import { HttpClient, HttpHeaders, HttpParams } from '@angular/common/http';
import { EMPTY, Observable, of, range } from 'rxjs';
import { catchError, map, shareReplay } from 'rxjs/operators';

export class DataService {

   private apiUrl = 'https://api.myjson.com/bins';
   private httpHeaders = new HttpHeaders({ 'Content-Type': 'application/json' });
   private endPoint: string;

   constructor(private http: HttpClient, endPoint: string, apiUrl?:string) {
      if(apiUrl){
         this.apiUrl = apiUrl;
      }
      this.endPoint = endPoint;
   }

   getValues(): Observable<any[]> {
      const url = `${this.apiUrl}/${this.endPoint}`;
      const response = this.http.get<any[]>(url);
      return response;
   }

   getSomething<T>(): Observable<T> {
      return this.http.get<T>(this.getUrl());
   }

   getEntities<T>(params?: {}): Observable<T[]> {
      let httpParams: HttpParams;
      if (params) {
         for (let param in params) {
            httpParams = new HttpParams().append(param, params[param]);
         }
      }
      return this.http.get<T[]>(this.getUrl(), { params: httpParams })
         .pipe(shareReplay());
   }

   getEntity<T>(id?: number, params?: {}): Observable<T> {
      if (id) {
         return this.http.get<T>(`${this.getUrl()}/${id}`);
      } else if (params) {
         let httpParams: HttpParams;

         for (let param in params) {
            httpParams = new HttpParams().append(param, params[param]);
         }
         return this.http.get<T>(this.getUrl(), { params: httpParams });
      }
      return EMPTY;
   }

   private getUrl(): string {
      return `${this.apiUrl}/${this.endPoint}`;
   }

   doSomething() {
      console.log('doing something')

      const url = `${this.apiUrl}/${this.endPoint}`;
      //let response = this.http.get(url).pipe(map(s => ({id: s}))).subscribe(s => console.log(s));
      // let response = this.http.get(url)
      range(1, 5)
         .pipe(map<number, { id: number }>(x => ({ id: x })))
         .subscribe(x => console.log(x));

   }

   saveValue<T>(params?: {}): Observable<T> {
      return this.http.post<T>(this.getUrl(),
         JSON.stringify(params),
         { headers: this.httpHeaders })
         .pipe(catchError((e, c) => {
            console.log(e);
            return of(e);
         }));
   }
}