/** Materials Database Search Engine 
 * @author Mikhail Chudinov e-mail: chudinov@yahoo.com
 * @copyright Copyright (c) 2008-2009 Mikhail Chudinov 
 * ************************************************************************/ 

if(typeof(Stringlib)=="undefined") {
   Stringlib={}
}


// Trim spaces from the beginning and end of the given string.
Stringlib.trim = function(string) {
    return string.replace(/(^\s+)|(\s+$)/g, "");
}


// Find position of first occurrence of a case-insensitive string.
// Javascript equivalent for PHP http://kevin.vanzonneveld.net/techblog
// *         example 1: stripos('ABC', 'a');
// *         returns 1: 0
Stringlib.stripos = function( f_haystack, f_needle, f_offset ) { 
    var haystack = f_haystack.toLowerCase();
    var needle = f_needle.toLowerCase();
    var index = 0;
 
    if(f_offset == undefined) {
        f_offset = 0;
    }
 
    if((index = haystack.indexOf(needle, f_offset)) > -1) {
        return index;
    }
 
    return false;
}


// Return part of a string.
// Javascript equivalent for PHP http://kevin.vanzonneveld.net/techblog
// *         example 1: substr('abcdef', 0, -1);
// *         returns 1: 'abcde' 
Stringlib.substr = function( f_string, f_start, f_length ) {
    if(f_start < 0) {
        f_start += f_string.length;
    }
 
    if(f_length == undefined) {
        f_length = f_string.length;
    } 
    else if(f_length < 0) {
        f_length += f_string.length;
    } 
    else {
        f_length += f_start;
    }
 
    if(f_length < f_start) {
        f_length = f_start;
    }
 
    return f_string.substring(f_start, f_length);
}


// Strip HTML and PHP tags from a string.
// Javascript equivalent for PHP http://kevin.vanzonneveld.net/techblog
// *     example 1: strip_tags('<p>Kevin</p> <br /><b>van</b> <i>Zonneveld</i>', '<i>,<b>');
// *     returns 1: 'Kevin <b>van</b> <i>Zonneveld</i>'
Stringlib.strip_tags = function(str, allowed_tags) {
    if(!str) return null;
        
    //var key = '', 
    var tag = '';
    var matches = allowed_array = [];
    var allowed_keys = {};
    
    // Build allowes tags associative array
    if (allowed_tags) {
        allowed_tags  = allowed_tags.replace(/[\<\> ]+/g, '');;
        allowed_array = allowed_tags.split(',');
        
        for (var i = 0; i < allowed_array.length; i++) {
            tag = allowed_array[i];
            allowed_keys['<' + tag + '>']   = true;
            allowed_keys['<' + tag + ' />'] = true;
            allowed_keys['</' + tag + '>']  = true;
        }
    }
    
    // Match tags
    matches = str.match(/(<\/?[^>]+>)/gi);
    var l = 0;
    if(matches) 
        l = matches.length;

    // Is tag not in allowed list? Remove from str! 
    for (var i = 0; i < l; i++) {
        tag = matches[i].toString();
        if (!allowed_keys[tag]) {
            reg = RegExp(tag, 'g');
            str = str.replace(reg, '');
        }
    }
    
    return str;
}


/** Strip all HTML tags from a string */
Stringlib.strip_tags_all = function(string) {
  return Stringlib.strip_tags(string,null);
}


/** Format e-mail based on the given string value */
Stringlib.format_email = function(value){
    return value ? ('<a href="mailto:'+value+'">'+value+'<\/a>') : ''; 
}


