cryptpad/www/common/cryptpad-common.js

define([
    '/api/config',
    '/customize/messages.js?app=' + window.location.pathname.split('/').filter(function (x) { return x; }).join('.'),
    '/common/fsStore.js',
    '/common/common-util.js',

    '/bower_components/chainpad-crypto/crypto.js?v=0.1.5',
    '/bower_components/alertifyjs/dist/js/alertify.js',
    '/common/clipboard.js',
    '/common/pinpad.js', /* TODO
load pinpad dynamically only after you know that it will be needed */
    '/customize/application_config.js',

    '/bower_components/jquery/dist/jquery.min.js',
], function (Config, Messages, Store, Util, Crypto, Alertify, Clipboard, Pinpad, AppConfig) {
/*  This file exposes functionality which is specific to Cryptpad, but not to
    any particular pad type. This includes functions for committing metadata
    about pads to your local storage for future use and improved usability.

    Additionally, there is some basic functionality for import/export.
*/
    var $ = window.jQuery;

    var common = window.Cryptpad = {
        Messages: Messages,
        Alertify: Alertify,
        Clipboard: Clipboard
    };

    var store;

    var PINNING_ENABLED = AppConfig.enablePinning;
    var rpc;

    var find = common.find = Util.find;
    var fixHTML = common.fixHTML = Util.fixHTML;
    var hexToBase64 = common.hexToBase64 = Util.hexToBase64;
    var base64ToHex = common.base64ToHex = Util.base64ToHex;
    var deduplicateString = common.deduplicateString = Util.deduplicateString;
    var uint8ArrayToHex = common.uint8ArrayToHex = Util.uint8ArrayToHex;
    var replaceHash = common.replaceHash = Util.replaceHash;
    var getHash = common.getHash = Util.getHash;
    var fixFileName = common.fixFileName = Util.fixFileName;

    var getStore = common.getStore = function () {
        if (store) { return store; }
        throw new Error("Store is not ready!");
    };
    var getProxy = common.getProxy = function () {
        if (store && store.getProxy()) {
            return store.getProxy().proxy;
        }
    };
    var getNetwork = common.getNetwork = function () {
        if (store) {
            if (store.getProxy() && store.getProxy().info) {
                return store.getProxy().info.network;
            }
        }
        return;
    };

    var getUid = common.getUid = function () {
        if (store) {
            if (store.getProxy() && store.getProxy().proxy) {
                return store.getProxy().proxy.uid;
            }
        }
    };

    var getRealtime = common.getRealtime = function () {
        if (store) {
            if (store.getProxy() && store.getProxy().info) {
                return store.getProxy().info.realtime;
            }
        }
        return;
    };

    common.feedback = function (action) {
        if (!action) { return; }
        try {
            if (!getStore().getProxy().proxy.allowUserFeedback) { return; }
        } catch (e) { return void console.error(e); }
        $.ajax({
            type: "HEAD",
            url: '/common/feedback.html?' + action + '=' + (+new Date()),
        });
    };

    var whenRealtimeSyncs = common.whenRealtimeSyncs = function (realtime, cb) {
        realtime.sync();
        window.setTimeout(function () {
            if (realtime.getAuthDoc() === realtime.getUserDoc()) {
                return void cb();
            }
            realtime.onSettle(function () {
                cb();
            });
        }, 0);
    };

    var getWebsocketURL = common.getWebsocketURL = function () {
        if (!Config.websocketPath) { return Config.websocketURL; }
        var path = Config.websocketPath;
        if (/^ws{1,2}:\/\//.test(path)) { return path; }

        var protocol = window.location.protocol.replace(/http/, 'ws');
        var host = window.location.host;
        var url = protocol + '//' + host + path;

        return url;
    };

    var userHashKey = common.userHashKey = 'User_hash';
    var userNameKey = common.userNameKey = 'User_name';
    var fileHashKey = common.fileHashKey = 'FS_hash';
    var displayNameKey = common.displayNameKey = 'cryptpad.username';

    var login = common.login = function (hash, name, cb) {
        if (!hash) { throw new Error('expected a user hash'); }
        if (!name) { throw new Error('expected a user name'); }
        localStorage.setItem(userHashKey, hash);
        localStorage.setItem(userNameKey, name);
        if (cb) { cb(); }
    };

    var eraseTempSessionValues = common.eraseTempSessionValues = function () {
        // delete sessionStorage values that might have been left over
        // from the main page's /user redirect
        [
            'login',
            'login_user',
            'login_pass',
            'login_rmb',
            'register'
        ].forEach(function (k) {
            delete sessionStorage[k];
        });
    };

    var logoutHandlers = [];
    var logout = common.logout = function (cb) {
        [
            userNameKey,
            userHashKey,
        ].forEach(function (k) {
            sessionStorage.removeItem(k);
            localStorage.removeItem(k);
            delete localStorage[k];
            delete sessionStorage[k];
        });
        // Make sure we have an FS_hash in localStorage before reloading all the tabs
        // so that we don't end up with tabs using different anon hashes
        if (!localStorage[fileHashKey]) {
            localStorage[fileHashKey] = common.createRandomHash();
        }
        eraseTempSessionValues();

        logoutHandlers.forEach(function (h) {
            if (typeof (h) === "function") { h(); }
        });

        if (cb) { cb(); }
    };
    var onLogout = common.onLogout = function (h) {
        if (typeof (h) !== "function") { return; }
        if (logoutHandlers.indexOf(h) !== -1) { return; }
        logoutHandlers.push(h);
    };

    var getUserHash = common.getUserHash = function () {
        var hash;
        [sessionStorage, localStorage].some(function (s) {
            var h = s[userHashKey];
            if (h) { return (hash = h); }
        });

        return hash;
    };

    var isLoggedIn = common.isLoggedIn = function () {
        return typeof getUserHash() === "string";
    };

    var isArray = common.isArray = $.isArray;

    var truncate = common.truncate = function (text, len) {
        if (typeof(text) === 'string' && text.length > len) {
            return text.slice(0, len) + '…';
        }
        return text;
    };

