KB.component('select-dropdown-autocomplete', function(containerElement, options) {
    var componentElement, inputElement, inputHiddenElement;

    function onKeyDown(e) {
        switch (e.keyCode) {
            case 27:
                inputElement.value = '';
                destroyDropdownMenu();
                break;
            case 38:
                e.preventDefault();
                e.stopImmediatePropagation();
                moveUp();
                break;
            case 40:
                e.preventDefault();
                e.stopImmediatePropagation();
                moveDown();
                break;
            case 13:
                e.preventDefault();
                e.stopImmediatePropagation();
                insertSelectedItem();
                break;
        }
    }

    function onInputChanged() {
        destroyDropdownMenu();
        renderDropdownMenu();
    }

    function onItemMouseOver(element) {
        if (KB.dom(element).hasClass('select-dropdown-menu-item')) {
            KB.find('.select-dropdown-menu-item.active').removeClass('active');
            KB.dom(element).addClass('active');
        }
    }

    function onItemClick() {
        insertSelectedItem();
    }

    function onDocumentClick(e) {
        if (! containerElement.contains(e.target)) {
            inputElement.value = '';
            destroyDropdownMenu();
        }
    }

    function toggleDropdownMenu() {
        var menuElement = KB.find('#select-dropdown-menu');

        if (menuElement === null) {
            renderDropdownMenu();
        } else {
            destroyDropdownMenu();
        }
    }

    function insertSelectedItem() {
        var element = KB.find('.select-dropdown-menu-item.active');
        var value = element.data('value');
        inputHiddenElement.value = value;
        inputElement.value = options.items[value];
        destroyDropdownMenu();

        if (options.redirect) {
            var regex = new RegExp(options.redirect.regex, 'g');
            window.location = options.redirect.url.replace(regex, value);
        }
    }

    function resetSelection() {
        var elements = document.querySelectorAll('.select-dropdown-menu-item');

        for (var i = 0; i < elements.length; i++) {
            if (KB.dom(elements[i]).hasClass('active')) {
                KB.dom(elements[i]).removeClass('active');
                break;
            }
        }

        return {items: elements, index: i};
    }

    function moveUp() {
        var result = resetSelection();

        if (result.index > 0) {
            result.index = result.index - 1;
        }

        KB.dom(result.items[result.index]).addClass('active');
    }

    function moveDown() {
        var result = resetSelection();

        if (result.index < result.items.length - 1) {
            result.index++;
        }

        KB.dom(result.items[result.index]).addClass('active');
    }

    function buildItems(items) {
        var elements = [];
        var keys = Object.keys(items);

        if (options.sortByKeys) {
            keys.sort();
        }

        for (var i = 0; i < keys.length; i++) {
            elements.push({
                'class': 'select-dropdown-menu-item',
                'text': items[keys[i]],
                'data-label': items[keys[i]],
                'data-value': keys[i]
            });
        }

        return elements;
    }

    function filterItems(text, items) {
        var filteredItems = [];
        var hasActiveItem = false;

        for (var i = 0; i < items.length; i++) {
            if (text.length === 0 || items[i]['data-label'].toLowerCase().indexOf(text.toLowerCase()) === 0) {
                var item = items[i];

                if (typeof options.defaultValue !== 'undefined' && String(options.defaultValue) === item['data-value']) {
                    item.class += ' active';
                    hasActiveItem = true;
                }

                filteredItems.push(item);
            }
        }

        if (! hasActiveItem && filteredItems.length > 0) {
            filteredItems[0].class += ' active';
        }

        return filteredItems;
    }

    function buildDropdownMenu() {
        var itemElements = filterItems(inputElement.value, buildItems(options.items));
        var componentPosition = componentElement.getBoundingClientRect();

        if (itemElements.length === 0) {
            return null;
        }

        return KB.dom('ul')
            .attr('id', 'select-dropdown-menu')
            .style('top', componentPosition.bottom + 'px')
            .style('left', componentPosition.left + 'px')
            .style('width', componentPosition.width + 'px')
            .style('maxHeight', (window.innerHeight - componentPosition.bottom - 20) + 'px')
            .mouseover(onItemMouseOver)
            .click(onItemClick)
            .for('li', itemElements)
            .build();
    }

    function destroyDropdownMenu() {
        var menuElement = KB.find('#select-dropdown-menu');

        if (menuElement !== null) {
            menuElement.remove();
        }

        document.removeEventListener('keydown', onKeyDown, false);
        document.removeEventListener('click', onDocumentClick, false);
    }

    function renderDropdownMenu() {
        var element = buildDropdownMenu();

        if (element !== null) {
            document.body.appendChild(element);
        }

        document.addEventListener('keydown', onKeyDown, false);
        document.addEventListener('click', onDocumentClick, false);
    }

    function getPlaceholderValue() {
        if (options.defaultValue && options.defaultValue in options.items) {
            return options.items[options.defaultValue];
        }

        if (options.placeholder) {
            return options.placeholder;
        }

        return '';
    }

    this.render = function () {
        var dropdownIconElement = KB.dom('i')
            .attr('class', 'fa fa-chevron-down select-dropdown-chevron')
            .click(toggleDropdownMenu)
            .build();

        inputHiddenElement = KB.dom('input')
            .attr('type', 'hidden')
            .attr('name', options.name)
            .attr('value', options.defaultValue || '')
            .build();

        inputElement = KB.dom('input')
            .attr('type', 'text')
            .attr('placeholder', getPlaceholderValue())
            .addClass('select-dropdown-input')
            .style('width', (containerElement.offsetWidth - 30) + 'px')
            .on('focus', toggleDropdownMenu)
            .on('input', onInputChanged, true)
            .build();

        componentElement = KB.dom('div')
            .addClass('select-dropdown-input-container')
            .add(inputHiddenElement)
            .add(inputElement)
            .add(dropdownIconElement)
            .build();

        containerElement.appendChild(componentElement);

        if (options.onFocus) {
            options.onFocus.forEach(function (eventName) {
                KB.on(eventName, function() { inputElement.focus(); });
            });
        }
    };
});