ComboBox.ts

import UI5Element from "@ui5/webcomponents-base/dist/UI5Element.js";
import { renderFinished } from "@ui5/webcomponents-base/dist/Render.js";
import customElement from "@ui5/webcomponents-base/dist/decorators/customElement.js";
import property from "@ui5/webcomponents-base/dist/decorators/property.js";
import event from "@ui5/webcomponents-base/dist/decorators/event.js";
import slot from "@ui5/webcomponents-base/dist/decorators/slot.js";
import litRender from "@ui5/webcomponents-base/dist/renderer/LitRenderer.js";
import ValueState from "@ui5/webcomponents-base/dist/types/ValueState.js";
import { isPhone, isAndroid } from "@ui5/webcomponents-base/dist/Device.js";
import Integer from "@ui5/webcomponents-base/dist/types/Integer.js";
import InvisibleMessageMode from "@ui5/webcomponents-base/dist/types/InvisibleMessageMode.js";
import { getEffectiveAriaLabelText } from "@ui5/webcomponents-base/dist/util/AriaLabelHelper.js";
import announce from "@ui5/webcomponents-base/dist/util/InvisibleMessage.js";
import { getScopedVarName } from "@ui5/webcomponents-base/dist/CustomElementsScope.js";
import "@ui5/webcomponents-icons/dist/slim-arrow-down.js";
import "@ui5/webcomponents-icons/dist/decline.js";
import "@ui5/webcomponents-icons/dist/not-editable.js";
import "@ui5/webcomponents-icons/dist/error.js";
import "@ui5/webcomponents-icons/dist/alert.js";
import "@ui5/webcomponents-icons/dist/sys-enter-2.js";
import "@ui5/webcomponents-icons/dist/information.js";
import type I18nBundle from "@ui5/webcomponents-base/dist/i18nBundle.js";
import { getI18nBundle } from "@ui5/webcomponents-base/dist/i18nBundle.js";
import { submitForm } from "@ui5/webcomponents-base/dist/features/InputElementsFormSupport.js";
import type { IFormInputElement } from "@ui5/webcomponents-base/dist/features/InputElementsFormSupport.js";
import {
	isBackSpace,
	isDelete,
	isShow,
	isUp,
	isDown,
	isEnter,
	isEscape,
	isTabNext,
	isTabPrevious,
	isPageUp,
	isPageDown,
	isHome,
	isEnd,
} from "@ui5/webcomponents-base/dist/Keys.js";
import type { IIcon } from "./Icon.js";
import * as Filters from "./Filters.js";

import {
	VALUE_STATE_SUCCESS,
	VALUE_STATE_ERROR,
	VALUE_STATE_WARNING,
	VALUE_STATE_INFORMATION,
	VALUE_STATE_TYPE_SUCCESS,
	VALUE_STATE_TYPE_INFORMATION,
	VALUE_STATE_TYPE_ERROR,
	VALUE_STATE_TYPE_WARNING,
	INPUT_SUGGESTIONS_TITLE,
	SELECT_OPTIONS,
	LIST_ITEM_POSITION,
	LIST_ITEM_GROUP_HEADER,
	INPUT_CLEAR_ICON_ACC_NAME,
	FORM_TEXTFIELD_REQUIRED,
} from "./generated/i18n/i18n-defaults.js";

// Templates
import ComboBoxTemplate from "./generated/templates/ComboBoxTemplate.lit.js";

// Styles
import ComboBoxCss from "./generated/themes/ComboBox.css.js";
import ComboBoxPopoverCss from "./generated/themes/ComboBoxPopover.css.js";
import ResponsivePopoverCommonCss from "./generated/themes/ResponsivePopoverCommon.css.js";
import ValueStateMessageCss from "./generated/themes/ValueStateMessage.css.js";
import SuggestionsCss from "./generated/themes/Suggestions.css.js";

import ComboBoxItem from "./ComboBoxItem.js";
import Icon from "./Icon.js";
import Popover from "./Popover.js";
import ResponsivePopover from "./ResponsivePopover.js";
import List from "./List.js";
import type { ListItemClickEventDetail } from "./List.js";
import BusyIndicator from "./BusyIndicator.js";
import Button from "./Button.js";
import ListItemStandard from "./ListItemStandard.js";
import ComboBoxItemGroup, { isInstanceOfComboBoxItemGroup } from "./ComboBoxItemGroup.js";
import ListItemGroup from "./ListItemGroup.js";
import ListItemGroupHeader from "./ListItemGroupHeader.js";
import ComboBoxFilter from "./types/ComboBoxFilter.js";
import PopoverHorizontalAlign from "./types/PopoverHorizontalAlign.js";
import Input from "./Input.js";
import type { InputEventDetail } from "./Input.js";
import SuggestionItem from "./SuggestionItem.js";

const SKIP_ITEMS_SIZE = 10;

/**
 * Interface for components that may be slotted inside a `ui5-combobox`
 * @public
 */
interface IComboBoxItem extends UI5Element {
	text: string,
	focused: boolean,
	isGroupItem?: boolean,
	selected?: boolean,
	additionalText?: string,
	stableDomRef: string,
	_isVisible?: boolean,
	items?: Array<IComboBoxItem>
}

type ValueStateAnnouncement = Record<Exclude<ValueState, ValueState.None>, string>;
type ValueStateTypeAnnouncement = Record<Exclude<ValueState, ValueState.None>, string>;

type ComboBoxListItem = ListItemStandard & {
	mappedItem: ComboBoxItem
};

enum ValueStateIconMapping {
	Negative = "error",
	Critical = "alert",
	Positive = "sys-enter-2",
	Information = "information",
}

type ComboBoxSelectionChangeEventDetail = {
	item: ComboBoxItem,
};

