import { Injectable } from '@angular/core';
import { CanActivate, GuardResult, MaybeAsync, Router } from '@angular/router';
import UserData from '@core/auth/UserData';
import { Configuration } from '@core/server';
import { OidcSecurityService } from 'angular-auth-oidc-client';
import { BehaviorSubject, Observable } from 'rxjs';

@Injectable({
    providedIn: 'root'
})
export class AuthService implements CanActivate {
    public $user: BehaviorSubject<UserData | undefined>;

    constructor(
        private readonly oidcSecurityService: OidcSecurityService, 
        protected apiConfig: Configuration,
        private router: Router
    ) {
        this.$user = new BehaviorSubject<UserData | undefined>(undefined);
        this.oidcSecurityService.checkAuth().subscribe(({ isAuthenticated, userData, accessToken }) => {
            apiConfig.credentials = {JWTAuth: accessToken};
            const isLoggedIn = isAuthenticated && userData != null && accessToken != '';
            this.$user.next(isLoggedIn ? {
                username: userData.preferred_username,
                verified: userData.email_verified
            } : undefined);
        });
    }

    canActivate(): MaybeAsync<GuardResult> {
        return new Observable(() => {
            this.oidcSecurityService.checkAuth().subscribe(({ isAuthenticated }) => {
                if (isAuthenticated) {
                    return true;
                }
                this.login();
                return false;
            });
        });
    }

    login() {
        this.oidcSecurityService.authorize();
    }

    logout() {
        this.oidcSecurityService.logoff().subscribe(() => { });
    }

}