class WorkerChat {

  int workerLongPollTick = 200;

  int workerLongPollMaxWait = 1000*30;

  long lastWorkerRequested; // timestamp for notification sound

  S mainAdminLink = "/";

  O html(DynNewBot2.Req req) null {

    SS params = req.params;

    S uri = req.uri, uri2 = appendSlash(uri);

    bool requestAuthed = req.auth != null;

    Conversation conv = req.conv;

    if (startsWith(uri2, "/worker/")) {

      if (!req.webRequest.isHttps())

        ret subBot_serveRedirect("https://" + req.webRequest.domain() + req.uri + htmlQuery(req.params));

      if (!requestAuthed) ret serveAuthForm(params.get('uri));

      if (nempty(params.get("turnBotOn")))

        conv.turnBotOn();

      ret serveWorkerPage(req);

    }

  }

  // auth is tested before we get here

  S serveWorkerPage(DynNewBot2.Req req) {

    AuthedDialogID auth = req.auth;

    Conversation conv = req.conv;

    S uri = req.uri;

    SS params = req.params;

    S cookie = conv.cookie;

    S uri2 = afterLastSlash(uri);

    if (eq(uri2, "availableWorkers"))

      ret "Available workers: " + or2(joinWithComma(map(workersAvailable(), w -> w.renderAsHTML())), "-");

    if (nempty(params.get('workerLogOut)))

      cset(auth, loggedIn := null);

    if (auth.loggedIn != null && nempty(params.get('workerAvailableBox)))

      if (cset_trueIfChanged(auth.loggedIn, available := nempty(params.get('workerAvailable))))

        noteConversationChange(); // update list of available workers

    if (nempty(params.get("acceptConversation"))) {

      if (conv.worker == null) { // only if not accepted by anyone

        cset(conv, worker := auth.loggedIn);

        conv.turnBotOff();

      }

    }

    S loginID = params.get('workerLogIn);

    if (nempty(loginID))

      cset(auth, loggedIn := getConcept Worker(parseLong(loginID)));

    Map map = prependEmptyOptionForHSelect(mapToOrderedMap(conceptsSortedByFieldCI(Worker, 'loginName),

      w -> pair(w.id, w.loginName)));

    if (auth.loggedIn == null)

      ret hsansserif() + p("You are not logged in as a worker")

        + hpostform(

          "Log in as: " + hselect("workerLogIn", map, conceptID(auth.loggedIn)) + " " + hsubmit("OK"), action := botMod().baseLink + "/worker");

    // We are logged in

    if (eq(uri2, "conversation")) {

      if (conv == null) ret "Conversation not found";

      // Serve the checkbox & the JavaScript

      S onOffURL = botMod().baseLink + "/worker/botOnOff" + hquery(+cookie) + "&on=";

      ret

         hsansserif() + loadJQuery()

       + hhidden(+cookie) // for other frame

       + hpostform(

         hhidden(+cookie) +

         p(renderBotStatus(conv))

          + p(conv.botOn

            ? hsubmit("Accept conversation", name := "acceptConversation")

            : hsubmit("Turn bot back on", name := "turnBotOn"))

          , action := botMod().baseLink + "/worker/innerFrameSet", target := "innerFrameSet")

       // include bot

       + hscriptsrc(botMod().baseLink + "/script" + hquery(workerMode := 1, cookie := conv.cookie));

    }

    if (eq(uri2, "conversations")) {

      cset(auth.loggedIn, lastOnline := now());

      bool poll = eq("1", params.get("poll")); // poll mode?

      S content = "";

      if (poll) {

        long seenChange = parseLong(params.get("lastChange"));

        vmBus_send chatBot_startingWorkerPoll(mc(), conv);

        long start = sysNow();

        L msgs;

        bool first = true;

        while (licensed() && sysNow() < start+workerLongPollMaxWait

          && lastConversationChange == seenChange)

          sleep(workerLongPollTick);

        printVars_str(+lastWorkerRequested, +seenChange);

        if (lastWorkerRequested > seenChange)

          content = hscript([[

            window.parent.parent.frames[0].sendDesktopNotification("A worker is requested!", { action: function() { window.focus(); } });

            window.parent.parent.frames[0].playWorkerRequestedSound();

          ]]);

        // if poll times out, send update anyway to update time calculations

      }

      long pingThreshold = now()-activeConversationTimeout();

      L<Conversation> convos = sortByCalculatedFieldDesc(c -> c.lastMsgTime(),

        conceptsWithFieldGreaterThan Conversation(lastPing := pingThreshold));

      content +=

          hhiddenWithID(+lastConversationChange) + tag table(

          hsimpletableheader("IP", "Country", "Bot/worker status", "Last change", "Last messages")

          + mapToLines(convos, c -> {

            L<Msg> lastMsgs = lastTwo(c.msgs);

            S style = c == conv ? "background: #90EE90" : null;