/**
 * @class
 *
 * ### Overview
 *
 * The `ui5-combobox` component represents a drop-down menu with a list of the available options and a text input field to narrow down the options.
 *
 * It is commonly used to enable users to select an option from a predefined list.
 *
 * ### Structure
 * The `ui5-combobox` consists of the following elements:
 *
 * -  Input field - displays the selected option or a custom user entry. Users can type to narrow down the list or enter their own value.
 * -  Drop-down arrow - expands\collapses the option list.
 * -  Option list - the list of available options.
 *
 * ### Keyboard Handling
 *
 * The `ui5-combobox` provides advanced keyboard handling.
 *
 * - [F4], [Alt]+[Up], or [Alt]+[Down] - Toggles the picker.
 * - [Escape] - Closes the picker, if open. If closed, cancels changes and reverts the typed in value.
 * - [Enter] or [Return] - If picker is open, takes over the currently selected item and closes it.
 * - [Down] - Selects the next matching item in the picker.
 * - [Up] - Selects the previous matching item in the picker.
 * - [Page Down] - Moves selection down by page size (10 items by default).
 * - [Page Up] - Moves selection up by page size (10 items by default).
 * - [Home] - If focus is in the ComboBox, moves cursor at the beginning of text. If focus is in the picker, selects the first item.
 * - [End] - If focus is in the ComboBox, moves cursor at the end of text. If focus is in the picker, selects the last item.
 *
 * ### ES6 Module Import
 *
 * `import "@ui5/webcomponents/dist/ComboBox.js";`
 * @constructor
 * @extends UI5Element
 * @public
 * @since 1.0.0-rc.6
 */
@customElement({
	tag: "ui5-combobox",
	languageAware: true,
	formAssociated: true,
	renderer: litRender,
	styles: [
		ComboBoxCss,
		ResponsivePopoverCommonCss,
		ValueStateMessageCss,
		ComboBoxPopoverCss,
		SuggestionsCss,
	],
	template: ComboBoxTemplate,
	dependencies: [
		ComboBoxItem,
		Icon,
		ResponsivePopover,
		List,
		BusyIndicator,
		Button,
		ListItemStandard,
		ListItemGroup,
		ListItemGroupHeader,
		Popover,
		ComboBoxItemGroup,
		Input,
		SuggestionItem,
	],
})
/**
 * Fired when the input operation has finished by pressing Enter, focusout or an item is selected.
 * @public
 */
@event("change")

/**
 * Fired when typing in input or clear icon is pressed.
 *
 * **Note:** filterValue property is updated, input is changed.
 * @public
 */
@event("input")
/**
 * Fired when selection is changed by user interaction
 * @param {IComboBoxItem} item item to be selected.
 * @public
 */
@event<ComboBoxSelectionChangeEventDetail>("selection-change", {
	detail: {
		/**
		* @public
		*/
		item: { type: HTMLElement },
	},
})

class ComboBox extends UI5Element implements IFormInputElement {
	/**
	 * Defines the value of the component.
	 * @default ""
	 * @formEvents change input
	 * @formProperty
	 * @public
	 */
	@property()
	value!: string;

	/**
	 * Determines the name by which the component will be identified upon submission in an HTML form.
	 *
	 * **Note:** This property is only applicable within the context of an HTML Form element.
	 * @default ""
	 * @public
	 * @since 2.0.0
	 */
	@property()
	name!: string;

	/**
	 * Defines whether the value will be autocompleted to match an item
	 * @default false
	 * @public
	 * @since 1.19.0
	 */
	@property({ type: Boolean })
	noTypeahead!: boolean;

	/**
	 * Defines the "live" value of the component.
	 *
	 * **Note:** If we have an item e.g. "Bulgaria", "B" is typed, "ulgaria" is typed ahead, value will be "Bulgaria", filterValue will be "B".
	 *
	 * **Note:** Initially the filter value is synced with value.
	 * @default ""
	 * @private
	 */
	@property()
	filterValue!: string;

	/**
	 * Defines a short hint intended to aid the user with data entry when the
	 * component has no value.
	 * @default ""
	 * @public
	 */
	@property()
	placeholder!: string;

	/**
	 * Defines whether the component is in disabled state.
	 *
	 * **Note:** A disabled component is completely noninteractive.
	 * @default false
	 * @public
	 */
	@property({ type: Boolean })
	disabled!: boolean;

	/**
	 * Defines the value state of the component.
	 * @default "None"
	 * @public
	 */
	@property({ type: ValueState, defaultValue: ValueState.None })
	valueState!: `${ValueState}`;

	/**
	 * Defines whether the component is read-only.
	 *
	 * **Note:** A read-only component is not editable,
	 * but still provides visual feedback upon user interaction.
	 * @default false
	 * @public
	 */
	@property({ type: Boolean })
	readonly!: boolean;

	/**
	 * Defines whether the component is required.
	 * @default false
	 * @public
	 */
	@property({ type: Boolean })
	required!: boolean;

	/**
	 * Indicates whether a loading indicator should be shown in the picker.
	 * @default false
	 * @public
	 */
	@property({ type: Boolean })
	loading!: boolean;

	/**
	 * Defines the filter type of the component.
	 * @default "StartsWithPerTerm"
	 * @public
	 */
	@property({ type: ComboBoxFilter, defaultValue: ComboBoxFilter.StartsWithPerTerm })
	filter!: `${ComboBoxFilter}`;