    var parseHash = common.parseHash = function (hash) {
        var parsed = {};
        if (hash.slice(0,1) !== '/' && hash.length >= 56) {
            // Old hash
            parsed.channel = hash.slice(0, 32);
            parsed.key = hash.slice(32);
            parsed.version = 0;
            return parsed;
        }
        var hashArr = hash.split('/');
        if (hashArr[1] && hashArr[1] === '1') {
            parsed.version = 1;
            parsed.mode = hashArr[2];
            parsed.channel = hashArr[3];
            parsed.key = hashArr[4];
            parsed.present = hashArr[5] && hashArr[5] === 'present';
            return parsed;
        }
        return;
    };
    var getEditHashFromKeys = common.getEditHashFromKeys = function (chanKey, keys) {
        if (typeof keys === 'string') {
            return chanKey + keys;
        }
        if (!keys.editKeyStr) { return; }
        return '/1/edit/' + hexToBase64(chanKey) + '/' + Crypto.b64RemoveSlashes(keys.editKeyStr);
    };
    var getViewHashFromKeys = common.getViewHashFromKeys = function (chanKey, keys) {
        if (typeof keys === 'string') {
            return;
        }
        return '/1/view/' + hexToBase64(chanKey) + '/' + Crypto.b64RemoveSlashes(keys.viewKeyStr);
    };

    var specialHashes = common.specialHashes = ['iframe'];

    /*
     * Returns all needed keys for a realtime channel
     * - no argument: use the URL hash or create one if it doesn't exist
     * - secretHash provided: use secretHash to find the keys
     */
    var getSecrets = common.getSecrets = function (secretHash) {
        var secret = {};
        var generate = function () {
            secret.keys = Crypto.createEditCryptor();
            secret.key = Crypto.createEditCryptor().editKeyStr;
        };
        if (!secretHash && !/#/.test(window.location.href)) {
            generate();
            return secret;
        } else {
            var hash = secretHash || window.location.hash.slice(1);
            if (hash.length === 0 || specialHashes.indexOf(hash) !== -1) {
                generate();
                return secret;
            }
            // old hash system : #{hexChanKey}{cryptKey}
            // new hash system : #/{hashVersion}/{b64ChanKey}/{cryptKey}
            if (hash.slice(0,1) !== '/' && hash.length >= 56) {
                // Old hash
                secret.channel = hash.slice(0, 32);
                secret.key = hash.slice(32);
            }
            else {
                // New hash
                var hashArray = hash.split('/');
                if (hashArray.length < 4) {
                    common.alert("Unable to parse the key");
                    throw new Error("Unable to parse the key");
                }
                var version = hashArray[1];
                if (version === "1") {
                    var mode = hashArray[2];
                    if (mode === 'edit') {
                        secret.channel = base64ToHex(hashArray[3]);
                        var keys = Crypto.createEditCryptor(hashArray[4].replace(/-/g, '/'));
                        secret.keys = keys;
                        secret.key = keys.editKeyStr;
                        if (secret.channel.length !== 32 || secret.key.length !== 24) {
                            common.alert("The channel key and/or the encryption key is invalid");
                            throw new Error("The channel key and/or the encryption key is invalid");
                        }
                    }
                    else if (mode === 'view') {
                        secret.channel = base64ToHex(hashArray[3]);
                        secret.keys = Crypto.createViewCryptor(hashArray[4].replace(/-/g, '/'));
                        if (secret.channel.length !== 32) {
                            common.alert("The channel key is invalid");
                            throw new Error("The channel key is invalid");
                        }
                    }
                }
            }
        }
        return secret;
    };

    var getHashes = common.getHashes = function (channel, secret) {
        var hashes = {};
        if (secret.keys.editKeyStr) {
            hashes.editHash = getEditHashFromKeys(channel, secret.keys);
        }
        if (secret.keys.viewKeyStr) {
            hashes.viewHash = getViewHashFromKeys(channel, secret.keys);
        }
        return hashes;
    };

    var createChannelId = common.createChannelId = function () {
        var id = uint8ArrayToHex(Crypto.Nacl.randomBytes(16));
        if (id.length !== 32 || /[^a-f0-9]/.test(id)) {
            throw new Error('channel ids must consist of 32 hex characters');
        }
        return id;
    };

    var createRandomHash = common.createRandomHash = function () {
        // 16 byte channel Id
        var channelId = hexToBase64(createChannelId());
        // 18 byte encryption key
        var key = Crypto.b64RemoveSlashes(Crypto.rand64(18));
        return '/1/edit/' + [channelId, key].join('/');
    };

    var storageKey = common.storageKey = 'CryptPad_RECENTPADS';

    /*
     *  localStorage formatting
     */
    /*
        the first time this gets called, your local storage will migrate to a
        new format. No more indices for values, everything is named now.

        * href
        * atime (access time)
        * title
        * ??? // what else can we put in here?
    */
    var checkObjectData = function (pad) {
        if (!pad.ctime) { pad.ctime = pad.atime; }
        if (/^https*:\/\//.test(pad.href)) {
            pad.href = common.getRelativeHref(pad.href);
        }
        var parsed = common.parsePadUrl(pad.href);
        if (!parsed || !parsed.hash) { return; }
        if (!pad.title) {
            pad.title = common.getDefaultname(parsed);
        }
        return parsed.hash;
    };
    // Migrate from legacy store (localStorage)
    var migrateRecentPads = common.migrateRecentPads = function (pads) {
        return pads.map(function (pad) {
            var hash;
            if (isArray(pad)) {
                var href = pad[0];
                href.replace(/\#(.*)$/, function (a, h) {
                    hash = h;
                });

                return {
                    href: pad[0],
                    atime: pad[1],
                    title: pad[2] || hash && hash.slice(0,8),
                    ctime: pad[1],
                };
            } else if (pad && typeof(pad) === 'object') {
                hash = checkObjectData(pad);
                if (!hash || !common.parseHash(hash)) { return; }
                return pad;
            } else {
                console.error("[Cryptpad.migrateRecentPads] pad had unexpected value");
                console.log(pad);
                return;
            }
        }).filter(function (x) { return x; });
    };
    // Remove everything from RecentPads that is not an object and check the objects
    var checkRecentPads = common.checkRecentPads = function (pads) {
        pads.forEach(function (pad, i) {
            if (pad && typeof(pad) === 'object') {
                var hash = checkObjectData(pad);
                if (!hash || !common.parseHash(hash)) { return; }
                return pad;
            }
            console.error("[Cryptpad.migrateRecentPads] pad had unexpected value");
            getStore().removeData(i);
        });
    };

