import { writable } from 'svelte/store';

export const track = writable(null);
export const loading = writable(false);
export const error = writable(null);

const CACHE_EXPIRY_MS = 60 * 1000;

function getCachedTrack() {
  if (typeof window === 'undefined') return null;

  const cached = localStorage.getItem('cachedTrack');
  if (!cached) return null;

  try {
    const parsed = JSON.parse(cached);
    if (!parsed.timestamp || !parsed.data) return null;

    const age = Date.now() - parsed.timestamp;
    if (age < CACHE_EXPIRY_MS) {
      return parsed.data;
    } else {
      localStorage.removeItem('cachedTrack');
      return null;
    }
  } catch {
    localStorage.removeItem('cachedTrack');
    return null;
  }
}

if (typeof window !== 'undefined') {
  const cachedTrack = getCachedTrack();
  if (cachedTrack) {
    track.set(cachedTrack);
  }
}

export async function fetchTrack() {
  if (typeof window !== 'undefined' && getCachedTrack()) {
    console.log('%c CACHED - skip fetching', 'font-weight: bold; color: orange;');
    return;
  }

  loading.set(true);
  error.set(null);

  try {
    const res = await fetch('https://lastfm-last-played.biancarosa.com.br/expect69420/latest-song');
    if (!res.ok) throw new Error(`Fetch failed: ${res.status}`);
    const data = await res.json();

    const normalizedTrack = {
      name: data.track.name,
      artist: data.track.artist['#text'],
      album: data.track.album['#text'],
      url: data.track.url,
      nowPlaying: data.track['@attr']?.nowplaying === 'true',
      image: data.track.image.find(img => img.size === 'medium')?.['#text'] || ''
    };

    track.set(normalizedTrack);

    if (typeof window !== 'undefined') {
      localStorage.setItem('cachedTrack', JSON.stringify({
        timestamp: Date.now(),
        data: normalizedTrack
      }));
    }
  } catch (e) {
    error.set(e.message);
    track.set(null);
    if (typeof window !== 'undefined') {
      localStorage.removeItem('cachedTrack');
    }
  } finally {
    loading.set(false);
  }
}