            S convLink = botMod().baseLink + "/worker/innerFrameSet" + hquery(cookie := c.cookie);

            ret tag tr(

              td(ahref(convLink, c.ip, target := "innerFrameSet")) +

              td(getCountry(c)) +

              td(renderBotStatus(c)) +

              td(renderHowLongAgo(c.lastMsgTime())) +

              td(ahref(convLink, hparagraphs(lambdaMap renderMsgForWorkerChat(lastMsgs)), target := "innerFrameSet", style := "text-decoration: none")), +style, /*class := "clickable-row", "data-href" := convLink*/);

          }), class := "responstable");

      if (poll) ret content;

      S incrementalURL = botMod().baseLink + "/worker/conversations?poll=1&lastChange=";

      ret hhtml(

          hhead(hsansserif() + loadJQuery()

        + hscript_clickableRows())

        + hbody(h3(botName)

        + hpostform(

            "Logged in as "

          + htmlEncode2(auth.loggedIn.loginName)

          + " (display name: " + htmlEncode2(auth.loggedIn.displayName) + ")"

          + hhidden(workerAvailableBox := 1)

          + "   "

          + hcheckboxWithText("workerAvailable", "I am available", auth.loggedIn.available, onclick := "form.submit()")

          + "   "

          + hsubmit("Log out", name := "workerLogOut"),

          target := "innerFrameSet", action := botMod().baseLink + "/worker/innerFrameSet")

        + p("Available workers: " + b(or2(joinWithComma(

          map(workersAvailable(), w -> w.displayName)), "none")))

        + h3("Active conversations")

        + hcss_responstable()

        + hdivWithID("contentArea", content)

        + hscript([[

          function poll_start() {

            var lastChange = $("#lastConversationChange").val();

            if (!lastChange)

              setTimeout(poll_start, 1000);

            else {

              var url = "#INCREMENTALURL#" + lastChange;

              console.log("Loading " + url);

              $.get(url, function(src) {

                if (src.match(/^ERROR/)) console.log(src);

                else {

                  console.log("Loaded " + src.length + " chars");

                  $("#contentArea").html(src);

                }

                setTimeout(poll_start, 1000);

              }, 'text')

                .fail(function() {

                  console.log("Rescheduling after fail");

                  setTimeout(poll_start, 1000);

                });

            }

          }

          poll_start();

        ]].replace("#INCREMENTALURL#", incrementalURL)

        ));

    } // end of worker/conversations part

    if (eq(uri2, "notificationArea"))

      ret hhtml(

          hhead(hsansserif() + loadJQuery())

        + hbody(hdesktopNotifications()

        + div(small(

            span(hbutton("CLICK HERE to enable notification sounds!"), id := "enableSoundsBtn")

          + " | "

          + span("", id := "notiStatus")), style := "float: right")

        + hscript([[

          function enableSounds() {

            document.removeEventListener('click', enableSounds);

            $("#enableSoundsBtn").html("Notification sounds enabled");

          }

          document.addEventListener('click', enableSounds);

          if (window.workerRequestedSound == null) {

            console.log("Loading worker requested sound");

            window.workerRequestedSound = new Audio("https://botcompany.de/files/1400404/worker-requested.mp3");

          }

          function playWorkerRequestedSound() {

            console.log("Playing worker requested sound");

            window.workerRequestedSound.play();

          }

          window.playWorkerRequestedSound = playWorkerRequestedSound;

        ]])));

    if (eq(uri2, "innerFrameSet"))

      // serve frame set 2

      ret hhtml(hhead_title("Worker Chat [" + auth.loggedIn.loginName + "]")

        + hframeset_cols("*,*", 

          tag frame("", name := "conversations", src := botMod().baseLink + "/worker/conversations" + hquery(+cookie)) +

          tag frame("", name := "conversation", src := conv == null ? null : botMod().baseLink + "/worker/conversation" + hquery(+cookie))));

    // serve frame set 1

    ret hhtml(hhead_title("Worker Chat [" + auth.loggedIn.loginName + "]")

      + hframeset_rows("50,*", 

        tag frame("", name := "notificationArea", src := botMod().baseLink + "/worker/notificationArea") +

        tag frame("", name := "innerFrameSet", src := conv == null ? null : botMod().baseLink + "/worker/innerFrameSet" + hquery(+cookie))));

  }

  S renderMsgForWorkerChat(Msg msg) {

    ret (msg.fromWorker != null ? htmlEncode2(msg.fromWorker.displayName) : msg.fromUser ? "User" : "Bot") + ": " + b(htmlEncode2If(shouldHtmlEncodeMsg(msg), msg.text));

  }

  Cl<Worker> workersAvailable() {

    long timestamp = now()-workerLongPollMaxWait-10000;

    ret filter(list(Worker), w -> w.available && w.lastOnline >= timestamp);

  }

  bool anyWorkersAvailable() {

    ret nempty(workersAvailable());

  }

  S renderBotStatus(Conversation conv) {

   ret "Bot is " + b(conv.botOn ? "on" : "off") + "<br>"

     + "Assigned worker: " + b(conv.worker == null ? "none" : conv.worker.displayName);

  }

}