    // Get the pads from localStorage to migrate them to the object store
    var getLegacyPads = common.getLegacyPads = function (cb) {
        require(['/customize/store.js'], function(Legacy) {
            Legacy.ready(function (err, legacy) {
                if (err) { cb(err, null); return; }
                legacy.get(storageKey, function (err2, recentPads) {
                    if (err2) { cb(err2, null); return; }
                    if (isArray(recentPads)) {
                        cb(void 0, migrateRecentPads(recentPads));
                        return;
                    }
                    cb(void 0, []);
                });
            });
        });
    };

    var getRelativeHref = common.getRelativeHref = function (href) {
        if (!href) { return; }
        if (href.indexOf('#') === -1) { return; }
        var parsed = common.parsePadUrl(href);
        return '/' + parsed.type + '/#' + parsed.hash;
    };

    var parsePadUrl = common.parsePadUrl = function (href) {
        var patt = /^https*:\/\/([^\/]*)\/(.*?)\//i;

        var ret = {};

        if (!href) { return ret; }

        if (!/^https*:\/\//.test(href)) {
            var idx = href.indexOf('/#');
            ret.type = href.slice(1, idx);
            ret.hash = href.slice(idx + 2);
            return ret;
        }

        var hash = href.replace(patt, function (a, domain, type, hash) {
            ret.domain = domain;
            ret.type = type;
            return '';
        });
        ret.hash = hash.replace(/#/g, '');
        return ret;
    };

    var isNameAvailable = function (title, parsed, pads) {
        return !pads.some(function (pad) {
            // another pad is already using that title
            if (pad.title === title) {
                return true;
            }
        });
    };

    // Create untitled documents when no name is given
    var getDefaultName = common.getDefaultName = function (parsed) {
        var type = parsed.type;
        var untitledIndex = 1;
        var name = (Messages.type)[type] + ' - ' + new Date().toString().split(' ').slice(0,4).join(' ');
        return name;
    };
    var isDefaultName = common.isDefaultName = function (parsed, title) {
        var name = getDefaultName(parsed);
        return title === name;
    };

    var makePad = function (href, title) {
        var now = +new Date();
        return {
            href: href,
            atime: now,
            ctime: now,
            title: title || window.location.hash.slice(1, 9),
        };
    };

    /* Sort pads according to how recently they were accessed */
    var mostRecent = common.mostRecent = function (a, b) {
        return new Date(b.atime).getTime() - new Date(a.atime).getTime();
    };

    // STORAGE
    var setPadAttribute = common.setPadAttribute = function (attr, value, cb) {
        getStore().setDrive([getHash(), attr].join('.'), value, function (err, data) {
            cb(err, data);
        });
    };
    var setAttribute = common.setAttribute = function (attr, value, cb) {
        getStore().set(["cryptpad", attr].join('.'), value, function (err, data) {
            cb(err, data);
        });
    };
    var setLSAttribute = common.setLSAttribute = function (attr, value) {
        localStorage[attr] = value;
    };

    // STORAGE
    var getPadAttribute = common.getPadAttribute = function (attr, cb) {
        getStore().getDrive([getHash(), attr].join('.'), function (err, data) {
            cb(err, data);
        });
    };
    var getAttribute = common.getAttribute = function (attr, cb) {
        getStore().get(["cryptpad", attr].join('.'), function (err, data) {
            cb(err, data);
        });
    };
    var getLSAttribute = common.getLSAttribute = function (attr) {
        return localStorage[attr];
    };

    // STORAGE - TEMPLATES
    var listTemplates = common.listTemplates = function (type) {
        var allTemplates = getStore().listTemplates();
        if (!type) { return allTemplates; }

        var templates = allTemplates.filter(function (f) {
            var parsed = parsePadUrl(f.href);
            return parsed.type === type;
        });
        return templates;
    };
    var addTemplate = common.addTemplate = function (data) {
        getStore().pushData(data);
        getStore().addPad(data.href, ['template']);
    };

    var isTemplate = common.isTemplate = function (href) {
        var rhref = getRelativeHref(href);
        var templates = listTemplates();
        return templates.some(function (t) {
            return t.href === rhref;
        });
    };
    var selectTemplate = common.selectTemplate = function (type, rt, Crypt) {
        if (!AppConfig.enableTemplates) { return; }
        var temps = listTemplates(type);
        if (temps.length === 0) { return; }
        var $content = $('<div>');
        $('<b>').text(Messages.selectTemplate).appendTo($content);
        $('<p>', {id:"selectTemplate"}).appendTo($content);
        common.alert($content.html(), null, true);
        var $p = $('#selectTemplate');
        temps.forEach(function (t, i) {
            $('<a>', {href: t.href, title: t.title}).text(t.title).click(function (e) {
                e.preventDefault();
                var parsed = parsePadUrl(t.href);
                if(!parsed) { throw new Error("Cannot get template hash"); }
                common.addLoadingScreen(null, true);
                Crypt.get(parsed.hash, function (err, val) {
                    if (err) { throw new Error(err); }
                    var p = parsePadUrl(window.location.href);
                    Crypt.put(p.hash, val, function (e) {
                        common.findOKButton().click();
                        common.removeLoadingScreen();
                    });
                });
            }).appendTo($p);
            if (i !== temps.length) { $('<br>').appendTo($p); }
        });
        common.findOKButton().text(Messages.cancelButton);
    };

    // STORAGE
    /* fetch and migrate your pad history from the store */
    var getRecentPads = common.getRecentPads = function (cb) {
        getStore().getDrive(storageKey, function (err, recentPads) {
            if (isArray(recentPads)) {
                checkRecentPads(recentPads);
                cb(void 0, recentPads);
                return;
            }
            cb(void 0, []);
        });
    };

    // STORAGE: Display Name
    var getLastName = common.getLastName = function (cb) {
        common.getAttribute('username', function (err, userName) {
            cb(err, userName);
        });
    };
    var _onDisplayNameChanged = [];
    var onDisplayNameChanged = common.onDisplayNameChanged = function (h) {
        if (typeof(h) !== "function") { return; }
        if (_onDisplayNameChanged.indexOf(h) !== -1) { return; }
        _onDisplayNameChanged.push(h);
    };
    var changeDisplayName = common.changeDisplayName = function (newName) {
        _onDisplayNameChanged.forEach(function (h) {
            h(newName);
        });
    };