	/**
	 * Defines whether the clear icon of the combobox will be shown.
	 * @default false
	 * @public
	 * @since 1.20.1
	 */
	@property({ type: Boolean })
	showClearIcon!: boolean;

	/**
	 * Indicates whether the input is focssed
	 * @private
	 */
	@property({ type: Boolean })
	focused!: boolean;

	/**
	 * Indicates whether the visual focus is on the value state header
	 * @private
	 */
	@property({ type: Boolean })
	_isValueStateFocused!: boolean;

	/**
	 * Defines the accessible ARIA name of the component.
	 * @default ""
	 * @public
	 * @since 1.0.0-rc.15
	 */
	@property()
	accessibleName!: string;

	/**
	 * Receives id(or many ids) of the elements that label the component
	 * @default ""
	 * @public
	 * @since 1.0.0-rc.15
	 */
	@property()
	accessibleNameRef!: string;

	@property({ type: Boolean, noAttribute: true })
	_iconPressed!: boolean;

	@property({ type: Object, noAttribute: true, multiple: true })
	_filteredItems!: Array<IComboBoxItem>;

	@property({ validator: Integer, noAttribute: true })
	_listWidth!: number;

	@property({ type: Boolean, noAttribute: true })
	_effectiveShowClearIcon!: boolean;

	/**
	 * Defines the component items.
	 * @public
	 */
	@slot({ type: HTMLElement, "default": true, invalidateOnChildChange: true })
	items!: Array<IComboBoxItem>;

	/**
	 * Defines the value state message that will be displayed as pop up under the component.
	 * The value state message slot should contain only one root element.
	 *
	 * **Note:** If not specified, a default text (in the respective language) will be displayed.
	 *
	 * **Note:** The `valueStateMessage` would be displayed,
	 * when the `ui5-combobox` is in `Information`, `Warning` or `Error` value state.
	 * @since 1.0.0-rc.9
	 * @public
	 */
	@slot()
	valueStateMessage!: Array<HTMLElement>;

	/**
	 * Defines the icon to be displayed in the input field.
	 * @public
	 * @since 1.0.0-rc.9
	 */
	@slot()
	icon!: Array<IIcon>;

	_initialRendering: boolean;
	_itemFocused: boolean;
	// used only for Safari fix (check onAfterRendering)
	_autocomplete: boolean;
	_isKeyNavigation: boolean;
	_selectionPerformed: boolean;
	_lastValue: string;
	_selectedItemText: string;
	_userTypedValue: string;
	responsivePopover?: ResponsivePopover;
	valueStatePopover?: Popover;
	static i18nBundle: I18nBundle;

	get formValidityMessage() {
		return ComboBox.i18nBundle.getText(FORM_TEXTFIELD_REQUIRED);
	}

	get formValidity(): ValidityStateFlags {
		return { valueMissing: this.required && !this.value };
	}

	async formElementAnchor() {
		return this.getFocusDomRefAsync();
	}

	get formFormattedValue() {
		return this.value;
	}

	constructor() {
		super();

		this._filteredItems = [];
		this._initialRendering = true;
		this._itemFocused = false;
		this._autocomplete = false;
		this._isKeyNavigation = false;
		// when an initial value is set it should be considered as a _lastValue
		this._lastValue = this.getAttribute("value") || "";
		this._selectionPerformed = false;
		this._selectedItemText = "";
		this._userTypedValue = "";
	}

	async onBeforeRendering() {
		const popover: Popover | undefined = this.valueStatePopover;

		this._effectiveShowClearIcon = (this.showClearIcon && !!this.value && !this.readonly && !this.disabled);

		if (this._initialRendering || this.filter === "None") {
			this._filteredItems = this.items;
		}

		if (this.open && !this._isKeyNavigation) {
			const items = this._filterItems(this.filterValue);
			this._filteredItems = (items.length && items) || [];
		}

		const hasNoVisibleItems = !this._filteredItems.length || !this._filteredItems.some(i => i._isVisible);

		// If there is no filtered items matching the value, show all items when the arrow is pressed
		if (((hasNoVisibleItems && !isPhone()) && this.value)) {
			this.items.forEach(this._makeAllVisible.bind(this));
			this._filteredItems = this.items;
		}

		if (!this._initialRendering && document.activeElement === this && !this._filteredItems.length && popover) {
			popover.open = false;
		}

		this._selectMatchingItem();
		this._initialRendering = false;

		this.style.setProperty(getScopedVarName("--_ui5-input-icons-count"), `${this.iconsCount}`);

		const suggestionsPopover = await this._getPicker();
		this.items.forEach(item => {
			item._getRealDomRef = () => suggestionsPopover.querySelector(`*[data-ui5-stable=${item.stableDomRef}]`)!;
		});
	}

	get iconsCount() {
		const slottedIconsCount = this.icon?.length || 0;
		const clearIconCount = Number(this._effectiveShowClearIcon) ?? 0;
		const arrowDownIconsCount = this.readonly ? 0 : 1;

		return slottedIconsCount + clearIconCount + arrowDownIconsCount;
	}

	async onAfterRendering() {
		const picker: ResponsivePopover = await this._getPicker();

		if ((await this.shouldClosePopover()) && !isPhone()) {
			picker.preventFocusRestore = true;
			picker.open = false;
			this._clearFocus();
			this._itemFocused = false;
		}

		this.toggleValueStatePopover(this.shouldOpenValueStateMessagePopover);
		this.storeResponsivePopoverWidth();

		if (isPhone()) {
			this.value = this.inner.value;
			this._selectMatchingItem();
		}
	}

	async shouldClosePopover(): Promise<boolean> {
		const popover: ResponsivePopover = await this._getPicker();

		return popover.open && !this.focused && !this._itemFocused && !this._isValueStateFocused;
	}

