define([
    "jquery",
    "underscore",
    "crel",
    "libs/FileSaver",
    "libs/stacktrace",
], function($, _, crel) {

    var utils = {};

    // Return a parameter from the URL
    utils.getURLParameter = function(name) {
        var regex = new RegExp(name + "=(.+?)(&|$)");
        try {
            return decodeURIComponent(regex.exec(location.search)[1]);
        }
        catch (e) {
            return undefined;
        }
    };

    // Transform a selector into a jQuery object
    function jqElt(element) {
        if(_.isString(element)) {
            return $(element);
        }
        return element;
    }

    // For input control
    function inputError(element, event) {
        if(event !== undefined) {
            element.stop(true, true).addClass("error").delay(1000).switchClass("error");
            event.stopPropagation();
        }
    }

    // Return input value
    utils.getInputValue = function(element) {
        element = jqElt(element);
        return element.val();
    };

    // Set input value
    utils.setInputValue = function(element, value) {
        element = jqElt(element);
        element.val(value);
    };

    // Return input text value
    utils.getInputTextValue = function(element, event, validationRegex) {
        element = jqElt(element);
        var value = element.val();
        if(value === undefined) {
            inputError(element, event);
            return undefined;
        }
        // trim
        value = utils.trim(value);
        if((value.length === 0) || (validationRegex !== undefined && !value.match(validationRegex))) {
            inputError(element, event);
            return undefined;
        }
        return value;
    };

    // Return input integer value
    utils.getInputIntValue = function(element, event, min, max) {
        element = jqElt(element);
        var value = utils.getInputTextValue(element, event);
        if(value === undefined) {
            return undefined;
        }
        value = parseInt(value);
        if((value === NaN) || (min !== undefined && value < min) || (max !== undefined && value > max)) {
            inputError(element, event);
            return undefined;
        }
        return value;
    };
    
    // Return input value and check that it's a valid RegExp
    utils.getInputRegExpValue = function(element, event) {
        element = jqElt(element);
        var value = utils.getInputTextValue(element, event);
        if(value === undefined) {
            return undefined;
        }
        try {
            new RegExp(value);
        }
        catch(e) {
            inputError(element, event);
            return undefined;
        }
        return value;
    };

    // Return input value and check that it's a valid JavaScript object
    utils.getInputJsValue = function(element, event) {
        element = jqElt(element);
        var value = utils.getInputTextValue(element, event);
        if(value === undefined) {
            return undefined;
        }
        try {
            eval("var test=" + value);
        }
        catch(e) {
            inputError(element, event);
            return undefined;
        }
        return value;
    };
    
    // Return checkbox boolean value
    utils.getInputChecked = function(element) {
        element = jqElt(element);
        return element.prop("checked");
    };

    // Set checkbox state
    utils.setInputChecked = function(element, checked) {
        element = jqElt(element);
        element.prop("checked", checked).change();
    };

    // Get radio button value
    utils.getInputRadio = function(name) {
        return $("input:radio[name=" + name + "]:checked").prop("value");
    };

    // Set radio button value
    utils.setInputRadio = function(name, value) {
        $("input:radio[name=" + name + "][value=" + value + "]").prop("checked", true).change();
    };

    // Reset input control in all modals
    utils.resetModalInputs = function() {
        $(".modal input[type=text]:not([disabled]), .modal input[type=password], .modal textarea").val("");
        $(".modal input[type=checkbox]").prop("checked", false).change();
    };

    // Basic trim function
    utils.trim = function(str) {
        return $.trim(str);
    };

    // Slug function
    utils.slugify = function(text) {
        return text.toLowerCase().replace(/\s+/g, '-') // Replace spaces with -
        .replace(/[^\w\-]+/g, '') // Remove all non-word chars
        .replace(/\-\-+/g, '-') // Replace multiple - with single -
        .replace(/^-+/, '') // Trim - from start of text
        .replace(/-+$/, ''); // Trim - from end of text
    };

    // Check an URL
    utils.checkUrl = function(url, addSlash) {
        if(!url) {
            return url;
        }
        if(url.indexOf("http") !== 0) {
            url = "http://" + url;
        }
        if(addSlash && url.indexOf("/", url.length - 1) === -1) {
            url += "/";
        }
        return url;
    };
    
    // Create the modal element and add to the body
    utils.addModal = function(id, content) {
        var modal = crel('div', {
            class: 'modal ' + id
        });
        modal.innerHTML = content;
        document.body.appendChild(modal);
    };

    // Create a backdrop and add to the body
    utils.createBackdrop = function(toggle, target) {
        var result = crel('div', {
            'class': 'modal-backdrop in'
        });
        document.body.appendChild(result);
        return result;
    };
    
