import { HttpClient } from '@angular/common/http';
import { computed, Injectable, inject, signal } from '@angular/core';

interface UserResponse {
  authenticated: boolean;
  username?: string;
  email?: string;
}

export type SessionStatus = 'checking' | 'authenticated' | 'anonymous' | 'signing-out' | 'error';

@Injectable({ providedIn: 'root' })
export class SessionService {
  private readonly http = inject(HttpClient);
  readonly status = signal<SessionStatus>('checking');
  readonly isLoggedIn = computed(() => this.status() === 'authenticated');
  readonly username = signal('');
  readonly email = signal('');

  refresh(): void {
    this.status.set('checking');
    this.http.get<UserResponse>('/api/user').subscribe({
      next: (user) => {
        this.status.set(user.authenticated ? 'authenticated' : 'anonymous');
        this.username.set(user.authenticated ? user.username || 'User' : '');
        this.email.set(user.authenticated ? user.email || '' : '');
      },
      error: () => {
        this.status.set('error');
        this.username.set('');
        this.email.set('');
      },
    });
  }

  logout(): void {
    if (this.status() === 'signing-out') return;
    this.status.set('signing-out');
    this.http.post('/logout', null, { responseType: 'text' }).subscribe({
      next: () => {
        window.location.href = '/';
      },
      error: () => {
        this.status.set('authenticated');
        window.alert('Impossible de vous déconnecter. Réessayez.');
      },
    });
  }
}