/*!
 * qiniu-js-sdk v1.0.17.1
 *
 * Copyright 2015 by Qiniu
 * Released under GPL V2 License.
 *
 * GitHub: https://github.com/qiniu/js-sdk
 *
 * Date: 2016-10-11
*/

/*global plupload ,mOxie*/
/*global ActiveXObject */
/*exported Qiniu */
/*exported QiniuJsSDK */

;(function( global ){

/**
 * Creates new cookie or removes cookie with negative expiration
 * @param  key       The key or identifier for the store
 * @param  value     Contents of the store
 * @param  exp       Expiration - creation defaults to 30 days
 */
function createCookie(key, value, exp) {
    var date = new Date();
    date.setTime(date.getTime() + (exp * 24 * 60 * 60 * 1000));
    var expires = "; expires=" + date.toGMTString();
    document.cookie = key + "=" + value + expires + "; path=/";
}

/**
 * Returns contents of cookie
 * @param  key       The key or identifier for the store
 */
function readCookie(key) {
    var nameEQ = key + "=";
    var ca = document.cookie.split(';');
    for (var i = 0, max = ca.length; i < max; i++) {
        var c = ca[i];
        while (c.charAt(0) === ' ') {
            c = c.substring(1, c.length);
        }
        if (c.indexOf(nameEQ) === 0) {
            return c.substring(nameEQ.length, c.length);
        }
    }
    return null;
}

// if current browser is not support localStorage
// use cookie to make a polyfill
if ( !window.localStorage ) {
    window.localStorage = {
        setItem: function (key, value) {
            createCookie(key, value, 30);
        },
        getItem: function (key) {
            return readCookie(key);
        },
        removeItem: function (key) {
            createCookie(key, '', -1);
        }
    };
}

function QiniuJsSDK() {

    var that = this;

    /**
     * detect IE version
     * if current browser is not IE
     *     it will return false
     * else
     *     it will return version of current IE browser
     * @return {Number|Boolean} IE version or false
     */
    this.detectIEVersion = function() {
        var v = 4,
            div = document.createElement('div'),
            all = div.getElementsByTagName('i');
        while (
            div.innerHTML = '<!--[if gt IE ' + v + ']><i></i><![endif]-->',
            all[0]
        ) {
            v++;
        }
        return v > 4 ? v : false;
    };

    var logger = {
        MUTE: 0,
        FATA: 1,
        ERROR: 2,
        WARN: 3,
        INFO: 4,
        DEBUG: 5,
        TRACE: 6,
        level: 0
    };

    function log(type, args){
        var header = "[qiniu-js-sdk]["+type+"]";
        var msg = header;
        for (var i = 0; i < args.length; i++) {
            if (typeof args[i] === "string") {
                msg += " " + args[i];
            } else {
                msg += " " + that.stringifyJSON(args[i]);
            }
        }
        if (that.detectIEVersion()) {
            // https://stackoverflow.com/questions/5538972/console-log-apply-not-working-in-ie9
            //var log = Function.prototype.bind.call(console.log, console);
            //log.apply(console, args);
            console.log(msg);
        }else{
            args.unshift(header);
            console.log.apply(console, args);
        }
        if (document.getElementById('qiniu-js-sdk-log')) {
            document.getElementById('qiniu-js-sdk-log').innerHTML += '<p>'+msg+'</p>';
        }
    }

    function makeLogFunc(code){
        var func = code.toLowerCase();
        logger[func] = function(){
            // logger[func].history = logger[func].history || [];
            // logger[func].history.push(arguments);
            if(window.console && window.console.log && logger.level>=logger[code]){
                var args = Array.prototype.slice.call(arguments);
                log(func,args);
            }
        };
    }

    for (var property in logger){
        if (logger.hasOwnProperty(property) && (typeof logger[property]) === "number" && !logger.hasOwnProperty(property.toLowerCase())) {
            makeLogFunc(property);
        }
    }


    var qiniuUploadUrl;
    if (window.location.protocol === 'https:') {
        qiniuUploadUrl = 'https://up.qbox.me';
    } else {
        qiniuUploadUrl = 'https://upload.qiniu.com';
    }

    /**
     * qiniu upload urls
     * 'qiniuUploadUrls' is used to change target when current url is not avaliable
     * @type {Array}
     */
    var qiniuUploadUrls = [
        "https://upload.qiniu.com",
        "https://up.qiniu.com"
    ];

    var qiniuUpHosts = {
       "http": [
           "https://upload.qiniu.com",
           "https://up.qiniu.com"
       ],
       "https": [
           "https://up.qbox.me"
       ]
    };

    var changeUrlTimes = 0;

    /**
     * reset upload url
     * if current page protocal is https
     *     it will always return 'https://up.qbox.me'
     * else
     *     it will set 'qiniuUploadUrl' value with 'qiniuUploadUrls' looply
     */
    this.resetUploadUrl = function(){
	var hosts = window.location.protocol === 'https:' ? qiniuUpHosts.https : qiniuUpHosts.http;
	var i = changeUrlTimes % hosts.length;
	qiniuUploadUrl = hosts[i];
	changeUrlTimes++;
	logger.debug('resetUploadUrl: '+qiniuUploadUrl);
    };

    // this.resetUploadUrl();


    /**
     * is image
     * @param  {String}  url of a file
     * @return {Boolean} file is a image or not
     */
    this.isImage = function(url) {
        url = url.split(/[?#]/)[0];
        return (/\.(png|jpg|jpeg|gif|bmp)$/i).test(url);
    };

    /**
     * get file extension
     * @param  {String} filename
     * @return {String} file extension
     * @example
     *     input: test.txt
     *     output: txt
     */
    this.getFileExtension = function(filename) {
        var tempArr = filename.split(".");
        var ext;
        if (tempArr.length === 1 || (tempArr[0] === "" && tempArr.length === 2)) {
            ext = "";
        } else {
            ext = tempArr.pop().toLowerCase(); //get the extension and make it lower-case
        }
        return ext;
    };

