// @flow
import { computed } from 'mobx';
import { concat, filter, last } from 'lodash';
import { client } from 'utils/ApiClient';

import BaseStore from './BaseStore';
import RootStore from './RootStore';
import Collection from 'models/Collection';
import naturalSort from 'shared/utils/naturalSort';

export type DocumentPathItem = {
  id: string,
  collectionId: string,
  title: string,
  url: string,
  type: 'collection' | 'document',
};

export type DocumentPath = DocumentPathItem & {
  path: DocumentPathItem[],
};

export default class CollectionsStore extends BaseStore<Collection> {
  constructor(rootStore: RootStore) {
    super(rootStore, Collection);
  }

  @computed
  get active(): ?Collection {
    return this.rootStore.ui.activeCollectionId
      ? this.data.get(this.rootStore.ui.activeCollectionId)
      : undefined;
  }

  @computed
  get orderedData(): Collection[] {
    return filter(
      naturalSort(Array.from(this.data.values()), 'name'),
      d => !d.deletedAt
    );
  }

  @computed
  get public(): Collection[] {
    return this.orderedData.filter(collection => !collection.private);
  }

  @computed
  get private(): Collection[] {
    return this.orderedData.filter(collection => collection.private);
  }

  /**
   * List of paths to each of the documents, where paths are composed of id and title/name pairs
   */
  @computed
  get pathsToDocuments(): DocumentPath[] {
    let results = [];
    const travelDocuments = (documentList, collectionId, path) =>
      documentList.forEach(document => {
        const { id, title, url } = document;
        const node = { id, collectionId, title, url, type: 'document' };
        results.push(concat(path, node));
        travelDocuments(document.children, collectionId, concat(path, [node]));
      });

    if (this.isLoaded) {
      this.data.forEach(collection => {
        const { id, name, url } = collection;
        const node = {
          id,
          collectionId: id,
          title: name,
          url,
          type: 'collection',
        };
        results.push([node]);
        travelDocuments(collection.documents, id, [node]);
      });
    }

    return results.map(result => {
      const tail = last(result);
      return {
        ...tail,
        path: result,
      };
    });
  }

  getPathForDocument(documentId: string): ?DocumentPath {
    return this.pathsToDocuments.find(path => path.id === documentId);
  }

  titleForDocument(documentUrl: string): ?string {
    const path = this.pathsToDocuments.find(path => path.url === documentUrl);
    if (path) return path.title;
  }

  delete(collection: Collection) {
    super.delete(collection);

    this.rootStore.documents.removeCollectionDocuments(collection.id);
    this.rootStore.documents.fetchRecentlyUpdated();
    this.rootStore.documents.fetchRecentlyViewed();
  }

  export = () => {
    return client.post('/collections.exportAll');
  };
}