gmail.js

///////////////////////////////////////////
// gmail.js
// Kartik Talwar
// https://github.com/KartikTalwar/gmail.js
//

/*eslint-env es6*/

var Gmail_ = function(localJQuery) {

    /*
      Use the provided "jQuery" if possible, in order to avoid conflicts with
      other extensions that use $ for other purposes.
    */
    var $;
    if (typeof localJQuery !== "undefined") {
        $ = localJQuery;
    } else if (typeof jQuery !== "undefined") {
        $ = jQuery;
    } else {
        // try load jQuery through node.
        try {
            $ = require("jquery");
        }
        catch(err) {
            // else leave $ undefined, which may be fine for some purposes.
        }
    }

    var api = {
        get : {},
        observe : {},
        check : {},
        tools : {},
        tracker : {},
        dom : {},
        chat : {},
        compose : {},
        helper : {get: {}}
    };

    api.version           = "0.6.4";
    api.tracker.globals   = typeof GLOBALS !== "undefined"
        ? GLOBALS
        : (
            typeof(window) !== "undefined" && window.opener !== null && typeof window.opener.GLOBALS !== "undefined"
                ? window.opener.GLOBALS
                : []
        );
    api.tracker.view_data = typeof VIEW_DATA !== "undefined"
        ? VIEW_DATA
        : (
            typeof(window) !== "undefined" && window.opener !== null && typeof window.opener.VIEW_DATA !== "undefined"
                ? window.opener.VIEW_DATA
                : []
        );
    api.tracker.ik        = api.tracker.globals[9] || "";
    api.tracker.hangouts  = undefined;


    api.get.last_active = function() {
        var data = api.tracker.globals[17][15];
        return {
            time : data[1],
            ip : data[3],
            mac_address : data[9],
            time_relative : data[10]
        };
    };


    api.get.loggedin_accounts = function() {
        var i, j, data;
        var users = [];

        var globals17 = api.tracker.globals[17];
        for (i in globals17) {
            // at least for the delegated inboxes, the index of the mla is not stable
            // it was observed to be somewhere between 22 and 24, but we should not depend on it
            data = globals17[i];

            if (data[0] === "mla") {
                for(j in data[1]) {
                    users.push({
                        name : data[1][j][4],
                        email : data[1][j][0],
                        index: data[1][j][3]
                    });
                }

                return users;
            }
        }

        return users;
    };


    api.get.user_email = function() {
        return api.tracker.globals[10];
    };


    api.get.manager_email = function() {
        if (api.helper.get.is_delegated_inbox()) {
            return api.get.delegated_to_email();
        }

        return api.get.user_email();
    };


    api.get.delegated_to_email = function() {
        if (!api.helper.get.is_delegated_inbox()) {
            return null;
        }

        var i, account;
        var userIndexPrefix = "/u/";
        var pathname = window.location.pathname;
        var delegatedToUserIndex = parseInt(pathname.substring(pathname.indexOf(userIndexPrefix) + userIndexPrefix.length), 10);

        var loggedInAccounts = api.get.loggedin_accounts();
        if (loggedInAccounts && loggedInAccounts.length > 0) {
            for (i in loggedInAccounts) {
                account = loggedInAccounts[i];
                if (account.index === delegatedToUserIndex) {
                    return account.email;
                }
            }
        }

        // as a last resort, we query the DOM of the upper right account selection menu
        return $(".gb_rb[href$='" + userIndexPrefix + delegatedToUserIndex + "'] .gb_yb").text().split(" ")[0];
    };

    api.helper.get.is_locale = function(locale) {
        // A locale is a string that begins with 2 letters, either lowercase or uppercase
        // The "lowercase" check distinguishes locales from other 2-letter strings like "US"
        // (the user"s location?).
        if (!locale || ((typeof locale) !== "string") || locale.length < 2) {
            return false;
        }

        var localePrefix = locale.slice(0, 2);
        return localePrefix.toLowerCase() === localePrefix ||
            localePrefix.toUpperCase() === localePrefix;
    };

    api.get.localization = function() {
        var globals = api.tracker.globals;

        // First candidate.
        var locale = globals[17] && globals[17][8] && globals[17][8][8];
        if (api.helper.get.is_locale(locale)) {
            return locale.toLowerCase();
        }

        // Second candidate.
        locale = globals[17] && globals[17][9] && globals[17][9][8];
        if (api.helper.get.is_locale(locale)) {
            return locale.toLowerCase();
        }

        return null;
    };


    api.check.is_thread = function() {
        var check_1 = $(".nH .if").children(":eq(1)").children().children(":eq(1)").children();
        var check_2 = api.get.email_ids();

        return check_1.length > 1 || check_2.length > 1;
    };


    api.dom.inbox_content = function() {
        return $("div[role=main]:first");
    };


    api.check.is_preview_pane = function() {
        var dom = api.dom.inbox_content();
        var boxes = dom.find("[gh=tl]");

        var previewPaneFound = false;
        boxes.each(function() {
            if($(this).hasClass("aia")) {
                previewPaneFound = true;
            }
        });

        return previewPaneFound;
    };

    api.check.is_multiple_inbox = function() {
        var dom = api.dom.inboxes();
        return dom.length > 1;
    };


    api.check.is_horizontal_split = function() {
        var dom = api.dom.inbox_content();
        var box = dom.find("[gh=tl]").find(".nn");

        return box.length === 0;
    };


    api.check.is_vertical_split = function() {
        return api.check.is_horizontal_split() === false;
    };


    api.check.is_tabbed_inbox = function() {
        return $(".aKh").length === 1;
    };


    api.check.is_right_side_chat = function() {
        var chat = $(".ApVoH");
        if(chat.length === 0) {
            return false;
        }

        return chat[0].getAttribute("aria-labelledby") === ":wf";
    };

    api.check.should_compose_fullscreen = function(){
        var bx_scfs = [];
        try {
            bx_scfs = api.tracker.globals[17][4][1][32];
        } catch(er) {
            bx_scfs = ["bx_scfs","false"];
        }
        return (bx_scfs[1] === "true" ) ? true : false;
    };


    api.check.is_google_apps_user =function() {
        var email = api.get.user_email();
        return email.indexOf("gmail.com", email.length - "gmail.com".length) === -1;
    };


    api.get.storage_info = function() {
        var div = $(".md.mj").find("div")[0];
        var used = $(div).find("span")[0].text;
        var total = $(div).find("span")[1].text;
        var percent = parseFloat(used.replace(/[^0-9\.]/g, "")) * 100 / parseFloat(total.replace(/[^0-9\.]/g, ""));

        return {used : used, total : total, percent : Math.floor(percent)};
    };


    api.dom.inboxes = function() {
        var dom = api.dom.inbox_content();
        return dom.find("[gh=tl]");
    };

    api.dom.email_subject = function () {
        var e = $(".hP");

        for(var i=0; i<e.length; i++) {
            if($(e[i]).is(":visible")) {
                return $(e[i]);
            }
        }

        return $();
    };


    api.get.email_subject = function() {
        var subject_dom = api.dom.email_subject();

        return subject_dom.text();
    };


    api.dom.email_body = function() {
        return $(".nH.hx");
    };

    api.dom.toolbar = function() {
        var tb = $("[gh='mtb']");

        while($(tb).children().length === 1){
            tb = $(tb).children().first();
        }

        return tb;
    };

    api.dom.right_toolbar = function() {
        var rtb = $("[gh='tm'] [gh='s']").parent();

        while($(rtb).children().length === 1){
            rtb = $(rtb).children().first();
        }

        return rtb;
    };

    api.check.is_inside_email = function() {
        if(api.get.current_page() !== "email" && !api.check.is_preview_pane()) {
            return false;
        }

        var items = $(".ii.gt .a3s.aXjCH");
        var ids = [];

        for(var i=0; i<items.length; i++) {
            var mail_id = items[i].getAttribute("class").split(" ")[2];
            if(mail_id !== "undefined" && mail_id !== undefined) {
                ids.push(items[i]);
            }
        }

        return ids.length > 0;
    };

    api.check.is_plain_text = function() {
        var settings = api.tracker.globals[17][4][1];

        for (var i = 0; i < settings.length; i++) {
            var plain_text_setting = settings[i];
            if (plain_text_setting[0] === "bx_cm") {
                return plain_text_setting[1] === "0";
            }
        }

        // default to rich text mode, which is more common nowadays
        return false;
    };

    api.dom.email_contents = function() {
        var items = $(".ii.gt div.a3s.aXjCH");
        var ids = [];

        for(var i=0; i<items.length; i++) {
            var mail_id = items[i].getAttribute("class").split(" ")[2];
            var is_editable = items[i].getAttribute("contenteditable");
            if(mail_id !== "undefined" && mail_id !== undefined) {
                if(is_editable !== "true") {
                    ids.push(items[i]);
                }
            }
        }

        return ids;
    };


    api.get.email_ids = function() {
        if(api.check.is_inside_email()) {
            var data = api.get.email_data();
            return Object.keys(data.threads);
        }
        return [];
    };


    api.get.compose_ids = function() {
        var ret = [];
        var dom = $(".M9 [name=draft]");
        for(var i = 0; i < dom.length; i++) {
            if(dom[i].value !== "undefined"){
                ret.push(dom[i].value);
            }
        }
        return ret;
    };


    api.get.email_id = function() {
        var hash = null;

        if(api.check.is_inside_email()) {
            if(api.check.is_preview_pane()) {
                var items = api.dom.email_contents();
                var text = [];

                for(var i=0; i<items.length; i++) {
                    var mail_id = items[i].className.split(" ")[2] || items[i].children[0].className.split(" ")[2];
                    var is_editable = items[i].getAttribute("contenteditable");
                    var is_visible = items[i].offsetWidth > 0 && items[i].offsetHeight > 0;
                    if(mail_id !== "undefined" && mail_id !== undefined && is_visible) {
                        if(is_editable !== "true") {
                            text.push(mail_id);
                        }
                    }
                }

                hash = text[0].substring(1, text[0].length);
            } else {
                hash = window.location.hash.split("/").pop().replace(/#/, "").split("?")[0];
            }
        }
        else {
            hash = api.tools.parse_url(window.location.href).th;
        }

        return hash;
    };


    api.check.is_priority_inbox = function() {
        return $(".qh").length > 0;
    };


    api.check.is_rapportive_installed = function() {
        return $("#rapportive-sidebar").length === 1;
    };


    api.check.is_streak_installed = function() {
        return $("[id^='bentoBox'],[id*=' bentoBox'],[class*=' bentoBox'],[class*='bentoBox']").length > 0;
    };


    api.check.is_anydo_installed = function() {
        return $("[id^='anydo'],[id*=' anydo'],[class*=' anydo'],[class*='anydo']").length > 0;
    };


    api.check.is_boomerang_installed = function() {
        return $("[id^='b4g_'],[id*=' b4g_'],[class*=' b4g_'],[class*='b4g_']").length > 0;
    };


    api.check.is_xobni_installed = function() {
        return $("#xobni_frame").length > 0;
    };


    api.check.is_signal_installed = function() {
        return $("[id^='Signal'],[id*=' Signal'],[class*=' signal'],[class*='signal']").length > 0;
    };


    api.check.are_shortcuts_enabled = function() {
        var flag_name = "bx_hs";
        var flag_value = undefined;

        var check = true; // Flag possibly missing in convo view.

