import { Injectable } from '@angular/core';
import { AngularFirestore, AngularFirestoreCollection } from '@angular/fire/firestore';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';

@Injectable({
  providedIn: 'root'
})
export class FirebaseService {

  private recordsCollection: AngularFirestoreCollection<any[]>;
  public records$: Observable<any[]>;

  constructor(private afs: AngularFirestore) {
    this.recordsCollection = this.afs.collection<any[]>('records');
    this.records$ = this.getDocs(this.recordsCollection);
  }

  getDocs(collection: AngularFirestoreCollection<any[]>): any {
    return collection.snapshotChanges()
      .pipe(
        map(actions => actions.map(a => {
          const data = a.payload.doc.data();
          const id = a.payload.doc.id;
          return { id, ...data };
        }))
      );
  }
}