/** Strip whitespace (or other characters) from the beginning and end of a string. 
* string trim( string str [, string charlist] )
*     example 1: trim('    Kevin van Zonneveld    ');
*     returns 1: 'Kevin van Zonneveld'
*     example 2: trim('Hello World', 'Hdle');
*     returns 2: 'o Wor'
*     example 3: trim(16, 1);
*     returns 3: 6 */
Stringlib.trim = function(str, charlist) { 
    var whitespace, l = 0, i = 0;
    str += '';
    
    if (!charlist) {
        // default list
        whitespace = " \n\r\t\f\x0b\xa0\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u200b\u2028\u2029\u3000";
    } else {
        // preg_quote custom list
        charlist += '';
        whitespace = charlist.replace(/([\[\]\(\)\.\?\/\*\{\}\+\$\^\:])/g, '\$1');
    }
    
    l = str.length;
    for (i = 0; i < l; i++) {
        if (whitespace.indexOf(str.charAt(i)) === -1) {
            str = str.substring(i);
            break;
        }
    }
    
    l = str.length;
    for (i = l - 1; i >= 0; i--) {
        if (whitespace.indexOf(str.charAt(i)) === -1) {
            str = str.substring(0, i + 1);
            break;
        }
    }
    
    return whitespace.indexOf(str.charAt(0)) === -1 ? str : '';
}


/** Javascript version of PHP's md5( string str [, bool raw_output] )
* Calculates the MD5 hash of str using the RSA Data Security MD5 
* Message-Digest Algorithm,  and returns that hash.
* -    depends on: utf8_encode
*     example 1: md5('Kevin van Zonneveld');
*     returns 1: '6e658d4bfcb59cc13f96c14450ac40b9' */
Stringlib.md5 = function( str ) {
    var RotateLeft = function(lValue, iShiftBits) {
        return (lValue<<iShiftBits) | (lValue>>>(32-iShiftBits));
    };
 
    var AddUnsigned = function(lX,lY) {
        var lX4,lY4,lX8,lY8,lResult;
        lX8 = (lX & 0x80000000);
        lY8 = (lY & 0x80000000);
        lX4 = (lX & 0x40000000);
        lY4 = (lY & 0x40000000);
        lResult = (lX & 0x3FFFFFFF)+(lY & 0x3FFFFFFF);
        if (lX4 & lY4) {
            return (lResult ^ 0x80000000 ^ lX8 ^ lY8);
        }
        if (lX4 | lY4) {
            if (lResult & 0x40000000) {
                return (lResult ^ 0xC0000000 ^ lX8 ^ lY8);
            } else {
                return (lResult ^ 0x40000000 ^ lX8 ^ lY8);
            }
        } else {
            return (lResult ^ lX8 ^ lY8);
        }
    };
 
    var F = function(x,y,z) { return (x & y) | ((~x) & z); };
    var G = function(x,y,z) { return (x & z) | (y & (~z)); };
    var H = function(x,y,z) { return (x ^ y ^ z); };
    var I = function(x,y,z) { return (y ^ (x | (~z))); };
 
    var FF = function(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(F(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };
 
    var GG = function(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(G(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };
 
    var HH = function(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(H(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };
 
    var II = function(a,b,c,d,x,s,ac) {
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(I(b, c, d), x), ac));
        return AddUnsigned(RotateLeft(a, s), b);
    };
 
    var ConvertToWordArray = function(str) {
        var lWordCount;
        var lMessageLength = str.length;
        var lNumberOfWords_temp1=lMessageLength + 8;
        var lNumberOfWords_temp2=(lNumberOfWords_temp1-(lNumberOfWords_temp1 % 64))/64;
        var lNumberOfWords = (lNumberOfWords_temp2+1)*16;
        var lWordArray=Array(lNumberOfWords-1);
        var lBytePosition = 0;
        var lByteCount = 0;
        while ( lByteCount < lMessageLength ) {
            lWordCount = (lByteCount-(lByteCount % 4))/4;
            lBytePosition = (lByteCount % 4)*8;
            lWordArray[lWordCount] = (lWordArray[lWordCount] | (str.charCodeAt(lByteCount)<<lBytePosition));
            lByteCount++;
        }
        lWordCount = (lByteCount-(lByteCount % 4))/4;
        lBytePosition = (lByteCount % 4)*8;
        lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80<<lBytePosition);
        lWordArray[lNumberOfWords-2] = lMessageLength<<3;
        lWordArray[lNumberOfWords-1] = lMessageLength>>>29;
        return lWordArray;
    };
 