    /**
     * encode string by utf8
     * @param  {String} string to encode
     * @return {String} encoded string
     */
    this.utf8_encode = function(argString) {
        // https://kevin.vanzonneveld.net
        // +   original by: Webtoolkit.info (https://www.webtoolkit.info/)
        // +   improved by: Kevin van Zonneveld (https://kevin.vanzonneveld.net)
        // +   improved by: sowberry
        // +    tweaked by: Jack
        // +   bugfixed by: Onno Marsman
        // +   improved by: Yves Sucaet
        // +   bugfixed by: Onno Marsman
        // +   bugfixed by: Ulrich
        // +   bugfixed by: Rafal Kukawski
        // +   improved by: kirilloid
        // +   bugfixed by: kirilloid
        // *     example 1: this.utf8_encode('Kevin van Zonneveld');
        // *     returns 1: 'Kevin van Zonneveld'

        if (argString === null || typeof argString === 'undefined') {
            return '';
        }

        var string = (argString + ''); // .replace(/\r\n/g, '\n').replace(/\r/g, '\n');
        var utftext = '',
            start, end, 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, (c1 & 63) | 128
                );
            } else if (c1 & 0xF800 ^ 0xD800 > 0) {
                enc = String.fromCharCode(
                    (c1 >> 12) | 224, ((c1 >> 6) & 63) | 128, (c1 & 63) | 128
                );
            } else { // surrogate pairs
                if (c1 & 0xFC00 ^ 0xD800 > 0) {
                    throw new RangeError('Unmatched trail surrogate at ' + n);
                }
                var c2 = string.charCodeAt(++n);
                if (c2 & 0xFC00 ^ 0xDC00 > 0) {
                    throw new RangeError('Unmatched lead surrogate at ' + (n - 1));
                }
                c1 = ((c1 & 0x3FF) << 10) + (c2 & 0x3FF) + 0x10000;
                enc = String.fromCharCode(
                    (c1 >> 18) | 240, ((c1 >> 12) & 63) | 128, ((c1 >> 6) & 63) | 128, (c1 & 63) | 128
                );
            }
            if (enc !== null) {
                if (end > start) {
                    utftext += string.slice(start, end);
                }
                utftext += enc;
                start = end = n + 1;
            }
        }

        if (end > start) {
            utftext += string.slice(start, stringl);
        }

        return utftext;
    };

    this.base64_decode = function (data) {
        // https://kevin.vanzonneveld.net
        // +   original by: Tyler Akins (https://rumkin.com)
        // +   improved by: Thunder.m
        // +      input by: Aman Gupta
        // +   improved by: Kevin van Zonneveld (https://kevin.vanzonneveld.net)
        // +   bugfixed by: Onno Marsman
        // +   bugfixed by: Pellentesque Malesuada
        // +   improved by: Kevin van Zonneveld (https://kevin.vanzonneveld.net)
        // +      input by: Brett Zamir (https://brett-zamir.me)
        // +   bugfixed by: Kevin van Zonneveld (https://kevin.vanzonneveld.net)
        // *     example 1: base64_decode('S2V2aW4gdmFuIFpvbm5ldmVsZA==');
        // *     returns 1: 'Kevin van Zonneveld'
        // mozilla has this native
        // - but breaks in 2.0.0.12!
        //if (typeof this.window['atob'] == 'function') {
        //    return atob(data);
        //}
        var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
        var o1, o2, o3, h1, h2, h3, h4, bits, i = 0,
        ac = 0,
        dec = "",
        tmp_arr = [];

        if (!data) {
            return data;
        }

        data += '';

        do { // unpack four hexets into three octets using index points in b64
            h1 = b64.indexOf(data.charAt(i++));
            h2 = b64.indexOf(data.charAt(i++));
            h3 = b64.indexOf(data.charAt(i++));
            h4 = b64.indexOf(data.charAt(i++));

            bits = h1 << 18 | h2 << 12 | h3 << 6 | h4;

            o1 = bits >> 16 & 0xff;
            o2 = bits >> 8 & 0xff;
            o3 = bits & 0xff;

            if (h3 === 64) {
                tmp_arr[ac++] = String.fromCharCode(o1);
            } else if (h4 === 64) {
                tmp_arr[ac++] = String.fromCharCode(o1, o2);
            } else {
                tmp_arr[ac++] = String.fromCharCode(o1, o2, o3);
            }
        } while (i < data.length);

        dec = tmp_arr.join('');

        return dec;
    };

    /**
     * encode data by base64
     * @param  {String} data to encode
     * @return {String} encoded data
     */
    this.base64_encode = function(data) {
        // https://kevin.vanzonneveld.net
        // +   original by: Tyler Akins (https://rumkin.com)
        // +   improved by: Bayron Guevara
        // +   improved by: Thunder.m
        // +   improved by: Kevin van Zonneveld (https://kevin.vanzonneveld.net)
        // +   bugfixed by: Pellentesque Malesuada
        // +   improved by: Kevin van Zonneveld (https://kevin.vanzonneveld.net)
        // -    depends on: this.utf8_encode
        // *     example 1: this.base64_encode('Kevin van Zonneveld');
        // *     returns 1: 'S2V2aW4gdmFuIFpvbm5ldmVsZA=='
        // mozilla has this native
        // - but breaks in 2.0.0.12!
        //if (typeof this.window['atob'] == 'function') {
        //    return atob(data);
        //}
        var b64 = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
        var o1, o2, o3, h1, h2, h3, h4, bits, i = 0,
            ac = 0,
            enc = '',
            tmp_arr = [];

        if (!data) {
            return data;
        }

        data = this.utf8_encode(data + '');

        do { // pack three octets into four hexets
            o1 = data.charCodeAt(i++);
            o2 = data.charCodeAt(i++);
            o3 = data.charCodeAt(i++);

            bits = o1 << 16 | o2 << 8 | o3;

            h1 = bits >> 18 & 0x3f;
            h2 = bits >> 12 & 0x3f;
            h3 = bits >> 6 & 0x3f;
            h4 = bits & 0x3f;

            // use hexets to index into b64, and append result to encoded string
            tmp_arr[ac++] = b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
        } while (i < data.length);

        enc = tmp_arr.join('');

        switch (data.length % 3) {
            case 1:
                enc = enc.slice(0, -2) + '==';
                break;
            case 2:
                enc = enc.slice(0, -1) + '=';
                break;
        }

        return enc;
    };

    /**
     * encode string in url by base64
     * @param {String} string in url
     * @return {String} encoded string
     */
    this.URLSafeBase64Encode = function(v) {
        v = this.base64_encode(v);
        return v.replace(/\//g, '_').replace(/\+/g, '-');
    };

    this.URLSafeBase64Decode = function(v) {
        v = v.replace(/_/g, '/').replace(/-/g, '+');
        return this.base64_decode(v);
    };

    // TODO: use mOxie
    /**
     * craete object used to AJAX
     * @return {Object}
     */
    this.createAjax = function(argument) {
        var xmlhttp = {};
        if (window.XMLHttpRequest) {
            xmlhttp = new XMLHttpRequest();
        } else {
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        return xmlhttp;
    };

