import { Injectable, inject } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Router } from '@angular/router';
import { BehaviorSubject, Observable, tap } from 'rxjs';

interface LoginResponse {
  token: string;
  username: string;
}

@Injectable({
  providedIn: 'root'
})
export class AuthService {
  private http = inject(HttpClient);
  private router = inject(Router);

  private tokenKey = 'flare_token';
  private usernameKey = 'flare_username';

  private loggedInSubject = new BehaviorSubject<boolean>(this.hasToken());
  public loggedIn$ = this.loggedInSubject.asObservable();

  login(username: string, password: string): Observable<LoginResponse> {
    return this.http.post<LoginResponse>('/api/login', { username, password })
      .pipe(
        tap(response => {
          this.setToken(response.token);
          this.setUsername(response.username);
          this.loggedInSubject.next(true);
        })
      );
  }

  logout(): void {
    localStorage.removeItem(this.tokenKey);
    localStorage.removeItem(this.usernameKey);
    this.loggedInSubject.next(false);
    this.router.navigate(['/login']);
  }

  getToken(): string | null {
    return localStorage.getItem(this.tokenKey);
  }

  getUsername(): string | null {
    return localStorage.getItem(this.usernameKey);
  }

  setToken(token: string): void {
    localStorage.setItem(this.tokenKey, token);
  }

  setUsername(username: string): void {
    localStorage.setItem(this.usernameKey, username);
  }

  hasToken(): boolean {
    return !!this.getToken();
  }

  isLoggedIn(): boolean {
    return this.hasToken();
  }
}