import Component from '@ember/component';
import { get, set } from '@ember/object';
import { task } from 'ember-concurrency';
import { nodeToQueryParams } from 'wherehows-web/constants';
import { IBrowserRouteParams } from 'wherehows-web/routes/browse/entity';
import { readPlatforms } from 'wherehows-web/utils/api/platforms/platform';
import { arrayMap } from 'wherehows-web/utils/array';
import { IReadDatasetsOptionBag } from 'wherehows-web/typings/api/datasets/dataset';

/**
 * Describes a node with parameters used by dynamic-link component to create links to items lised in the rail
 * @interface IRailNode
 */
interface IRailNode {
  title: string;
  text: string;
  route: 'browse.entity';
  model: IBrowserRouteParams['entity'];
  queryParams: Partial<IReadDatasetsOptionBag>;
}

/**
 * Given a platform and entity, returns a closure function that maps each node to a
 * list of IRailNode
 * @param {string} platform
 * @param {IBrowserRouteParams['entity']} entity
 * @returns {(array: string[]) => IRailNode[]}
 */
export const mapNodeToRoute = (
  platform: string,
  entity: IBrowserRouteParams['entity']
): ((array: string[]) => IRailNode[]) =>
  arrayMap((node: string): IRailNode => ({
    title: node,
    text: node,
    route: 'browse.entity',
    model: entity,
    queryParams: nodeToQueryParams({ platform, node })
  }));

export default class BrowserRail extends Component {
  /**
   * Passed in parameters containing route or queryparameters values to be used in request
   * @type {IBrowserRouteParams}
   * @memberof BrowserRail
   */
  params: IBrowserRouteParams;

  /**
   * Maintains a list the nodes platforms or prefixes available in the selected entity
   * @type {Array<IRailNode>}
   * @memberof BrowserRail
   */
  nodes: Array<IRailNode> = [];

  didUpdateAttrs() {
    this._super(...arguments);
    get(this, 'getNodesTask').perform();
  }

  didInsertElement() {
    this._super(...arguments);
    get(this, 'getNodesTask').perform();
  }

  /**
   * Gets the nodes: platforms, or prefixes for the selected entity
   * @type {TaskProperty<Promise<string[]>> & {perform: (a?: {} | undefined) => TaskInstance<Promise<string[]>>}}
   * @memberof BrowserRail
   */
  getNodesTask = task(function*(this: BrowserRail): IterableIterator<Promise<Array<string>>> {
    const { prefix, platform, entity } = get(this, 'params');
    const nodes: Array<IRailNode> = mapNodeToRoute(platform, entity)(yield readPlatforms({ platform, prefix }));

    set(this, 'nodes', nodes);
  }).drop();
}