    // TODO: enhance IE compatibility
    /**
     * parse json string to javascript object
     * @param  {String} json string
     * @return {Object} object
     */
    this.parseJSON = function(data) {
        // Attempt to parse using the native JSON parser first
        if (window.JSON && window.JSON.parse) {
            return window.JSON.parse(data);
        }

        //var rx_one = /^[\],:{}\s]*$/,
        //    rx_two = /\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g,
        //    rx_three = /"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g,
        //    rx_four = /(?:^|:|,)(?:\s*\[)+/g,
        var    rx_dangerous = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g;

        //var json;

        var text = String(data);
        rx_dangerous.lastIndex = 0;
        if(rx_dangerous.test(text)){
            text = text.replace(rx_dangerous, function(a){
               return '\\u' + ('0000' + a.charCodeAt(0).toString(16)).slice(-4);
            });
        }

        // todo 使用一下判断,增加安全性
        //if (
        //    rx_one.test(
        //        text
        //            .replace(rx_two, '@')
        //            .replace(rx_three, ']')
        //            .replace(rx_four, '')
        //    )
        //) {
        //    return eval('(' + text + ')');
        //}

        return eval('('+text+')');
    };

    /**
     * parse javascript object to json string
     * @param  {Object} object
     * @return {String} json string
     */
    this.stringifyJSON = function(obj) {
        // Attempt to parse using the native JSON parser first
        if (window.JSON && window.JSON.stringify) {
            return window.JSON.stringify(obj);
        }
        switch (typeof (obj)) {
            case 'string':
                return '"' + obj.replace(/(["\\])/g, '\\$1') + '"';
            case 'array':
                return '[' + obj.map(that.stringifyJSON).join(',') + ']';
            case 'object':
                if (obj instanceof Array) {
                    var strArr = [];
                    var len = obj.length;
                    for (var i = 0; i < len; i++) {
                        strArr.push(that.stringifyJSON(obj[i]));
                    }
                    return '[' + strArr.join(',') + ']';
                } else if (obj === null) {
                    return 'null';
                } else {
                    var string = [];
                    for (var property in obj) {
                        if (obj.hasOwnProperty(property)) {
                            string.push(that.stringifyJSON(property) + ':' + that.stringifyJSON(obj[property]));
                        }
                    }
                    return '{' + string.join(',') + '}';
                }
                break;
            case 'number':
                return obj;
            case false:
                return obj;
            case 'boolean':
                return obj;
        }
    };

    /**
     * trim space beside text
     * @param  {String} untrimed string
     * @return {String} trimed string
     */
    this.trim = function(text) {
        return text === null ? "" : text.replace(/^\s+|\s+$/g, '');
    };

    /**
     * create a uploader by QiniuJsSDK
     * @param  {object} options to create a new uploader
     * @return {object} uploader
     */
    this.uploader = function(op) {

        /********** inner function define start **********/

        // according the different condition to reset chunk size
        // and the upload strategy according with the chunk size
        // when chunk size is zero will cause to direct upload
        // see the statement binded on 'BeforeUpload' event
        var reset_chunk_size = function() {
            var ie = that.detectIEVersion();
            var BLOCK_BITS, MAX_CHUNK_SIZE, chunk_size;
            // case Safari 5、Windows 7、iOS 7 set isSpecialSafari to true
            var isSpecialSafari = (mOxie.Env.browser === "Safari" && mOxie.Env.version <= 5 && mOxie.Env.os === "Windows" && mOxie.Env.osVersion === "7") || (mOxie.Env.browser === "Safari" && mOxie.Env.os === "iOS" && mOxie.Env.osVersion === "7");
            // case IE 9-，chunk_size is not empty and flash is included in runtimes
            // set op.chunk_size to zero
            //if (ie && ie < 9 && op.chunk_size && op.runtimes.indexOf('flash') >= 0) {
            if (ie && ie < 9 && op.chunk_size && op.runtimes.indexOf('flash') >= 0) {
                //  link: https://www.plupload.com/docs/Frequently-Asked-Questions#when-to-use-chunking-and-when-not
                //  when plupload chunk_size setting is't null ,it cause bug in ie8/9  which runs  flash runtimes (not support html5) .
                op.chunk_size = 0;
            } else if (isSpecialSafari) {
                // win7 safari / iOS7 safari have bug when in chunk upload mode
                // reset chunk_size to 0
                // disable chunk in special version safari
                op.chunk_size = 0;
            } else {
                BLOCK_BITS = 20;
                MAX_CHUNK_SIZE = 4 << BLOCK_BITS; //4M

                chunk_size = plupload.parseSize(op.chunk_size);
                if (chunk_size > MAX_CHUNK_SIZE) {
                    op.chunk_size = MAX_CHUNK_SIZE;
                }
                // qiniu service  max_chunk_size is 4m
                // reset chunk_size to max_chunk_size(4m) when chunk_size > 4m
            }
            // if op.chunk_size set 0 will be cause to direct upload
        };

        var getHosts = function(hosts) {
            var result = [];
            for (var i = 0; i < hosts.length; i++) {
                var host = hosts[i];
                if (host.indexOf('-H') === 0) {
                    result.push(host.split(' ')[2]);
                } else {
                    result.push(host);
                }
            }
            return result;
        };

        var getPutPolicy = function (uptoken) {
            var segments = uptoken.split(":");
            var ak = segments[0];
            var putPolicy = that.parseJSON(that.URLSafeBase64Decode(segments[2]));
            putPolicy.ak = ak;
            if (putPolicy.scope.indexOf(":") >= 0) {
                putPolicy.bucket = putPolicy.scope.split(":")[0];
                putPolicy.key = putPolicy.scope.split(":")[1];
            } else {
                putPolicy.bucket = putPolicy.scope;
            }
            return putPolicy;
        };

