(function () {
  'use strict';

  // ── Page→Extension messaging (used by the snotes helper page) ─────────────
  window.addEventListener('message', function (event) {
    if (event.source !== window) return;
    var msg = event.data;
    if (!msg || typeof msg.kind !== 'string') return;

    switch (msg.kind) {
      case 'snotes-ping':
        window.postMessage({ kind: 'snotes-pong', version: '1.0.0' }, '*');
        break;
      case 'snotes-settings': {
        var data = {};
        if (msg.serverUrl !== undefined) data.serverUrl = msg.serverUrl;
        if (Object.keys(data).length > 0) browser.storage.sync.set(data);
        window.postMessage({ kind: 'snotes-settings-ack', ok: true }, '*');
        break;
      }
    }
  });

  // ── Extension→Page messaging (capture context for the popup) ──────────────
  browser.runtime.onMessage.addListener(function (msg) {
    if (!msg || typeof msg.kind !== 'string') return Promise.resolve(undefined);

    if (msg.kind === 'get_context') {
      var selection = '';
      try { selection = window.getSelection().toString().trim(); } catch (e) {}
      return Promise.resolve({
        selection: selection,
        title: document.title || '',
        url: window.location.href || '',
      });
    }

    if (msg.kind === 'get_viewport') {
      var ph = Math.max(
        document.documentElement ? document.documentElement.scrollHeight : 0,
        document.body ? document.body.scrollHeight : 0
      );
      return Promise.resolve({
        viewportWidth: window.innerWidth || document.documentElement.clientWidth || 0,
        viewportHeight: window.innerHeight || document.documentElement.clientHeight || 0,
        pageHeight: ph,
        devicePixelRatio: window.devicePixelRatio || 1,
        scrollY: window.scrollY || window.pageYOffset || 0,
      });
    }

    if (msg.kind === 'scroll_to') {
      window.scrollTo(0, msg.y);
      return Promise.resolve({ y: window.scrollY || window.pageYOffset || 0 });
    }

    return Promise.resolve(undefined);
  });
})();