	_focusin(e: FocusEvent) {
		this.focused = true;
		this._autocomplete = false;

		!isPhone() && (e.target as HTMLInputElement).setSelectionRange(0, this.value.length);
	}

	_focusout(e: FocusEvent) {
		const toBeFocused = e.relatedTarget as HTMLElement;
		const focusedOutToValueStateMessage = toBeFocused?.shadowRoot?.querySelector(".ui5-valuestatemessage-root");
		const clearIconWrapper = this.shadowRoot!.querySelector(".ui5-input-clear-icon-wrapper");
		const focusedOutToClearIcon = clearIconWrapper === toBeFocused || clearIconWrapper?.contains(toBeFocused);

		if (this._effectiveShowClearIcon && focusedOutToClearIcon) {
			return;
		}

		this._fireChangeEvent();

		if (focusedOutToValueStateMessage) {
			e.stopImmediatePropagation();
			return;
		}

		const popover = this.shadowRoot!.querySelector("[ui5-responsive-popover]");
		if (!(this.getDomRef()!.contains(toBeFocused)) && (popover !== e.relatedTarget)) {
			this.focused = false;
			!isPhone() && this._closeRespPopover(e);
		}
	}

	_afterOpenPopover() {
		this._iconPressed = true;
		this.inner.focus();
	}

	_afterClosePopover() {
		this._iconPressed = false;
		this._filteredItems = this.items;
		this.filterValue = "";

		// close device's keyboard and prevent further typing
		if (isPhone()) {
			this.blur();
		}

		if (this._selectionPerformed) {
			this._lastValue = this.value;
			this._selectionPerformed = false;
		}
	}

	async _toggleRespPopover() {
		const picker: ResponsivePopover = await this._getPicker();

		if (picker.open) {
			this._closeRespPopover();
		} else {
			this._openRespPopover();
		}
	}

	async storeResponsivePopoverWidth() {
		if (this.open && !this._listWidth) {
			this._listWidth = (await this._getPicker()).offsetWidth;
		}
	}

	toggleValueStatePopover(open: boolean) {
		if (open) {
			this.openValueStatePopover();
		} else {
			this.closeValueStatePopover();
		}
	}

	async openValueStatePopover() {
		const valueStatePopover = await this._getValueStatePopover();
		if (valueStatePopover) {
			valueStatePopover.opener = this;
			valueStatePopover.open = true;
		}
	}

	async closeValueStatePopover() {
		const valueStatePopover = await this._getValueStatePopover();
		if (valueStatePopover) {
			valueStatePopover.open = false;
		}
	}

	async _getValueStatePopover() {
		await renderFinished();
		const popover: Popover = this.shadowRoot!.querySelector<Popover>(".ui5-valuestatemessage-popover")!;

		// backward compatibility
		// rework all methods to work with async getters
		this.valueStatePopover = popover;

		return popover;
	}

	_resetFilter() {
		this._userTypedValue = "";
		this.inner.setSelectionRange(0, this.value.length);
		this._filteredItems = this._filterItems("");
		this._selectMatchingItem();
	}

	_resetItemVisibility() {
		this.items.forEach(item => {
			if (isInstanceOfComboBoxItemGroup(item)) {
				item.items?.forEach(i => {
					i._isVisible = false;
				});
				return;
			}

			item._isVisible = false;
		});
	}

	_arrowClick() {
		this.inner.focus();
		this._resetFilter();

		if (isPhone() && this.value && !this._lastValue) {
			this._lastValue = this.value;
		}

		this._toggleRespPopover();
	}

	_handleMobileInput(e: CustomEvent<InputEventDetail>) {
		const { target } = e;
		this.filterValue = (target as Input).value;
		this.value = (target as Input).value;
		this.fireEvent("input");
	}

	_input(e: InputEvent) {
		const { value } = e.target as HTMLInputElement;
		const shouldAutocomplete = this.shouldAutocomplete(e);

		if (e.target === this.inner) {
			// stop the native event, as the semantic "input" would be fired.
			e.stopImmediatePropagation();
			this.focused = true;
			this._isValueStateFocused = false;
		}

		this._filteredItems = this._filterItems(value);

		this.value = value;
		this.filterValue = value;

		this._clearFocus();

		// autocomplete
		if (shouldAutocomplete && !isAndroid()) {
			const item = this._getFirstMatchingItem(value);
			item && this._applyAtomicValueAndSelection(item, value, true);

			if (value !== "" && (item && !item.selected && !item.isGroupItem)) {
				this.fireEvent<ComboBoxSelectionChangeEventDetail>("selection-change", {
					item: item as ComboBoxItem,
				});
			}
		}

		this.fireEvent("input");

		if (isPhone()) {
			return;
		}

		if (!this._filteredItems.length || value === "") {
			this._closeRespPopover();
		} else {
			this._openRespPopover();
		}
	}
	shouldAutocomplete(e: InputEvent): boolean {
		const eventType = e.inputType;
		const allowedEventTypes = [
			"deleteWordBackward",
			"deleteWordForward",
			"deleteSoftLineBackward",
			"deleteSoftLineForward",
			"deleteEntireSoftLine",
			"deleteHardLineBackward",
			"deleteHardLineForward",
			"deleteByDrag",
			"deleteByCut",
			"deleteContent",
			"deleteContentBackward",
			"deleteContentForward",
			"historyUndo",
		];

		return !this.noTypeahead && !allowedEventTypes.includes(eventType);
	}

	_startsWithMatchingItems(str: string): Array<IComboBoxItem> {
		const allItems:Array<IComboBoxItem> = this._getItems();
		return Filters.StartsWith(str, allItems, "text");
	}

