import { inject, Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { KeycloakProfile } from 'keycloak-js';
import { BehaviorSubject, catchError, EMPTY, Observable, tap } from 'rxjs';
import { User } from '../model/User';

@Injectable({
  providedIn: 'root',
})
export class UserService {
  private http: HttpClient = inject(HttpClient);
  private currentUserSubject = new BehaviorSubject<User | null>(null);
  public currentUser$ = this.currentUserSubject.asObservable();

  constructor() {
    // Initialize with current user data
    this.getCurrentUser().subscribe();
  }

  public getUser(id: string): Observable<User | null> {
    return this.http.get<User | null>(`/backend/user/${id}`).pipe(
      catchError(() => EMPTY),
      tap((user) => this.currentUserSubject.next(user))
    );
  }

  public getCurrentUser(): Observable<User | null> {
    return this.http.get<User | null>('/backend/user').pipe(
      catchError(() => EMPTY),
      tap((user) => this.currentUserSubject.next(user))
    );
  }

  public refreshCurrentUser(): void {
    this.getCurrentUser().subscribe();
  }

  public createUser(id: string, username: string): Observable<User> {
    return this.http
      .post<User>('/backend/user', {
        keycloakId: id,
        username: username,
      })
      .pipe(tap((user) => this.currentUserSubject.next(user)));
  }

  public async getOrCreateUser(userProfile: KeycloakProfile) {
    if (userProfile.id == null) {
      return;
    }
    return await this.getUser(userProfile.id)
      .toPromise()
      .then(async (user) => {
        if (user) {
          return user;
        }

        return await this.createUser(userProfile.id ?? '', userProfile.username ?? '').toPromise();
      });
  }
}