function toggle_nudge_dropdown(user_id, button_index) {
  var dropdown_elt = document.getElementById('nudge-dropdown-' + user_id);
  if(!dropdown_elt) return;
  if(dropdown_elt.className == 'nudge-dropdown nudge-dropdown-closed') {
    dropdown_elt.className = 'nudge-dropdown nudge-dropdown-open';
    hide_nudge_buttons_except(button_index);
  }
  else {
    dropdown_elt.className = 'nudge-dropdown nudge-dropdown-closed';
    reveal_all_nudge_buttons();
  }
}


function send_nudge(nudge_type, user_id) {
  var dropdown_elt = document.getElementById('nudge-dropdown-' + user_id);

  if(!dropdown_elt) return;
  dropdown_elt.className = 'nudge-dropdown nudge-dropdown-sending';

  var ajax_url = '/nudges/send_nudge_ajax';
  new Ajax.Request(ajax_url, {
    method: 'post',
    parameters: {
      to_user_id: user_id + '',
      nudge_type: nudge_type
    },
    onSuccess: function (transport) {
      dropdown_elt.className = 'nudge-dropdown nudge-dropdown-sent-successfully';
      reveal_all_nudge_buttons();
    },
    onFailure: function (transport) {
      dropdown_elt.className = 'nudge-dropdown nudge-dropdown-failed';
      reveal_all_nudge_buttons();
    }
  });
  return false;
}


function hide_nudge_buttons_except(button_index) {
  var i, elt;
  for(i = 0; ; i++) {
    if((elt = document.getElementById('nudge-button-index-' + i)) != null) {
      if(i != button_index)
        Element.hide(elt);
    }
    else
      break;
  }
}


function reveal_all_nudge_buttons() {
  var i, elt;
  for(i = 0; ; i++) {
    if((elt = document.getElementById('nudge-button-index-' + i)) != null) 
      Element.show(elt);
    else
      break;
  }
}