        var getUpHosts = function(uptoken) {
            var putPolicy = getPutPolicy(uptoken);
            // var uphosts_url = "//uc.qbox.me/v1/query?ak="+ak+"&bucket="+putPolicy.scope;
            // IE 9- is not support protocal relative url
            var uphosts_url = window.location.protocol + "//uc.qbox.me/v1/query?ak=" + putPolicy.ak + "&bucket=" + putPolicy.bucket;
            logger.debug("putPolicy: ", putPolicy);
            logger.debug("get uphosts from: ", uphosts_url);
            var ie = that.detectIEVersion();
            var ajax;
            if (ie && ie <= 9) {
                ajax = new mOxie.XMLHttpRequest();
                mOxie.Env.swf_url = op.flash_swf_url;
            }else{
                ajax = that.createAjax();
            }
            ajax.open('GET', uphosts_url, true);
            var onreadystatechange = function(){
                logger.debug("ajax.readyState: ", ajax.readyState);
                if (ajax.readyState === 4) {
                    logger.debug("ajax.status: ", ajax.status);
                    if (ajax.status < 400) {
                        var res = that.parseJSON(ajax.responseText);
                        qiniuUpHosts.http = getHosts(res.http.up);
                        qiniuUpHosts.https = getHosts(res.https.up);
                        logger.debug("get new uphosts: ", qiniuUpHosts);
                        that.resetUploadUrl();
                    } else {
                        logger.error("get uphosts error: ", ajax.responseText);
                    }
                }
            };
            if (ie && ie <= 9) {
                ajax.bind('readystatechange', onreadystatechange);
            }else{
                ajax.onreadystatechange = onreadystatechange;
            }
            ajax.send();
            // ajax.send();
            // if (ajax.status < 400) {
            //     var res = that.parseJSON(ajax.responseText);
            //     qiniuUpHosts.http = getHosts(res.http.up);
            //     qiniuUpHosts.https = getHosts(res.https.up);
            //     logger.debug("get new uphosts: ", qiniuUpHosts);
            //     that.resetUploadUrl();
            // } else {
            //     logger.error("get uphosts error: ", ajax.responseText);
            // }
            return;
        };

        var getUptoken = function(file) {
            if (!that.token || that.tokenInfo.isExpired()) {
                return getNewUpToken(file);
            } else {
                return that.token;
            }
        };

        // getNewUptoken maybe called at Init Event or BeforeUpload Event
        // case Init Event, the file param of getUptken will be set a null value
        // if op.uptoken has value, set uptoken with op.uptoken
        // else if op.uptoken_url has value, set uptoken from op.uptoken_url
        // else if op.uptoken_func has value, set uptoken by result of op.uptoken_func
        var getNewUpToken = function(file) {
            if (op.uptoken) {
                that.token = op.uptoken;
            } else if (op.uptoken_url) {
                logger.debug("get uptoken from: ", that.uptoken_url);
                // TODO: use mOxie
                var ajax = that.createAjax();
                ajax.open('GET', that.uptoken_url, false);
                ajax.setRequestHeader("If-Modified-Since", "0");
                // ajax.onreadystatechange = function() {
                //     if (ajax.readyState === 4 && ajax.status === 200) {
                //         var res = that.parseJSON(ajax.responseText);
                //         that.token = res.uptoken;
                //     }
                // };
                ajax.send();
                if (ajax.status === 200) {
                    var res = that.parseJSON(ajax.responseText);
                    that.token = res.uptoken;
                    var segments = that.token.split(":");
                    var putPolicy = that.parseJSON(that.URLSafeBase64Decode(segments[2]));
                    if (!that.tokenMap) {
                        that.tokenMap = {};
                    }
                    var getTimestamp = function(time) {
                        return Math.ceil(time.getTime()/1000);
                    };
                    var serverTime = getTimestamp(new Date(ajax.getResponseHeader("date")));
                    var clientTime = getTimestamp(new Date());
                    that.tokenInfo = {
                        serverDelay: clientTime - serverTime,
                        deadline: putPolicy.deadline,
                        isExpired: function() {
                            var leftTime = this.deadline - getTimestamp(new Date()) + this.serverDelay;
                            return leftTime < 600;
                        }
                    };
                    logger.debug("get new uptoken: ", that.token);
                    logger.debug("get token info: ", that.tokenInfo);
                } else {
                    logger.error("get uptoken error: ", ajax.responseText);
                }
            } else if (op.uptoken_func) {
                logger.debug("get uptoken from uptoken_func");
                that.token = op.uptoken_func(file);
                logger.debug("get new uptoken: ", that.token);
            } else {
                logger.error("one of [uptoken, uptoken_url, uptoken_func] settings in options is required!");
            }
            if (that.token) {
                getUpHosts(that.token);
            }
            return that.token;
        };

        // get file key according with the user passed options
        var getFileKey = function(up, file, func) {
            // WARNING
            // When you set the key in putPolicy by "scope": "bucket:key"
            // You should understand the risk of override a file in the bucket
            // So the code below that automatically get key from uptoken has been commented
            // var putPolicy = getPutPolicy(that.token)
            // if (putPolicy.key) {
            //     logger.debug("key is defined in putPolicy.scope: ", putPolicy.key)
            //     return putPolicy.key
            // }
            var key = '',
                unique_names = false;
            if (!op.save_key) {
                unique_names = up.getOption && up.getOption('unique_names');
                unique_names = unique_names || (up.settings && up.settings.unique_names);
                if (unique_names) {
                    var ext = that.getFileExtension(file.name);
                    key = ext ? file.id + '.' + ext : file.id;
                } else if (typeof func === 'function') {
                    key = func(up, file);
                } else {
                    key = file.name;
                }
            }
            return key;
        };

        /********** inner function define end **********/

        if (op.log_level) {
            logger.level = op.log_level;
        }

        if (!op.domain) {
            throw 'domain setting in options is required!';
        }

        if (!op.browse_button) {
            throw 'browse_button setting in options is required!';
        }

        if (!op.uptoken && !op.uptoken_url && !op.uptoken_func) {
            throw 'one of [uptoken, uptoken_url, uptoken_func] settings in options is required!';
        }

        logger.debug("init uploader start");

        logger.debug("environment: ", mOxie.Env);

        logger.debug("userAgent: ", navigator.userAgent);

        var option = {};

        // hold the handler from user passed options
        var _Error_Handler = op.init && op.init.Error;
        var _FileUploaded_Handler = op.init && op.init.FileUploaded;

        // replace the handler for intercept
        op.init.Error = function() {};
        op.init.FileUploaded = function() {};

        that.uptoken_url = op.uptoken_url;
        that.token = '';
        that.key_handler = typeof op.init.Key === 'function' ? op.init.Key : '';
        this.domain = op.domain;
        // TODO: ctx is global in scope of a uploader instance
        // this maybe cause error
        var ctx = '';
        var speedCalInfo = {
            isResumeUpload: false,
            resumeFilesize: 0,
            startTime: '',
            currentTime: ''
        };

        reset_chunk_size();
        logger.debug("invoke reset_chunk_size()");
        logger.debug("op.chunk_size: ", op.chunk_size);

        var defaultSetting = {
            url: qiniuUploadUrl,
            multipart_params: {
                token: ''
            }
        };
        var ie = that.detectIEVersion();
        // case IE 9-
        // add accept in multipart params
        if (ie && ie <= 9) {
            defaultSetting.multipart_params.accept = 'text/plain; charset=utf-8';
            logger.debug("add accept text/plain in multipart params");
        }

