export class Auth {
  constructor(baseUrl = "http://localhost:5000") {
    this.baseUrl = baseUrl;
  }

  /**
   * Verify a session token against the fake auth API.
   * Returns the user ID if valid, or null if invalid.
   */
  async verifySessionToken(token) {
    try {
      const res = await fetch(`${this.baseUrl}/api/verify/${encodeURIComponent(token)}`);
      if (!res.ok) return null;
      const data = await res.json();
      return data.id ?? null;
    } catch (err) {
      console.warn("[Auth] verifySessionToken error:", err);
      return null;
    }
  }

  /**
   * Look up the user's display name by ID.
   */
  async getUserNameById(id) {
    try {
      const res = await fetch(`${this.baseUrl}/api/users`);
      if (!res.ok) return "Unknown";
      const data = await res.json();
      return data[id] ?? `User${id}`;
    } catch (err) {
      console.warn("[Auth] getUserNameById error:", err);
      return `User${id}`;
    }
  }
}