/*
 * Copyright 2017 Palantir Technologies, Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

export interface ItemModifiers {
    /** Whether this is the "active" (focused) item, meaning keyboard interactions will act upon it. */
    active: boolean;

    /** Whether this item is disabled and should ignore interactions. */
    disabled: boolean;

    /** Whether this item matches the predicate. A typical renderer could hide `false` values. */
    matchesPredicate: boolean;
}

/**
 * An object describing how to render a particular item.
 * An `itemRenderer` receives the item as its first argument, and this object as its second argument.
 *
 * Make sure to forward the provided `ref` to the rendered element (usually via `<MenuItem ref={ref} />`)
 * to ensure that scrolling to active items works correctly.
 *
 * @template T type of the DOM element rendered for this item to which we can attach a ref (defaults to MenuItem's HTMLLIElement)
 */
export interface ItemRendererProps<T extends HTMLElement = HTMLLIElement> {
    /**
     * A ref attached the native HTML element rendered by this item.
     *
     * N.B. this is optional to preserve backwards-compatibilty with @blueprintjs/select version < 4.9.0
     */
    ref?: React.Ref<T>;

    /** Click event handler to select this item. */
    handleClick: React.MouseEventHandler<HTMLElement>;

    /**
     * Focus event handler to set this as the "active" item.
     *
     * N.B. this is optional to preserve backwards-compatibility with @blueprintjs/select version < 4.2.0
     */
    handleFocus?: () => void;

    /** Index of the item in the QueryList items array. */
    index: number;

    /** Unique identifier for this item, used for accessibility. */
    id?: string;

    /** Modifiers that describe how to render this item, such as `active` or `disabled`. */
    modifiers: ItemModifiers;

    /** The current query string used to filter the items. */
    query: string;
}

/**
 * Type alias for a function that receives an item and props and renders a JSX element (or `null`).
 *
 * @template T list item data type
 */
export type ItemRenderer<T> = (item: T, itemProps: ItemRendererProps) => React.JSX.Element | null;