        var array_with_flag = api.tracker.globals[17][4][1];

        for(var i=0; i<array_with_flag.length; i++) {
            var current = array_with_flag[i];

            if(current[0] === flag_name) {
                flag_value = current[1];
                break;
            }
        }

        if(flag_value !== undefined) {
            var values = {
                "0": true,
                "1": false
            };

            check = values[flag_value];
        }

        return check;
    };


    api.dom.get_left_sidebar_links = function() {
        return $("div[role=navigation] [title]");
    };


    api.dom.search_bar = function() {
        return $("[gh=sb]");
    };


    api.get.search_query = function() {
        var dom = api.dom.search_bar();
        return dom.find("input")[0].value;
    };


    api.get.unread_inbox_emails = function() {
        var dom = $("div[role=navigation]").find("[title*='" + api.tools.i18n("inbox") + "']");

        if(dom.length > 0) {
            if(dom[0].text.indexOf("(") !== -1) {
                return parseInt(dom[0].text.split(":")[0].replace(/[^0-9]/g, ""));
            }
        }

        return 0;
    };


    api.get.unread_draft_emails = function() {
        var dom = $("div[role=navigation]").find("[title*='" + api.tools.i18n("drafts") + "']");

        if(dom.length > 0) {
            if(dom[0].text.indexOf("(") !== -1) {
                return parseInt(dom[0].text.replace(/[^0-9]/g, ""));
            }
        }

        return 0;
    };


    api.get.unread_spam_emails = function() {
        var dom = $("div[role=navigation]").find("[title*='" + api.tools.i18n("spam") + "']");

        if(dom.length > 0) {
            if(dom[0].text.indexOf("(") !== -1) {
                return parseInt(dom[0].text.replace(/[^0-9]/g, ""));
            }
        }

        return 0;
    };


    api.get.unread_forum_emails = function() {
        var dom = $("div[role=navigation]").find("[title*='" + api.tools.i18n("forums") + "']");

        if(dom.length > 0) {
            if(dom[0].text.indexOf("(") !== -1) {
                return parseInt(dom[0].text.replace(/[^0-9]/g, ""));
            }
        }

        return 0;
    };


    api.get.unread_update_emails = function() {
        var dom = $("div[role=navigation]").find("[title*='" + api.tools.i18n("updates") + "']");

        if(dom.length > 0) {
            if(dom[0].text.indexOf("(") !== -1) {
                return parseInt(dom[0].text.replace(/[^0-9]/g, ""));
            }
        }

        return 0;
    };


    api.get.unread_promotion_emails = function() {
        var dom = $("div[role=navigation]").find("[title*='" + api.tools.i18n("promotions") + "']");

        if(dom.length > 0) {
            if(dom[0].text.indexOf("(") !== -1) {
                return parseInt(dom[0].text.replace(/[^0-9]/g, ""));
            }
        }

        return 0;
    };


    api.get.unread_social_emails = function() {
        var dom = $("div[role=navigation]").find("[title*='" + api.tools.i18n("social_updates") + "']");

        if(dom.length > 0) {
            if(dom[0].text.indexOf("(") !== -1) {
                return parseInt(dom[0].text.replace(/[^0-9]/g, ""));
            }
        }

        return 0;
    };


    api.get.beta = function() {
        var features = {
            "new_nav_bar" : $("#gbz").length === 0
        };

        return features;
    };


    api.get.unread_emails = function() {
        return {
            inbox         : api.get.unread_inbox_emails(),
            drafts        : api.get.unread_draft_emails(),
            spam          : api.get.unread_spam_emails(),
            forum         : api.get.unread_forum_emails(),
            update        : api.get.unread_update_emails(),
            promotions    : api.get.unread_promotion_emails(),
            social        : api.get.unread_social_emails()
        };
    };


    api.tools.error = function(str) {
        if (console) {
            console.error(str);
        } else {
            throw(str);
        }
    };

    api.tools.parse_url = function(url) {
        var regex = /[?&]([^=#]+)=([^&#]*)/g;
        var params = {};
        var match = regex.exec(url);

        while (match) {
            params[match[1]] = match[2];
            match = regex.exec(url);
        }

        return params;
    };

    api.tools.sleep = function(milliseconds) {
        var start = new Date().getTime();
        while(true) {
            if ((new Date().getTime() - start) > milliseconds){
                break;
            }
        }
    };


    api.tools.multitry = function(delay, tries, func, check, counter, retval) {
        if(counter !== undefined && counter >= tries) {
            return retval;
        }

        counter = (counter === undefined) ? 0 : counter;

        var value = func();

        if(check(value)) {
            return value;
        } else {
            api.tools.sleep(delay);
            api.tools.multitry(delay, tries, func, check, counter+1, value);
        }
    };


    api.tools.deparam = function (params, coerce) {

        var each = function (arr, fnc) {
            var data = [];
            for (var i = 0; i < arr.length; i++) {
                data.push(fnc(arr[i]));
            }
            return data;
        };

        var isArray = Array.isArray || function(obj) {
            return Object.prototype.toString.call(obj) === "[object Array]";
        };

        var obj = {},
            coerce_types = {
                "true": !0,
                "false": !1,
                "null": null
            };
        each(params.replace(/\+/g, " ").split("&"), function (v, j) {
            var param = v.split("="),
                key = decodeURIComponent(param[0]),
                val,
                cur = obj,
                i = 0,
                keys = key.split("]["),
                keys_last = keys.length - 1;
            if (/\[/.test(keys[0]) && /\]$/.test(keys[keys_last])) {
                keys[keys_last] = keys[keys_last].replace(/\]$/, "");
                keys = keys.shift().split("[").concat(keys);
                keys_last = keys.length - 1;
            } else {
                keys_last = 0;
            }
            if (param.length === 2) {
                val = decodeURIComponent(param[1]);
                if (coerce) {
                    val = val && !isNaN(val) ? +val : val === "undefined" ? undefined : coerce_types[val] !== undefined ? coerce_types[val] : val;
                }
                if (keys_last) {
                    for (; i <= keys_last; i++) {
                        key = keys[i] === "" ? cur.length : keys[i];
                        cur = cur[key] = i < keys_last ? cur[key] || (keys[i + 1] && isNaN(keys[i + 1]) ? {} : []) : val;
                    }
                } else {
                    if (isArray(obj[key])) {
                        obj[key].push(val);
                    } else if (obj[key] !== undefined) {
                        obj[key] = [obj[key], val];
                    } else {
                        obj[key] = val;
                    }
                }
            } else if (key) {
                obj[key] = coerce ? undefined : "";
            }
        });
        return obj;
    };

    api.tools.parse_actions = function(params, xhr) {

        // upload_attachment event - if found, don"t check other observers. See issue #22
        if(params.url.act === "fup" || params.url.act === "fuv" || params.body_is_object) {
            return params.body_is_object && api.observe.bound("upload_attachment") ? { upload_attachment: [ params.body_params ] } : false; // trigger attachment event
        }

        if(params.url.search !== undefined) {
            // console.log(params.url, params.body, params.url_raw);
        }

        var triggered = {}; // store an object of event_name: [response_args] for events triggered by parsing the actions
        var action_map = {
            "tae"         : "add_to_tasks",
            "rc_^i"       : "archive",
            "tr"          : "delete",
            "dm"          : "delete_message_in_thread",
            "dl"          : "delete_forever",
            "dc_"         : "delete_label",
            "dr"          : "discard_draft",
            "el"          : "expand_categories",
            "cffm"        : "filter_messages_like_these",
            "arl"         : "label",
            "mai"         : "mark_as_important",
            "mani"        : "mark_as_not_important",
            "us"          : "mark_as_not_spam",
            "sp"          : "mark_as_spam",
            "mt"          : "move_label",
            "ib"          : "move_to_inbox",
            "ig"          : "mute",
            "rd"          : "read",
            "sd"          : "save_draft",
            "sm"          : "send_message",
            "mo"          : "show_newly_arrived_message",
            "st"          : "star",
            "cs"          : "undo_send",
            "ug"          : "unmute",
            "ur"          : "unread",
            "xst"         : "unstar",
            "new_mail"    : "new_email",
            "poll"        : "poll",
            "refresh"     : "refresh",
            "rtr"         : "restore_message_in_thread",
            "open_email"  : "open_email",
            "toggle_threads"  : "toggle_threads"
        };

        if(typeof params.url.ik === "string") {
            api.tracker.ik = params.url.ik;
        }

        if(typeof params.url.at === "string") {
            api.tracker.at = params.url.at;
        }

        if(typeof params.url.rid === "string") {
            if(params.url.rid.indexOf("mail") !== -1) {
                api.tracker.rid = params.url.rid;
            }
        }

        var action      = decodeURIComponent(params.url.act);
        var sent_params = params.body_params;
        var email_ids   = (typeof sent_params.t === "string") ? [sent_params.t] : sent_params.t;
        var response    = null;

        switch(action) {
        case "cs":
        case "ur":
        case "rd":
        case "tr":
        case "sp":
        case "us":
        case "ib":
        case "dl":
        case "st":
        case "xst":
        case "mai":
        case "mani":
        case "ig":
        case "ug":
        case "dr":
        case "mt":
        case "cffm":
        case "rc_^i":
            response = [email_ids, params.url, params.body];
            break;

        case "arl":
        case "dc_":
            response = [email_ids, params.url, params.body, params.url.acn];
            break;

        case "sd":
            response = [email_ids, params.url, sent_params];
            break;

        case "tae":
        case "sm":
            response = [params.url, params.body, sent_params];
            break;

        case "el":
            response = [params.url, params.body, sent_params.ex === "1"];
            break;

        case "dm":
        case "rtr":
        case "mo":
            response = [sent_params.m, params.url, params.body];
            break;