        // compose options with user passed options and default setting
        plupload.extend(option, op, defaultSetting);

        logger.debug("option: ", option);

        // create a new uploader with composed options
        var uploader = new plupload.Uploader(option);

        logger.debug("new plupload.Uploader(option)");

        // bind getNewUpToken to 'Init' event
        uploader.bind('Init', function(up, params) {
            logger.debug("Init event activated");
            // if op.get_new_uptoken is not true
            //      invoke getNewUptoken when uploader init
            // else
            //      getNewUptoken everytime before a new file upload
            if(!op.get_new_uptoken){
                getNewUpToken(null);
            }
            //getNewUpToken(null);
        });

        logger.debug("bind Init event");

        // bind 'FilesAdded' event
        // when file be added and auto_start has set value
        // uploader will auto start upload the file
        uploader.bind('FilesAdded', function(up, files) {
            logger.debug("FilesAdded event activated");
            var auto_start = up.getOption && up.getOption('auto_start');
            auto_start = auto_start || (up.settings && up.settings.auto_start);
            logger.debug("auto_start: ", auto_start);
            logger.debug("files: ", files);

            // detect is iOS
            var is_ios = function (){
                if(mOxie.Env.OS.toLowerCase()==="ios") {
                    return true;
                } else {
                    return false;
                }
            };

            // if current env os is iOS change file name to [time].[ext]
            if (is_ios()) {
                for (var i = 0; i < files.length; i++) {
                    var file = files[i];
                    var ext = that.getFileExtension(file.name);
                    file.name = file.id + "." + ext;
                }
            }

            if (auto_start) {
                setTimeout(function(){
                    up.start();
                    logger.debug("invoke up.start()");
                }, 0);
                // up.start();
                // plupload.each(files, function(i, file) {
                //     up.start();
                //     logger.debug("invoke up.start()")
                //     logger.debug("file: ", file);
                // });
            }
            up.refresh(); // Reposition Flash/Silverlight
        });

        logger.debug("bind FilesAdded event");

        // bind 'BeforeUpload' event
        // intercept the process of upload
        // - prepare uptoken
        // - according the chunk size to make differnt upload strategy
        // - resume upload with the last breakpoint of file
        uploader.bind('BeforeUpload', function(up, file) {
            logger.debug("BeforeUpload event activated");
            // add a key named speed for file object
            file.speed = file.speed || 0;
            ctx = '';

            if(op.get_new_uptoken){
                getNewUpToken(file);
            }

            var directUpload = function(up, file, func) {
                speedCalInfo.startTime = new Date().getTime();
                var multipart_params_obj;
                if (op.save_key) {
                    multipart_params_obj = {
                        'token': that.token
                    };
                } else {
                    multipart_params_obj = {
                        'key': getFileKey(up, file, func),
                        'token': that.token
                    };
                }
                var ie = that.detectIEVersion();
                // case IE 9-
                // add accept in multipart params
                if (ie && ie <= 9) {
                    multipart_params_obj.accept = 'text/plain; charset=utf-8';
                    logger.debug("add accept text/plain in multipart params");
                }

                logger.debug("directUpload multipart_params_obj: ", multipart_params_obj);

                var x_vars = op.x_vars;
                if (x_vars !== undefined && typeof x_vars === 'object') {
                    for (var x_key in x_vars) {
                        if (x_vars.hasOwnProperty(x_key)) {
                            if (typeof x_vars[x_key] === 'function') {
                                multipart_params_obj['x:' + x_key] = x_vars[x_key](up, file);
                            } else if (typeof x_vars[x_key] !== 'object') {
                                multipart_params_obj['x:' + x_key] = x_vars[x_key];
                            }
                        }
                    }
                }

                up.setOption({
                    'url': qiniuUploadUrl,
                    'multipart': true,
                    'chunk_size': is_android_weixin_or_qq() ? op.max_file_size : undefined,
                    'multipart_params': multipart_params_obj
                });
            };

            // detect is weixin or qq inner browser
            var is_android_weixin_or_qq = function (){
                var ua = navigator.userAgent.toLowerCase();
                if((ua.match(/MicroMessenger/i) || mOxie.Env.browser === "QQBrowser" || ua.match(/V1_AND_SQ/i)) && mOxie.Env.OS.toLowerCase()==="android") {
                    return true;
                } else {
                    return false;
                }
            };

            var chunk_size = up.getOption && up.getOption('chunk_size');
            chunk_size = chunk_size || (up.settings && up.settings.chunk_size);

            logger.debug("uploader.runtime: ",uploader.runtime);
            logger.debug("chunk_size: ",chunk_size);

            // TODO: flash support chunk upload
            if ((uploader.runtime === 'html5' || uploader.runtime === 'flash') && chunk_size) {
                if (file.size < chunk_size || is_android_weixin_or_qq()) {
                    logger.debug("directUpload because file.size < chunk_size || is_android_weixin_or_qq()");
                    // direct upload if file size is less then the chunk size
                    directUpload(up, file, that.key_handler);
                } else {
                    // TODO: need a polifill to make it work in IE 9-
                    // ISSUE: if file.name is existed in localStorage
                    // but not the same file maybe cause error
                    var localFileInfo = localStorage.getItem(file.name);
                    var blockSize = chunk_size;
                    if (localFileInfo) {
                        // TODO: although only the html5 runtime will enter this statement
                        // but need uniform way to make convertion between string and json
                        localFileInfo = that.parseJSON(localFileInfo);
                        var now = (new Date()).getTime();
                        var before = localFileInfo.time || 0;
                        var aDay = 24 * 60 * 60 * 1000; //  milliseconds of one day
                        // if the last upload time is within one day
                        //      will upload continuously follow the last breakpoint
                        // else
                        //      will reupload entire file
                        if (now - before < aDay) {

                            if (localFileInfo.percent !== 100) {
                                if (file.size === localFileInfo.total) {
                                    // TODO: if file.name and file.size is the same
                                    // but not the same file will cause error
                                    file.percent = localFileInfo.percent;
                                    file.loaded = localFileInfo.offset;
                                    ctx = localFileInfo.ctx;

                                    // set speed info
                                    speedCalInfo.isResumeUpload = true;
                                    speedCalInfo.resumeFilesize = localFileInfo.offset;