    // STORAGE
    var forgetPad = common.forgetPad = function (href, cb) {
        var parsed = parsePadUrl(href);

        var callback = function (err, data) {
            if (err) {
                cb(err);
                return;
            }

            getStore().keys(function (err, keys) {
                if (err) {
                    cb(err);
                    return;
                }
                var toRemove = keys.filter(function (k) {
                    return k.indexOf(parsed.hash) === 0;
                });

                if (!toRemove.length) {
                    cb();
                    return;
                }
                getStore().removeBatch(toRemove, function (err, data) {
                    cb(err, data);
                });
            });
        };

        if (typeof(getStore().forgetPad) === "function") {
            getStore().forgetPad(common.getRelativeHref(href), callback);
        }
    };

    // STORAGE
    var findWeaker = common.findWeaker = function (href, recents) {
        var rHref = href || getRelativeHref(window.location.href);
        var parsed = parsePadUrl(rHref);
        if (!parsed.hash) { return false; }
        var weaker;
        recents.some(function (pad) {
            var p = parsePadUrl(pad.href);
            if (p.type !== parsed.type) { return; } // Not the same type
            if (p.hash === parsed.hash) { return; } // Same hash, not stronger
            var pHash = parseHash(p.hash);
            var parsedHash = parseHash(parsed.hash);
            if (!parsedHash || !pHash) { return; }
            if (pHash.version !== parsedHash.version) { return; }
            if (pHash.channel !== parsedHash.channel) { return; }
            if (pHash.mode === 'view' && parsedHash.mode === 'edit') {
                weaker = pad.href;
                return true;
            }
            return;
        });
        return weaker;
    };
    var findStronger = common.findStronger = function (href, recents) {
        var rHref = href || getRelativeHref(window.location.href);
        var parsed = parsePadUrl(rHref);
        if (!parsed.hash) { return false; }
        var stronger;
        recents.some(function (pad) {
            var p = parsePadUrl(pad.href);
            if (p.type !== parsed.type) { return; } // Not the same type
            if (p.hash === parsed.hash) { return; } // Same hash, not stronger
            var pHash = parseHash(p.hash);
            var parsedHash = parseHash(parsed.hash);
            if (!parsedHash || !pHash) { return; }
            if (pHash.version !== parsedHash.version) { return; }
            if (pHash.channel !== parsedHash.channel) { return; }
            if (pHash.mode === 'edit' && parsedHash.mode === 'view') {
                stronger = pad.href;
                return true;
            }
            return;
        });
        return stronger;
    };
    var isNotStrongestStored = common.isNotStrongestStored = function (href, recents) {
        return findStronger(href, recents);
    };

    // TODO integrate pinning
    var setPadTitle = common.setPadTitle = function (name, cb) {
        var href = window.location.href;
        var parsed = parsePadUrl(href);
        href = getRelativeHref(href);
        // getRecentPads return the array from the drive, not a copy
        // We don't have to call "set..." at the end, everything is stored with listmap
        getRecentPads(function (err, recent) {
            if (err) {
                cb(err);
                return;
            }

            var updateWeaker = [];
            var contains;
            var renamed = recent.map(function (pad) {
                var p = parsePadUrl(pad.href);

                if (p.type !== parsed.type) { return pad; }

                var shouldUpdate = p.hash === parsed.hash;

                // Version 1 : we have up to 4 differents hash for 1 pad, keep the strongest :
                // Edit > Edit (present) > View > View (present)
                var pHash = parseHash(p.hash);
                var parsedHash = parseHash(parsed.hash);

                if (!pHash) { return; } // We may have a corrupted pad in our storage, abort here in that case

                if (!shouldUpdate && pHash.version === 1 && parsedHash.version === 1 && pHash.channel === parsedHash.channel) {
                    if (pHash.mode === 'view' && parsedHash.mode === 'edit') { shouldUpdate = true; }
                    else if (pHash.mode === parsedHash.mode && pHash.present) { shouldUpdate = true; }
                    else {
                        // Editing a "weaker" version of a stored hash : update the date and do not push the current hash
                        pad.atime = +new Date();
                        contains = true;
                        return pad;
                    }
                }

                if (shouldUpdate) {
                    contains = true;
                    // update the atime
                    pad.atime = +new Date();

                    // set the name
                    pad.title = name;

                    // If we now have a stronger version of a stored href, replace the weaker one by the strong one
                    if (pad && pad.href && href !== pad.href) {
                        updateWeaker.push({
                            o: pad.href,
                            n: href
                        });
                    }
                    pad.href = href;
                }
                return pad;
            });

            if (!contains) {
                var data = makePad(href, name);
                getStore().pushData(data);
                getStore().addPad(href, common.initialPath, common.initialName || name);
            }
            if (updateWeaker.length > 0) {
                updateWeaker.forEach(function (obj) {
                    getStore().replaceHref(obj.o, obj.n);
                });
            }
            cb(err, recent);
        });
    };

    // STORAGE
    var getPadTitle = common.getPadTitle = function (cb) {
        var href = window.location.href;
        var parsed = parsePadUrl(window.location.href);
        var hashSlice = window.location.hash.slice(1,9);
        var title = '';

        getRecentPads(function (err, pads) {
            if (err) {
                cb(err);
                return;
            }
            pads.some(function (pad) {
                var p = parsePadUrl(pad.href);
                if (p.hash === parsed.hash && p.type === parsed.type) {
                    title = pad.title || hashSlice;
                    return true;
                }
            });

            if (title === '') { title = getDefaultName(parsed, pads); }

            cb(void 0, title);
        });
    };

    var newPadNameKey = common.newPadNameKey = "newPadName";
    var newPadPathKey = common.newPadPathKey = "newPadPath";

    // local name?
    common.ready = function (f) {
        var block = 0;
        var env = {};

        var cb = function () {
            block--;
            if (!block) {
                f(void 0, env);
            }
        };

        if (sessionStorage[newPadNameKey]) {
            common.initialName = sessionStorage[newPadNameKey];
            delete sessionStorage[newPadNameKey];
        }
        if (sessionStorage[newPadPathKey]) {
            common.initialPath = sessionStorage[newPadPathKey];
            delete sessionStorage[newPadPathKey];
        }

