import { Component, OnInit, OnDestroy } from '@angular/core';
import { Store, select } from '@ngrx/store';
import { Observable, of, Subscription } from 'rxjs';
import { catchError, exhaustMap, map, tap } from 'rxjs/operators';

import { RPCClientError } from '@loafer/ng-rpc';

import { MetaCrawler } from '@overflow/commons-typescript/model/meta';

import { MetaCrawlerEntitySelector } from '../../store';
import * as MetaCrawlerEntityStore from '../../store/entity/meta-crawler';
import { MetaCrawlerService } from '../../service/meta-crawler.service';

export abstract class MetaCrawlerComponent implements OnInit, OnDestroy {
  metaCrawlers$: Observable<MetaCrawler[]>;
  pending$: Observable<boolean>;
  error$: Observable<any>;

  constructor(
    protected store: Store<any>,
    protected metaCrawlerService: MetaCrawlerService,
  ) {
  }

  ngOnInit() {
    this.metaCrawlers$ = this.store.pipe(select(MetaCrawlerEntitySelector.selectAll));
    this.pending$ = this.store.pipe(select(MetaCrawlerEntitySelector.selectPending));
    this.error$ = this.store.pipe(select(MetaCrawlerEntitySelector.selectError));

    this.store.pipe(
      select(MetaCrawlerEntitySelector.selectAll),
      map((metaCrawlers: MetaCrawler[]) => {
        if (0 < metaCrawlers.length) {
          return;
        }
        this.store.dispatch(new MetaCrawlerEntityStore.ReadAll());
      }),
    ).take(1).subscribe();
  }

  ngOnDestroy(): void {
  }
}