	_clearFocus() {
		const allItems = this._getItems();

		allItems.map(item => {
			item.focused = false;

			return item;
		});
	}

	// Get groups and items as a flat array for filtering
	_getItems() {
		const allItems: Array<IComboBoxItem> = [];

		this._filteredItems.forEach(item => {
			if (isInstanceOfComboBoxItemGroup(item)) {
				const groupedItems = [item, ...item.items];
				allItems.push(...groupedItems);
				return;
			}

			allItems.push(item);
		});

		return allItems;
	}

	handleNavKeyPress(e: KeyboardEvent) {
		const allItems = this._getItems();

		if (this.focused && (isHome(e) || isEnd(e)) && this.value) {
			return;
		}

		const isOpen = this.open;
		const currentItem = allItems.find(item => {
			return isOpen ? item.focused : item.selected;
		});

		const indexOfItem = currentItem ? allItems.indexOf(currentItem) : -1;
		e.preventDefault();

		if (this.focused && isOpen && (isUp(e) || isPageUp(e) || isPageDown(e))) {
			return;
		}

		if (allItems.length - 1 === indexOfItem && isDown(e)) {
			return;
		}

		this._isKeyNavigation = true;

		if (
			e.key === "ArrowDown"
			|| e.key === "ArrowUp"
			|| e.key === "PageUp"
			|| e.key === "PageDown"
			|| e.key === "Home"
			|| e.key === "End"
		) {
			this[`_handle${e.key}`](e, indexOfItem);
		}
	}

	_handleItemNavigation(e: KeyboardEvent, indexOfItem: number, isForward: boolean) {
		const allItems = this._getItems();

		const isOpen = this.open;
		const currentItem: IComboBoxItem = allItems[indexOfItem];
		const isGroupItem = currentItem && currentItem.isGroupItem;
		const nextItem = isForward ? allItems[indexOfItem + 1] : allItems[indexOfItem - 1];

		if ((!isOpen) && ((isGroupItem && !nextItem) || (!isGroupItem && !currentItem))) {
			return;
		}

		this._clearFocus();

		if (isOpen) {
			this._itemFocused = true;
			this.value = isGroupItem ? "" : currentItem.text;
			this.focused = false;

			currentItem.focused = true;
		} else {
			this.focused = true;
			this.value = isGroupItem ? nextItem.text : currentItem.text;
			currentItem.focused = false;
		}

		this._isValueStateFocused = false;

		this._announceSelectedItem(indexOfItem);
		this._scrollToItem(indexOfItem, isForward);

		if (isGroupItem && isOpen) {
			return;
		}
		// autocomplete
		const item = this._getFirstMatchingItem(this.value);
		item && this._applyAtomicValueAndSelection(item, (this.open ? this._userTypedValue : ""), true);

		if ((item && !item.selected)) {
			this.fireEvent<ComboBoxSelectionChangeEventDetail>("selection-change", {
				item: item as ComboBoxItem,
			});
		}

		this.fireEvent("input");
	}

	_handleArrowDown(e: KeyboardEvent, indexOfItem: number) {
		const isOpen = this.open;

		if (this.focused && indexOfItem === -1 && this.hasValueStateText && isOpen) {
			this._isValueStateFocused = true;
			this._announceValueStateText();
			this.focused = false;
			return;
		}

		indexOfItem = !isOpen && this.hasValueState && indexOfItem === -1 ? 0 : indexOfItem;

		this._handleItemNavigation(e, ++indexOfItem, true /* isForward */);
	}

	_handleArrowUp(e: KeyboardEvent, indexOfItem: number) {
		const isOpen = this.open;

		if (indexOfItem === 0 && !this.hasValueStateText) {
			this._clearFocus();
			this.focused = true;
			this._itemFocused = false;
			return;
		}

		if (indexOfItem === 0 && this.hasValueStateText && isOpen) {
			this._clearFocus();
			this._itemFocused = false;
			this._isValueStateFocused = true;
			this._announceValueStateText();
			this._filteredItems[0].selected = false;
			return;
		}

		if (this._isValueStateFocused) {
			this.focused = true;
			this._isValueStateFocused = false;
			return;
		}

		indexOfItem = !isOpen && this.hasValueState && indexOfItem === -1 ? 0 : indexOfItem;
		this._handleItemNavigation(e, --indexOfItem, false /* isForward */);
	}

