import { Component, OnInit } from '@angular/core';
import { DataloaderService } from 'app/services/dataloader.service';
import { Post } from '../../model/post';
import { Observable } from 'rxjs/Observable';

import 'rxjs/add/operator/map';
import 'rxjs/add/operator/merge';
import 'rxjs/add/operator/concatMap';
import 'rxjs/add/observable/from';
import 'rxjs/add/operator/distinct';

@Component({
  selector: 'app-posts',
  templateUrl: './posts.component.html',
  styleUrls: ['./posts.component.css']
})
export class PostsComponent implements OnInit {

  postTypes: Observable<String[]>;
  posts:Observable<Post[]>;

  constructor(private dataloaderService:DataloaderService) { }

  ngOnInit() {
    //fetch the posts
    this.posts = this.dataloaderService.getPosts();
    this.postTypes = this.getPostTypes();
    this.postTypes.subscribe(test=>{
      console.log('result of subscribe: '+test);
    });
  }

  getPostTypes():Observable<String[]> {
    return this.posts.map(posts=>{
      let result = new Set<String>();
      for(let post of posts) {
        result.add(post.type);
      }
      console.log('got these post types!');
      console.log(result);
      return Array.from(result);
    });
  }

  filterOnType(type:String): void {
    
  }
}