright (C) 2005-2007  Audacious development team.
 *
 *  BMP - Cross-platform multimedia player
 *  Copyright (C) 2003-2004  BMP development team.
 *
 *  Based on XMMS:
 *  Copyright (C) 1998-2003  XMMS development team.
 *
 *  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; under version 3 of the License.
 *
 *  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, see <http://www.gnu.org/licenses>.
 *
 *  The Audacious team does not consider modular code linking to
 *  Audacious or using our public API to be a derived work.
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#include "strings.h"

#include <glib/gi18n.h>
#include <string.h>
#include <ctype.h>

#include "main.h"

#ifdef USE_CHARDET
#include "../libguess/libguess.h"
#  ifdef HAVE_UDET
#    include <libudet_c.h>
#  endif
#endif

/*
 * escape_shell_chars()
 *
 * Escapes characters that are special to the shell inside double quotes.
 */

gchar *
escape_shell_chars(const gchar * string)
{
    const gchar *special = "$`\"\\";    /* Characters to escape */
    const gchar *in = string;
    gchar *out, *escaped;
    gint num = 0;

    while (*in != '\0')
        if (strchr(special, *in++))
            num++;

    escaped = g_malloc(strlen(string) + num + 1);

    in = string;
    out = escaped;

    while (*in != '\0') {
        if (strchr(special, *in))
            *out++ = '\\';
        *out++ = *in++;
    }
    *out = '\0';

    return escaped;
}

/* replace %20 with ' ' in place */
static gchar *
str_twenty_to_space(gchar * str)
{
    gchar *match, *match_end;

    g_return_val_if_fail(str != NULL, NULL);

    while ((match = strstr(str, "%20"))) {
        match_end = match + 3;
        *match++ = ' ';
        while (*match_end)
            *match++ = *match_end++;
        *match = 0;
    }

    return str;
}

/* replace drive letter with '/' in place */
static gchar *
str_replace_drive_letter(gchar * str)
{
    gchar *match, *match_end;

    g_return_val_if_fail(str != NULL, NULL);

    while ((match = strstr(str, ":\\"))) {
        match--;
        match_end = match + 3;
        *match++ = '/';
        while (*match_end)
            *match++ = *match_end++;
        *match = 0; /* the end of line */
    }

    return str;
}

static gchar *
str_replace_char(gchar * str, gchar old, gchar new)
{
    gchar *match;

    g_return_val_if_fail(str != NULL, NULL);

    match = str;
    while ((match = strchr(match, old)))
        *match = new;

    return str;
}

gchar *
str_append(gchar * str, const gchar * add_str)
{
    return str_replace(str, g_strconcat(str, add_str, NULL));
}

gchar *
str_replace(gchar * str, gchar * new_str)
{
    g_free(str);
    return new_str;
}

void
str_replace_in(gchar ** str, gchar * new_str)
{
    *str = str_replace(*str, new_str);
}


gboolean
str_has_prefix_nocase(const gchar * str, const gchar * prefix)
{
    /* strncasecmp causes segfaults when str is NULL*/
    return (str && (strncasecmp(str, prefix, strlen(prefix)) == 0));
}

gboolean
str_has_suffix_nocase(const gchar * str, const gchar * suffix)
{
    return (strcasecmp(str + strlen(str) - strlen(suffix), suffix) == 0);
}

gboolean
str_has_suffixes_nocase(const gchar * str, gchar * const *suffixes)
{
    gchar *const *suffix;

    g_return_val_if_fail(str != NULL, FALSE);
    g_return_val_if_fail(suffixes != NULL, FALSE);

    for (suffix = suffixes; *suffix; suffix++)
        if (str_has_suffix_nocase(str, *suffix))
            return TRUE;

    return FALSE;
}

gchar *
str_to_utf8_fallback(const gchar * str)
{
    gchar *out_str, *convert_str, *chr;

    /* NULL in NULL out */
    if (!str)
        return NULL;

    convert_str = g_strdup(str);
    for (chr = convert_str; *chr; chr++) {
        if (*chr & 0x80)
            *chr = '?';
    }

    out_str = g_strconcat(convert_str, _("  (invalid UTF-8)"), NULL);
    g_free(convert_str);

    return out_str;
}

/* convert name of absolute path in local file system encoding into utf8 string */
gchar *
filename_to_utf8(const gchar * filename)
{
    gchar *out_str;

    /* NULL in NULL out */
    if (!filename)
        return NULL;

    if ((out_str = g_filename_to_utf8(filename, -1, NULL, NULL, NULL)))
        return out_str;

    return str_to_utf8_fallback(filename);
}

/* derives basename from uri. basename is in utf8 */
gchar *
uri_to_display_basename(const gchar * uri)
{
    gchar *realfn, *utf8fn, *basename;

    g_return_val_if_fail(uri, NULL);

    realfn = g_filename_from_uri(uri, NULL, NULL);
    utf8fn = g_filename_display_name(realfn ? realfn : uri); // guaranteed to be non-NULL
    basename = g_path_get_basename(utf8fn);

    g_free(realfn); g_free(utf8fn);

    return basename;
}

/* derives dirname from uri. dirname is in utf8 */
gchar *
uri_to_display_dirname(const gchar * uri)
{
    gchar *realfn, *utf8fn, *dirname;

    g_return_val_if_fail(uri, NULL);

    realfn = g_filename_from_uri(uri, NULL, NULL);
    utf8fn = g_filename_display_name(realfn ? realfn : uri);  // guaranteed to be non-NULL
    dirname = g_path_get_dirname(utf8fn);

    g_free(realfn); g_free(utf8fn);

    return dirname;
}

gchar *
str_to_utf8(const gchar * str)
{
    gchar *out_str;