                                    // set block size
                                    if (localFileInfo.offset + blockSize > file.size) {
                                        blockSize = file.size - localFileInfo.offset;
                                    }
                                } else {
                                    // remove file info when file.size is conflict with file info
                                    localStorage.removeItem(file.name);
                                }

                            } else {
                                // remove file info when upload percent is 100%
                                // avoid 499 bug
                                localStorage.removeItem(file.name);
                            }
                        } else {
                            // remove file info when last upload time is over one day
                            localStorage.removeItem(file.name);
                        }
                    }
                    speedCalInfo.startTime = new Date().getTime();
                    var multipart_params_obj = {};
                    var ie = that.detectIEVersion();
                    // case IE 9-
                    // add accept in multipart params
                    if (ie && ie <= 9) {
                        multipart_params_obj.accept = 'text/plain; charset=utf-8';
                        logger.debug("add accept text/plain in multipart params");
                    }
                    // TODO: to support bput
                    // https://developer.qiniu.com/docs/v6/api/reference/up/bput.html
                    up.setOption({
                        'url': qiniuUploadUrl + '/mkblk/' + blockSize,
                        'multipart': false,
                        'chunk_size': chunk_size,
                        'required_features': "chunks",
                        'headers': {
                            'Authorization': 'UpToken ' + getUptoken(file)
                        },
                        'multipart_params': multipart_params_obj
                    });
                }
            } else {
                logger.debug("directUpload because uploader.runtime !== 'html5' || uploader.runtime !== 'flash' || !chunk_size");
                // direct upload if runtime is not html5
                directUpload(up, file, that.key_handler);
            }
        });

        logger.debug("bind BeforeUpload event");

        // bind 'UploadProgress' event
        // calculate upload speed
        uploader.bind('UploadProgress', function(up, file) {
            logger.trace("UploadProgress event activated");
            speedCalInfo.currentTime = new Date().getTime();
            var timeUsed = speedCalInfo.currentTime - speedCalInfo.startTime; // ms
            var fileUploaded = file.loaded || 0;
            if (speedCalInfo.isResumeUpload) {
                fileUploaded = file.loaded - speedCalInfo.resumeFilesize;
            }
            file.speed = (fileUploaded / timeUsed * 1000).toFixed(0) || 0; // unit: byte/s
        });

        logger.debug("bind UploadProgress event");

        // bind 'ChunkUploaded' event
        // store the chunk upload info and set next chunk upload url
        uploader.bind('ChunkUploaded', function(up, file, info) {
            logger.debug("ChunkUploaded event activated");
            logger.debug("file: ", file);
            logger.debug("info: ", info);
            var res = that.parseJSON(info.response);
            logger.debug("res: ", res);
            // ctx should look like '[chunk01_ctx],[chunk02_ctx],[chunk03_ctx],...'
            ctx = ctx ? ctx + ',' + res.ctx : res.ctx;
            var leftSize = info.total - info.offset;
            var chunk_size = up.getOption && up.getOption('chunk_size');
            chunk_size = chunk_size || (up.settings && up.settings.chunk_size);
            if (leftSize < chunk_size) {
                up.setOption({
                    'url': qiniuUploadUrl + '/mkblk/' + leftSize
                });
                logger.debug("up.setOption url: ", qiniuUploadUrl + '/mkblk/' + leftSize);
            }
            up.setOption({
                'headers': {
                    'Authorization': 'UpToken ' + getUptoken(file)
                }
            });
            localStorage.setItem(file.name, that.stringifyJSON({
                ctx: ctx,
                percent: file.percent,
                total: info.total,
                offset: info.offset,
                time: (new Date()).getTime()
            }));
        });

        logger.debug("bind ChunkUploaded event");

        var retries = qiniuUploadUrls.length;

        // if error is unkown switch upload url and retry
        var unknow_error_retry = function(file){
            if (retries-- > 0) {
                setTimeout(function(){
                    that.resetUploadUrl();
                    file.status = plupload.QUEUED;
                    uploader.stop();
                    uploader.start();
                }, 0);
                return true;
            }else{
                retries = qiniuUploadUrls.length;
                return false;
            }
        };

        // bind 'Error' event
        // check the err.code and return the errTip
        uploader.bind('Error', (function(_Error_Handler) {
            return function(up, err) {
                logger.error("Error event activated");
                logger.error("err: ", err);
                var errTip = '';
                var file = err.file;
                if (file) {
                    switch (err.code) {
                        case plupload.FAILED:
                            errTip = '上传失败。请稍后再试。';
                            break;
                        case plupload.FILE_SIZE_ERROR:
                            var max_file_size = up.getOption && up.getOption('max_file_size');
                            max_file_size = max_file_size || (up.settings && up.settings.max_file_size);
                            errTip = '浏览器最大可上传' + max_file_size + '。更大文件请使用命令行工具。';
                            break;
                        case plupload.FILE_EXTENSION_ERROR:
                            errTip = '文件验证失败。请稍后重试。';
                            break;
                        case plupload.HTTP_ERROR:
                            if (err.response === '') {
                                // Fix parseJSON error ,when http error is like net::ERR_ADDRESS_UNREACHABLE
                                errTip = err.message || '未知网络错误。';
                                if (!unknow_error_retry(file)) {
                                    return;
                                }
                                break;
                            }
                            var errorObj = that.parseJSON(err.response);
                            var errorText = errorObj.error;
                            switch (err.status) {
                                case 400:
                                    errTip = "请求报文格式错误。";
                                    break;
                                case 401:
                                    errTip = "客户端认证授权失败。请重试或提交反馈。";
                                    break;
                                case 405:
                                    errTip = "客户端请求错误。请重试或提交反馈。";
                                    break;
                                case 579:
                                    errTip = "资源上传成功，但回调失败。";
                                    break;
                                case 599:
                                    errTip = "网络连接异常。请重试或提交反馈。";
                                    if (!unknow_error_retry(file)) {
                                        return;
                                    }
                                    break;
                                case 614:
                                    errTip = "文件已存在。";
                                    try {
                                        errorObj = that.parseJSON(errorObj.error);
                                        errorText = errorObj.error || 'file exists';
                                    } catch (e) {
                                        errorText = errorObj.error || 'file exists';
                                    }
                                    break;
                                case 631:
                                    errTip = "指定空间不存在。";
                                    break;
                                case 701:
                                    errTip = "上传数据块校验出错。请重试或提交反馈。";
                                    break;
                                default:
                                    errTip = "未知错误。";
                                    if (!unknow_error_retry(file)) {
                                        return;
                                    }
                                    break;
                            }
                            errTip = errTip + '(' + err.status + '：' + errorText + ')';
                            break;
                        case plupload.SECURITY_ERROR:
                            errTip = '安全配置错误。请联系网站管理员。';
                            break;
                        case plupload.GENERIC_ERROR:
                            errTip = '上传失败。请稍后再试。';
                            break;
                        case plupload.IO_ERROR:
                            errTip = '上传失败。请稍后再试。';
                            break;
                        case plupload.INIT_ERROR:
                            errTip = '网站配置错误。请联系网站管理员。';
                            uploader.destroy();
                            break;
                        default:
                            errTip = err.message + err.details;
                            if (!unknow_error_retry(file)) {
                                return;
                            }
                            break;
                    }
                    if (_Error_Handler) {
                        _Error_Handler(up, err, errTip);
                    }
                }
                up.refresh(); // Reposition Flash/Silverlight
            };
        })(_Error_Handler));

        logger.debug("bind Error event");

