import { LazyStore } from '@tauri-apps/plugin-store';
import { writable, type Writable } from 'svelte/store';

// Spotify User interface
export interface SpotifyUser {
  id: string;
  display_name: string;
  email?: string;
  country?: string;
  product?: string; // premium, free, etc.
  images?: Array<{ url: string }>;
}

// Spotify auth state
export interface SpotifyAuthState {
  // Developer credentials
  clientId: string | null;
  clientSecret: string | null;
  // OAuth tokens
  accessToken: string | null;
  refreshToken: string | null;
  expiresAt: number | null; // Unix timestamp in milliseconds
  // User data
  user: SpotifyUser | null;
  loggedIn: boolean;
  cacheTimestamp: number | null; // Unix timestamp in seconds
}

// Initialize the store with spotify.json
const store = new LazyStore('spotify.json');

// Default state
const defaultState: SpotifyAuthState = {
  clientId: null,
  clientSecret: null,
  accessToken: null,
  refreshToken: null,
  expiresAt: null,
  user: null,
  loggedIn: false,
  cacheTimestamp: null
};

// Create a writable store for reactive UI updates
export const spotifyAuth: Writable<SpotifyAuthState> = writable(defaultState);

// Load Spotify auth state from store
export async function loadSpotifyAuth(): Promise<void> {
  const clientId = await store.get<string>('clientId');
  const clientSecret = await store.get<string>('clientSecret');
  const accessToken = await store.get<string>('accessToken');
  const refreshToken = await store.get<string>('refreshToken');
  const expiresAt = await store.get<number>('expiresAt');
  const user = await store.get<SpotifyUser>('user');
  const cacheTimestamp = await store.get<number>('cacheTimestamp');

  spotifyAuth.set({
    clientId: clientId ?? null,
    clientSecret: clientSecret ?? null,
    accessToken: accessToken ?? null,
    refreshToken: refreshToken ?? null,
    expiresAt: expiresAt ?? null,
    user: user ?? null,
    loggedIn: !!(accessToken && user),
    cacheTimestamp: cacheTimestamp ?? null
  });
}

// Save client credentials (developer app credentials)
export async function saveClientCredentials(clientId: string, clientSecret: string): Promise<void> {
  await store.set('clientId', clientId);
  await store.set('clientSecret', clientSecret);
  await store.save();

  spotifyAuth.update(s => ({
    ...s,
    clientId,
    clientSecret
  }));
}

// Save OAuth tokens
export async function saveTokens(accessToken: string, refreshToken: string, expiresIn: number): Promise<void> {
  const expiresAt = Date.now() + (expiresIn * 1000);

  await store.set('accessToken', accessToken);
  await store.set('refreshToken', refreshToken);
  await store.set('expiresAt', expiresAt);
  await store.save();

  spotifyAuth.update(s => ({
    ...s,
    accessToken,
    refreshToken,
    expiresAt
  }));
}

// Save user data
export async function saveUser(user: SpotifyUser): Promise<void> {
  await store.set('user', user);
  await store.save();

  spotifyAuth.update(s => ({
    ...s,
    user,
    loggedIn: true
  }));
}

// Clear auth (logout)
export async function clearSpotifyAuth(): Promise<void> {
  await store.delete('accessToken');
  await store.delete('refreshToken');
  await store.delete('expiresAt');
  await store.delete('user');
  await store.save();

  spotifyAuth.update(s => ({
    ...s,
    accessToken: null,
    refreshToken: null,
    expiresAt: null,
    user: null,
    loggedIn: false
  }));
}

// Check if token is expired or about to expire (within 5 minutes)
export function isTokenExpired(expiresAt: number | null): boolean {
  if (!expiresAt) return true;
  const bufferTime = 5 * 60 * 1000; // 5 minutes in milliseconds
  return Date.now() >= (expiresAt - bufferTime);
}

// Save cache timestamp
export async function saveCacheTimestamp(timestamp: number): Promise<void> {
  await store.set('cacheTimestamp', timestamp);
  await store.save();

  spotifyAuth.update(s => ({
    ...s,
    cacheTimestamp: timestamp
  }));
}

// Initialize on module load
loadSpotifyAuth();