    // Create an centered popup window
    utils.popupWindow = function(url, title, width, height) {
        var left = (screen.width / 2) - (width / 2);
        var top = (screen.height / 2) - (height / 2);
        return window.open(url, title, [
            'toolbar=no, ',
            'location=no, ',
            'directories=no, ',
            'status=no, ',
            'menubar=no, ',
            'scrollbars=no, ',
            'resizable=no, ',
            'copyhistory=no, ',
            'width=' + width + ', ',
            'height=' + height + ', ',
            'top=' + top + ', ',
            'left=' + left
        ].join(""));
    };

    // Export data on disk
    utils.saveAs = function(content, filename) {
        if(saveAs !== undefined) {
            var blob = new Blob([
                content
            ], {
                type: "text/plain;charset=utf-8"
            });
            saveAs(blob, filename);
        }
        else {
            var uriContent = "data:application/octet-stream;base64," + utils.encodeBase64(content);
            window.open(uriContent, 'file');
        }
    };

    // Generates a random string
    utils.randomString = function() {
        return _.random(4294967296).toString(36);
    };

    // Time shared by others modules
    utils.updateCurrentTime = function() {
        utils.currentTime = new Date().getTime();
    };
    utils.updateCurrentTime();

    // Serialize sync/publish attributes and store it in the localStorage
    utils.storeAttributes = function(attributes) {
        var storeIndex = attributes.syncIndex || attributes.publishIndex;
        // Don't store sync/publish index
        var storedAttributes = _.omit(attributes, "syncIndex", "publishIndex", "provider");
        // Store providerId instead of provider
        storedAttributes.provider = attributes.provider.providerId;
        localStorage[storeIndex] = JSON.stringify(storedAttributes);
    };
    
    // Retrieve/parse an index array from localStorage
    utils.retrieveIndexArray = function(storeIndex) {
        try {
            return _.compact(localStorage[storeIndex].split(";"));
        }
        catch(e) {
            localStorage[storeIndex] = ";";
            return [];
        }
    };
    
    // Append an index to an array in localStorage
    utils.appendIndexToArray = function(storeIndex, index) {
        localStorage[storeIndex] += index + ";";
    };
    
    // Remove an index from an array in localStorage
    utils.removeIndexFromArray = function(storeIndex, index) {
        localStorage[storeIndex] = localStorage[storeIndex].replace(";" + index + ";", ";");
    };

    // Retrieve/parse an object from localStorage. Returns undefined if error.
    utils.retrieveIgnoreError = function(storeIndex) {
        try {
            return JSON.parse(localStorage[storeIndex]);
        }
        catch(e) {
            return undefined;
        }
    };
    
    var eventList = [];
    utils.logValue = function(value) {
        eventList.unshift(value);
        if(eventList.length > 5) {
            eventList.pop();
        }
    };
    utils.logStackTrace = function() {
        eventList.unshift(printStackTrace());
        if(eventList.length > 5) {
            eventList.pop();
        }
    };
    utils.formatEventList = function() {
        var result = [];
        _.each(eventList, function(event) {
            result.push("\n");
            if(_.isString(event)) {
                result.push(event);
            }
            else if(_.isArray(event)) {
                result.push(event[5] || "");
                result.push(event[6] || "");
            }
        });
        return result.join("");
    };
    
    // Base64 conversion
    utils.encodeBase64 = function(str) {
        if(str.length === 0) {
            return "";
        }

        // UTF-8 to byte array
        var bytes = [], offset = 0, length, char;

        str = encodeURI(str);
        length = str.length;

        while (offset < length) {
            char = str[offset];
            offset += 1;

            if('%' !== char) {
                bytes.push(char.charCodeAt(0));
            }
            else {
                char = str[offset] + str[offset + 1];
                bytes.push(parseInt(char, 16));
                offset += 2;
            }
        }

        // byte array to base64
        var padchar = '=';
        var alpha = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';

        var i, b10;
        var x = [];

        var imax = bytes.length - bytes.length % 3;

        for (i = 0; i < imax; i += 3) {
            b10 = (bytes[i] << 16) | (bytes[i + 1] << 8) | bytes[i + 2];
            x.push(alpha.charAt(b10 >> 18));
            x.push(alpha.charAt((b10 >> 12) & 0x3F));
            x.push(alpha.charAt((b10 >> 6) & 0x3f));
            x.push(alpha.charAt(b10 & 0x3f));
        }
        switch (bytes.length - imax) {
        case 1:
            b10 = bytes[i] << 16;
            x.push(alpha.charAt(b10 >> 18) + alpha.charAt((b10 >> 12) & 0x3F) + padchar + padchar);
            break;
        case 2:
            b10 = (bytes[i] << 16) | (bytes[i + 1] << 8);
            x.push(alpha.charAt(b10 >> 18) + alpha.charAt((b10 >> 12) & 0x3F) + alpha.charAt((b10 >> 6) & 0x3f) + padchar);
            break;
        }
        return x.join('');
    };