    var WordToHex = function(lValue) {
        var WordToHexValue="",WordToHexValue_temp="",lByte,lCount;
        for (lCount = 0;lCount<=3;lCount++) {
            lByte = (lValue>>>(lCount*8)) & 255;
            WordToHexValue_temp = "0" + lByte.toString(16);
            WordToHexValue = WordToHexValue + WordToHexValue_temp.substr(WordToHexValue_temp.length-2,2);
        }
        return WordToHexValue;
    };
 
    var x=Array();
    var k,AA,BB,CC,DD,a,b,c,d;
    var S11=7, S12=12, S13=17, S14=22;
    var S21=5, S22=9 , S23=14, S24=20;
    var S31=4, S32=11, S33=16, S34=23;
    var S41=6, S42=10, S43=15, S44=21;
 
    str = utf8_encode(str);
    x = ConvertToWordArray(str);
    a = 0x67452301; b = 0xEFCDAB89; c = 0x98BADCFE; d = 0x10325476;
    
    xl = x.length;
    for (k=0;k<xl;k+=16) {
        AA=a; BB=b; CC=c; DD=d;
        a=FF(a,b,c,d,x[k+0], S11,0xD76AA478);
        d=FF(d,a,b,c,x[k+1], S12,0xE8C7B756);
        c=FF(c,d,a,b,x[k+2], S13,0x242070DB);
        b=FF(b,c,d,a,x[k+3], S14,0xC1BDCEEE);
        a=FF(a,b,c,d,x[k+4], S11,0xF57C0FAF);
        d=FF(d,a,b,c,x[k+5], S12,0x4787C62A);
        c=FF(c,d,a,b,x[k+6], S13,0xA8304613);
        b=FF(b,c,d,a,x[k+7], S14,0xFD469501);
        a=FF(a,b,c,d,x[k+8], S11,0x698098D8);
        d=FF(d,a,b,c,x[k+9], S12,0x8B44F7AF);
        c=FF(c,d,a,b,x[k+10],S13,0xFFFF5BB1);
        b=FF(b,c,d,a,x[k+11],S14,0x895CD7BE);
        a=FF(a,b,c,d,x[k+12],S11,0x6B901122);
        d=FF(d,a,b,c,x[k+13],S12,0xFD987193);
        c=FF(c,d,a,b,x[k+14],S13,0xA679438E);
        b=FF(b,c,d,a,x[k+15],S14,0x49B40821);
        a=GG(a,b,c,d,x[k+1], S21,0xF61E2562);
        d=GG(d,a,b,c,x[k+6], S22,0xC040B340);
        c=GG(c,d,a,b,x[k+11],S23,0x265E5A51);
        b=GG(b,c,d,a,x[k+0], S24,0xE9B6C7AA);
        a=GG(a,b,c,d,x[k+5], S21,0xD62F105D);
        d=GG(d,a,b,c,x[k+10],S22,0x2441453);
        c=GG(c,d,a,b,x[k+15],S23,0xD8A1E681);
        b=GG(b,c,d,a,x[k+4], S24,0xE7D3FBC8);
        a=GG(a,b,c,d,x[k+9], S21,0x21E1CDE6);
        d=GG(d,a,b,c,x[k+14],S22,0xC33707D6);
        c=GG(c,d,a,b,x[k+3], S23,0xF4D50D87);
        b=GG(b,c,d,a,x[k+8], S24,0x455A14ED);
        a=GG(a,b,c,d,x[k+13],S21,0xA9E3E905);
        d=GG(d,a,b,c,x[k+2], S22,0xFCEFA3F8);
        c=GG(c,d,a,b,x[k+7], S23,0x676F02D9);
        b=GG(b,c,d,a,x[k+12],S24,0x8D2A4C8A);
        a=HH(a,b,c,d,x[k+5], S31,0xFFFA3942);
        d=HH(d,a,b,c,x[k+8], S32,0x8771F681);
        c=HH(c,d,a,b,x[k+11],S33,0x6D9D6122);
        b=HH(b,c,d,a,x[k+14],S34,0xFDE5380C);
        a=HH(a,b,c,d,x[k+1], S31,0xA4BEEA44);
        d=HH(d,a,b,c,x[k+4], S32,0x4BDECFA9);
        c=HH(c,d,a,b,x[k+7], S33,0xF6BB4B60);
        b=HH(b,c,d,a,x[k+10],S34,0xBEBFBC70);
        a=HH(a,b,c,d,x[k+13],S31,0x289B7EC6);
        d=HH(d,a,b,c,x[k+0], S32,0xEAA127FA);
        c=HH(c,d,a,b,x[k+3], S33,0xD4EF3085);
        b=HH(b,c,d,a,x[k+6], S34,0x4881D05);
        a=HH(a,b,c,d,x[k+9], S31,0xD9D4D039);
        d=HH(d,a,b,c,x[k+12],S32,0xE6DB99E5);
        c=HH(c,d,a,b,x[k+15],S33,0x1FA27CF8);
        b=HH(b,c,d,a,x[k+2], S34,0xC4AC5665);
        a=II(a,b,c,d,x[k+0], S41,0xF4292244);
        d=II(d,a,b,c,x[k+7], S42,0x432AFF97);
        c=II(c,d,a,b,x[k+14],S43,0xAB9423A7);
        b=II(b,c,d,a,x[k+5], S44,0xFC93A039);
        a=II(a,b,c,d,x[k+12],S41,0x655B59C3);
        d=II(d,a,b,c,x[k+3], S42,0x8F0CCC92);
        c=II(c,d,a,b,x[k+10],S43,0xFFEFF47D);
        b=II(b,c,d,a,x[k+1], S44,0x85845DD1);
        a=II(a,b,c,d,x[k+8], S41,0x6FA87E4F);
        d=II(d,a,b,c,x[k+15],S42,0xFE2CE6E0);
        c=II(c,d,a,b,x[k+6], S43,0xA3014314);
        b=II(b,c,d,a,x[k+13],S44,0x4E0811A1);
        a=II(a,b,c,d,x[k+4], S41,0xF7537E82);
        d=II(d,a,b,c,x[k+11],S42,0xBD3AF235);
        c=II(c,d,a,b,x[k+2], S43,0x2AD7D2BB);
        b=II(b,c,d,a,x[k+9], S44,0xEB86D391);
        a=AddUnsigned(a,AA);
        b=AddUnsigned(b,BB);
        c=AddUnsigned(c,CC);
        d=AddUnsigned(d,DD);
    }
 