        }

        if(typeof params.url._reqid === "string" && params.url.view === "tl" && params.url.auto !== undefined) {
            response = [params.url.th, params.url, params.body];
            if(api.observe.bound("new_email")) {
                triggered.new_email = response;
            }
        }

        if((params.url.view === "cv" || params.url.view === "ad") && typeof params.url.th === "string" && typeof params.url.search === "string" && params.url.rid === undefined) {
            response = [params.url.th, params.url, params.body];
            if(api.observe.bound("open_email")) {
                triggered.open_email = response;
            }
        }

        if((params.url.view === "cv" || params.url.view === "ad") && typeof params.url.th === "object" && typeof params.url.search === "string" && params.url.rid !== undefined) {
            response = [params.url.th, params.url, params.body];
            if(api.observe.bound("toggle_threads")) {
                triggered.toggle_threads = response;
            }
        }

        if((params.url.view === "cv" || params.url.view === "ad") && typeof params.url.th === "string" && typeof params.url.search === "string" && params.url.rid !== undefined) {
            if(params.url.msgs !== undefined) {
                response = [params.url.th, params.url, params.body];
                if(api.observe.bound("toggle_threads")) {
                    triggered.toggle_threads = response;
                }
            }
        }

        if(typeof params.url.SID === "string" && typeof params.url.zx === "string" && params.body.indexOf("req0_") !== -1) {
            api.tracker.SID = params.url.SID;
            response = [params.url, params.body, sent_params];
            if(api.observe.bound("poll")) {
                triggered.poll = response;
            }
        }

        if(typeof params.url.ik === "string" && typeof params.url.search === "string" && params.body.length === 0 && typeof params.url._reqid === "string") {
            response = [params.url, params.body, sent_params];
            if(api.observe.bound("refresh")) {
                triggered.refresh = response;
            }
        }

        if(response && action_map[action] && api.observe.bound(action_map[action])) {
            triggered[action_map[action]] = response;
        }

        if(params.method === "POST" && (typeof params.url.SID === "string"
                                       || typeof params.url.ik === "string"
                                       || typeof params.url.act === "string")) {
            triggered.http_event = [params]; // send every event and all data
        }

        return triggered;
    };

    api.tools.parse_response = function(response) {
        var parsedResponse = [],
            data, dataLength, endIndex, realData;

        try {

            // gmail post response structure
            // )}]"\n<datalength><rawData>\n<dataLength><rawData>...

            // prepare response, remove eval protectors
            response = response.replace(/\n/g, " ");
            response = response.substring(response.indexOf("'") + 1, response.length);

            while(response.replace(/\s/g, "").length > 1) {

                // how long is the data to get
                dataLength = response.substring(0, response.indexOf("[")).replace(/\s/g, "");
                if (!dataLength) {dataLength = response.length;}

                endIndex = (parseInt(dataLength, 10) - 2) + response.indexOf("[");
                data = response.substring(response.indexOf("["), endIndex);

                var json = JSON.parse(data);
                parsedResponse.push(json);

                // prepare response for next loop
                response = response.substring(response.indexOf("["), response.length);
                response = response.substring(data.length, response.length);
            }
        } catch (e) {
            console.log("Gmail post response parsing failed.", e);
        }

        return parsedResponse;
    };

    /**
       parses a download_url attribute from the attachments main span-element.
     */
    api.tools.parse_attachment_url = function(url) {
        var parts = url.split(":");
        return {
            type: parts[0],
            url: parts[2] + ":" + parts[3]
        };
    };

    /**
       Node-friendly function to extend objects without depending on jQuery
       (which requires a browser-context)
       */
    var extend = function(target, extension) {
        for (var key in extension) {
            target[key] = extension[key];
        }
    };

    /**
       Node-friendly function to merge arrays without depending on jQuery
       (which requires a browser-context).

       All subsequent arrays are merged into the first one, to match
       $.merge's behaviour.
    */
    var merge = function(target, mergee) {

        for (var i=0; i < mergee.length; i++) {
            var value = mergee[i];
            target.push(value);
        }

        return target;
    };

    api.tools.parse_requests = function(params, xhr) {
        params.url_raw = params.url;
        params.url = api.tools.parse_url(params.url);
        if(typeof params.body === "object") {
            params.body_params = params.body;
            params.body_is_object = true;
        } else {
            params.body_params = api.tools.deparam(params.body);
        }

        if(typeof api.tracker.events !== "object" && typeof api.tracker.actions !== "object") {
            api.tracker.events  = [];
            api.tracker.actions = [];
        }

        api.tracker.events.unshift(params);
        var events = api.tools.parse_actions(params, xhr);

        if(params.method === "POST" && typeof params.url.act === "string") {
            api.tracker.actions.unshift(params);
        }

        if(api.tracker.events.length > 50) {
            api.tracker.events.pop();
        }

        if(api.tracker.actions.length > 10) {
            api.tracker.actions.pop();
        }
        return events;
    };


    api.tools.xhr_watcher = function () {
        if (!api.tracker.xhr_init) {
            api.tracker.xhr_init = true;
            var js_frame = null;
            if (top.document.getElementById("js_frame")){
                js_frame = top.document.getElementById("js_frame");
            } else if (window.opener) {
                js_frame = window.opener.top.document.getElementById("js_frame");
            }
            if (!js_frame){
                throw "Cannot register the xhr watcher as mail.google.com is not fully loaded yet. Please wrap your code in `gmail.observe.on(\"load\")`";
            }
            var win = js_frame.contentDocument.defaultView;

            if (!win.gjs_XMLHttpRequest_open) {
                win.gjs_XMLHttpRequest_open = win.XMLHttpRequest.prototype.open;
            }

            win.XMLHttpRequest.prototype.open = function (method, url, async, user, password) {
                var out = win.gjs_XMLHttpRequest_open.apply(this, arguments);
                this.xhrParams = {
                    method: method.toString(),
                    url: url.toString()
                };
                return out;
            };

            if (!win.gjs_XMLHttpRequest_send) {
                win.gjs_XMLHttpRequest_send = win.XMLHttpRequest.prototype.send;
            }

            win.XMLHttpRequest.prototype.send = function (body) {
                // parse the xhr request to determine if any events should be triggered
                var events = false;
                if (this.xhrParams) {
                    this.xhrParams.body = body;
                    events = api.tools.parse_requests(this.xhrParams, this);
                }

                // fire before events
                if(api.observe.trigger("before", events, this)) {

                    // if before events were fired, rebuild arguments[0]/body strings
                    // TODO: recreate the url if we want to support manipulating url args (is there a use case where this would be needed?)
                    body = arguments[0] = this.xhrParams.body_is_object ? this.xhrParams.body_params : $.param(this.xhrParams.body_params,true).replace(/\+/g, "%20");
                }

                // if any matching after events, bind onreadystatechange callback
                if(api.observe.bound(events,"after")) {
                    var curr_onreadystatechange = this.onreadystatechange;
                    var xhr = this;
                    this.onreadystatechange = function(progress) {
                        if (this.readyState === this.DONE) {
                            xhr.xhrResponse = api.tools.parse_response(progress.target.responseText);
                            api.observe.trigger("after", events, xhr);
                        }
                        if (curr_onreadystatechange) {
                            curr_onreadystatechange.apply(this, arguments);
                        }
                    };
                }

                // send the original request
                var out = win.gjs_XMLHttpRequest_send.apply(this, arguments);

                // fire on events
                api.observe.trigger("on", events, this);
                return out;
            };
        }
    };


    api.observe.http_requests = function() {
        return api.tracker.events;
    };


    api.observe.actions = function() {
        return api.tracker.actions;
    };

    /**
       Bind a specified callback to an array of callbacks against a specified type & action
    */
    api.observe.bind = function(type, action, callback) {

        // set up watchdog data structure
        if(typeof api.tracker.watchdog !== "object") {
            api.tracker.watchdog = {
                before: {},
                on: {},
                after: {},
                dom: {}
            };
            api.tracker.bound = {};
        }
        if(typeof api.tracker.watchdog[type] !== "object") {
            api.tools.error("api.observe.bind called with invalid type: " + type);
        }

        // ensure we are watching xhr requests
        if(type !== "dom" && !api.tracker.xhr_init) {
            api.tools.xhr_watcher();
        }

        // add callback to an array in the watchdog
        if(typeof api.tracker.watchdog[type][action] !== "object") {
            api.tracker.watchdog[type][action] = [];
        }
        api.tracker.watchdog[type][action].push(callback);

        // allow checking for bound events to specific action/type as efficiently as possible (without in looping) - bit dirtier code,
        // but lookups (api.observer.bound) are executed by the hundreds & I think the extra efficiency is worth the tradeoff
        api.tracker.bound[action] = typeof api.tracker.bound[action] === "undefined" ? 1 : api.tracker.bound[action]+1;
        api.tracker.bound[type] = typeof api.tracker.bound[type] === "undefined" ? 1 : api.tracker.bound[type]+1;
        //api.tracker.watchdog[action] = callback;
    };

    /**
       an on event is observed just after gmail sends an xhr request
    */
    api.observe.on = function(action, callback, response_callback) {

        // check for DOM observer actions, and if none found, the assume an XHR observer
        if(api.observe.on_dom(action, callback)) return true;

        // bind xhr observers
        api.observe.bind("on", action, callback);
        if (response_callback) {
            api.observe.after(action, callback);
        }
    };

    /**
       an before event is observed just prior to the gmail xhr request being sent
       before events have the ability to modify the xhr request before it is sent
    */
    api.observe.before = function(action, callback) {
        api.observe.bind("before", action, callback);
    };

    /**
       an after event is observed when the gmail xhr request returns from the server
       with the server response
    */
    api.observe.after = function(action, callback) {
        api.observe.bind("after", action, callback);
    };

    /**
       Checks if a specified action & type has anything bound to it
       If type is null, will check for this action bound on any type
       If action is null, will check for any actions bound to a type
    */
    api.observe.bound = function(action, type) {
        if (typeof api.tracker.watchdog !== "object") return false;
        if (action) {

            // if an object of actions (triggered events of format { event: [response] }) is passed, check if any of these are bound
            if(typeof action === "object") {
                var match = false;
                $.each(action,function(key,response){
                    if(typeof api.tracker.watchdog[type][key] === "object") match = true;
                });
                return match;
            }
            if(type) return typeof api.tracker.watchdog[type][action] === "object";
            return api.tracker.bound[action] > 0;
        } else {
            if(type) return api.tracker.bound[type] > 0;
            api.tools.error("api.observe.bound called with invalid args");
        }
    };

    /**
       Clear all callbacks for a specific type (before, on, after, dom) and action
       If action is null, all actions will be cleared
       If type is null, all types will be cleared
    */
    api.observe.off = function(action, type) {

        // if watchdog is not set, bind has not yet been called so nothing to turn off
        if(typeof api.tracker.watchdog !== "object") return true;

        // loop through applicable types
        var types = type ? [ type ] : [ "before", "on", "after", "dom" ];
        $.each(types, function(idx, type) {
            if(typeof api.tracker.watchdog[type] !== "object") return true; // no callbacks for this type

            // if action specified, remove any callbacks for this action, otherwise remove all callbacks for all actions
            if(action) {
                if(typeof api.tracker.watchdog[type][action] === "object") {
                    api.tracker.bound[action] -= api.tracker.watchdog[type][action].length;
                    api.tracker.bound[type] -= api.tracker.watchdog[type][action].length;
                    delete api.tracker.watchdog[type][action];
                }
            } else {
                $.each(api.tracker.watchdog[type], function(act,callbacks) {
                    if(typeof api.tracker.watchdog[type][act] === "object") {
                        api.tracker.bound[act] -= api.tracker.watchdog[type][act].length;
                        api.tracker.bound[type] -= api.tracker.watchdog[type][act].length;
                        delete api.tracker.watchdog[type][act];
                    }
                });
            }
        });
    };