    // CRC32 algorithm
    var mHash = [
        0,
        1996959894,
        3993919788,
        2567524794,
        124634137,
        1886057615,
        3915621685,
        2657392035,
        249268274,
        2044508324,
        3772115230,
        2547177864,
        162941995,
        2125561021,
        3887607047,
        2428444049,
        498536548,
        1789927666,
        4089016648,
        2227061214,
        450548861,
        1843258603,
        4107580753,
        2211677639,
        325883990,
        1684777152,
        4251122042,
        2321926636,
        335633487,
        1661365465,
        4195302755,
        2366115317,
        997073096,
        1281953886,
        3579855332,
        2724688242,
        1006888145,
        1258607687,
        3524101629,
        2768942443,
        901097722,
        1119000684,
        3686517206,
        2898065728,
        853044451,
        1172266101,
        3705015759,
        2882616665,
        651767980,
        1373503546,
        3369554304,
        3218104598,
        565507253,
        1454621731,
        3485111705,
        3099436303,
        671266974,
        1594198024,
        3322730930,
        2970347812,
        795835527,
        1483230225,
        3244367275,
        3060149565,
        1994146192,
        31158534,
        2563907772,
        4023717930,
        1907459465,
        112637215,
        2680153253,
        3904427059,
        2013776290,
        251722036,
        2517215374,
        3775830040,
        2137656763,
        141376813,
        2439277719,
        3865271297,
        1802195444,
        476864866,
        2238001368,
        4066508878,
        1812370925,
        453092731,
        2181625025,
        4111451223,
        1706088902,
        314042704,
        2344532202,
        4240017532,
        1658658271,
        366619977,
        2362670323,
        4224994405,
        1303535960,
        984961486,
        2747007092,
        3569037538,
        1256170817,
        1037604311,
        2765210733,
        3554079995,
        1131014506,
        879679996,
        2909243462,
        3663771856,
        1141124467,
        855842277,
        2852801631,
        3708648649,
        1342533948,
        654459306,
        3188396048,
        3373015174,
        1466479909,
        544179635,
        3110523913,
        3462522015,
        1591671054,
        702138776,
        2966460450,
        3352799412,
        1504918807,
        783551873,
        3082640443,
        3233442989,
        3988292384,
        2596254646,
        62317068,
        1957810842,
        3939845945,
        2647816111,
        81470997,
        1943803523,
        3814918930,
        2489596804,
        225274430,
        2053790376,
        3826175755,
        2466906013,
        167816743,
        2097651377,
        4027552580,
        2265490386,
        503444072,
        1762050814,
        4150417245,
        2154129355,
        426522225,
        1852507879,
        4275313526,
        2312317920,
        282753626,
        1742555852,
        4189708143,
        2394877945,
        397917763,
        1622183637,
        3604390888,
        2714866558,
        953729732,
        1340076626,
        3518719985,
        2797360999,
        1068828381,
        1219638859,
        3624741850,
        2936675148,
        906185462,
        1090812512,
        3747672003,
        2825379669,
        829329135,
        1181335161,
        3412177804,
        3160834842,
        628085408,
        1382605366,
        3423369109,
        3138078467,
        570562233,
        1426400815,
        3317316542,
        2998733608,
        733239954,
        1555261956,
        3268935591,
        3050360625,
        752459403,
        1541320221,
        2607071920,
        3965973030,
        1969922972,
        40735498,
        2617837225,
        3943577151,
        1913087877,
        83908371,
        2512341634,
        3803740692,
        2075208622,
        213261112,
        2463272603,
        3855990285,
        2094854071,
        198958881,
        2262029012,
        4057260610,
        1759359992,
        534414190,
        2176718541,
        4139329115,
        1873836001,
        414664567,
        2282248934,
        4279200368,
        1711684554,
        285281116,
        2405801727,
        4167216745,
        1634467795,
        376229701,
        2685067896,
        3608007406,
        1308918612,
        956543938,
        2808555105,
        3495958263,
        1231636301,
        1047427035,
        2932959818,
        3654703836,
        1088359270,
        936918000,
        2847714899,
        3736837829,
        1202900863,
        817233897,
        3183342108,
        3401237130,
        1404277552,
        615818150,
        3134207493,
        3453421203,
        1423857449,
        601450431,
        3009837614,
        3294710456,
        1567103746,
        711928724,
        3020668471,
        3272380065,
        1510334235,
        755167117
    ];
    utils.crc32 = function(str) {
        var n = 0, crc = -1;
        for ( var i = 0; i < str.length; i++) {
            n = (crc ^ str.charCodeAt(i)) & 0xFF;
            crc = (crc >>> 8) ^ mHash[n];
        }
        crc = crc ^ (-1);
        if(crc < 0) {
            crc = 0xFFFFFFFF + crc + 1;
        }
        return crc.toString(16);
    };

    return utils;
});