import { createQuicksliceClient } from 'quickslice-client-js';
import { router } from '../router.js';
import { grainApi } from './grain-api.js';

class AuthService {
  #client = null;
  #user = null;
  #listeners = new Set();
  #initialized = false;

  async init() {
    if (this.#initialized) return;

    this.#client = await createQuicksliceClient({
      server: 'https://quickslice-production-9cf4.up.railway.app',
      clientId: 'client_h62Ea0FUeXTJ4pWBg4ZIkQ',
      scope: 'atproto blob:image/* repo:social.grain.gallery repo:social.grain.gallery.item repo:social.grain.photo repo:social.grain.favorite repo:social.grain.graph.follow repo:social.grain.actor.profile repo:social.grain.comment'
    });

    // Handle OAuth callback if present
    if (window.location.search.includes('code=')) {
      await this.#client.handleRedirectCallback();

      // Check if user has a Grain profile
      const hasProfile = await grainApi.hasGrainProfile(this.#client);

      if (!hasProfile) {
        // First-time user - redirect to onboarding
        window.location.replace('/onboarding');
        return;
      }

      // Existing user - redirect to their destination
      const returnUrl = sessionStorage.getItem('oauth_return_url') || '/';
      sessionStorage.removeItem('oauth_return_url');
      window.location.replace(returnUrl);
      return;
    }

    // Load user if authenticated
    if (await this.#client.isAuthenticated()) {
      await this.#loadUser();
    }

    this.#initialized = true;
  }

  async #loadUser() {
    const clientUser = this.#client.getUser();
    const did = clientUser?.did || clientUser?.sub;
    const result = await this.#client.query(`
      query {
        viewer {
          did
          handle
          socialGrainActorProfileByDid {
            displayName
            avatar { url(preset: "avatar") }
          }
        }
      }
    `);
    const viewer = result.viewer;
    const grainProfile = viewer?.socialGrainActorProfileByDid;
    this.#user = {
      did: did || viewer?.did,
      handle: viewer?.handle,
      displayName: grainProfile?.displayName || '',
      avatar: grainProfile?.avatar || null
    };
    this.#notify();
  }

  async login(handle) {
    sessionStorage.setItem('oauth_return_url', window.location.pathname);
    sessionStorage.setItem('oauth_handle', handle);
    window.location.href = '/oauth/callback?start=1';
  }

  async startOAuthFromCallback() {
    const handle = sessionStorage.getItem('oauth_handle');
    sessionStorage.removeItem('oauth_handle');
    if (!handle) {
      router.replace('/');
      return;
    }
    await this.#client.loginWithRedirect({ handle });
  }

  logout() {
    this.#client.logout();
  }

  get user() {
    return this.#user;
  }

  get isAuthenticated() {
    return !!this.#user;
  }

  subscribe(callback) {
    this.#listeners.add(callback);
    return () => this.#listeners.delete(callback);
  }

  #notify() {
    this.#listeners.forEach(cb => cb(this.#user));
  }

  getClient() {
    return this.#client;
  }

  async refreshUser() {
    await this.#loadUser();
  }
}

// Preserve auth instance across HMR
export const auth = window.__auth || (window.__auth = new AuthService());