    /**
       Trigger any specified events bound to the passed type
       Returns true or false depending if any events were fired
    */
    api.observe.trigger = function(type, events, xhr) {
        if(!events) return false;
        var fired = false;
        $.each(events, function(action,response) {

            // we have to do this here each time to keep backwards compatibility with old response_callback implementation
            response = $.extend([], response); // break the reference so it doesn"t keep growing each trigger
            if(type === "after") response.push(xhr.xhrResponse); // backwards compat for after events requires we push onreadystatechange parsed response first
            response.push(xhr);
            if(api.observe.bound(action, type)) {
                fired = true;
                $.each(api.tracker.watchdog[type][action], function(idx, callback) {
                    callback.apply(undefined, response);
                });
            }
        });
        return fired;
    };

    /**
       Trigger any specified DOM events passing a specified element & optional handler
    */
    api.observe.trigger_dom = function(observer, element, handler) {

        // if no defined handler, just call the callback
        if (!handler) {
            handler = function(match, callback) {
                callback(match);
            };
        }
        if (!api.tracker.watchdog.dom[observer]) {
            return;
        }
        $.each(api.tracker.watchdog.dom[observer], function(idx, callback) {
            handler(element, callback);
        });
    };

    // pre-configured DOM observers
    // map observers to DOM class names
    // as elements are inserted into the DOM, these classes will be checked for and mapped events triggered,
    // receiving "e" event object, and a jquery bound inserted DOM element
    // NOTE: supported observers and sub_observers must be registered in the supported_observers array as well as the dom_observers config
    // Config example: event_name: {
    //                   class: "className", // required - check for this className in the inserted DOM element
    //                   selector: "div.className#myId", // if you need to match more than just the className of a specific element to indicate a match, you can use this selector for further checking (uses element.is(selector) on matched element). E.g. if there are multiple elements with a class indicating an observer should fire, but you only want it to fire on a specific id, then you would use this
    //                   sub_selector: "div.className", // if specified, we do a jquery element.find for the passed selector on the inserted element and ensure we can find a match
    //                   handler: function( matchElement, callback ) {}, // if specified this handler is called if a match is found. Otherwise default calls the callback & passes the jQuery matchElement
    //                   sub_observers: { }, // hash of event_name: config_hash"s - config hash supports all properties of this config hash. Observer will be bound as DOMNodeInserted to the matching class+sub_selector element.
    //                 },
    // TODO: current limitation allows only 1 action per watched className (i.e. each watched class must be
    //       unique). If this functionality is needed this can be worked around by pushing actions to an array
    //       in api.tracker.dom_observer_map below
    // console.log( "Observer set for", action, callback);
    api.observe.initialize_dom_observers = function() {
        api.tracker.dom_observer_init = true;
        api.tracker.supported_observers = ["view_thread", "view_email", "load_email_menu", "recipient_change", "compose"];
        api.tracker.dom_observers = {

            // when a thread is clicked on in a mailbox for viewing - note: this should fire at a similar time (directly after) as the open_email XHR observer
            // which is triggered by the XHR request rather than nodes being inserted into the DOM (and thus returns different information)
            "view_thread": {
                class: ["Bu", "nH"], // class depends if is_preview_pane - Bu for preview pane, nH for standard view
                sub_selector: "div.if",
                handler: function(match, callback) {
                    match = new api.dom.thread(match);
                    callback(match);

                    // look for any email elements in this thread that are currently displaying
                    // and fire off any view_email sub_observers for each of them
                    var email = match.dom("opened_email");
                    if (email.length) {
                        api.observe.trigger_dom("view_email", email, api.tracker.dom_observers.view_thread.sub_observers.view_email.handler);
                    }
                },
                sub_observers: {

                    // when an individual email is loaded within a thread (also fires when thread loads displaying the latest email)
                    "view_email": {
                        class: "",
                        sub_selector: "div.adn",
                        handler: function(match, callback) {
                            match = new api.dom.email(match);
                            callback(match);
                        }
                    },

                    // when the dropdown menu next to the reply button is inserted into the DOM when viewing an email
                    "load_email_menu": {
                        class: "J-N",
                        selector: "div[role=menu] div[role=menuitem]:first-child", // use the first menu item in the popoup as the indicator to trigger this observer
                        handler: function(match, callback) {
                            match = match.closest("div[role=menu]");
                            callback(match);
                        }
                    }
                }
            },

            // a new email address is added to any of the to,cc,bcc fields when composing a new email or replying/forwarding
            "recipient_change": {
                class: "vR",
                handler: function(match, callback) {
                    // console.log("compose:recipient handler called",match,callback);

                    // we need to small delay on the execution of the handler as when the recipients field initialises on a reply (or reinstated compose/draft)
                    // then multiple DOM elements will be inserted for each recipient causing this handler to execute multiple times
                    // in reality we only want a single callback, so give other nodes time to be inserted & then only execute the callback once
                    if(typeof api.tracker.recipient_matches !== "object") {
                        api.tracker.recipient_matches = [];
                    }
                    api.tracker.recipient_matches.push(match);
                    setTimeout(function(){
                        // console.log("recipient timeout handler", api.tracker.recipient_matches.length);
                        if(!api.tracker.recipient_matches.length) return;

                        // determine an array of all emails specified for To, CC and BCC and extract addresses into an object for the callback
                        var compose = new api.dom.compose(api.tracker.recipient_matches[0].closest("div.M9"));
                        var recipients = compose.recipients();
                        callback(compose, recipients, api.tracker.recipient_matches);

                        // reset matches so no future delayed instances of this function execute
                        api.tracker.recipient_matches = [];
                    },100);
                }
            },

            // this will fire if a new compose, reply or forward is created. it won"t fire if a reply changes to a forward & vice versa
            // passes a type of compose, reply, or forward to the callback
            "compose": {
                class: "An", // M9 would be better but this isn"t set at the point of insertion
                handler: function(match, callback) {
                    // console.log("reply_forward handler called", match, callback);

                    var originalMatch = match;
                    // look back up the DOM tree for M9 (the main reply/forward node)
                    match = match.closest("div.M9");
                    if (!match.length) return;
                    match = new api.dom.compose(match);
                    var type;
                    if (match.is_inline()) {
                        type = match.find("input[name=subject]").val().indexOf("Fw") === 0 ? "forward" : "reply";
                    } else {
                        type = "compose";

                        //Find the close button and set an event listener so we can forward the compose_cancelled event.
                        var composeWindow = originalMatch.closest("div.AD");
                        composeWindow.find(".Ha").mouseup(function() {
                            if(api.tracker.composeCancelledCallback) {
                                api.tracker.composeCancelledCallback(match);
                            }
                            return true;
                        });

                    }
                    callback(match,type);
                }
            }
        };

        // support extending with custom observers
        if (api.tracker.custom_supported_observers) {
            $.merge(api.tracker.supported_observers, api.tracker.custom_supported_observers);
            $.extend(true, api.tracker.dom_observers, api.tracker.custom_dom_observers); // deep copy to copy in sub_observers where relevant
        }

        // map observed classNames to actions
        api.tracker.dom_observer_map = {};
        $.each(api.tracker.dom_observers, function(act,config){
            if(!$.isArray(config.class)) config.class = [config.class];
            $.each(config.class, function(idx, className) {
                api.tracker.dom_observer_map[className] = act;
            });
        });
        //console.log( "observer_config", api.tracker.dom_observers, "dom_observer_map", api.tracker.dom_observer_map);
    };

    /**
       Allow an application to register a custom DOM observer specific to their app.
       Adds it to the configured DOM observers and is supported by the dom insertion observer
       This method can be called two different ways:
       Args:
       action - the name of the new DOM observer
       className / args - for a simple observer, this arg can simply be the class on an inserted DOM element that identifies this event should be
       triggered. For a more complicated observer, this can be an object containing properties for each of the supported DOM observer config arguments
       parent - optional - if specified, this observer will be registered as a sub_observer for the specified parent
    */
    api.observe.register = function(action, args, parent) {

        // check observers configured
        if (api.tracker.dom_observer_init) {
            api.tools.error("Error: Please register all custom DOM observers before binding handlers using gmail.observe.on etc");
        }
        if (!api.tracker.custom_supported_observers) {
            api.tracker.custom_supported_observers = [];
            api.tracker.custom_dom_observers = {};
        }

        // was an object of arguments passed, or just a className
        var config = {};
        if (typeof args === "object" && !$.isArray(args)) {

            // copy over supported config
            $.each(["class","selector","sub_selector","handler"], function(idx, arg) {
                if(args[arg]) {
                    config[arg] = args[arg];
                }
            });
        } else {
            config["class"] = args;
        }
        api.tracker.custom_supported_observers.push(action);
        if (parent) {
            if (!api.tracker.custom_dom_observers[parent]) {
                api.tracker.custom_dom_observers[parent] = {sub_observers: {}};
            }
            api.tracker.custom_dom_observers[parent].sub_observers[action] = config;
        } else {
            api.tracker.custom_dom_observers[action] = config;
        }
    };

    /**
       Observe DOM nodes being inserted. When a node with a class defined in api.tracker.dom_observers is inserted,
       trigger the related event and fire off any relevant bound callbacks
       This function should return true if a dom observer is found for the specified action
    */
    api.observe.on_dom = function(action, callback) {

        // check observers configured
        if(!api.tracker.dom_observer_init) {
            api.observe.initialize_dom_observers();
        }

        // support for DOM observers
        if($.inArray(action, api.tracker.supported_observers) > -1) {

            //console.log("observer found",api.tracker.dom_observers[action]);

            // if we haven"t yet bound the DOM insertion observer, do it now
            if(!api.tracker.observing_dom) {
                api.tracker.observing_dom = true;
                //api.tracker.dom_watchdog = {}; // store passed observer callbacks for different DOM events

                // this listener will check every element inserted into the DOM
                // for specified classes (as defined in api.tracker.dom_observers above) which indicate
                // related actions which need triggering
                $(window.document).bind("DOMNodeInserted", function(e) {
                    api.tools.insertion_observer(e.target, api.tracker.dom_observers, api.tracker.dom_observer_map);
                });

                // recipient_change also needs to listen to removals
                var mutationObserver = new MutationObserver(function(mutations) {
                    for (var i = 0; i < mutations.length; i++) {
                        var mutation = mutations[i];
                        var removedNodes = mutation.removedNodes;
                        for (var j = 0; j < removedNodes.length; j++) {
                            var removedNode = removedNodes[j];
                            if (removedNode.className === "vR") {
                                var observer = api.tracker.dom_observer_map["vR"];
                                var handler = api.tracker.dom_observers.recipient_change.handler;
                                api.observe.trigger_dom(observer, $(mutation.target), handler);
                            }
                        }
                    }
                });
                mutationObserver.observe(document.body, {subtree: true, childList: true});

