let serverUrl = '';

browser.storage.sync.get('serverUrl').then(r => {
  if (r.serverUrl) serverUrl = r.serverUrl.replace(/\/+$/, '');
});

browser.storage.onChanged.addListener(changes => {
  if (changes.serverUrl) {
    serverUrl = changes.serverUrl.newValue.replace(/\/+$/, '');
  }
});

browser.runtime.onMessage.addListener((msg, sender) => {
  switch (msg.kind) {
    case 'list_users':
      return listUsers();
    case 'save_note':
      return saveNote(msg);
    default:
      return Promise.reject(new Error('Unknown message kind'));
  }
});

async function request(path, opts) {
  if (!serverUrl) throw new Error('Server URL not configured');
  opts = opts || {};
  opts.credentials = 'include';
  const res = await fetch(serverUrl + path, opts);
  if (!res.ok) {
    const err = await res.json().catch(() => ({}));
    throw new Error(err.detail || 'HTTP ' + res.status);
  }
  return res.json();
}

async function listUsers() {
  const users = await request('/api/users', { headers: { 'Accept': 'application/json' } });
  return { users: users };
}

async function saveNote(msg) {
  const body = { body: msg.body };
  if (msg.username) body.username = msg.username;

  if (msg.id) {
    return request('/api/notes/' + msg.id, {
      method: 'PUT',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(body),
    });
  }
  return request('/api/notes', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(body),
  });
}