        Store.ready(function (err, storeObj) {
            store = common.store = env.store = storeObj;

            var proxy = getProxy();
            var network = getNetwork();

            $(function() {
                // Race condition : if document.body is undefined when alertify.js is loaded, Alertify
                // won't work. We have to reset it now to make sure it uses a correct "body"
                Alertify.reset();

                // Load the new pad when the hash has changed
                var oldHash  = document.location.hash.slice(1);
                window.onhashchange = function () {
                    var newHash = document.location.hash.slice(1);
                    var parsedOld = parseHash(oldHash);
                    var parsedNew = parseHash(newHash);
                    if (parsedOld && parsedNew && (
                          parsedOld.channel !== parsedNew.channel
                          || parsedOld.mode !== parsedNew.mode
                          || parsedOld.key !== parsedNew.key)) {
                        document.location.reload();
                        return;
                    }
                    if (parsedNew) {
                        oldHash = newHash;
                    }
                };

                if (PINNING_ENABLED && isLoggedIn()) {
                    console.log("logged in. pads will be pinned");
                    block++;

                    // TODO setTimeout in case rpc doesn't
                    // activate in reasonable time?
                    Pinpad.create(network, proxy, function (e, call) {
                        if (e) {
                            console.error(e);
                            return cb();
                        }

                        console.log('RPC handshake complete');
                        rpc = common.rpc = env.rpc = call;

                        // TODO check if pin list is up to date
                        // if not, reset
                        common.arePinsSynced(function (err, yes) {
                            if (!yes) {
                                common.resetPins(function (err, hash) {
                                    console.log('RESET DONE');
                                });
                            }
                        });
                        cb();
                    });
                } else if (PINNING_ENABLED) {
                    console.log('not logged in. pads will not be pinned');
                } else {
                    console.log('pinning disabled');
                }

                // Everything's ready, continue...
                if($('#pad-iframe').length) {
                    block++;
                    var $iframe = $('#pad-iframe');
                    var iframe = $iframe[0];
                    var iframeDoc = iframe.contentDocument || iframe.contentWindow.document;
                    if (iframeDoc.readyState === 'complete') {
                        cb();
                        return;
                    }
                    $iframe.load(cb);
                    return;
                }

                block++;
                cb();
            });
        }, common);
    };

    var errorHandlers = [];
    common.onError = function (h) {
        if (typeof h !== "function") { return; }
        errorHandlers.push(h);
    };
    common.storeError = function () {
        errorHandlers.forEach(function (h) {
            if (typeof h === "function") {
                h({type: "store"});
            }
        });
    };

    var LOADING = 'loading';
    var getRandomTip = function () {
        if (!Messages.tips || !Object.keys(Messages.tips).length) { return ''; }
        var keys = Object.keys(Messages.tips);
        var rdm = Math.floor(Math.random() * keys.length);
        return Messages.tips[keys[rdm]];
    };
    common.addLoadingScreen = function (loadingText, hideTips) {
        var $loading, $container;
        if ($('#' + LOADING).length) {
            $loading = $('#' + LOADING).show();
            if (loadingText) {
                $('#' + LOADING).find('p').text(loadingText);
            }
            $container = $loading.find('.loadingContainer');
        } else {
            $loading = $('<div>', {id: LOADING});
            $container = $('<div>', {'class': 'loadingContainer'});
            $container.append('<img class="cryptofist" src="/customize/cryptofist_small.png" />');
            var $spinner = $('<div>', {'class': 'spinnerContainer'});
            common.spinner($spinner).show();
            var $text = $('<p>').text(loadingText || Messages.loading);
            $container.append($spinner).append($text);
            $loading.append($container);
            $('body').append($loading);
        }
        if (Messages.tips && !hideTips) {
            var $loadingTip = $('<div>', {'id': 'loadingTip'});
            var $tip = $('<span>', {'class': 'tips'}).text(getRandomTip()).appendTo($loadingTip);
            $loadingTip.css({
                'top': $('body').height()/2 + $container.height()/2 + 20 + 'px'
            });
            $('body').append($loadingTip);
        }
    };
    common.removeLoadingScreen = function (cb) {
        $('#' + LOADING).fadeOut(750, cb);
        $('#loadingTip').css('top', '');
        window.setTimeout(function () {
            $('#loadingTip').fadeOut(750);
        }, 3000);
    };
    common.errorLoadingScreen = function (error, transparent) {
        if (!$('#' + LOADING).is(':visible')) { common.addLoadingScreen(undefined, true); }
        $('.spinnerContainer').hide();
        if (transparent) { $('#' + LOADING).css('opacity', 0.8); }
        $('#' + LOADING).find('p').html(error || Messages.error);
    };

    var importContent = common.importContent = function (type, f) {
        return function () {
            var $files = $('<input type="file">').click();
            $files.on('change', function (e) {
                var file = e.target.files[0];
                var reader = new FileReader();
                reader.onload = function (e) { f(e.target.result, file); };
                reader.readAsText(file, type);
            });
        };
    };

    /*
     * Buttons
     */
    var renamePad = common.renamePad = function (title, callback) {
        if (title === null) { return; }

        if (title.trim() === "") {
            var parsed = parsePadUrl(window.location.href);
            title = getDefaultName(parsed);
        }

        common.setPadTitle(title, function (err, data) {
            if (err) {
                console.log("unable to set pad title");
                console.log(err);
                return;
            }
            callback(null, title);
        });
    };

    var hrefToHexChannelId = common.hrefToHexChannelId = function (href) {
        var parsed = common.parsePadUrl(href);
        if (!parsed || !parsed.hash) { return; }

        parsed = common.parseHash(parsed.hash);

        if (parsed.version === 0) {
            return parsed.channel;
        } else if (parsed.version !== 1) {
            console.error("parsed href had no version");
            console.error(parsed);
            return;
        }

        var channel = parsed.channel;
        if (!channel) { return; }

        var hex = common.base64ToHex(channel);
        return hex;
    };

    var getUserChannelList = common.getUserChannelList = function () {
        var store = common.getStore();
        var proxy = store.getProxy();
        var fo = proxy.fo;