    var temp = WordToHex(a)+WordToHex(b)+WordToHex(c)+WordToHex(d);
 
    return temp.toLowerCase();
}


/** Javascript version of PHP's utf8_encode()
* This function encodes the string data to UTF-8, and returns the encoded version.
*     example 1: utf8_encode('Kevin van Zonneveld');
*     returns 1: 'Kevin van Zonneveld'  */
Stringlib.utf8_encode = function( string ) {
    string = (string+'').replace(/\r\n/g, "\n").replace(/\r/g, "\n");
 
    var utftext = "";
    var start, end;
    var stringl = 0;
 
    start = end = 0;
    stringl = string.length;
    for (var n = 0; n < stringl; n++) {
        var c1 = string.charCodeAt(n);
        var enc = null;
 
        if (c1 < 128) {
            end++;
        } else if((c1 > 127) && (c1 < 2048)) {
            enc = String.fromCharCode((c1 >> 6) | 192) + String.fromCharCode((c1 & 63) | 128);
        } else {
            enc = String.fromCharCode((c1 >> 12) | 224) + String.fromCharCode(((c1 >> 6) & 63) | 128) + String.fromCharCode((c1 & 63) | 128);
        }
        if (enc != null) {
            if (end > start) {
                utftext += string.substring(start, end);
            }
            utftext += enc;
            start = end = n+1;
        }
    }
 
    if (end > start) {
        utftext += string.substring(start, string.length);
    }
 
    return utftext;
}