	_handlePageUp(e: KeyboardEvent, indexOfItem: number) {
		const allItems = this._getItems();
		const isProposedIndexValid = indexOfItem - SKIP_ITEMS_SIZE > -1;
		indexOfItem = isProposedIndexValid ? indexOfItem - SKIP_ITEMS_SIZE : 0;
		const shouldMoveForward = isInstanceOfComboBoxItemGroup(allItems[indexOfItem]) && !this.open;

		if (!isProposedIndexValid && this.hasValueStateText && this.open) {
			this._clearFocus();
			this._itemFocused = false;
			this._isValueStateFocused = true;
			this._announceValueStateText();
			return;
		}

		this._handleItemNavigation(e, indexOfItem, shouldMoveForward);
	}

	_handlePageDown(e: KeyboardEvent, indexOfItem: number) {
		const allItems = this._getItems();
		const itemsLength = allItems.length;
		const isProposedIndexValid = indexOfItem + SKIP_ITEMS_SIZE < itemsLength;

		indexOfItem = isProposedIndexValid ? indexOfItem + SKIP_ITEMS_SIZE : itemsLength - 1;
		const shouldMoveForward = isInstanceOfComboBoxItemGroup(allItems[indexOfItem]) && !this.open;

		this._handleItemNavigation(e, indexOfItem, shouldMoveForward);
	}

	_handleHome(e: KeyboardEvent) {
		const shouldMoveForward = isInstanceOfComboBoxItemGroup(this._filteredItems[0]) && !this.open;

		if (this.hasValueStateText && this.open) {
			this._clearFocus();
			this._itemFocused = false;
			this._isValueStateFocused = true;
			this._announceValueStateText();
			return;
		}

		this._handleItemNavigation(e, 0, shouldMoveForward);
	}

	_handleEnd(e: KeyboardEvent) {
		this._handleItemNavigation(e, this._getItems().length - 1, true /* isForward */);
	}

	_keyup() {
		this._userTypedValue = this.value.substring(0, this.inner.selectionStart || 0);
	}

	_keydown(e: KeyboardEvent) {
		const isNavKey = isDown(e) || isUp(e) || isPageUp(e) || isPageDown(e) || isHome(e) || isEnd(e);
		const picker = this.responsivePopover;
		const allItems: Array<IComboBoxItem> = this._getItems();

		this._autocomplete = !(isBackSpace(e) || isDelete(e));
		this._isKeyNavigation = false;

		if (isNavKey && !this.readonly && this._filteredItems.length) {
			this.handleNavKeyPress(e);
		}

		if (isEnter(e)) {
			let focusedItem: IComboBoxItem | undefined;

			this._filteredItems.forEach(item => {
				if (isInstanceOfComboBoxItemGroup(item) && !focusedItem) {
					focusedItem = item.items.find(groupItem => groupItem.focused);
				}

				if (item.focused) {
					focusedItem = item;
				}
			});

			this._fireChangeEvent();

			if (picker?.open && !focusedItem?.isGroupItem) {
				this._closeRespPopover();
				this.focused = true;
				this.inner.setSelectionRange(this.value.length, this.value.length);
			} else if (this._internals?.form) {
				submitForm(this);
			}
		}

		if (isEscape(e)) {
			this.focused = true;
			this.value = !this.open ? this._lastValue : this.value;
			this._isValueStateFocused = false;
		}

		if ((isTabNext(e) || isTabPrevious(e)) && this.open) {
			this._closeRespPopover();
		}

		if (isShow(e) && !this.readonly && !this.disabled) {
			e.preventDefault();

			this._resetFilter();
			this._toggleRespPopover();

			const selectedItem = allItems.find(item => {
				return item.selected;
			});

			if (selectedItem && this.open) {
				this._itemFocused = true;
				selectedItem.focused = true;
				this.focused = false;
			} else if (this.open && this._filteredItems.length) {
				// If no item is selected, select the first one on "Show" (F4, Alt+Up/Down)
				this._handleItemNavigation(e, 0, true /* isForward */);
			} else {
				this.focused = true;
			}
		}
	}

	_click() {
		if (isPhone() && !this.readonly) {
			this._openRespPopover();
		}
	}

	_closeRespPopover(e?: Event) {
		const picker = this.responsivePopover;

		if (e && (e.target as HTMLElement).classList.contains("ui5-responsive-popover-close-btn") && this._selectedItemText) {
			this.value = this._selectedItemText;
			this.filterValue = this._selectedItemText;
		}

		if (e && (e.target as HTMLElement).classList.contains("ui5-responsive-popover-close-btn")) {
			this.value = this._lastValue || "";
			this.filterValue = this._lastValue || "";
		}

		if (isPhone()) {
			this._fireChangeEvent();
		}

		this._isValueStateFocused = false;
		this._clearFocus();

		if (picker) {
			picker.preventFocusRestore = false;
			picker.open = false;
		}
	}

	async _openRespPopover() {
		const picker = await this._getPicker();
		picker.opener = this;
		picker.open = true;
	}

	_filterItems(str: string) {
		let filteredItem:IComboBoxItem;
		let filteredGroupItems: Array<IComboBoxItem> = [];
		const filteredItems: Array<IComboBoxItem> = [];
		const filteredItemGroups: Array<IComboBoxItem> = [];

		this._resetItemVisibility();
		this.items.forEach(item => {
			if (isInstanceOfComboBoxItemGroup(item)) {
				filteredGroupItems = (Filters[this.filter] || Filters.StartsWithPerTerm)(str, item.items, "text");
				filteredGroupItems.forEach(i => {
					i._isVisible = true;
				});

				if (filteredGroupItems.length) {
					filteredItemGroups.push(item);
				}

				return;
			}

			[filteredItem] = (Filters[this.filter] || Filters.StartsWithPerTerm)(str, [item], "text");

			if (filteredItem) {
				filteredItem._isVisible = true;
				filteredItems.push(filteredItem);
			}
		});

		return [...filteredItemGroups, ...filteredItems];
	}

	_getFirstMatchingItem(current: string): IComboBoxItem | void {
		const allItems = this._getItems();
		const currentlyFocusedItem = allItems.find(item => item.focused === true);

		if (currentlyFocusedItem?.isGroupItem) {
			this.value = this.filterValue;
			return;
		}

		const matchingItems: Array<IComboBoxItem> = (this._startsWithMatchingItems(current).filter(item => !isInstanceOfComboBoxItemGroup(item)));

		if (matchingItems.length) {
			return matchingItems[0];
		}
	}

	_applyAtomicValueAndSelection(item: IComboBoxItem, filterValue: string, highlightValue: boolean) {
		const value = (item && item.text) || "";

		this.inner.value = value;
		if (highlightValue) {
			this.inner.setSelectionRange(filterValue.length, value.length);
		}
		this.value = value;
	}

