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

// https://gist.github.com/martinobordin/39bb1fe3400a29c1078dec00ff76bba9
@Injectable()
export class MwHttpDateInterceptor implements HttpInterceptor {
  // Migrated from AngularJS https://raw.githubusercontent.com/Ins87/angular-date-interceptor/master/src/angular-date-interceptor.js
  iso8601 = /^\d{4}-\d\d-\d\dT\d\d:\d\d:\d\d(\.\d+)?(([+-]\d\d:\d\d)|Z)?$/;

  intercept(
    req: HttpRequest<any>,
    next: HttpHandler
  ): Observable<HttpEvent<any>> {
    return next.handle(req).pipe(
      tap(
        (event: HttpEvent<any>) => {
          if (event instanceof HttpResponse) {
            const body = event.body;
            this.convertToDate(body);
          }
        },
        (err: any) => {
          if (err instanceof HttpErrorResponse) {
            if (err.status === 401) {
            }
          }
        }
      )
    );
  }

  convertToDate(body: any): any {
    if (body === null || body === undefined) {
      return body;
    }

    if (typeof body !== 'object') {
      return body;
    }

    for (const key of Object.keys(body)) {
      const value = body[key];
      if (this.isIso8601(value)) {
        body[key] = new Date(value);
      } else if (typeof value === 'object') {
        this.convertToDate(value);
      }
    }
  }

  isIso8601(value: string): boolean {
    if (value === null || value === undefined) {
      return false;
    }

    return this.iso8601.test(value);
  }
}