// String Manipulation Module
// created by Volv <http://www.volv.net/>
// This file and contents can be reused and redistributed freely
//
// Functionality:
// - randomString	> Creates a random alphanumeric string
//				> Parameters:
//					- numChars - The number of characters in the random string.
//
// - str_reverse	> Reverses a string
//				> Parameters:
//					- strString - The string to reverse.
//
// - base64_encode	> Base64 encode a string
//				> Parameters:
//					- strInput - The string to be encoded.
//
// - base64_decode	> Decodes a Base64 encoded string
//				> Parameters:
//					- strInput - The Base64 encoded string to be decoded.
//
// - StringToBinary	> Converts an ascii string to binary data
//					> Parameters:
//						- strAscii - The ascii string data to be converted.
//
// - BinaryToString	> Converts binary data to an ascii string
//					> Parameters:
//						- binData - The binary data to be converted.
//
// - AppendToBinary	> Appends/Concatenates binary data
//					> Parameters:
//						- binData - The binary data to append.
//						- AppendTo - The binary data to be appended to.
//
// - LinearSearch	> Finds the location of a string in an array
//				> Parameters:
//					- SearchFor - The string to search for.
//					- SearchIn - The array of strings to search in.
//					- boolFindLike (Optional) - False: Find an element in the array exactly matching,
//					                            True: Find an element in the array which contains the string to search for.

//Creates a random alphanumeric string of length numChars
function randomString(numChars)
{
	var randString = '';
	for(var i = 0; i < numChars; i++) {
		var rndInt = (Math.random()*3);
		if(rndInt >= 2) {
			//Uppercase
			randString += String.fromCharCode((Math.random()*26)+65);
		} else if(rndInt >= 1) {
			//Lowercase
			randString += String.fromCharCode((Math.random()*26)+97);
		} else {
			//Numbers
			randString += String.fromCharCode((Math.random()*10)+48);
		}
	}
	return randString;
}

function str_reverse(strString) {
	var revStr = '';
	for (i = strString.length - 1; i >= 0; i--) {
		revStr += strString.charAt(i);
	}
	return revStr;
}

//Base64 encode a string
//Thanks to http://rumkin.com/tools/compression/base64.php
function base64_encode(strInput) {
	var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
	var strEnc = "";
	var chr1, chr2, chr3;
	var enc1, enc2, enc3, enc4;
	var i = 0;

	do {
		chr1 = strInput.charCodeAt(i++);
		chr2 = strInput.charCodeAt(i++);
		chr3 = strInput.charCodeAt(i++);

		enc1 = chr1 >> 2;
		enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
		enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
		enc4 = chr3 & 63;

		if (isNaN(chr2)) {
			enc3 = enc4 = 64;
		} else if (isNaN(chr3)) {
			enc4 = 64;
		}

		strEnc = strEnc + keyStr.charAt(enc1) + keyStr.charAt(enc2) + keyStr.charAt(enc3) + keyStr.charAt(enc4);
	} while (i < strInput.length);
	
	return strEnc;
}

//Decode a Base64 encoded string
//Thanks to http://rumkin.com/tools/compression/base64.php
function base64_decode(strInput) {
	var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
	var strDec = "";
	var chr1, chr2, chr3;
	var enc1, enc2, enc3, enc4;
	var i = 0;

	// remove all characters that are not A-Z, a-z, 0-9, +, /, or =
	strInput = strInput.replace(/[^A-Za-z0-9\+\/\=]/g, "");

	do {
		enc1 = keyStr.indexOf(strInput.charAt(i++));
		enc2 = keyStr.indexOf(strInput.charAt(i++));
		enc3 = keyStr.indexOf(strInput.charAt(i++));
		enc4 = keyStr.indexOf(strInput.charAt(i++));

		chr1 = (enc1 << 2) | (enc2 >> 4);
		chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
		chr3 = ((enc3 & 3) << 6) | enc4;

		strDec = strDec + String.fromCharCode(chr1);

		if (enc3 != 64) {
			strDec = strDec + String.fromCharCode(chr2);
		}
		if (enc4 != 64) {
			strDec = strDec + String.fromCharCode(chr3);
		}
	} while (i < strInput.length);

	return strDec;
}

function StringToBinary(strAscii)
{
	var fstream = new ActiveXObject("ADODB.Stream");

	//Write ascii to stream
	fstream.Type = 2; //adTypeString
	fstream.CharSet = "ascii";
	fstream.Open;
	fstream.WriteText(strAscii);
	
	//Read binary from stream
	fstream.Position = 0;
	fstream.Type = 1; //adTypeBinary
	
	return fstream.Read;
}

function BinaryToString(binData)
{
	var fstream = new ActiveXObject("ADODB.Stream");
	
	//Write binary to stream
	fstream.Type = 1; //adTypeBinary
	fstream.Open;
	fstream.Write(binData);
	
	//Read ascii from stream
	fstream.Position = 0;
	fstream.Type = 2; //adTypeString
	fstream.CharSet = "ascii";
	
	return fstream.ReadText;
}

function AppendToBinary(binData, binAppendTo)
{
	var fstream = new ActiveXObject("ADODB.Stream");
	
	//Write binary to stream
	fstream.Type = 1; //adTypeBinary
	fstream.Open;
	fstream.Write(binAppendTo);
	fstream.Write(binData);
	fstream.Position = 0;
	return fstream.Read;
}

function LinearSearch(SearchFor, SearchIn, boolFindLike)
{
	for(var i = 0; i < SearchIn.length; i++) {
		if(boolFindLike) {
			if(SearchIn[i].indexOf(SearchFor) >= 0) {
				return i;
			}
		} else if (SearchIn[i] == SearchFor) {
			return i;
		}
	}
	
	return -1;
}

function WriteMultiStringW (datablock, string) {
    var pos = 0;
    datablock.WriteString(0, string);
    pos = string.indexOf("|", pos);
    while (pos != -1) {
        datablock.WriteWORD(2 * pos, 0);
        pos = string.indexOf("|", pos + 1);
    }
}

function Space(number) {
    var i;
    var s = "";
    for (i = 0; i < number; i++) {
        s += " ";
    }
    return s;
}