import { Injectable, signal } from '@angular/core';
import { Router } from '@angular/router';

export type UserRole = 'admin' | 'employee';

export interface User {
  role: UserRole;
  displayName: string;
}


@Injectable({
  providedIn: 'root',
})
export class AuthService {
  private readonly SESSION_KEY = 'userRole';

  private readonly USERS: Record<UserRole, { password: string; displayName: string }> = {
    admin: { password: 'admin123', displayName: 'Admin' },
    employee: { password: 'employee123', displayName: 'Mitarbeiter' },
  };

  user = signal<User | null>(this.loadUserFromSession());

  constructor(private router: Router) {}

  private loadUserFromSession(): User | null {
    const stored = sessionStorage.getItem(this.SESSION_KEY);
    return stored ? JSON.parse(stored) as User : null;
  }

  login(role: UserRole, password: string): boolean {
    const user = this.USERS[role];
    if (!user) {
      return false
    };

    if (password === user.password) {
      const userObj: User = { role, displayName: user.displayName };
      sessionStorage.setItem(this.SESSION_KEY, JSON.stringify(userObj));
      this.user.set(userObj);
      return true;
    }
    return false;
  }

  logout() {
    sessionStorage.removeItem(this.SESSION_KEY);
    this.user.set(null);
    this.router.navigate(['/']);
  }

  getUserDataByRole(role: UserRole): User | null {
    const userDef = this.USERS[role];
    return userDef ? { role, displayName: userDef.displayName } : null;
  }

  isLoggedIn(role?: UserRole): boolean {
    const current = this.user();
    if (!current) return false;
    return role ? current.role === role : true;
  }
}