    /* NULL in NULL out */
    /* g_return_val_if_fail(str != NULL, NULL); */
    if (!str)
        return NULL;

    /* Note: Currently, playlist calls this function repeatedly, even
     * if the string is already converted into utf-8.
     * chardet_to_utf8() would convert a valid utf-8 string into a
     * different utf-8 string, if fallback encodings were supplied and
     * the given string could be treated as a string in one of
     * fallback encodings. To avoid this, g_utf8_validate() had been
     * used at the top of evaluation.
     */

    /* Note 2: g_utf8_validate() has so called encapsulated utf-8
     * problem, thus chardet_to_utf8() took the place of that.
     */

    /* Note 3: As introducing madplug, the problem of conversion from
     * ISO-8859-1 to UTF-8 arose. This may be coped with g_convert()
     * located near the end of chardet_to_utf8(), but it requires utf8
     * validation guard where g_utf8_validate() was. New
     * dfa_validate_utf8() employs libguess' DFA engine to validate
     * utf-8 and can properly distinguish examples of encapsulated
     * utf-8. It is considered to be safe to use as a guard.
     */
    
    /* already UTF-8? */
    if (dfa_validate_utf8(str, strlen(str)))
        return g_strdup(str);

    /* chardet encoding detector */
    if ((out_str = chardet_to_utf8(str, strlen(str), NULL, NULL, NULL)))
        return out_str;

    /* assume encoding associated with locale */
    if ((out_str = g_locale_to_utf8(str, -1, NULL, NULL, NULL)))
        return out_str;

    /* all else fails, we mask off character codes >= 128,
       replace with '?' */
    return str_to_utf8_fallback(str);
}


const gchar *
str_skip_chars(const gchar * str, const gchar * chars)
{
    while (strchr(chars, *str))
        str++;
    return str;
}

gchar *
convert_title_text(gchar * title)
{
    g_return_val_if_fail(title != NULL, NULL);

    if (cfg.convert_slash)
	    str_replace_char(title, '\\', '/');
    
    if (cfg.convert_underscore)
        str_replace_char(title, '_', ' ');

    if (cfg.convert_twenty)
        str_twenty_to_space(title);

    return title;
}

gchar *
convert_dos_path(gchar * path)
{
    g_return_val_if_fail(path != NULL, NULL);

    /* replace drive letter with '/' */
    str_replace_drive_letter(path);

    /* replace '\' with '/' */
    str_replace_char(path, '\\', '/');

    return path;
}

gchar *
chardet_to_utf8(const gchar *str, gssize len,
                       gsize *arg_bytes_read, gsize *arg_bytes_write,
					   GError **arg_error)
{
#ifdef USE_CHARDET
	char  *det = NULL, *encoding = NULL;
#endif
	gchar *ret = NULL;
	gsize *bytes_read, *bytes_write;
	GError **error;
	gsize my_bytes_read, my_bytes_write;

	bytes_read  = arg_bytes_read ? arg_bytes_read : &my_bytes_read;
	bytes_write = arg_bytes_write ? arg_bytes_write : &my_bytes_write;
	error       = arg_error ? arg_error : NULL;

	g_return_val_if_fail(str != NULL, NULL);

#ifdef USE_CHARDET
	if(cfg.chardet_detector)
		det = cfg.chardet_detector;

	guess_init();

	if(det){
		encoding = (char *) guess_encoding(str, strlen(str), det);
		if (!encoding)
			goto fallback;

		ret = g_convert(str, len, "UTF-8", encoding, bytes_read, bytes_write, error);
	}

fallback:
#endif
	if(!ret && cfg.chardet_fallback){
		gchar **encs=NULL, **enc=NULL;
		encs = g_strsplit_set(cfg.chardet_fallback, " ,:;|/", 0);

		if(encs){
			enc = encs;
			for(enc=encs; *enc ; enc++){
				ret = g_convert(str, len, "UTF-8", *enc, bytes_read, bytes_write, error);
				if(len == *bytes_read){
					break;
				}
			}
			g_strfreev(encs);
		}
	}

	if(!ret){
		ret = g_convert(str, len, "UTF-8", "ISO-8859-1", bytes_read, bytes_write, error);
	}

	if(ret){
		if(g_utf8_validate(ret, -1, NULL))
			return ret;
		else {
			g_free(ret);
			ret = NULL;
		}
	}
	
	return NULL;	/* if I have no idea, return NULL. */
}