            }
            api.observe.bind("dom",action,callback);
            // console.log(api.tracker.observing_dom,"dom_watchdog is now:",api.tracker.dom_watchdog);
            return true;

            // support for gmail interface load event
        }
        else if(action === "compose_cancelled") {
            console.log("set compose cancelled callback");
            api.tracker.composeCancelledCallback = callback;
        }
        else if(action === "load") {

            // wait until the gmail interface has finished loading and then
            // execute the passed handler. If interface is already loaded,
            // then will just execute callback
            if(api.dom.inbox_content().length) return callback();
            var load_count = 0;
            var delay = 200; // 200ms per check
            var attempts = 50; // try 50 times before giving up & assuming an error
            var timer = setInterval(function() {
                var test = api.dom.inbox_content().length;
                if(test > 0) {
                    clearInterval(timer);
                    return callback();
                } else if(++load_count > attempts) {
                    clearInterval(timer);
                    console.log("Failed to detect interface load in " + (delay*attempts/1000) + " seconds. Will automatically fire event in 5 further seconds.");
                    setTimeout(callback, 5000);
                }
            }, delay);
            return true;
        }
    };

    // observes every element inserted into the DOM by Gmail and looks at the classes on those elements,
    // checking for any configured observers related to those classes
    api.tools.insertion_observer = function(target, dom_observers, dom_observer_map, sub) {
        //console.log("insertion", target, target.className);
        if(!api.tracker.dom_observer_map) return;

        // loop through each of the inserted elements classes & check for a defined observer on that class
        var cn = target.className || "";
        var classes = cn.trim().split(/\s+/);
        if(!classes.length) classes.push(""); // if no class, then check for anything observing nodes with no class
        $.each(classes, function(idx, className) {
            var observer = dom_observer_map[className];

            // check if this is a defined observer, and callbacks are bound to that observer
            if(observer && api.tracker.watchdog.dom[observer]) {
                var element = $(target);
                var config = dom_observers[observer];

                // if a config id specified for this observer, ensure it matches for this element
                if(config.selector && !element.is(config.selector)) {
                    return;
                }

                // check for any defined sub_selector match - if not found, then this is not a match for this observer
                // if found, then set the matching element to be the one that matches the sub_selector
                if(config.sub_selector) {
                    element = element.find(config.sub_selector);
                    // console.log("checking for subselector", config.sub_selector, element);
                }

                // if an element has been found, execute the observer handler (or if none defined, execute the callback)
                if(element.length) {

                    var handler = config.handler ? config.handler : function(match, callback) { callback(match); };
                    // console.log( "inserted DOM: class match in watchdog",observer,api.tracker.watchdog.dom[observer] );
                    api.observe.trigger_dom(observer, element, handler);

                    // if sub_observers are configured for this observer, bind a DOMNodeInsertion listener to this element & to check for specific elements being added to this particular element
                    if(config.sub_observers) {

                        // create observer_map for the sub_observers
                        var observer_map = {};
                        $.each(config.sub_observers, function(act,cfg){
                            observer_map[cfg.class] = act;
                        });

                        // this listener will check every element inserted into the DOM below the current element
                        // and repeat this method, but specifically below the current element rather than the global DOM
                        element.bind("DOMNodeInserted", function(e) {
                            api.tools.insertion_observer(e.target, config.sub_observers, observer_map, "SUB ");
                        });
                    }
                }
            }
        });
    };


    api.tools.make_request = function (_link, method, disable_cache) {
        var link = decodeURIComponent(_link.replace(/%23/g, "#-#-#"));
        method  = method || "GET";

        link = encodeURI(link).replace(/#-#-#/gi, "%23");
        var config = {type: method, url: link, async: false};
        if (disable_cache) {
            config.cache = false;
        }
        var request = $.ajax(config);
        return request.responseText;
    };


    api.tools.make_request_async = function (_link, method, callback, error_callback, disable_cache) {
        var link = decodeURIComponent(_link.replace(/%23/g, "#-#-#"));
        method  = method || "GET";

        link = encodeURI(link).replace(/#-#-#/gi, "%23");
        var config = {type: method, url: link, async: true, dataType: "text"};
        if (disable_cache){
            config.cache = false;
        }
        $.ajax(config)
            .done(function(data, textStatus, jqxhr) {
                callback(jqxhr.responseText);
            })
            .fail(function(jqxhr, textStatus, errorThrown) {
                console.error("Request Failed", errorThrown);
                if (typeof error_callback === 'function'){
                    error_callback(jqxhr, textStatus, errorThrown);
                }
            });
    };

    /**
       Creates a request to download user-content from Gmail.
       This can be used to download email_source or attachments.

       Set `preferBinary` to receive data as an Uint8Array which is unaffected
       by string-parsing or resolving of text-encoding.

       This is required in order to correctly download attachments!
    */
    api.tools.make_request_download_promise = function (url, preferBinary) {
        // if we try to download the same email/url several times,
        // something weird happens with our cookies, causing the 302
        // redirect to mail-attachment.googleusercontent.com (MAGUC)
        // to redirect back to mail.google.com.
        //
        // mail.google.com does NOT have CORS-headers for MAGUC, so
        // this redirect (and thus our request) fails.
        //
        // Adding a random variable with a constantly changing value defeats
        // any cache, and seems to solve our problem.
        const timeStamp = Date.now();
        url += "&cacheCounter=" + timeStamp;

        let responseType = "text";
        if (preferBinary) {
            responseType = "arraybuffer";
        }

        // now go download!
        return new Promise((resolve, reject) => {
            const request = new XMLHttpRequest();
            request.open("GET", url, true);
            request.responseType = responseType;

            request.onreadystatechange = () => {
                if (request.readyState !== XMLHttpRequest.DONE) {
                    return;
                }

                if (request.status >= 200 && request.status <= 302) {
                    const result = request.response;
                    if (result) {
                        if (preferBinary) {
                            const byteArray = new Uint8Array(result);
                            resolve(byteArray);
                        } else {
                            // result is regular text!
                            resolve(result);
                        }
                    }
                }
            };
            request.onerror = (ev) => {
                reject(ev);
            };

            request.send();
        });
    };


    api.tools.parse_view_data = function(view_data) {
        var parsed = [];
        var data = [];

        for(var j=0; j < view_data.length; j++) {
            if(view_data[j][0] === "tb") {
                for(var k=0; k < view_data[j][2].length; k++) {
                    data.push(view_data[j][2][k]);
                }
            }
        }

        for(var i=0; i < data.length; i++) {
            var x = data[i];

            parsed.push({
                id: x[0],
                title : x[9],
                excerpt : x[10],
                time : x[15],
                sender : x[28],
                attachment : x[13],
                labels: x[5]
            });
        }

        return parsed;
    };


    api.helper.get.is_delegated_inbox = function() {
        return api.tracker.globals[17][5][0] === "fwd";
    };


    api.helper.get.visible_emails_pre = function() {
        var page = api.get.current_page();
        var url = window.location.origin + window.location.pathname + "?ui=2&ik=" + api.tracker.ik+"&rid=" + api.tracker.rid + "&view=tl&num=120&rt=1";
        var start = $(".aqK:visible .Dj").find("span:first").text().replace(",", "").replace(".", "");
        if (start) {
            start = parseInt(start - 1);
            url += "&start=" + start +
                   "&sstart=" + start;
        } else {
            url += "&start=0";
        }

        var cat_label = "";

        if(page.indexOf("label/") === 0) {
            url += "&cat=" + page.split("/")[1] +"&search=cat";
        } else if(page.indexOf("category/") === 0) {
            if(page.indexOf("forums") !== -1) {
                cat_label = "group";
            } else if(page.indexOf("updates") !== -1) {
                cat_label = "notification";
            } else if(page.indexOf("promotion") !== -1) {
                cat_label = "promo";
            } else if(page.indexOf("social") !== -1) {
                cat_label = "social";
            }
            url += "&cat=^smartlabel_" + cat_label +"&search=category";
        } else if(page.indexOf("search/") === 0) {
            var at = $("input[name=at]").val();
            url += "&qs=true&q=" + page.split("/")[1] +"&at=" + at + "&search=query";
        } else if(page === "inbox"){
            if ($("div[aria-label='Social']").attr("aria-selected") === "true") {
                cat_label = "social";
                url += "&cat=^smartlabel_" + cat_label + "&search=category";
            } else if ($("div[aria-label='Promotions']").attr("aria-selected") === "true") {
                cat_label = "promo";
                url += "&cat=^smartlabel_" + cat_label + "&search=category";
            } else if ($("div[aria-label='Updates']").attr("aria-selected") === "true") {
                cat_label = "notification";
                url += "&cat=^smartlabel_" + cat_label + "&search=category";
            } else if ($("div[aria-label='Forums']").attr("aria-selected") === "true") {
                cat_label = "group";
                url += "&cat=^smartlabel_" + cat_label + "&search=category";
            } else {
                url += "&search=" + "inbox";
            }
        }else {
            url += "&search=" + page;
        }
        return url;
    };


    api.helper.get.visible_emails_post = function(get_data) {
        var emails = [];

        if (!get_data) {
            return emails;
        }

        var data = get_data.substring(get_data.indexOf("["), get_data.length);
        var json = JSON.parse(data);
        api.tracker.view_data = json;

        for(var i in api.tracker.view_data) {
            if (typeof(api.tracker.view_data[i]) === "function") {
                continue;
            }

            var cdata = api.tools.parse_view_data(api.tracker.view_data[i]);
            if(cdata.length > 0) {
                merge(emails, cdata);
            }
        }
        return emails;
    };

    // dispatch mousedown and mouseup event on passed element
    api.helper.trigger_mouse_click = function(element) {
        if(element) {
            //Trigger mouse down event
            var mouseDown = document.createEvent("MouseEvents");
            mouseDown.initEvent( "mousedown", true, false );
            element.dispatchEvent(mouseDown);

