/*
 * Copyright 2020 Adobe. All rights reserved.
 * This file is licensed to you 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 REPRESENTATIONS
 * OF ANY KIND, either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */

import {Key} from '@react-types/shared';
import {LinkDOMProps} from './dom';
import {ReactElement, ReactNode} from 'react';

export interface ItemProps<T> extends LinkDOMProps {
  /** Rendered contents of the item or child items. */
  children: ReactNode,
  /** Rendered contents of the item if `children` contains child items. */
  title?: ReactNode, // label?? contents?
  /** A string representation of the item's contents, used for features like typeahead. */
  textValue?: string,
  /** An accessibility label for this item. */
  'aria-label'?: string,
  /** A list of child item objects. Used for dynamic collections. */
  childItems?: Iterable<T>,
  /** Whether this item has children, even if not loaded yet. */
  hasChildItems?: boolean
}

export type ItemElement<T> = ReactElement<ItemProps<T>>;
export type ItemRenderer<T> = (item: T) => ItemElement<T>;
export type LoadingState = 'loading' | 'sorting' | 'loadingMore' | 'error' | 'idle' | 'filtering';

export interface AsyncLoadable {
  /** Whether the items are currently loading. */
  isLoading?: boolean, // possibly isLoadingMore
  /** Handler that is called when more items should be loaded, e.g. while scrolling near the bottom. */
  onLoadMore?: () => any
}

export interface SectionProps<T> {
  /** Rendered contents of the section, e.g. a header. */
  title?: ReactNode,
  /** An accessibility label for the section. */
  'aria-label'?: string,
  /** Static child items or a function to render children. */
  children: ItemElement<T> | ItemElement<T>[] | ItemRenderer<T>,
  /** Item objects in the section. */
  items?: Iterable<T>
}

export type SectionElement<T> = ReactElement<SectionProps<T>>;

export type CollectionElement<T> = SectionElement<T> | ItemElement<T>;
export type CollectionChildren<T> = CollectionElement<T> | CollectionElement<T>[] | ((item: T) => CollectionElement<T>);
export interface CollectionBase<T> {
  /** The contents of the collection. */
  children: CollectionChildren<T>,
  /** Item objects in the collection. */
  items?: Iterable<T>,
  /** The item keys that are disabled. These items cannot be selected, focused, or otherwise interacted with. */
  disabledKeys?: Iterable<Key>
}

export interface CollectionStateBase<T, C extends Collection<Node<T>> = Collection<Node<T>>> extends Partial<CollectionBase<T>> {
  /** A pre-constructed collection to use instead of building one from items and children. */
  collection?: C
}

export interface Expandable {
  /** The currently expanded keys in the collection (controlled). */
  expandedKeys?: Iterable<Key>,
  /** The initial expanded keys in the collection (uncontrolled). */
  defaultExpandedKeys?: Iterable<Key>,
  /** Handler that is called when items are expanded or collapsed. */
  onExpandedChange?: (keys: Set<Key>) => any
}

export interface Sortable {
  /** The current sorted column and direction. */
  sortDescriptor?: SortDescriptor,
  /** Handler that is called when the sorted column or direction changes. */
  onSortChange?: (descriptor: SortDescriptor) => any
}

export interface SortDescriptor {
  /** The key of the column to sort by. */
  column?: Key,
  /** The direction to sort by. */
  direction?: SortDirection
}

export type SortDirection = 'ascending' | 'descending';

export interface KeyboardDelegate {
  /** Returns the key visually below the given one, or `null` for none. */
  getKeyBelow?(key: Key): Key | null,

  /** Returns the key visually above the given one, or `null` for none. */
  getKeyAbove?(key: Key): Key | null,

  /** Returns the key visually to the left of the given one, or `null` for none. */
  getKeyLeftOf?(key: Key): Key | null,

  /** Returns the key visually to the right of the given one, or `null` for none. */
  getKeyRightOf?(key: Key): Key | null,

  /** Returns the key visually one page below the given one, or `null` for none. */
  getKeyPageBelow?(key: Key): Key | null,

  /** Returns the key visually one page above the given one, or `null` for none. */
  getKeyPageAbove?(key: Key): Key | null,

  /** Returns the first key, or `null` for none. */
  getFirstKey?(key?: Key, global?: boolean): Key | null,

  /** Returns the last key, or `null` for none. */
  getLastKey?(key?: Key, global?: boolean): Key | null,

  /** Returns the next key after `fromKey` that matches the given search string, or `null` for none. */
  getKeyForSearch?(search: string, fromKey?: Key): Key | null
}

/**
 * A generic interface to access a readonly sequential
 * collection of unique keyed items.
 */
export interface Collection<T> extends Iterable<T> {
  /** The number of items in the collection. */
  readonly size: number,

  /** Iterate over all keys in the collection. */
  getKeys(): Iterable<Key>,

  /** Get an item by its key. */
  getItem(key: Key): T | null,

  /** Get an item by the index of its key. */
  at(idx: number): T | null,

  /** Get the key that comes before the given key in the collection. */
  getKeyBefore(key: Key): Key | null,

  /** Get the key that comes after the given key in the collection. */
  getKeyAfter(key: Key): Key | null,

  /** Get the first key in the collection. */
  getFirstKey(): Key | null,

  /** Get the last key in the collection. */
  getLastKey(): Key | null,

  /** Iterate over the child items of the given key. */
  getChildren?(key: Key): Iterable<T>,

  /** Returns a string representation of the item's contents. */
  getTextValue?(key: Key): string
}

export interface Node<T> {
  /** The type of item this node represents. */
  type: string,
  /** A unique key for the node. */
  key: Key,
  /** The object value the node was created from. */
  value: T | null,
  /** The level of depth this node is at in the heirarchy. */
  level: number,
  /** Whether this item has children, even if not loaded yet. */
  hasChildNodes: boolean,
  /**
   * The loaded children of this node.
   * @deprecated Use `collection.getChildren(node.key)` instead.
   */
  childNodes: Iterable<Node<T>>,
  /** The rendered contents of this node (e.g. JSX). */
  rendered: ReactNode,
  /** A string value for this node, used for features like typeahead. */
  textValue: string,
  /** An accessibility label for this node. */
  'aria-label'?: string,
  /** The index of this node within its parent. */
  index?: number,
  /** A function that should be called to wrap the rendered node. */
  wrapper?: (element: ReactElement) => ReactElement,
  /** The key of the parent node. */
  parentKey?: Key | null,
  /** The key of the node before this node. */
  prevKey?: Key | null,
  /** The key of the node after this node. */
  nextKey?: Key | null,
  /** Additional properties specific to a particular node type. */
  props?: any,
  /** @private */
  shouldInvalidate?: (context: unknown) => boolean
}