
/*
 * Binary Ajax 0.1.10
 * Copyright (c) 2008 Jacob Seidelin, cupboy@gmail.com, http://blog.nihilogic.dk/
 * Licensed under the MPL License [http://www.nihilogic.dk/licenses/mpl-license.txt]
 */


var BinaryFile = function(strData, iDataOffset, iDataLength) {
    var data = strData;
    var dataOffset = iDataOffset || 0;
    var dataLength = 0;

    this.getRawData = function() {
        return data;
    }

    if (typeof strData === "string") {
        dataLength = iDataLength || data.length;

        this.getByteAt = function(iOffset) {
            return data.charCodeAt(iOffset + dataOffset) & 0xFF;
        }

        this.getBytesAt = function(iOffset, iLength) {
            var aBytes = [];

            for (var i = 0; i < iLength; i++) {
                aBytes[i] = data.charCodeAt((iOffset + i) + dataOffset) & 0xFF
            };

            return aBytes;
        }
    } else if (typeof strData === "unknown") {
        dataLength = iDataLength || IEBinary_getLength(data);

        this.getByteAt = function(iOffset) {
            return IEBinary_getByteAt(data, iOffset + dataOffset);
        }

        this.getBytesAt = function(iOffset, iLength) {
            return new VBArray(IEBinary_getBytesAt(data, iOffset + dataOffset, iLength)).toArray();
        }
    }

    this.getLength = function() {
        return dataLength;
    }

    this.getSByteAt = function(iOffset) {
        var iByte = this.getByteAt(iOffset);
        if (iByte > 127)
            return iByte - 256;
        else
            return iByte;
    }

    this.getShortAt = function(iOffset, bBigEndian) {
        var iShort = bBigEndian ? 
            (this.getByteAt(iOffset) << 8) + this.getByteAt(iOffset + 1)
            : (this.getByteAt(iOffset + 1) << 8) + this.getByteAt(iOffset)
            if (iShort < 0) iShort += 65536;
        return iShort;
    }
    this.getSShortAt = function(iOffset, bBigEndian) {
        var iUShort = this.getShortAt(iOffset, bBigEndian);
        if (iUShort > 32767)
            return iUShort - 65536;
        else
            return iUShort;
    }
    this.getLongAt = function(iOffset, bBigEndian) {
        var iByte1 = this.getByteAt(iOffset),
            iByte2 = this.getByteAt(iOffset + 1),
            iByte3 = this.getByteAt(iOffset + 2),
            iByte4 = this.getByteAt(iOffset + 3);

        var iLong = bBigEndian ? 
            (((((iByte1 << 8) + iByte2) << 8) + iByte3) << 8) + iByte4
            : (((((iByte4 << 8) + iByte3) << 8) + iByte2) << 8) + iByte1;
        if (iLong < 0) iLong += 4294967296;
        return iLong;
    }
    this.getSLongAt = function(iOffset, bBigEndian) {
        var iULong = this.getLongAt(iOffset, bBigEndian);
        if (iULong > 2147483647)
            return iULong - 4294967296;
        else
            return iULong;
    }

    this.getStringAt = function(iOffset, iLength) {
        var aStr = [];

        var aBytes = this.getBytesAt(iOffset, iLength);
        for (var j=0; j < iLength; j++) {
            aStr[j] = String.fromCharCode(aBytes[j]);
        }
        return aStr.join("");
    }

    this.getCharAt = function(iOffset) {
        return String.fromCharCode(this.getByteAt(iOffset));
    }
    this.toBase64 = function() {
        return window.btoa(data);
    }
    this.fromBase64 = function(strBase64) {
        data = window.atob(strBase64);
    }
}


var BinaryAjax = (function() {

        function createRequest() {
        var oHTTP = null;
        if (window.ActiveXObject) {
        oHTTP = new ActiveXObject("Microsoft.XMLHTTP");
        } else if (window.XMLHttpRequest) {
        oHTTP = new XMLHttpRequest();
        }
        return oHTTP;
        }

        function getHead(strURL, fncCallback, fncError) {
        var oHTTP = createRequest();
        if (oHTTP) {
        if (fncCallback) {
        if (typeof(oHTTP.onload) != "undefined") {
        oHTTP.onload = function() {
        if (oHTTP.status === "200") {
        fncCallback(this);
        } else {
            if (fncError) fncError();
        }
        oHTTP = null;
        };
        } else {
            oHTTP.onreadchange = function() {
                if (oHTTP.readyState === 4) {
                    if (oHTTP.status === "200") {
                        fncCallback(this);
                    } else {
                        if (fncError) fncError();
                    }
                    oHTTP = null;
                }
            };
        }
        }
        oHTTP.open("HEAD", strURL, true);
        oHTTP.send(null);
        } else {
            if (fncError) fncError();
        }
        }