        // bind 'FileUploaded' event
        // intercept the complete of upload
        // - get downtoken from downtoken_url if bucket is private
        // - invoke mkfile api to compose chunks if upload strategy is chunk upload
        uploader.bind('FileUploaded', (function(_FileUploaded_Handler) {
            return function(up, file, info) {
                logger.debug("FileUploaded event activated");
                logger.debug("file: ", file);
                logger.debug("info: ", info);
                var last_step = function(up, file, info) {
                    if (op.downtoken_url) {
                        // if op.dowontoken_url is not empty
                        // need get downtoken before invoke the _FileUploaded_Handler
                        var ajax_downtoken = that.createAjax();
                        ajax_downtoken.open('POST', op.downtoken_url, true);
                        ajax_downtoken.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
                        ajax_downtoken.onreadystatechange = function() {
                            if (ajax_downtoken.readyState === 4) {
                                if (ajax_downtoken.status === 200) {
                                    var res_downtoken;
                                    try {
                                        res_downtoken = that.parseJSON(ajax_downtoken.responseText);
                                    } catch (e) {
                                        throw ('invalid json format');
                                    }
                                    var info_extended = {};
                                    plupload.extend(info_extended, that.parseJSON(info), res_downtoken);
                                    if (_FileUploaded_Handler) {
                                        _FileUploaded_Handler(up, file, that.stringifyJSON(info_extended));
                                    }
                                } else {
                                    uploader.trigger('Error', {
                                        status: ajax_downtoken.status,
                                        response: ajax_downtoken.responseText,
                                        file: file,
                                        code: plupload.HTTP_ERROR
                                    });
                                }
                            }
                        };
                        ajax_downtoken.send('key=' + that.parseJSON(info).key + '&domain=' + op.domain);
                    } else if (_FileUploaded_Handler) {
                        _FileUploaded_Handler(up, file, info);
                    }
                };

                var res = that.parseJSON(info.response);
                ctx = ctx ? ctx : res.ctx;
                // if ctx is not empty
                //      that means the upload strategy is chunk upload
                //      befroe the invoke the last_step
                //      we need request the mkfile to compose all uploaded chunks
                // else
                //      invalke the last_step
                logger.debug("ctx: ", ctx);
                if (ctx) {
                    var key = '';
                    logger.debug("save_key: ", op.save_key);
                    if (!op.save_key) {
                        key = getFileKey(up, file, that.key_handler);
                        key = key ? '/key/' + that.URLSafeBase64Encode(key) : '';
                    }

                    var fname = '/fname/' + that.URLSafeBase64Encode(file.name);

                    logger.debug("op.x_vars: ", op.x_vars);
                    var x_vars = op.x_vars,
                        x_val = '',
                        x_vars_url = '';
                    if (x_vars !== undefined && typeof x_vars === 'object') {
                        for (var x_key in x_vars) {
                            if (x_vars.hasOwnProperty(x_key)) {
                                if (typeof x_vars[x_key] === 'function') {
                                    x_val = that.URLSafeBase64Encode(x_vars[x_key](up, file));
                                } else if (typeof x_vars[x_key] !== 'object') {
                                    x_val = that.URLSafeBase64Encode(x_vars[x_key]);
                                }
                                x_vars_url += '/x:' + x_key + '/' + x_val;
                            }
                        }
                    }

                    var url = qiniuUploadUrl + '/mkfile/' + file.size + key + fname + x_vars_url;

                    var ie = that.detectIEVersion();
                    var ajax;
                    if (ie && ie <= 9) {
                        ajax = new mOxie.XMLHttpRequest();
                        mOxie.Env.swf_url = op.flash_swf_url;
                    }else{
                        ajax = that.createAjax();
                    }
                    ajax.open('POST', url, true);
                    ajax.setRequestHeader('Content-Type', 'text/plain;charset=UTF-8');
                    ajax.setRequestHeader('Authorization', 'UpToken ' + that.token);
                    var onreadystatechange = function(){
                        logger.debug("ajax.readyState: ", ajax.readyState);
                        if (ajax.readyState === 4) {
                            localStorage.removeItem(file.name);
                            var info;
                            if (ajax.status === 200) {
                                info = ajax.responseText;
                                logger.debug("mkfile is success: ", info);
                                last_step(up, file, info);
                            } else {
                                info = {
                                    status: ajax.status,
                                    response: ajax.responseText,
                                    file: file,
                                    code: -200
                                };
                                logger.debug("mkfile is error: ", info);
                                uploader.trigger('Error', info);
                            }
                        }
                    };
                    if (ie && ie <= 9) {
                        ajax.bind('readystatechange', onreadystatechange);
                    }else{
                        ajax.onreadystatechange = onreadystatechange;
                    }
                    ajax.send(ctx);
                    logger.debug("mkfile: ", url);
                } else {
                    last_step(up, file, info.response);
                }

            };
        })(_FileUploaded_Handler));

        logger.debug("bind FileUploaded event");

        // init uploader
        uploader.init();

        logger.debug("invoke uploader.init()");

        logger.debug("init uploader end");

        return uploader;
    };

    /**
     * get url by key
     * @param  {String} key of file
     * @return {String} url of file
     */
    this.getUrl = function(key) {
        if (!key) {
            return false;
        }
        key = encodeURI(key);
        var domain = this.domain;
        if (domain.slice(domain.length - 1) !== '/') {
            domain = domain + '/';
        }
        return domain + key;
    };