            //Trigger mouse up event
            var mouseUp = document.createEvent("MouseEvents");
            mouseUp.initEvent( "mouseup", true, false );
            element.dispatchEvent(mouseUp);

            return true;
        }
        return false;
    };

    api.get.visible_emails = function() {
        var url = api.helper.get.visible_emails_pre();
        var get_data = api.tools.make_request(url);
        var emails = api.helper.get.visible_emails_post(get_data);

        return emails;
    };


    api.get.visible_emails_async = function(callback) {
        var url = api.helper.get.visible_emails_pre();
        api.tools.make_request_async(url, "GET", function(get_data) {
            var emails = api.helper.get.visible_emails_post(get_data);
            callback(emails);
        });
    };


    api.get.selected_emails_data = function(){
        var selected_emails = [];
        if(!api.check.is_inside_email()){
            if($("[gh='tl'] div[role='checkbox'][aria-checked='true']").length){
                var email = null;
                var emails = api.get.visible_emails();
                $("[gh='tl'] div[role='checkbox']").each(function(index){
                    if($(this).attr("aria-checked") === "true"){
                        email = api.get.email_data(emails[index].id);
                        selected_emails.push(email);
                    }
                });
            }
        }else {
            selected_emails.push(api.get.email_data());
        }
        return selected_emails;
    };


    api.get.current_page = function(hash) {
        hash = hash || window.location.hash;

        var hashPart  = hash.split("#").pop().split("?").shift() || "inbox";

        if(hashPart.match(/\/[0-9a-f]{16,}$/gi)) {
            return "email";
        }

        var isTwopart = (hashPart.indexOf("search/") === 0
                         || hashPart.indexOf("category/") === 0
                         || hashPart.indexOf("label/") === 0);

        var result = null;
        if (!isTwopart) {
            result = hashPart.split("/").shift();
            return result;
        } else {
            var parts = hashPart.split("/");
            result = parts[0] + "/" + parts[1];
            return result;
        }
    };


    api.tools.infobox = function(message, time, html){
        var top = $(".b8.UC");

        // initial Gmail style I noticed on 26 / 05 / 2014 for $(".b8.UC") :
        // style="position: relative; top: -10000px;"
        // Seems that when Gmail shows infobox, the style is simply removed
        // - from what I can see in DevTools Elements Panel

        if(top.length > 0){
            top.stop(false, true); // cancel any existing fade so we can start again
            var info = top.find(".vh");
            if (!html) {
                info.text(message);
            } else {
                info.html(message);
            }
            if(typeof time !== "undefined"){
                var initialInfoboxStyle = top.attr("style");            // backup initial style
                top.removeAttr("style").fadeTo(time, 0, function(){     // simply remove then restore
                    $(this).attr("style", initialInfoboxStyle);           // style attribute insteed of playing
                });                             // on visibility property
            }
            else{
                top.removeAttr("style");                    // dito
            }
        }
    };

    /**
     * Re-renders the UI using the available data.
     *
     * This method does _not_ cause Gmail to fetch new data. This method is useful
     * in circumstances where Gmail has data available but does not immediately
     * render it. `observe.after` may be used to detect when Gmail has fetched the
     * relevant data. For instance, to refresh a conversation after Gmail fetches
     * its data:
     *
     *     gmail.observe.after("refresh", function(url, body, data, xhr) {
     *       if (url.view === "cv") {
     *         gmail.tools.rerender();
     *       }
     *     });
     *
     * If a callback is passed, it will be invoked after re-rendering is complete.
     */
    api.tools.rerender = function(callback) {
        var url = window.location.href;
        var hash = window.location.hash;

        // Get Gmail to re-render by navigating away and then back to the current URL. We keep the
        // UI from changing as we navigate away by visiting an equivalent URL: the current URL with the
        // first parameter of the hash stripped ("#inbox/14a16fab4adc1456" -> "#/14a16fab4adc1456" or
        // "#inbox" -> "#").
        var tempUrl;
        if (hash.indexOf("/") !== -1) {
            tempUrl = url.replace(/#.*?\//, "#/");
        } else {
            tempUrl = url.replace(/#.*/, "#");
        }
        window.location.replace(tempUrl);

        // Return to the original URL after a 0-timeout to force Gmail to navigate to the temp URL.
        setTimeout(function() {
            window.location.replace(url);

            // For some reason, the two replace operations above create a history entry (tested in
            // Chrome 39.0.2171.71). Pop it to hide our URL manipulation.
            window.history.back();

            if (callback) callback();
        }, 0);
    };

    api.tools.get_reply_to = function(ms13) {
        // reply to is an array if exists
        var reply_to = ms13 ? ms13[4] : [];

        // if reply to set get email from it and return it
        if (reply_to.length !== 0) {
            return api.tools.extract_email_address(reply_to[0]);
        }

        // otherwise return null
        return null;
    };

    api.tools.parse_attachment_data = function(x) {
        if (!x[7] || ! x[7][0])
        {
            return null;
        }

        var baseUrl = "";
        if (typeof(window) !== "undefined") {
            baseUrl =  window.location.origin + window.location.pathname;
        }

        var ad = x[7][0];
        api.tracker.attachment_data = ad;

        var attachments = [];
        for (var i = 0; i < ad.length; i++)
        {
            var a = ad[i];
            attachments.push({
                attachment_id: a[0],
                name: a[1],
                type: a[2],
                size: a[3],
                url: baseUrl + a[9]
            });
        }
        return attachments;
    };

    api.tools.parse_email_data = function(email_data) {
        var data = {};

        for(var i in email_data) {
            var x = email_data[i];
            if(x[0] === "cs") {
                data.thread_id = x[1];
                data.first_email= x[8][0];
                data.last_email = x[2];
                data.total_emails = x[3];
                data.total_threads = x[8];
                data.people_involved = x[15];
                data.subject = x[23];
            }

            if(x[0] === "ms") {
                if(data.threads === undefined) {
                    data.threads = {};
                }

                data.threads[x[1]] = {};
                data.threads[x[1]].is_deleted = (x[9] && x[9].indexOf("^k") > -1);
                data.threads[x[1]].reply_to_id = x[2];
                data.threads[x[1]].from = x[5];
                data.threads[x[1]].from_email = x[6];
                data.threads[x[1]].timestamp = x[7];
                data.threads[x[1]].datetime = x[24];
                data.threads[x[1]].attachments = x[21].split(",");
                data.threads[x[1]].attachments_details = x[13] ? api.tools.parse_attachment_data(x[13]) : null;
                data.threads[x[1]].subject = x[12];
                data.threads[x[1]].content_html = x[13] ? x[13][6] : x[8];
                data.threads[x[1]].to = x[13] ? x[13][1] : ((x[37] !== undefined) ? x[37][1]:[]);
                data.threads[x[1]].cc = x[13] ? x[13][2] : [];
                data.threads[x[1]].bcc = x[13] ? x[13][3] : [];
                data.threads[x[1]].reply_to = api.tools.get_reply_to(x[13]);
                data.threads[x[1]].labels = x[9];

                try { // jQuery will sometime fail to parse x[13][6], if so, putting the raw HTML
                    data.threads[x[1]].content_plain = x[13] ? $(x[13][6]).text() : x[8];
                }
                catch(e) {
                    data.threads[x[1]].content_plain = x[13] ? x[13][6] : x[8];
                }
            }
        }

        return data;
    };


    api.helper.get.email_data_pre = function(email_id) {
        if(api.check.is_inside_email() && email_id === undefined) {
            email_id = api.get.email_id();
        }

        var url = null;
        if(email_id !== undefined) {
            url = window.location.origin + window.location.pathname + "?ui=2&ik=" + api.tracker.ik + "&rid=" + api.tracker.rid + "&view=cv&th=" + email_id + "&msgs=&mb=0&rt=1&search=inbox";
        }
        return url;
    };


    api.helper.get.email_data_post = function(get_data) {
        if (!get_data) {
            return {};
        }
        var data = get_data.substring(get_data.indexOf("["), get_data.length);
        var json = JSON.parse(data);

        api.tracker.email_data = json[0];
        return api.tools.parse_email_data(api.tracker.email_data);
    };


    api.get.email_data = function(email_id) {
        var url = api.helper.get.email_data_pre(email_id);

        if (url !== null) {
            var get_data = api.tools.make_request(url);
            var email_data = api.helper.get.email_data_post(get_data);
            return email_data;
        }

        return {};
    };


    api.get.email_data_async = function(email_id, callback) {
        var url = api.helper.get.email_data_pre(email_id);
        if (url !== null) {
            api.tools.make_request_async(url, "GET", function (get_data) {
                var email_data = api.helper.get.email_data_post(get_data);
                callback(email_data);
            });
        } else {
            callback({});
        }
    };


    api.helper.get.email_source_pre = function(email_id) {
        if(!email_id && api.check.is_inside_email()) {
            email_id = api.get.email_id();
        }

        if(!email_id) {
            return null;
        }

        return window.location.origin + window.location.pathname + "?view=att&th=" + email_id + "&attid=0&disp=comp&safe=1&zw";
    };


    api.get.email_source = function(email_id) {
        console.warn("Gmail.js: This function has been deprecated and will be removed in an upcoming release! Please migrate to email_source_async!");
        var url = api.helper.get.email_source_pre(email_id);
        if (url !== null) {
            return api.tools.make_request(url, "GET", true);
        }
        return "";
    };


    api.get.email_source_async = function(email_id, callback, error_callback, preferBinary) {
        api.get.email_source_promise(email_id, preferBinary)
            .then(callback)
            .catch(error_callback);
    };

    api.get.email_source_promise = function(email_id, preferBinary) {
        const url = api.helper.get.email_source_pre(email_id);
        if (url !== null) {
            return api.tools.make_request_download_promise(url, preferBinary);
        } else {
            return new Promise((resolve, reject) => {
                reject("Unable to resolve URL for email source!");
            });
        }
    };

    api.get.displayed_email_data = function() {
        var email_data = api.get.email_data();

        if (api.check.is_conversation_view()) {
            return get_displayed_email_data_for_thread(email_data);
        }
        else { // Supposing only one displayed email.
            return get_displayed_email_data_for_single_email(email_data);
        }
    };

    api.get.displayed_email_data_async = function (callback) {
        api.get.email_data_async(undefined, function (email_data) {
            if (api.check.is_conversation_view()) {
                callback(get_displayed_email_data_for_thread(email_data));
            }
            else { // Supposing only one displayed email.
                callback(get_displayed_email_data_for_single_email(email_data));
            }
        });
    };

    var get_displayed_email_data_for_thread = function(email_data) {
        var displayed_email_data = email_data;

        var threads = displayed_email_data.threads;
        var total_threads = displayed_email_data.total_threads;

        var hash = window.location.hash.split("#")[1] || "";
        var is_in_trash = (hash.indexOf("trash") === 0);

        for (var id in threads) {
            var email = threads[id];
            var keep_email = (is_in_trash) ? email.is_deleted : !email.is_deleted;

            if (!keep_email) {
                delete threads[id];
                total_threads.splice(total_threads.indexOf(id), 1);
                displayed_email_data.total_emails--;
                // TODO: remove people involved only in this email.
            }
        }
        return displayed_email_data;
    };

    var get_displayed_email_data_for_single_email = function(email_data) {
        var displayed_email_data = {};
        for (var id in email_data.threads) {
            var message_class_id = "m"+id;
            var displayed_email_element = $(".ii.gt .a3s.aXjCH." + message_class_id);

            if (displayed_email_element.length > 0) {
                var email = email_data.threads[id];

