/**
 * Forage Chrome Extension — Background Service Worker
 *
 * Receives capture/signal messages from content.js, reads config from
 * chrome.storage.sync, and POSTs to the Forage server.
 */

const DEFAULT_CONFIG = {
  server: 'http://localhost:4242',
  user_id: 1,
  token: '',
  enabled: true,
};

async function getConfig() {
  return new Promise(resolve => {
    chrome.storage.sync.get(DEFAULT_CONFIG, resolve);
  });
}

function authHeaders(token) {
  const h = { 'Content-Type': 'application/json' };
  if (token) h['Authorization'] = `Bearer ${token}`;
  return h;
}

chrome.runtime.onMessage.addListener((msg, _sender, sendResponse) => {
  handleMessage(msg)
    .then(sendResponse)
    .catch(err => {
      console.error('[Forage bg] error:', err.message);
      sendResponse({ ok: false, error: err.message });
    });
  return true; // keep channel open for async response
});

async function handleMessage(msg) {
  const cfg = await getConfig();
  if (!cfg.enabled) return { ok: false, reason: 'disabled' };

  if (msg.type === 'capture') {
    let res;
    try {
      res = await fetch(`${cfg.server}/capture`, {
        method: 'POST',
        headers: authHeaders(cfg.token),
        body: JSON.stringify({
          url: msg.url,
          canonical_url: msg.canonical_url || '',
          title: msg.title,
          source: msg.source,
          description: msg.description,
          reading_time_min: msg.reading_time_min,
          user_id: cfg.user_id,
        }),
      });
    } catch (e) {
      console.warn('[Forage bg] /capture network error:', e.message);
      return { ok: false, error: e.message };
    }
    const data = await res.json().catch(() => ({}));
    // Store last capture for popup display
    await chrome.storage.local.set({
      last_capture: { title: msg.title, time: Date.now(), item_id: data.item_id },
    });
    return { ok: res.ok, item_id: data.item_id };
  }

  if (msg.type === 'dwell') {
    if (!msg.item_id) return { ok: false, reason: 'no item_id' };
    try {
      await fetch(`${cfg.server}/signal`, {
        method: 'POST',
        headers: authHeaders(cfg.token),
        body: JSON.stringify({
          user_id: cfg.user_id,
          item_id: msg.item_id,
          signal_type: 'dwell',
          duration_ms: msg.duration_ms,
        }),
      });
    } catch (e) {
      console.warn('[Forage bg] /signal network error:', e.message);
      return { ok: false, error: e.message };
    }
    return { ok: true };
  }

  return { ok: false, reason: 'unknown message type' };
}