    /**
     * invoke the imageView2 api of Qiniu
     * @param  {Object} api params
     * @param  {String} key of file
     * @return {String} url of processed image
     */
    this.imageView2 = function(op, key) {
        var mode = op.mode || '',
            w = op.w || '',
            h = op.h || '',
            q = op.q || '',
            format = op.format || '';
        if (!mode) {
            return false;
        }
        if (!w && !h) {
            return false;
        }

        var imageUrl = 'imageView2/' + mode;
        imageUrl += w ? '/w/' + w : '';
        imageUrl += h ? '/h/' + h : '';
        imageUrl += q ? '/q/' + q : '';
        imageUrl += format ? '/format/' + format : '';
        if (key) {
            imageUrl = this.getUrl(key) + '?' + imageUrl;
        }
        return imageUrl;
    };

    /**
     * invoke the imageMogr2 api of Qiniu
     * @param  {Object} api params
     * @param  {String} key of file
     * @return {String} url of processed image
     */
    this.imageMogr2 = function(op, key) {
        var auto_orient = op['auto-orient'] || '',
            thumbnail = op.thumbnail || '',
            strip = op.strip || '',
            gravity = op.gravity || '',
            crop = op.crop || '',
            quality = op.quality || '',
            rotate = op.rotate || '',
            format = op.format || '',
            blur = op.blur || '';
        //Todo check option

        var imageUrl = 'imageMogr2';

        imageUrl += auto_orient ? '/auto-orient' : '';
        imageUrl += thumbnail ? '/thumbnail/' + thumbnail : '';
        imageUrl += strip ? '/strip' : '';
        imageUrl += gravity ? '/gravity/' + gravity : '';
        imageUrl += quality ? '/quality/' + quality : '';
        imageUrl += crop ? '/crop/' + crop : '';
        imageUrl += rotate ? '/rotate/' + rotate : '';
        imageUrl += format ? '/format/' + format : '';
        imageUrl += blur ? '/blur/' + blur : '';

        if (key) {
            imageUrl = this.getUrl(key) + '?' + imageUrl;
        }
        return imageUrl;
    };

    /**
     * invoke the watermark api of Qiniu
     * @param  {Object} api params
     * @param  {String} key of file
     * @return {String} url of processed image
     */
    this.watermark = function(op, key) {
        var mode = op.mode;
        if (!mode) {
            return false;
        }

        var imageUrl = 'watermark/' + mode;

        if (mode === 1) {
            var image = op.image || '';
            if (!image) {
                return false;
            }
            imageUrl += image ? '/image/' + this.URLSafeBase64Encode(image) : '';
        } else if (mode === 2) {
            var text = op.text ? op.text : '',
                font = op.font ? op.font : '',
                fontsize = op.fontsize ? op.fontsize : '',
                fill = op.fill ? op.fill : '';
            if (!text) {
                return false;
            }
            imageUrl += text ? '/text/' + this.URLSafeBase64Encode(text) : '';
            imageUrl += font ? '/font/' + this.URLSafeBase64Encode(font) : '';
            imageUrl += fontsize ? '/fontsize/' + fontsize : '';
            imageUrl += fill ? '/fill/' + this.URLSafeBase64Encode(fill) : '';
        } else {
            // Todo mode3
            return false;
        }

        var dissolve = op.dissolve || '',
            gravity = op.gravity || '',
            dx = op.dx || '',
            dy = op.dy || '';

        imageUrl += dissolve ? '/dissolve/' + dissolve : '';
        imageUrl += gravity ? '/gravity/' + gravity : '';
        imageUrl += dx ? '/dx/' + dx : '';
        imageUrl += dy ? '/dy/' + dy : '';

        if (key) {
            imageUrl = this.getUrl(key) + '?' + imageUrl;
        }
        return imageUrl;
    };

    /**
     * invoke the imageInfo api of Qiniu
     * @param  {String} key of file
     * @return {Object} image info
     */
    this.imageInfo = function(key) {
        if (!key) {
            return false;
        }
        var url = this.getUrl(key) + '?imageInfo';
        var xhr = this.createAjax();
        var info;
        var that = this;
        xhr.open('GET', url, false);
        xhr.onreadystatechange = function() {
            if (xhr.readyState === 4 && xhr.status === 200) {
                info = that.parseJSON(xhr.responseText);
            }
        };
        xhr.send();
        return info;
    };

    /**
     * invoke the exif api of Qiniu
     * @param  {String} key of file
     * @return {Object} image exif
     */
    this.exif = function(key) {
        if (!key) {
            return false;
        }
        var url = this.getUrl(key) + '?exif';
        var xhr = this.createAjax();
        var info;
        var that = this;
        xhr.open('GET', url, false);
        xhr.onreadystatechange = function() {
            if (xhr.readyState === 4 && xhr.status === 200) {
                info = that.parseJSON(xhr.responseText);
            }
        };
        xhr.send();
        return info;
    };

    /**
     * invoke the exif or imageInfo api of Qiniu
     * according with type param
     * @param  {String} ['exif'|'imageInfo']type of info
     * @param  {String} key of file
     * @return {Object} image exif or info
     */
    this.get = function(type, key) {
        if (!key || !type) {
            return false;
        }
        if (type === 'exif') {
            return this.exif(key);
        } else if (type === 'imageInfo') {
            return this.imageInfo(key);
        }
        return false;
    };

    /**
     * invoke api of Qiniu like a pipeline
     * @param  {Array of Object} params of a series api call
     * each object in array is options of api which name is set as 'fop' property
     * each api's output will be next api's input
     * @param  {String} key of file
     * @return {String|Boolean} url of processed image
     */
    this.pipeline = function(arr, key) {
        var isArray = Object.prototype.toString.call(arr) === '[object Array]';
        var option, errOp, imageUrl = '';
        if (isArray) {
            for (var i = 0, len = arr.length; i < len; i++) {
                option = arr[i];
                if (!option.fop) {
                    return false;
                }
                switch (option.fop) {
                    case 'watermark':
                        imageUrl += this.watermark(option) + '|';
                        break;
                    case 'imageView2':
                        imageUrl += this.imageView2(option) + '|';
                        break;
                    case 'imageMogr2':
                        imageUrl += this.imageMogr2(option) + '|';
                        break;
                    default:
                        errOp = true;
                        break;
                }
                if (errOp) {
                    return false;
                }
            }
            if (key) {
                imageUrl = this.getUrl(key) + '?' + imageUrl;
                var length = imageUrl.length;
                if (imageUrl.slice(length - 1) === '|') {
                    imageUrl = imageUrl.slice(0, length - 1);
                }
            }
            return imageUrl;
        }
        return false;
    };
}

var Qiniu = new QiniuJsSDK();

global.Qiniu = Qiniu;

global.QiniuJsSDK = QiniuJsSDK;

})( window );