	_selectMatchingItem() {
		const currentlyFocusedItem = this.items.find(item => item.focused);
		const shouldSelectionBeCleared = currentlyFocusedItem && currentlyFocusedItem.isGroupItem;
		let itemToBeSelected: IComboBoxItem | undefined;

		this._filteredItems.forEach(item => {
			if (!shouldSelectionBeCleared && !itemToBeSelected) {
				itemToBeSelected = ((!item.isGroupItem && (item.text === this.value)) ? item : item?.items?.find(i => i.text === this.value));
			}
		});

		this._filteredItems = this._filteredItems.map(item => {
			if (!isInstanceOfComboBoxItemGroup(item)) {
				item.selected = item === itemToBeSelected;
				return item;
			}

			item.items?.forEach(groupItem => {
				groupItem.selected = itemToBeSelected === groupItem;
			});

			return item;
		});
	}

	_fireChangeEvent() {
		if (this.value !== this._lastValue) {
			this.fireEvent("change");
			this._lastValue = this.value;
		}
	}

	_inputChange(e: Event) {
		e.preventDefault();
	}

	_itemMousedown(e: MouseEvent) {
		e.preventDefault();
	}

	_selectItem(e: CustomEvent<ListItemClickEventDetail>) {
		const listItem = e.detail.item as ComboBoxListItem;

		this._selectedItemText = listItem.mappedItem.text;
		this._selectionPerformed = true;

		const sameItemSelected = this.value === this._selectedItemText;
		const sameSelectionPerformed = this.value.toLowerCase() === this.filterValue.toLowerCase();

		if (sameItemSelected && sameSelectionPerformed) {
			this._fireChangeEvent(); // Click on an already typed, but not memoized value shouold also trigger the change event
			return this._closeRespPopover();
		}

		this.value = this._selectedItemText;

		if (!listItem.mappedItem.selected) {
			this.fireEvent<ComboBoxSelectionChangeEventDetail>("selection-change", {
				item: listItem.mappedItem,
			});
		}

		this._filteredItems.map(item => {
			item.selected = (item === listItem.mappedItem && !item.isGroupItem);
			return item;
		});

		this._fireChangeEvent();
		this._closeRespPopover();

		// reset selection
		this.inner.setSelectionRange(this.value.length, this.value.length);
	}

	_onItemFocus() {
		this._itemFocused = true;
	}

	_announceSelectedItem(indexOfItem: number) {
		const allItems = this._getItems();
		const currentItem = allItems[indexOfItem];
		const nonGroupItems = allItems.filter(item => !item.isGroupItem);
		const currentItemAdditionalText = currentItem?.additionalText || "";
		const isGroupItem = currentItem?.isGroupItem;
		const itemPositionText = ComboBox.i18nBundle.getText(LIST_ITEM_POSITION, nonGroupItems.indexOf(currentItem) + 1, nonGroupItems.length);
		const groupHeaderText = ComboBox.i18nBundle.getText(LIST_ITEM_GROUP_HEADER);

		if (isGroupItem) {
			announce(`${groupHeaderText} ${currentItem.text}`, InvisibleMessageMode.Polite);
		} else {
			announce(`${currentItemAdditionalText} ${itemPositionText}`.trim(), InvisibleMessageMode.Polite);
		}
	}

	_clear() {
		const selectedItem = this.items.find(item => item.selected);

		if (selectedItem?.text === this.value) {
			this.fireEvent("change");
		}

		this.value = "";
		this.fireEvent("input");

		if (this._isPhone) {
			this._lastValue = "";
			this.fireEvent("change");
		} else {
			this.focus();
		}
	}

	_makeAllVisible(item: IComboBoxItem) {
		if (isInstanceOfComboBoxItemGroup(item)) {
			item.items.forEach(groupItem => {
				groupItem._isVisible = true;
			});
			return;
		}

		item._isVisible = true;
	}

	async _scrollToItem(indexOfItem: number, forward: boolean) {
		const picker = await this._getPicker();
		const list = picker.querySelector(".ui5-combobox-items-list") as List;
		const listItem = list?.listItems[indexOfItem];

		if (listItem) {
			const pickerRect = picker.getBoundingClientRect();
			const listItemRect = listItem.getBoundingClientRect();
			const isListItemInVisibleArea = listItemRect.top >= pickerRect.top && listItemRect.bottom <= pickerRect.bottom;

			if (!isListItemInVisibleArea) {
				listItem.scrollIntoView({ behavior: "instant", block: forward ? "end" : "start", inline: "nearest" });
			}
		}
	}

	_announceValueStateText() {
		const valueStateText = this.shouldDisplayDefaultValueStateMessage ? this.valueStateDefaultText : this.valueStateMessageText.map(el => el.textContent).join(" ");

		if (valueStateText) {
			announce(valueStateText, InvisibleMessageMode.Polite);
		}
	}

	get _headerTitleText() {
		return ComboBox.i18nBundle.getText(INPUT_SUGGESTIONS_TITLE);
	}

	get _iconAccessibleNameText() {
		return ComboBox.i18nBundle.getText(SELECT_OPTIONS);
	}

	get inner(): HTMLInputElement {
		return isPhone() ? this.responsivePopover!.querySelector("[ui5-input]")!.shadowRoot!.querySelector("input")! : this.shadowRoot!.querySelector("[inner-input]")!;
	}

	async _getPicker() {
		await renderFinished();
		const picker = this.shadowRoot!.querySelector<ResponsivePopover>("[ui5-responsive-popover]")!;

