import { Injectable } from "@angular/core";
import { HttpClient, HttpHeaders } from "@angular/common/http";

import { Observable, of } from "rxjs";
import { distinctUntilChanged, switchMap, catchError, map } from "rxjs/operators";

import { LatLng } from "leaflet";

import { environment } from '@environments/environment';
import { AuthService } from './auth.service';

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

  constructor(private readonly http: HttpClient, private readonly authSvc: AuthService) {
  }

  getForcastAt(loc: LatLng): Observable<any> {
    const _headers = new HttpHeaders({
      'Accept': 'application/json',
      'Content-Type': 'application/json; charset=utf-8',
    });
    const fcUrl = `/forecast/current.json?key=${environment.weatherKey}&q=${loc.lat},${loc.lng}&aqi=no&lang=${this.authSvc.locale}`;
    return this.http.get(fcUrl, { headers: _headers });
  }

  atLocation(loc: Observable<LatLng>) {
    return loc.pipe(
      distinctUntilChanged(),
      switchMap(
        loc => {
          return this.getForcastAt(loc).pipe(
            map(data => {
              data['reqLatLon'] = loc;
              return data;
            }),
            catchError(err => {
              if (err.error && err.error.error && err.error.error.code)
                return of({ error: { '.tag': err.error.error.code.toString(), 'text': err.error.error.message } });
              return of({ error: { '.tag': 'unknown_error' } });
            }));
        })
    );
  }

}