        // start with your userHash...
        var userHash = localStorage && localStorage.User_hash;
        if (!userHash) { return null; }

        var userChannel = common.parseHash(userHash).channel;
        if (!userChannel) { return null; }

        var list = fo.getFilesDataFiles().map(hrefToHexChannelId)
            .filter(function (x) { return x; });

        list.push(common.base64ToHex(userChannel));
        list.sort();

        return list;
    };

    var getCanonicalChannelList = common.getCanonicalChannelList = function () {
        return deduplicateString(getUserChannelList()).sort();
    };

    var pinsReady = common.pinsReady = function () {
        if (!isLoggedIn()) {
            return false;
        }
        if (!PINNING_ENABLED) {
            console.error('[PINNING_DISABLED]');
            return false;
        }
        if (!rpc) {
            console.error('[RPC_NOT_READY]');
            return false;
        }
        return true;
    };

    var arePinsSynced = common.arePinsSynced = function (cb) {
        if (!pinsReady()) { return void cb ('[RPC_NOT_READY]'); }

        var list = getCanonicalChannelList();
        var local = rpc.hashChannelList(list);
        rpc.getServerHash(function (e, hash) {
            if (e) { return void cb(e); }
            cb(void 0, hash === local);
        });
    };

    var resetPins = common.resetPins = function (cb) {
        if (!pinsReady()) { return void cb ('[RPC_NOT_READY]'); }

        var list = getCanonicalChannelList();
        rpc.reset(list, function (e, hash) {
            if (e) { return void cb(e); }
            cb(void 0, hash);
        });
    };

    var pinPads = common.pinPads = function (pads, cb) {
        if (!pinsReady()) { return void cb ('[RPC_NOT_READY]'); }

        rpc.pin(pads, function (e, hash) {
            if (e) { return void cb(e); }
            cb(void 0, hash);
        });
    };

    var unpinPads = common.unpinPads = function (pads, cb) {
        if (!pinsReady()) { return void cb ('[RPC_NOT_READY]'); }

        rpc.unpin(pads, function (e, hash) {
            if (e) { return void cb(e); }
            cb(void 0, hash);
        });
    };

    var createButton = common.createButton = function (type, rightside, data, callback) {
        var button;
        var size = "17px";
        switch (type) {
            case 'export':
                button = $('<button>', {
                    title: Messages.exportButtonTitle,
                }).append($('<span>', {'class':'fa fa-download', style: 'font:'+size+' FontAwesome'}));
                if (callback) {
                    button.click(callback);
                }
                break;
            case 'import':
                button = $('<button>', {
                    title: Messages.importButtonTitle,
                }).append($('<span>', {'class':'fa fa-upload', style: 'font:'+size+' FontAwesome'}));
                if (callback) {
                    button.click(common.importContent('text/plain', function (content, file) {
                        callback(content, file);
                    }));
                }
                break;
            case 'template':
                if (!AppConfig.enableTemplates) { return; }
                button = $('<button>', {
                    title: Messages.saveTemplateButton,
                }).append($('<span>', {'class':'fa fa-bookmark', style: 'font:'+size+' FontAwesome'}));
                if (data.rt && data.Crypt) {
                    button.click(function () {
                        var title = data.getTitle() || document.title;
                        var todo = function (val) {
                            if (typeof(val) !== "string") { return; }
                            var toSave = data.rt.getUserDoc();
                            if (val.trim()) {
                                val = val.trim();
                                title = val;
                                try {
                                    var parsed = JSON.parse(toSave);
                                    var meta;
                                    if (Array.isArray(parsed) && typeof(parsed[3]) === "object") {
                                        meta = parsed[3].metadata; // pad
                                    } else if (parsed.info) {
                                        meta = parsed.info; // poll
                                    } else {
                                        meta = parsed.metadata;
                                    }
                                    if (typeof(meta) === "object") {
                                        meta.title = val;
                                        meta.defaultTitle = val;
                                        delete meta.users;
                                    }
                                    toSave = JSON.stringify(parsed);
                                } catch(e) {
                                    console.error("Parse error while setting the title", e);
                                }
                            }
                            var p = parsePadUrl(window.location.href);
                            if (!p.type) { return; }
                            var hash = createRandomHash();
                            var href = '/' + p.type + '/#' + hash;
                            data.Crypt.put(hash, toSave, function (e) {
                                if (e) { throw new Error(e); }
                                common.addTemplate(makePad(href, title));
                                whenRealtimeSyncs(getStore().getProxy().info.realtime, function () {
                                    common.alert(Messages.templateSaved);
                                });
                            });
                        };
                        common.prompt(Messages.saveTemplatePrompt, title || document.title, todo);
                    });
                }
                break;
            case 'forget':
                button = $('<button>', {
                    id: 'cryptpad-forget',
                    title: Messages.forgetButtonTitle,
                    'class': "fa fa-trash cryptpad-forget",
                    style: 'font:'+size+' FontAwesome'
                });
                getRecentPads(function (err, recent) {
                    if (isNotStrongestStored(window.location.href, recent)) {
                        button.addClass('hidden');
                    }
                });
                if (callback) {
                    button.click(function() {
                        var href = window.location.href;
                        common.confirm(Messages.forgetPrompt, function (yes) {
                            if (!yes) { return; }
                            common.forgetPad(href, function (err, data) {
                                if (err) {
                                    console.log("unable to forget pad");
                                    console.error(err);
                                    callback(err, null);
                                    return;
                                }
                                var n = getNetwork();
                                var r = getRealtime();
                                if (n && r) {
                                    whenRealtimeSyncs(r, function () {
                                        n.disconnect();
                                        callback();
                                    });
                                } else {
                                    callback();
                                }
                                common.alert(Messages.movedToTrash, undefined, true);
                                return;
                            });
                        });

                    });
                }
                break;
            case 'present':
                button = $('<button>', {
                    title: Messages.presentButtonTitle,
                    'class': "fa fa-play-circle cryptpad-present-button", // class used in slide.js
                    style: 'font:'+size+' FontAwesome'
                });
                break;
            case 'source':
                button = $('<button>', {
                    title: Messages.sourceButtonTitle,
                    'class': "fa fa-stop-circle cryptpad-source-button", // class used in slide.js
                    style: 'font:'+size+' FontAwesome'
                });
                break;
            default:
                button = $('<button>', {
                    'class': "fa fa-question",
                    style: 'font:'+size+' FontAwesome'
                });
        }
        if (rightside) {
            button.addClass('rightside-button');
        }
        return button;
    };