		// backward compatibility
		// rework all methods to work with async getters
		this.responsivePopover = picker;

		return picker;
	}

	get hasValueState(): boolean {
		return this.valueState !== ValueState.None;
	}

	get hasValueStateText(): boolean {
		return this.hasValueState && this.valueState !== ValueState.Positive;
	}

	get ariaValueStateHiddenText(): string {
		if (!this.hasValueState) {
			return "";
		}

		let text = "";

		if (this.valueState !== ValueState.None) {
			text = this.valueStateTypeMappings[this.valueState];
		}

		if (this.shouldDisplayDefaultValueStateMessage) {
			return `${text} ${this.valueStateDefaultText || ""}`;
		}

		return `${text}`.concat(" ", this.valueStateMessageText.map(el => el.textContent).join(" "));
	}

	get valueStateDefaultText(): string | undefined {
		if (this.valueState === ValueState.None) {
			return;
		}

		return this.valueStateTextMappings[this.valueState];
	}

	get valueStateMessageText(): Array<Node> {
		return this.getSlottedNodes("valueStateMessage").map(el => el.cloneNode(true));
	}

	get valueStateTextMappings(): ValueStateAnnouncement {
		return {
			[ValueState.Positive]: ComboBox.i18nBundle.getText(VALUE_STATE_SUCCESS),
			[ValueState.Negative]: ComboBox.i18nBundle.getText(VALUE_STATE_ERROR),
			[ValueState.Critical]: ComboBox.i18nBundle.getText(VALUE_STATE_WARNING),
			[ValueState.Information]: ComboBox.i18nBundle.getText(VALUE_STATE_INFORMATION),
		};
	}

	get valueStateTypeMappings(): ValueStateTypeAnnouncement {
		return {
			[ValueState.Positive]: ComboBox.i18nBundle.getText(VALUE_STATE_TYPE_SUCCESS),
			[ValueState.Information]: ComboBox.i18nBundle.getText(VALUE_STATE_TYPE_INFORMATION),
			[ValueState.Negative]: ComboBox.i18nBundle.getText(VALUE_STATE_TYPE_ERROR),
			[ValueState.Critical]: ComboBox.i18nBundle.getText(VALUE_STATE_TYPE_WARNING),
		};
	}

	get shouldOpenValueStateMessagePopover(): boolean {
		return this.focused && !this.readonly && this.hasValueStateText && !this._iconPressed
			&& !this.open && !this._isPhone;
	}

	get shouldDisplayDefaultValueStateMessage(): boolean {
		return !this.valueStateMessage.length && this.hasValueStateText;
	}

	get _valueStatePopoverHorizontalAlign(): `${PopoverHorizontalAlign}` {
		return this.effectiveDir !== "rtl" ? PopoverHorizontalAlign.Start : PopoverHorizontalAlign.End;
	}

	/**
	 * This method is relevant for sap_horizon theme only
	 */
	get _valueStateMessageIcon(): string {
		return this.valueState !== ValueState.None ? ValueStateIconMapping[this.valueState] : "";
	}

	get open(): boolean {
		return this?.responsivePopover?.open || false;
	}

	get _isPhone(): boolean {
		return isPhone();
	}

	get itemTabIndex() {
		return undefined;
	}

	get ariaLabelText(): string | undefined {
		return getEffectiveAriaLabelText(this);
	}

	get clearIconAccessibleName() {
		return ComboBox.i18nBundle.getText(INPUT_CLEAR_ICON_ACC_NAME);
	}

	static async onDefine() {
		ComboBox.i18nBundle = await getI18nBundle("@ui5/webcomponents");
	}

	get styles() {
		const remSizeInPx = parseInt(getComputedStyle(document.documentElement).fontSize);
		return {
			popoverHeader: {
				"width": `${this.offsetWidth}px`,
			},
			suggestionPopoverHeader: {
				"display": this._listWidth === 0 ? "none" : "inline-block",
				"width": `${this._listWidth || ""}px`,
			},
			suggestionsPopover: {
				"min-width": `${this.offsetWidth || 0}px`,
				"max-width": (this.offsetWidth / remSizeInPx) > 40 ? `${this.offsetWidth}px` : "40rem",
			},
			popoverValueStateMessage: {},
		};
	}

	get classes() {
		return {
			popover: {
				"ui5-suggestions-popover": true,
				"ui5-popover-with-value-state-header-phone": this._isPhone && this.hasValueStateText,
				"ui5-popover-with-value-state-header": !this._isPhone && this.hasValueStateText,
			},
			popoverValueState: {
				"ui5-valuestatemessage-header": true,
				"ui5-valuestatemessage-root": true,
				"ui5-valuestatemessage--success": this.valueState === ValueState.Positive,
				"ui5-valuestatemessage--error": this.valueState === ValueState.Negative,
				"ui5-valuestatemessage--warning": this.valueState === ValueState.Critical,
				"ui5-valuestatemessage--information": this.valueState === ValueState.Information,
			},
		};
	}
}

ComboBox.define();

export default ComboBox;

export type {
	ComboBoxSelectionChangeEventDetail,
	IComboBoxItem,
};