const Chat = (function(){
    const cs = {
      e:{/*map of certain DOM elements.*/
        messageInjectPoint: E1('#message-inject-point'),
        pageTitle: E1('head title'),
        loadToolbar: undefined /* the load-posts toolbar (dynamically created) */,
        inputWrapper: E1("#chat-input-area"),
        fileSelectWrapper: E1('#chat-input-file-area'),
        messagesWrapper: E1('#chat-messages-wrapper'),
        inputForm: E1('#chat-form'),
        btnSubmit: E1('#chat-message-submit'),
        inputSingle: E1('#chat-input-single'),
        inputMulti: E1('#chat-input-multi'),
        inputCurrent: undefined/*one of inputSingle or inputMulti*/,
        inputFile: E1('#chat-input-file'),

         list if atEnd is falsy, else at the end of the list, before
         the load-history widget. */
      injectMessageElem: function f(e, atEnd){
        const mip = atEnd ? this.e.loadToolbar : this.e.messageInjectPoint;
        if(atEnd){
          mip.parentNode.insertBefore(e, mip);
        }else{
          const self = this;

          if(false && this.isUiFlipped()){
            /* When UI is flipped, new messages start out under the
               text input area because of its position:sticky
               style. We have to scroll them up. When the page footer
               is not hidden but is not on-screen, this causes a
               slight amount of UI jarring as the footer is *also*
               scrolled into view (for whatever reason).

               The remaining problem here is messages with IMG tags.
               At this point in the process their IMG.src has not yet
               been loaded - that's async. We scroll the message into
               view, but then the downstream loading of IMG.src pushes
               the message content back down, sliding the message
               behind the input field. This can be verified by delaying the
               message scroll by a second or so to give the image time
               to load (from a local server instance).
            */
            D.addClass(self.e.inputWrapper,'unsticky');
          }
          if(mip.nextSibling) mip.parentNode.insertBefore(e, mip.nextSibling);
          else mip.parentNode.appendChild(e);
          if(this.isUiFlipped()){
            //e.scrollIntoView();
            setTimeout(function(){
              //self.e.inputWrapper.scrollIntoView();
              //self.e.fileSelectWrapper.scrollIntoView();
              //e.scrollIntoView();
              //D.removeClass(self.e.inputWrapper,'unsticky');
              self.e.inputWrapper.scrollIntoView();
            },0);
          }
        }
      },
      /** Returns true if chat-only mode is enabled. */
      isChatOnlyMode: ()=>document.body.classList.contains('chat-only-mode'),
      /** Returns true if the UI seems to be in "bottom-up" mode. */
      isUiFlipped: function(){

        updateDropZoneContent(false/*clear prev state*/);
        updateDropZoneContent(items[0].getAsFile());
      }
    }, false);
    /* Add help button for drag/drop/paste zone */
    Chat.e.inputFile.parentNode.insertBefore(
      F.helpButtonlets.create(
        Chat.e.fileSelectWrapper.querySelector('.help-buttonlet')
      ), Chat.e.inputFile
    );
    ////////////////////////////////////////////////////////////
    // File drag/drop visual notification.
    const dropHighlight = Chat.e.inputFile /* target zone */;
    const dropEvents = {
      drop: function(ev){

    p.then(x=>x.json())
      .then(y=>newcontent(y))
      .catch(e=>console.error(e))
    /* ^^^ we don't use Chat.reportError(e) here b/c the polling
       fails exepectedly when it times out, but is then immediately
       resumed, and reportError() produces a loud error message. */
      .finally(function(x){
        if(isFirstCall){
          Chat.ajaxEnd();
          Chat.e.inputWrapper.scrollIntoView();
        }
        poll.running=false;
      });
  }
  poll.running = false;
  poll(true);
  setInterval(poll, 1000);
  F.page.chat = Chat/* enables testing the APIs via the dev tools */;
})();

       z-index higher than this one. */;
}
body.chat.chat-bottom-up #chat-input-area {
  border-bottom: none;
  border-top: 1px solid black;
  margin-bottom: 0;
  margin-top: 0.5em;
  position: initial /*sticky currently disabled due to scrolling-related issues*/;
  bottom: 0;
}
/* An internal hack to try to help resolve a message-scrolling quirk
   when #chat-input-area is sticky on the bottom of the screen. */
body.chat.chat-bottom-up #chat-input-area.unsticky {
  position: initial;
}
/* Widget holding the chat message input field, send button, and
   settings button. */
body.chat #chat-input-line {
  display: flex;
  flex-direction: row;
  margin-bottom: 0.25em;