                displayed_email_data.first_email = id;
                displayed_email_data.last_email = id;
                displayed_email_data.subject = email_data.subject;

                displayed_email_data.threads = {};
                displayed_email_data.threads[id] = email;
                displayed_email_data.total_emails = 1;
                displayed_email_data.total_threads = [id];

                displayed_email_data.people_involved = [];

                displayed_email_data.people_involved.push(
                    [email.from, email.from_email]
                );

                email.to.forEach(function(recipient) {
                    var address = api.tools.extract_email_address(recipient);
                    var name = api.tools.extract_name(recipient.replace(address, "")) || "";

                    displayed_email_data.people_involved.push(
                        [name, address]
                    );
                });

                break;
            }
        }
        return displayed_email_data;
    };


    api.check.is_conversation_view = function() {
        var flag_name = "bx_vmb";
        var flag_value = undefined;

        var array_with_flag = api.tracker.globals[17][4][1];

        for (var i = 0; i < array_with_flag.length; i++) {
            var current = array_with_flag[i];

            if (current[0] === flag_name) {
                flag_value = current[1];

                break;
            }
        }

        return flag_value === "0" || flag_value === undefined;
    };


    api.tools.extract_email_address = function(str) {
        var regex = /[\+a-z0-9._-]+@[a-z0-9._-]+\.[a-z0-9._-]+/gi;
        var matches = (str) ? str.match(regex) : undefined;

        return (matches) ? matches[0] : undefined;
    };


    api.tools.extract_name = function(str) {
        var regex = /[a-z\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF"._\s-]+/gi;
        var matches = (str) ? str.match(regex) : undefined;

        return (matches && matches[0]) ? matches[0].trim() : undefined;
    };


    api.tools.i18n = function(label) {
        var locale = api.get.localization();
        var dictionary;

        switch (locale) {
        case "fr":
            dictionary = {
                "inbox": "Boîte de réception",
                "drafts": "Brouillons",
                "spam": "Spam",
                "forums": "Forums",
                "updates": "Mises à jour",
                "promotions": "Promotions",
                "social_updates": "Réseaux sociaux"
            };
            break;

        case "nl":
            dictionary = {
                "inbox": "Postvak IN",
                "drafts": "Concepten",
                "spam": "Spam",
                "forums": "Forums",
                "updates": "Updates",
                "promotions": "Reclame",
                "social_updates": "Sociaal"
            };
            break;

        case "en":
        default:
            dictionary = {
                "inbox": "Inbox",
                "drafts": "Drafts",
                "spam": "Spam",
                "forums": "Forums",
                "updates": "Updates",
                "promotions": "Promotions",
                "social_updates": "Social Updates"
            };
            break;
        }

        return dictionary[label];
    };

    var create_generic_toolbar_button = function(content_html, onClickFunction, basicStyle, defaultStyle, styleClass, selector) {
        var container = $(document.createElement("div"));
        container.attr("class","G-Ni J-J5-Ji");

        var button = $(document.createElement("div"));
        var buttonClasses = "T-I J-J5-Ji ";
        if(styleClass !== undefined &&
           styleClass !== null &&
           styleClass !== ""){
            buttonClasses += basicStyle+styleClass;
        }else{
            buttonClasses += basicStyle+defaultStyle;
        }
        button.attr("class", buttonClasses);

        button.html(content_html);
        button.click(onClickFunction);

        var content = $(document.createElement("div"));
        content.attr("class","asa");

        container.html(button);

        selector.append(container);

        return container;
    };

    api.tools.add_toolbar_button = function(content_html, onClickFunction, styleClass) {
        var basicLeftStyle = "lS ";
        var defaultLeftStyle = "T-I-ax7 ar7";

        return create_generic_toolbar_button(content_html, onClickFunction, basicLeftStyle, defaultLeftStyle, styleClass, api.dom.toolbar());
    };

    api.tools.add_right_toolbar_button = function(content_html, onClickFunction, styleClass) {
        var basicRightStyle = "ash ";
        var defaultRightStyle = "T-I-ax7 L3";

        return create_generic_toolbar_button(content_html, onClickFunction, basicRightStyle, defaultRightStyle, styleClass, api.dom.right_toolbar());
    };

    api.tools.add_compose_button =  function(composeWindow, content_html, onClickFunction, styleClass) {
        var button = $(document.createElement("div"));
        var buttonClasses = "T-I J-J5-Ji aoO L3 ";
        if(styleClass !== undefined){
            buttonClasses += styleClass;
        }
        button.attr("class", buttonClasses);
        button.html(content_html);
        button.click(onClickFunction);

        composeWindow.find(".gU.Up  > .J-J5-Ji").append(button);

        return button;
    };

    /**
       adds a button to an email attachment.

       'attachment'-parameter must be the object returned from api.dom.email().attachments().
       'contentHtml' should represent a 21x21 image of some kind. optional.
       'customCssClass' styling used on the buttons central area. optional.
       'tooltip' will be shown on hover.

       return-value is jQuery-instance representing the created button.
       */
    api.tools.add_attachment_button = function(attachment, contentHtml, customCssClass, tooltip, onClickFunction) {
        var button = $(document.createElement("div"));
        button.attr("class", "T-I J-J5-Ji aQv T-I-ax7 L3");
        button.attr("style", "user-select: none;");
        button.attr("aria-label", tooltip);
        button.attr("data-tooltip", tooltip);

        // make hover-state match existing buttons
        var hoverClass = "T-I-JW";
        button.mouseover(function() { this.classList.add(hoverClass); });
        button.mouseout(function() { this.classList.remove(hoverClass); });

        var div = $(document.createElement("div"));
        var divClass = "wtScjd J-J5-Ji aYr";
        if (customCssClass) {
            divClass += " " + customCssClass;
        }
        div.attr("class", divClass);
        if (contentHtml) {
            div.html(contentHtml);
        }

        button.append(div);
        button.click(onClickFunction);
        attachment.$el.find("div.aQw").append(button);

        return button;
    };

    api.tools.remove_modal_window = function() {
        $("#gmailJsModalBackground").remove();
        $("#gmailJsModalWindow").remove();
    };

    api.tools.add_modal_window = function(title, content_html, onClickOk, onClickCancel, onClickClose) {
        // By default, clicking on cancel or close should clean up the modal window
        onClickClose = onClickClose || api.tools.remove_modal_window;
        onClickCancel = onClickCancel || api.tools.remove_modal_window;

        var background = $(document.createElement("div"));
        background.attr("id","gmailJsModalBackground");
        background.attr("class","Kj-JD-Jh");
        background.attr("aria-hidden","true");
        background.attr("style","opacity:0.75;width:100%;height:100%;");

        // Modal window wrapper
        var container = $(document.createElement("div"));
        container.attr("id","gmailJsModalWindow");
        container.attr("class", "Kj-JD");
        container.attr("tabindex", "0");
        container.attr("role", "alertdialog");
        container.attr("aria-labelledby", "gmailJsModalWindowTitle");
        container.attr("style", "left:50%;top:50%;opacity:1;");

        // Modal window header contents
        var header = $(document.createElement("div"));
        header.attr("class", "Kj-JD-K7 Kj-JD-K7-GIHV4");

        var heading = $(document.createElement("span"));
        heading.attr("id", "gmailJsModalWindowTitle");
        heading.attr("class", "Kj-JD-K7-K0");
        heading.attr("role", "heading");
        heading.html(title);

        var closeButton = $(document.createElement("span"));
        closeButton.attr("id", "gmailJsModalWindowClose");
        closeButton.attr("class", "Kj-JD-K7-Jq");
        closeButton.attr("role", "button");
        closeButton.attr("tabindex", "0");
        closeButton.attr("aria-label", "Close");
        closeButton.click(onClickClose);

        header.append(heading);
        header.append(closeButton);

        // Modal window contents
        var contents = $(document.createElement("div"));
        contents.attr("id", "gmailJsModalWindowContent");
        contents.attr("class", "Kj-JD-Jz");
        contents.html(content_html);

        // Modal window controls
        var controls = $(document.createElement("div"));
        controls.attr("class", "Kj-JD-Jl");

        var okButton = $(document.createElement("button"));
        okButton.attr("id", "gmailJsModalWindowOk");
        okButton.attr("class", "J-at1-auR J-at1-atl");
        okButton.attr("name", "ok");
        okButton.text("OK");
        okButton.click(onClickOk);

        var cancelButton = $(document.createElement("button"));
        cancelButton.attr("id", "gmailJsModalWindowCancel");
        cancelButton.attr("name", "cancel");
        cancelButton.text("Cancel");
        cancelButton.click(onClickCancel);

        controls.append(okButton);
        controls.append(cancelButton);

        container.append(header);
        container.append(contents);
        container.append(controls);

        $(document.body).append(background);
        $(document.body).append(container);

        var center = function() {
            container.css({
                top: ($(window).height() - container.outerHeight()) / 2,
                left: ($(window).width() - container.outerWidth()) / 2
            });
        };

        center();

        container.bind("DOMSubtreeModified", center);
        $(window).resize(center);
    };

    api.tools.toggle_minimize = function (){
        //The minimize button
        var minimizeButton = $("[alt='Minimize']")[0];

        if(minimizeButton) {
            api.helper.trigger_mouse_click(minimizeButton);

            return true;
        }
        return false;
    };

    api.chat.is_hangouts = function() {
        if(api.tracker.hangouts !== undefined) {
            return api.tracker.hangouts;
        }

        // Returns true if the user is using hangouts instead of the classic chat
        var dwClasses = $(".dw");
        if(dwClasses.length > 1) {
            throw "Figuring out is hangouts - more than one dw classes found";
        }
        if(dwClasses.length === 0) {
            throw "Figuring out is hangouts - no dw classes found";
        }

        var dw = dwClasses[0];

        var chatWindows = $(".nH.aJl.nn", dw);
        if(chatWindows.length > 0) {
            // hangouts
            api.tracker.hangouts = true;
            return true;
        }

        chatWindows = $(".nH.nn", dw);

        if(chatWindows.length > 2) {
            // classic
            api.tracker.hangouts = false;
            return false;
        }
        return undefined;
    };

    // retrieve queue of compose window dom objects
    // latest compose at the start of the queue (index 0)
    api.dom.composes = function() {
        var objs = [];
        $("div.M9").each(function(idx, el) {
            objs.push( new api.dom.compose(el));
        });
        return objs;
    };

    /**
       A compose object. Represents a compose window in the DOM and provides a bunch of methods and properties to access & interact with the window
       Expects a jQuery DOM element for the compose div
    */
    api.dom.compose = function(element) {
        if (this.constructor !== api.dom.compose) {
            // if not invoked through new(), nothing works as expected!
            return new api.dom.compose(element);
        }

        element = $(element);
        if(!element || (!element.hasClass("M9") && !element.hasClass("AD"))) api.tools.error("api.dom.compose called with invalid element");
        this.$el = element;
        return this;
    };

    extend(api.dom.compose.prototype, {
        /**
           Retrieve the compose id
        */
        id: function() {
            return this.dom("id").val();
        },