    // Create a button with a dropdown menu
    // input is a config object with parameters:
    //  - container (optional): the dropdown container (span)
    //  - text (optional): the button text value
    //  - options: array of {tag: "", attributes: {}, content: "string"}
    //
    // allowed options tags: ['a', 'hr', 'p']
    var createDropdown = common.createDropdown = function (config) {
        if (typeof config !== "object" || !isArray(config.options)) { return; }

        var allowedTags = ['a', 'p', 'hr'];
        var isValidOption = function (o) {
            if (typeof o !== "object") { return false; }
            if (!o.tag || allowedTags.indexOf(o.tag) === -1) { return false; }
            return true;
        };

        // Container
        var $container = $(config.container);
        var containerConfig = {
            'class': 'dropdown-bar'
        };
        if (config.buttonTitle) {
            containerConfig.title = config.buttonTitle;
        }

        if (!config.container) {
            $container = $('<span>', containerConfig);
        }

        // Button
        var $button = $('<button>', {
            'class': ''
        }).append($('<span>', {'class': 'buttonTitle'}).html(config.text || ""));
        $('<span>', {
            'class': 'fa fa-caret-down',
        }).appendTo($button);

        // Menu
        var $innerblock = $('<div>', {'class': 'cryptpad-dropdown dropdown-bar-content'});
        if (config.left) { $innerblock.addClass('left'); }

        config.options.forEach(function (o) {
            if (!isValidOption(o)) { return; }
            $('<' + o.tag + '>', o.attributes || {}).html(o.content || '').appendTo($innerblock);
        });

        $container.append($button).append($innerblock);

        var value = config.initialValue || '';

        var setActive = function ($el) {
            if ($el.length !== 1) { return; }
            $innerblock.find('.active').removeClass('active');
            $el.addClass('active');
            var scroll = $el.position().top + $innerblock.scrollTop();
            if (scroll < $innerblock.scrollTop()) {
                $innerblock.scrollTop(scroll);
            } else if (scroll > ($innerblock.scrollTop() + 280)) {
                $innerblock.scrollTop(scroll-270);
            }
        };

        var hide = function () {
            window.setTimeout(function () { $innerblock.hide(); }, 0);
        };

        var show = function () {
            $innerblock.show();
            $innerblock.find('.active').removeClass('active');
            if (config.isSelect && value) {
                var $val = $innerblock.find('[data-value="'+value+'"]');
                setActive($val);
                $innerblock.scrollTop($val.position().top + $innerblock.scrollTop());
            }
        };

        $button.click(function (e) {
            e.stopPropagation();
            var state = $innerblock.is(':visible');
            $('.dropdown-bar-content').hide();
            try {
                $('iframe').each(function (idx, ifrw) {
                    $(ifrw).contents().find('.dropdown-bar-content').hide();
                });
            } catch (er) {
                // empty try catch in case this iframe is problematic (cross-origin)
            }
            if (state) {
                hide();
                return;
            }
            show();
        });

        if (config.isSelect) {
            var pressed = '';
            var to;
            $container.keydown(function (e) {
                var $value = $innerblock.find('[data-value].active');
                if (e.which === 38) { // Up
                    if ($value.length) {
                        var $prev = $value.prev();
                        setActive($prev);
                    }
                }
                if (e.which === 40) { // Down
                    if ($value.length) {
                        var $next = $value.next();
                        setActive($next);
                    }
                }
                if (e.which === 13) { //Enter
                    if ($value.length) {
                        $value.click();
                        hide();
                    }
                }
                if (e.which === 27) { // Esc
                    hide();
                }
            });
            $container.keypress(function (e) {
                window.clearTimeout(to);
                var c = String.fromCharCode(e.which);
                pressed += c;
                var $value = $innerblock.find('[data-value^="'+pressed+'"]:first');
                if ($value.length) {
                    setActive($value);
                    $innerblock.scrollTop($value.position().top + $innerblock.scrollTop());
                }
                to = window.setTimeout(function () {
                    pressed = '';
                }, 1000);
            });

            $container.setValue = function (val) {
                value = val;
                var $val = $innerblock.find('[data-value="'+val+'"]');
                var textValue = $val.html() || val;
                $button.find('.buttonTitle').html(textValue);
            };
            $container.getValue = function () {
                return value || '';
            };
        }

        return $container;
    };

    // Provide $container if you want to put the generated block in another element
    // Provide $initBlock if you already have the menu block and you want the content inserted in it
    var createLanguageSelector = common.createLanguageSelector = function ($container, $initBlock) {
        var options = [];
        var languages = Messages._languages;
        var keys = Object.keys(languages).sort();
        keys.forEach(function (l) {
            options.push({
                tag: 'a',
                attributes: {
                    'class': 'languageValue',
                    'data-value': l,
                    'href': '#',
                },
                content: languages[l] // Pretty name of the language value
            });
        });
        var dropdownConfig = {
            text: Messages.language, // Button initial text
            options: options, // Entries displayed in the menu
            left: true, // Open to the left of the button
            container: $initBlock, // optional
            isSelect: true
        };
        var $block = createDropdown(dropdownConfig);
        $block.attr('id', 'language-selector');

        if ($container) {
            $block.appendTo($container);
        }

        Messages._initSelector($block);

        return $block;
    };

