console.log('Pre-request Script from Request start');

// We don't need to do anything if it's GET or x-csrf-token header is explicitly presented
if (pm.request.method !== 'GET' && !(pm.request.headers.has('x-csrf-token'))) {

  var csrfRequest = pm.request.clone();
  csrfRequest.method = 'GET';
  if (pm.request.method === 'POST') {
    // for POST method usually it is ....<something>Collection in the URL
    // so we add $top=1 just to quickly get csrf token;
    // for PUT, PATCH or DELETE the same URL would be enough,
    // because it points to the actual entity
    csrfRequest.url = pm.request.url + '?$top=1';
  }

  csrfRequest.upsertHeader({
    key: 'x-csrf-token',
    value: 'fetch'
  });

  pm.sendRequest(csrfRequest, function(err, res) {
    console.log('pm.sendRequest start');
    if (err) {
      console.log(err);
    } else {
      var csrfToken = res.headers.get('x-csrf-token');
      if (csrfToken) {
        console.log('csrfToken fetched:' + csrfToken);
        pm.request.headers.upsert({
          key: 'x-csrf-token',
          value: csrfToken
        });
      } else {
        console.log('No csrf token fetched');
      }
    }
    console.log('pm.sendRequest end');
  });
}

console.log('Pre-request Script from Request end');