        /**
           Retrieve the draft email id
        */
        email_id: function() {
            return this.dom("draft").val();
        },

        /**
           Is this compose instance inline (as with reply & forwards) or a popup (as with a new compose)
        */
        is_inline: function() {
            return this.$el.closest("td.Bu").length > 0;
        },

        /**
           Retrieves to, cc, bcc and returns them in a hash of arrays
           Parameters:
           options.type  string  to, cc, or bcc to check a specific one
           options.flat  boolean if true will just return an array of all recipients instead of splitting out into to, cc, and bcc
        */
        recipients: function(options) {
            if( typeof options !== "object" ) options = {};
            var name_selector = options.type ? "[name=" + options.type + "]" : "";

            // determine an array of all emails specified for To, CC and BCC and extract addresses into an object for the callback
            var recipients = options.flat ? [] : {};
            this.$el.find(".GS input[type=hidden]"+name_selector).each(function(idx, recipient ){
                if(options.flat) {
                    recipients.push(recipient.value);
                } else {
                    if(!recipients[recipient.name]) recipients[recipient.name] = [];
                    recipients[recipient.name].push(recipient.value);
                }
            });
            return recipients;
        },

        /**
           Retrieve the current "to" recipients
        */
        to: function(to) {
            return this.dom("to").val(to);
        },

        /**
           Retrieve the current "cc" recipients
        */
        cc: function(cc) {
            return this.dom("cc").val(cc);
        },

        /**
           Retrieve the current "bcc" recipients
        */
        bcc: function(bcc) {
            return this.dom("bcc").val(bcc);
        },

        /**
           Get/Set the current subject
           Parameters:
           subject   string  set as new subject
        */
        subject: function(subject) {
            if(subject) this.dom("all_subjects").val(subject);
            subject = this.dom("subjectbox").val();
            return subject ? subject : this.dom("subject").val();
        },

        /**
           Get the from email
           if user only has one email account they can send from, returns that email address
        */
        from: function() {
            var el = this.dom("from");
            if (el.length) {
                var fromNameAndEmail = el.val();
                if (fromNameAndEmail) {
                    return api.tools.extract_email_address(fromNameAndEmail);
                }
            }
            return api.get.user_email();
        },

        /**
           Get/Set the email body
        */
        body: function(body) {
            var el = this.dom("body");
            if(body) el.html(body);
            return el.html();
        },

        /**
          Triggers the same action as clicking the "send" button would do.
          */
        send: function() {
            return this.dom("send_button").click();
        },

        /**
           Map find through to jquery element
        */
        find: function(selector) {
            return this.$el.find(selector);
        },

        /**
           Retrieve preconfigured dom elements for this compose window
        */
        dom: function(lookup) {
            if (!lookup) return this.$el;
            var config = {
                to:"textarea[name=to]",
                cc:"textarea[name=cc]",
                bcc:"textarea[name=bcc]",
                id: "input[name=composeid]",
                draft: "input[name=draft]",
                subject: "input[name=subject]",
                subjectbox: "input[name=subjectbox]",
                all_subjects: "input[name=subjectbox], input[name=subject]",
                body: "div[contenteditable=true]",
                reply: "M9",
                forward: "M9",
                from: "input[name=from]",
                send_button: "div.T-I.T-I-atl"
            };
            if(!config[lookup]) api.tools.error("Dom lookup failed. Unable to find config for \"" + lookup + "\"",config,lookup,config[lookup]);
            return this.$el.find(config[lookup]);
        }

    });

    /**
       An object for interacting with an email currently present in the DOM. Represents an individual email message within a thread
       Provides a number of methods and properties to access & interact with it
       Expects a jQuery DOM element for the email div (div.adn as returned by the "view_email" observer), or an email_id
    */
    api.dom.email = function(element) {
        if (this.constructor !== api.dom.email) {
            // if not invoked through new(), nothing works as expected!
            return new api.dom.email(element);
        }

        if (typeof element === "string") {
            this.id = element;
            var message_class_id = "m" + this.id;
            this.id_element = $("div.ii.gt div.a3s.aXjCH." + message_class_id);
            element = this.id_element.closest("div.adn");
        } else {
            element = $(element);
        }
        if (!element || (!element.hasClass("adn"))) api.tools.error("api.dom.email called with invalid element/id");

        // if no id specified, extract from the body wrapper class (starts with "m" followed by the id)
        if (!this.id) {
            this.id_element = element.find("div.ii.gt div.a3s.aXjCH");
            var classValue = this.id_element.attr("class");
            if (classValue !== null) {
                var matches = classValue.match(/(^|\s)m([\S]*)/);
                if (matches !== null) {
                    this.id = matches.pop();
                }
            }
        }
        this.$el = element;
        return this;
    };

    extend(api.dom.email.prototype, {

        /**
           Get/Set the full email body as it sits in the DOM
           If you want the actual DOM element use .dom("body");
           Note: This gets & sets the body html after it has been parsed & marked up by GMAIL. To retrieve it as it exists in the email message source, use a call to .data();
        */
        body: function(body) {
            var el = this.dom("body");
            if (body) {
                el.html(body);
            }
            return el.html();
        },

        /**
           Get/Set the sender
           Optionally receives email and name properties. If received updates the values in the DOM
           Returns an object containing email & name of the sender and dom element
        */
        from: function(email, name) {
            var el = this.dom("from");
            if (email) {
                el.attr("email",email);
            }
            if (name) {
                el.attr("name",name);
                el.html(name);
            }
            return {
                email: el.attr("email"),
                name: el.attr("name"),
                el: el
            };
        },

        /**
           Get/Set who the email is showing as To
           Optionally receives an object containing email and/or name properties. If received updates the values in the DOM.
           Optionally receives an array of these objects if multiple recipients
           Returns an array of objects containing email & name of who is showing in the DOM as the email is to
        */
        to: function(to_array) {

            // if update data has been passeed, loop through & create a new to_wrapper contents
            if (to_array) {
                if (!$.isArray(to_array)) {
                    to_array = [to_array];
                }
                var html = [];
                $.each(to_array, function(index, obj) {
                    html.push( $("<span />").attr({
                        dir: "ltr",
                        email: obj.email,
                        name: obj.name
                    }).addClass("g2").html(obj.name).wrap("<p/>").parent().html());
                });
                this.dom("to_wrapper").html("to " + html.join(", "));
            }


            // loop through any matching to elements & prepare for output
            var out = [];

            this.dom("to").each(function() {
                var el = $(this);
                out.push({
                    email:  el.attr("email"),
                    name: el.attr("name"),
                    el: el
                });
            });
            return out;
        },

        /**
           Retries the DOM elements which represents the emails attachments.
           Returns undefined if UI-elements are not yet ready for parsing.
        */
        attachments: function() {
            var out = [];
            var failed = false;

            this.dom("attachments").each(function() {
                var el = $(this);

                var result = {};
                result.$el = el;
                result.name = el.find(".aV3").html();
                result.size = el.find(".SaH2Ve").html();

                // Gmail only emits the following attribute for Chrome!
                // use email_data.threads[].attachments_details in other browsers!
                var url = el.attr("download_url");
                if (url) {
                    var url_type = api.tools.parse_attachment_url(url);
                    result.url = url_type.url;
                    result.type = url_type.type;
                }

                out.push(result);
            });

            if (failed) {
                return undefined;
            } else {
                return out;
            }
        },

        /**
           Retrieve relevant email from the Gmail servers for this email
           Makes use of the gmail.get.email_data() method
           Returns an object
        */
        data: function() {
            if (typeof api.dom.email_cache !== "object") {
                api.dom.email_cache = {};
            }
            if (!api.dom.email_cache[this.id]) {

                // retrieve & cache the data for this whole thread of emails
                var data = api.get.email_data(this.id);
                $.each(data.threads, function(email_id, email_data) {
                    api.dom.email_cache[email_id] = email_data;
                });
            }
            return api.dom.email_cache[this.id];
        },

        /**
           Retrieve email source for this email from the Gmail servers
           Makes use of the gmail.get.email_source() method
           Returns string of email raw source
        */
        source: function() {
            return api.get.email_source(this.id);
        },

        /**
           Retrieve preconfigured dom elements for this email
        */
        dom: function(lookup) {
            if (!lookup) return this.$el;
            var config = {
                body: "div.a3s",
                from: "span[email].gD",
                to: "span[email].g2",
                to_wrapper: "span.hb",
                timestamp: "span.g3",
                star: "div.zd",
                attachments: "div.hq.gt div.aQH span.aZo",

                // buttons
                reply_button: "div[role=button].aaq",
                menu_button: "div[role=button].aap",
                details_button: "div[role=button].ajz"
            };
            if(!config[lookup]) api.tools.error("Dom lookup failed. Unable to find config for \"" + lookup + "\"");
            return this.$el.find(config[lookup]);
        }

    });

    /**
       An object for interacting with an email currently present in the DOM. Represents a conversation thread
       Provides a number of methods and properties to access & interact with it
       Expects a jQuery DOM element for the thread wrapper div (div.if as returned by the "view_thread" observer)
    */
    api.dom.thread = function(element) {
        if (this.constructor !== api.dom.thread) {
            // if not invoked through new(), nothing works as expected!
            return new api.dom.thread(element);
        }

        if (!element || (!element.hasClass("if"))) api.tools.error("api.dom.thread called with invalid element/id");
        this.$el = element;
        return this;
    };

    extend(api.dom.thread.prototype, {

        /**
           Retrieve preconfigured dom elements for this email
        */
        dom: function(lookup) {
            if (!lookup) return this.$el;
            var config = {
                opened_email: "div.adn",
                subject: "h2.hP",
                labels: "div.hN"
            };
            if(!config[lookup]) api.tools.error("Dom lookup failed. Unable to find config for \"" + lookup + "\"");
            return this.$el.find(config[lookup]);
        }

    });

    /**
     *  Show a compose window
     * @returns {boolean}
     */
    api.compose.start_compose = function() {

        //The compose button
        var composeEl = $(".T-I.J-J5-Ji.T-I-KE.L3")[0];

        if(composeEl) {
            api.helper.trigger_mouse_click(composeEl);

            return true;
        }
        return false;
    };

    return api;
};

function initializeOnce(fn) {
    var result;
    return function() {
        if (fn) {
            result = fn.apply(this, arguments);
        }
        fn = null;
        return result;
    };
}

// required to avoid error in NodeJS.
var GmailClass = initializeOnce(Gmail_);
if (typeof(window) !== "undefined" && !window.Gmail) {
    window.Gmail = GmailClass;
}

// make class accessible to require()-users.
if (typeof(exports) !== "undefined") {
    exports.Gmail = GmailClass;
}