//--
//-- Filesystem utilities
//--

function convertUTF8ToUnicode(u)
{
	return config.browser.isOpera || !window.netscape ? manualConvertUTF8ToUnicode(u) : mozConvertUTF8ToUnicode(u);
}

//# UTF-8 encoding rules:
//# 0x0000 - 0x007F:  0xxxxxxx
//# 0x0080 - 0x07FF:  110xxxxx 10xxxxxx
//# 0x0800 - 0xFFFF:  1110xxxx 10xxxxxx 10xxxxxx

function manualConvertUTF8ToUnicode(utf)
{
	var uni = utf;
	var src = 0;
	var dst = 0;
	var b1, b2, b3;
	var c;
	while(src < utf.length) {
		b1 = utf.charCodeAt(src++);
		if(b1 < 0x80) {
			dst++;
		} else if(b1 < 0xE0) {
			b2 = utf.charCodeAt(src++);
			c = String.fromCharCode(((b1 & 0x1F) << 6) | (b2 & 0x3F));
			uni = uni.substring(0,dst++).concat(c,utf.substr(src));
		} else {
			b2 = utf.charCodeAt(src++);
			b3 = utf.charCodeAt(src++);
			c = String.fromCharCode(((b1 & 0xF) << 12) | ((b2 & 0x3F) << 6) | (b3 & 0x3F));
			uni = uni.substring(0,dst++).concat(c,utf.substr(src));
		}
	}
	return uni;
}

function mozConvertUTF8ToUnicode(u)
{
	try {
		netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
		var converter = Components.classes["@mozilla.org/intl/scriptableunicodeconverter"].createInstance(Components.interfaces.nsIScriptableUnicodeConverter);
		converter.charset = "UTF-8";
	} catch(ex) {
		return manualConvertUTF8ToUnicode(u);
	} // fallback
	var s = converter.ConvertToUnicode(u);
	var fin = converter.Finish();
	return fin.length > 0 ? s+fin : s;
}

//# convert unicode string to a format suitable for saving to file
//# this should be UTF8, unless the browser does not support saving non-ASCII characters
function convertUnicodeToFileFormat(s)
{
	return config.browser.isOpera || !window.netscape ? (config.browser.isIE ? convertUnicodeToHtmlEntities(s) : s) : mozConvertUnicodeToUTF8(s);
}

function convertUnicodeToHtmlEntities(s)
{
	var re = /[^\u0000-\u007F]/g;
	return s.replace(re,function($0) {return "&#" + $0.charCodeAt(0).toString() + ";";});
}

function convertUnicodeToUTF8(s)
{
// return convertUnicodeToFileFormat to allow plugin migration
	return convertUnicodeToFileFormat(s);
}

function manualConvertUnicodeToUTF8(s)
{
	return unescape(encodeURIComponent(s));
}

function mozConvertUnicodeToUTF8(s)
{
	try {
		netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
		var converter = Components.classes["@mozilla.org/intl/scriptableunicodeconverter"].createInstance(Components.interfaces.nsIScriptableUnicodeConverter);
		converter.charset = "UTF-8";
	} catch(ex) {
		return manualConvertUnicodeToUTF8(s);
	} // fallback
	var u = converter.ConvertFromUnicode(s);
	var fin = converter.Finish();
	return fin.length > 0 ? u + fin : u;
}

function convertUriToUTF8(uri,charSet)
{
	if(window.netscape == undefined || charSet == undefined || charSet == "")
		return uri;
	try {
		netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
		var converter = Components.classes["@mozilla.org/intl/utf8converterservice;1"].getService(Components.interfaces.nsIUTF8ConverterService);
	} catch(ex) {
		return uri;
	}
	return converter.convertURISpecToUTF8(uri,charSet);
}