class AuthService {
  static TOKEN_KEY = 'access_token';
  static REFRESH_KEY = 'refresh_token';

  static async login(credentials) {
    const url = `${import.meta.env.VITE_DJANGO_BASE_URL}/api/token/`;

    const resp = await fetch(url, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(credentials),
    });

    if (!resp.ok) {
      let errMsg = resp.statusText;
      try {
        const errData = await resp.json();
        errMsg = errData?.detail ?? errData?.message ?? errMsg;
      } catch (_) { /* ignore */ }
      throw new Error(errMsg);
    }

    const data = await resp.json();

    if (data.access && data.refresh) {
      localStorage.setItem(this.TOKEN_KEY, data.access);
      localStorage.setItem(this.REFRESH_KEY, data.refresh);
    }

    return data;
  }

  static getAccessToken() {
    return localStorage.getItem(this.TOKEN_KEY);
  }

  static getRefreshToken() {
    return localStorage.getItem(this.REFRESH_KEY);
  }

  static async refresh() {
    const refresh = this.getRefreshToken();
    if (!refresh) throw new Error('No refresh token');

    const url = `${import.meta.env.VITE_DJANGO_BASE_URL}/api/token/refresh/`;
    const resp = await fetch(url, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ refresh }),
    });

    if (!resp.ok) {
      const errData = await resp.json().catch(() => ({}));
      throw new Error(errData?.detail ?? resp.statusText);
    }

    const data = await resp.json();
    localStorage.setItem(this.TOKEN_KEY, data.access);
    return data.access;
  }

  static isAuthenticated() {
    return !!this.getAccessToken();
  }

  static logout() {
    localStorage.removeItem(this.TOKEN_KEY);
    localStorage.removeItem(this.REFRESH_KEY);
  }
}

export default AuthService;