var commandHooks = null;
            var commandHooksRequest = null;
            var commandMenuGeneration = 0;
            var suppressCommandMenuKeypress = false;
            var serverCommandFallbacks = [
                {command:'defcon',args:'[<level>]',description:'Set or show Ergo emergency restrictions',insertion:'/quote DEFCON',serverCommand:true},
                {command:'deoper',args:'',description:'Remove IRC operator privileges',insertion:'/quote DEOPER',serverCommand:true},
                {command:'dline',args:'[<duration>] <ip>/<net> [<reason>] || LIST',description:'Add or list IP/network bans',insertion:'/quote DLINE',serverCommand:true},
                {command:'kline',args:'[<duration>] <mask> [<reason>] || LIST',description:'Add or list client-mask bans',insertion:'/quote KLINE',serverCommand:true},
                {command:'uban',args:'ADD|DEL|LIST|INFO <target>',description:'Manage unified bans',insertion:'/quote UBAN',serverCommand:true},
                {command:'undline',args:'<ip>/<net>',description:'Remove an IP/network ban',insertion:'/quote UNDLINE',serverCommand:true},
                {command:'unkline',args:'<mask>',description:'Remove a client-mask ban',insertion:'/quote UNKLINE',serverCommand:true}
            ];

            var mergeCommandHooks = function(hooks) {
                var unique = Object.create(null);
                var hasOwn = Object.prototype.hasOwnProperty;
                hooks.forEach(function(hook) {
                    var key = String(hook.command || '').toLowerCase();
                    if (key && (!hasOwn.call(unique, key) || hook.priority > unique[key].priority)) {
                        unique[key] = Object.assign({}, hook, {command:key});
                    }
                });
                serverCommandFallbacks.forEach(function(hook) {
                    if (!hasOwn.call(unique, hook.command)) unique[hook.command] = hook;
                });
                return Object.keys(unique).map(function(key){return unique[key];}).sort(function(left,right){return left.command.localeCompare(right.command);});
            };

            $scope.commandMenuOpen = false;
            $scope.commandMenuLoading = false;
            $scope.commandMenuMatches = [];
            $scope.commandMenuIndex = 0;

            var closeCommandMenu = function() {
                $scope.commandMenuOpen = false;
                $scope.commandMenuLoading = false;
                $scope.commandMenuMatches = [];
                $scope.commandMenuIndex = 0;
            };

            var updateCommandMenu = function() {
                var match = /^\/([^\s]*)$/.exec($scope.command || '');
                if (!match) {
                    closeCommandMenu();
                    return;
                }

                $scope.commandMenuOpen = true;
                $scope.commandMenuIndex = 0;
                if (commandHooks === null) {
                    $scope.commandMenuLoading = true;
                    if (commandHooksRequest === null) {
                        var requestGeneration = commandMenuGeneration;
                        commandHooksRequest = connection.requestCommandHooks().then(function(hooks) {
                            if (requestGeneration !== commandMenuGeneration) {
                                return;
                            }
                            commandHooks = mergeCommandHooks(hooks);
                            commandHooksRequest = null;
                            updateCommandMenu();
                        }, function() {
                            if (requestGeneration !== commandMenuGeneration) {
                                return;
                            }
                            commandHooks = mergeCommandHooks([]);
                            commandHooksRequest = null;
                            updateCommandMenu();
                        });
                    }
                    return;
                }

                var prefix = match[1].toLowerCase();
                var activeBuffer = models.getActiveBuffer();
                var isIrcBuffer = activeBuffer && activeBuffer.plugin === 'irc';
                $scope.commandMenuLoading = false;
                $scope.commandMenuMatches = commandHooks.filter(function(hook) {
                    return (!hook.serverCommand || isIrcBuffer) && hook.command.indexOf(prefix) === 0;
                });
            };

            $scope.selectCommand = function(item) {
                var suffix = item.args ? ' ' : '';
                $scope.command = (item.insertion || ('/' + item.command.toLowerCase())) + suffix;
                closeCommandMenu();
                setTimeout(function() {
                    var inputNode = $scope.getInputNode();
                    inputNode.focus();
                    inputNode.setSelectionRange($scope.command.length, $scope.command.length);
                }, 0);
            };

            var scrollCommandMenuSelection = function() {
                setTimeout(function() {
                    var selected = document.getElementById(
                        $scope.inputId + '-command-' + $scope.commandMenuIndex
                    );
                    if (selected) {
                        selected.scrollIntoView({block: 'nearest'});
                    }
                }, 0);
            };

            $scope.handleCommandMenuKey = function(event, code, inputNode) {
                if (suppressCommandMenuKeypress && event.type === 'keypress' &&
                        (code === 9 || code === 13)) {
                    event.preventDefault();
                    return true;
                }
                if (!$scope.commandMenuOpen || event.type !== 'keydown' ||
                        document.activeElement !== inputNode || event.altKey ||
                        event.ctrlKey || event.metaKey) {
                    return false;
                }

                var count = $scope.commandMenuMatches.length;
                if ((code === 38 || code === 40) && count > 0) {
                    var direction = code === 38 ? -1 : 1;
                    $scope.commandMenuIndex = ($scope.commandMenuIndex + direction + count) % count;
                    scrollCommandMenuSelection();
                    event.preventDefault();
                    return true;
                }
                if ((code === 9 || code === 13) && count > 0 && !event.shiftKey) {
                    $scope.selectCommand($scope.commandMenuMatches[$scope.commandMenuIndex]);
                    suppressCommandMenuKeypress = true;
                    setTimeout(function() { suppressCommandMenuKeypress = false; }, 0);
                    event.preventDefault();
                    return true;
                }
                if (code === 27) {
                    closeCommandMenu();
                    event.preventDefault();
                    return true;
                }
                return false;
            };

            var removeCommandMenuDisconnect = $rootScope.$on('relayDisconnect', function() {
                commandMenuGeneration++;
                commandHooks = null;
                commandHooksRequest = null;
                closeCommandMenu();
            });
            $scope.$on('$destroy', removeCommandMenuDisconnect);