    var createUserAdminMenu = common.createUserAdminMenu = function (config) {
        var $displayedName = $('<span>', {'class': config.displayNameCls || 'displayName'});
        var accountName = localStorage[common.userNameKey];
        var account = isLoggedIn();
        var $userName = $('<span>', {'class': 'userDisplayName'});
        var options = [];
        if (config.displayNameCls) {
            var $userAdminContent = $('<p>');
            if (account) {
                var $userAccount = $('<span>', {'class': 'userAccount'}).append(Messages.user_accountName + ': ' + fixHTML(accountName));
                $userAdminContent.append($userAccount);
                $userAdminContent.append($('<br>'));
            }
            if (config.displayName) {
                // Hide "Display name:" in read only mode
                $userName.append(Messages.user_displayName + ': ');
                $userName.append($displayedName.clone());
            }
            $userAdminContent.append($userName);
            options.push({
                tag: 'p',
                attributes: {'class': 'accountData'},
                content: $userAdminContent.html()
            });
        }
        var parsed = parsePadUrl(window.location.href);
        if (parsed && (!parsed.type || parsed.type && parsed.type !== 'drive')) {
            options.push({
                tag: 'a',
                attributes: {
                    'target': '_blank',
                    'href': '/drive/'
                },
                content: Messages.login_accessDrive
            });
        }
        // Add the change display name button if not in read only mode
        if (config.changeNameButtonCls && config.displayChangeName) {
            options.push({
                tag: 'a',
                attributes: {'class': config.changeNameButtonCls},
                content: Messages.user_rename
            });
        }
        if (parsed && (!parsed.type || parsed.type !== 'settings')) {
            options.push({
                tag: 'a',
                attributes: {'class': 'settings'},
                content: Messages.settingsButton
            });
        }
        // Add login or logout button depending on the current status
        if (account) {
            options.push({
                tag: 'a',
                attributes: {'class': 'logout'},
                content: Messages.logoutButton
            });
        } else {
            options.push({
                tag: 'a',
                attributes: {'class': 'login'},
                content: Messages.login_login
            });
            options.push({
                tag: 'a',
                attributes: {'class': 'register'},
                content: Messages.login_register
            });
        }
        var $icon = $('<span>', {'class': 'fa fa-user'});
        var $userbig = $('<span>', {'class': 'big'}).append($displayedName.clone());
        var $userButton = $('<div>').append($icon).append($userbig);
        if (account && config.displayNameCls) {
            $userbig.append($('<span>', {'class': 'account-name'}).text('(' + accountName + ')'));
        } else if (account) {
            // If no display name, do not display the parentheses
            $userbig.append($('<span>', {'class': 'account-name'}).text(accountName));
        }
        var dropdownConfigUser = {
            text: $userButton.html(), // Button initial text
            options: options, // Entries displayed in the menu
            left: true, // Open to the left of the button
            container: config.$initBlock // optional
        };
        var $userAdmin = createDropdown(dropdownConfigUser);

        $userAdmin.find('a.logout').click(function (e) {
            common.logout();
            window.location.href = '/';
        });
        $userAdmin.find('a.settings').click(function (e) {
            if (parsed && parsed.type) {
                window.open('/settings/');
            } else {
                window.location.href = '/settings/';
            }
        });
        $userAdmin.find('a.login').click(function (e) {
            if (window.location.pathname !== "/") {
                sessionStorage.redirectTo = window.location.href;
            }
            window.location.href = '/login/';
        });
        $userAdmin.find('a.register').click(function (e) {
            if (window.location.pathname !== "/") {
                sessionStorage.redirectTo = window.location.href;
            }
            window.location.href = '/register/';
        });

        return $userAdmin;
    };

    /*
     *  Alertifyjs
     */
    var findCancelButton = common.findCancelButton = function () {
        return $('button.cancel');
    };

    var findOKButton = common.findOKButton = function () {
        return $('button.ok');
    };

    var listenForKeys = common.listenForKeys = function (yes, no) {
        var handler = function (e) {
            switch (e.which) {
                case 27: // cancel
                    if (typeof(no) === 'function') { no(e); }
                    no();
                    break;
                case 13: // enter
                    if (typeof(yes) === 'function') { yes(e); }
                    break;
            }
        };

        $(window).keyup(handler);
        return handler;
    };

    var stopListening = common.stopListening = function (handler) {
        $(window).off('keyup', handler);
    };

    common.alert = function (msg, cb, force) {
        cb = cb || function () {};
        if (force !== true) { msg = fixHTML(msg); }
        var close = function (e) {
            findOKButton().click();
        };
        var keyHandler = listenForKeys(close, close);
        Alertify.alert(msg, function (ev) {
            cb(ev);
            stopListening(keyHandler);
        });
        window.setTimeout(function () {
            findOKButton().focus();
        });
    };

    common.prompt = function (msg, def, cb, opt, force) {
        opt = opt || {};
        cb = cb || function () {};
        if (force !== true) { msg = fixHTML(msg); }

        var keyHandler = listenForKeys(function (e) { // yes
            findOKButton().click();
        }, function (e) { // no
            findCancelButton().click();
        });

        Alertify
            .defaultValue(def || '')
            .okBtn(opt.ok || Messages.okButton || 'OK')
            .cancelBtn(opt.cancel || Messages.cancelButton || 'Cancel')
            .prompt(msg, function (val, ev) {
                cb(val, ev);
                stopListening(keyHandler);
            }, function (ev) {
                cb(null, ev);
                stopListening(keyHandler);
            });
    };

    common.confirm = function (msg, cb, opt, force, styleCB) {
        opt = opt || {};
        cb = cb || function () {};
        if (force !== true) { msg = fixHTML(msg); }

        var keyHandler = listenForKeys(function (e) {
            findOKButton().click();
        }, function (e) {
            findCancelButton().click();
        });

        Alertify
            .okBtn(opt.ok || Messages.okButton || 'OK')
            .cancelBtn(opt.cancel || Messages.cancelButton || 'Cancel')
            .confirm(msg, function () {
                cb(true);
                stopListening(keyHandler);
            }, function () {
                cb(false);
                stopListening(keyHandler);
            });

        window.setTimeout(function () {
            var $ok = findOKButton();
            var $cancel = findCancelButton();
            if (opt.okClass) { $ok.addClass(opt.okClass); }
            if (opt.cancelClass) { $cancel.addClass(opt.cancelClass); }
            if (opt.reverseOrder) {
                $ok.insertBefore($ok.prev());
            }
            if (typeof(styleCB) === 'function') {
                styleCB($ok.closest('.dialog'));
            }
        }, 0);
    };

    common.log = function (msg) {
        Alertify.success(fixHTML(msg));
    };

    common.warn = function (msg) {
        Alertify.error(fixHTML(msg));
    };

    /*
     *  spinner
     */
    common.spinner = function (parent) {
        var $target = $('<span>', {
            'class': 'fa fa-spinner fa-pulse fa-4x fa-fw'
        }).hide();

        $(parent).append($target);

        return {
            show: function () {
                $target.show();
                return this;
            },
            hide: function () {
                $target.hide();
                return this;
            },
            get: function () {
                return $target;
            },
        };
    };

    $(function () {
        Messages._applyTranslation();
    });

    Alertify._$$alertify.delay = AppConfig.notificationTimeout || 5000;

    return common;
});