import { JhiAlertService } from 'ng-jhipster';
import { HttpInterceptor, HttpRequest, HttpResponse, HttpHandler, HttpEvent } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { Observable } from 'rxjs';
import { tap } from 'rxjs/operators';

@Injectable()
export class NotificationInterceptor implements HttpInterceptor {
    constructor(private alertService: JhiAlertService) {}

    intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        return next.handle(request).pipe(
            tap(
                (event: HttpEvent<any>) => {
                    if (event instanceof HttpResponse) {
                        const arr = event.headers.keys();
                        let alert = null;
                        let alertParams = null;
                        arr.forEach(entry => {
                            if (entry.toLowerCase().endsWith('app-alert')) {
                                alert = event.headers.get(entry);
                            } else if (entry.toLowerCase().endsWith('app-params')) {
                                alertParams = event.headers.get(entry);
                            }
                        });
                        if (alert) {
                            if (typeof alert === 'string') {
                                this.alertService.success(alert, { param: alertParams }, null);
                            }
                        }
                    }
                },
                (err: any) => {}
            )
        );
    }
}