import { HttpErrorResponse, HttpInterceptorFn } from '@angular/common/http';
import { inject } from '@angular/core';
import { AuthService } from '../service/auth.service';
import { catchError, from, switchMap, throwError } from 'rxjs';
import { Router } from '@angular/router';

export const authInterceptor: HttpInterceptorFn = (req, next) => {
    const authService = inject(AuthService);
    const router = inject(Router);
    const token = authService.accessToken();
    if (token) {
        // first we try with the current token
        return next(
            req.clone({
                headers: req.headers.set('Authorization', `Bearer ${token}`),
            }),
        ).pipe(
            catchError((error: HttpErrorResponse) => {
                // if the request with the current token returned 401,
                // try refreshing, then retry the request with the new token
                // for this first scenario, do not retry if we are getting 401 from login or refreshing
                if (
                    error.status === 401 &&
                    !(error.url?.endsWith('auth/login') || error.url?.endsWith('auth/refresh'))
                ) {
                    return authService.refresh().pipe(
                        switchMap((loginView) => {
                            const newToken = loginView.accessToken;
                            return next(
                                req.clone({
                                    headers: req.headers.set('Authorization', `Bearer ${newToken}`),
                                }),
                            );
                        }),
                    );
                } else if (error.status === 401 && error.url?.endsWith('auth/refresh')) {
                    // our refresh token is expired
                    // redirect to login page
                    return from(router.navigate(['/'])).pipe(
                        switchMap(() => throwError(() => error)),
                    );
                } else {
                    return throwError(() => error);
                }
            }),
        );
    } else {
        return next(req);
    }
};