        function sendRequest(strURL, fncCallback, fncError, aRange, bAcceptRanges, iFileSize) {
            var oHTTP = createRequest();
            if (oHTTP) {

                var iDataOffset = 0;
                if (aRange && !bAcceptRanges) {
                    iDataOffset = aRange[0];
                }
                var iDataLen = 0;
                if (aRange) {
                    iDataLen = aRange[1]-aRange[0]+1;
                }

                if (fncCallback) {
                    if (typeof(oHTTP.onload) != "undefined") {
                        oHTTP.onload = function() {
                            if (oHTTP.status === "200" || oHTTP.status === "206" || oHTTP.status === "0") {
                                oHTTP.binaryResponse = new BinaryFile(oHTTP.responseText, iDataOffset, iDataLen);
                                oHTTP.fileSize = iFileSize || oHTTP.getResponseHeader("Content-Length");
                                fncCallback(oHTTP);
                            } else {
                                if (fncError) fncError();
                            }
                            oHTTP = null;
                        };
                    } else {
                        oHTTP.onreadchange = function() {
                            if (oHTTP.readyState === 4) {
                                if (oHTTP.status === "200" || oHTTP.status === "206" || oHTTP.status === "0") {
                                    // IE6 craps if we try to extend the XHR object
                                    var oRes = {
status : oHTTP.status,
         // IE needs responseBody, Chrome/Safari needs responseText
         binaryResponse : new BinaryFile(
                 typeof oHTTP.responseBody === "unknown" ? oHTTP.responseBody : oHTTP.responseText, iDataOffset, iDataLen
                 ),
         fileSize : iFileSize || oHTTP.getResponseHeader("Content-Length")
                                    };
                                    fncCallback(oRes);
                                } else {
                                    if (fncError) fncError();
                                }
                                oHTTP = null;
                            }
                        };
                    }
                }
                oHTTP.open("GET", strURL, true);

                if (oHTTP.overrideMimeType) oHTTP.overrideMimeType('text/plain; charset=x-user-defined');

                if (aRange && bAcceptRanges) {
                    oHTTP.setRequestHeader("Range", "bytes=" + aRange[0] + "-" + aRange[1]);
                }

                oHTTP.setRequestHeader("If-Modified-Since", "Sat, 1 Jan 1970 00:00:00 GMT");

                oHTTP.send(null);
            } else {
                if (fncError) fncError();
            }
        }

        return function(strURL, fncCallback, fncError, aRange) {

            if (aRange) {
                getHead(
                        strURL, 
                        function(oHTTP) {
                        var iLength = parseInt(oHTTP.getResponseHeader("Content-Length"),10);
                        var strAcceptRanges = oHTTP.getResponseHeader("Accept-Ranges");

                        var iStart, iEnd;
                        iStart = aRange[0];
                        if (aRange[0] < 0) 
                        iStart += iLength;
                        iEnd = iStart + aRange[1] - 1;

                        sendRequest(strURL, fncCallback, fncError, [iStart, iEnd], (strAcceptRanges === "bytes"), iLength);
                        }
                       );

            } else {
                sendRequest(strURL, fncCallback, fncError);
            }
        }

}());

/*
   document.write(
   "<script type='text/vbscript'>\r\n"
   + "Function IEBinary_getByteAt(strBinary, iOffset)\r\n"
   + "	IEBinary_getByteAt = AscB(MidB(strBinary,iOffset+1,1))\r\n"
   + "End Function\r\n"
   + "Function IEBinary_getLength(strBinary)\r\n"
   + "	IEBinary_getLength = LenB(strBinary)\r\n"
   + "End Function\r\n"
   + "</script>\r\n"
   );
   */

document.write(
        "<script type='text/vbscript'>\r\n"
        + "Function IEBinary_getByteAt(strBinary, iOffset)\r\n"
        + "	IEBinary_getByteAt = AscB(MidB(strBinary, iOffset + 1, 1))\r\n"
        + "End Function\r\n"
        + "Function IEBinary_getBytesAt(strBinary, iOffset, iLength)\r\n"
        + "  Dim aBytes()\r\n"
        + "  ReDim aBytes(iLength - 1)\r\n"
        + "  For i = 0 To iLength - 1\r\n"
        + "   aBytes(i) = IEBinary_getByteAt(strBinary, iOffset + i)\r\n"  
        + "  Next\r\n"
        + "  IEBinary_getBytesAt = aBytes\r\n" 
        + "End Function\r\n"
        + "Function IEBinary_getLength(strBinary)\r\n"
        + "	IEBinary_getLength = LenB(strBinary)\r\n"
        + "End Function\r\n"
        + "</script>\r\n"
        );
