define(['jquery', 'core/log', 'mod_minilesson/definitions',
        'mod_minilesson/ttrecorder', 'core/templates', 'core/str', 'core/fragment'],
function($, log, def, ttrecorder, templates, str, Fragment) {
    "use strict"; // jshint ;_;

    /*
    This file is to manage the free speaking item type
        */

      log.debug('MiniLesson AudioChat: initialising');

    return {
        autocreateresponse : false, // If true, the response will be created automatically
        gradingrequesttag: "gradingrequest", // Tag for the grading request
        gradingData: false, // Data returne by the grading request
        strings: {},
        controls: {}, // Controls for the item
        itemdata: {}, // Item data for the item
        index: 0, // Index of the item in the quiz
        quizhelper: {}, // Quiz helper for the item
        pc: null,
        dc: null,
        cantChat: false,
        audiochat_voice: "alloy", // Default voice for the AI
        isSessionStarted: false,
        isSessionStopped: false,
        isSessionActive: false,
        isLoading: false,
        isMicActive: false,
        isMicInitialized: false, // True when getUserMedia has successfully run once
        loadingMessages: new Set(), // To track messages that are currently loading,
        audioContext: null,
        analyser: null,
        dataArray: null,
        sourceNode: null,
        mediaStream: null,
        animationFrameId: null,
        canvasCtx: null,
        eventlogs: [],
        items: {},
        responses: {},
        abortcontroller: new AbortController(),
        datainputbuffer: false,
        inputBufferInterval: null,
        //Turn detection - semantic is good for native speakers, but awful for language learners
        // time based we give 3.5s of silence detection before posting
        semantic_vad: {
            type: "semantic_vad",
            eagerness: "low",
        },

        timebased_vad: {
            type: "server_vad",
            silence_duration_ms: 3500,
            create_response: true, // true = it will turn on and off the mic and respond
            interrupt_response: true, // only in conversation mode
            threshold: 0.3,
            //  "prefix_padding_ms": 300,
        },

        // For making multiple instances
        clone: function() {
            return $.extend(true, {}, this);
        },

        init: function(index, itemdata, quizhelper) {
            this.itemdata = itemdata;
            this.autocreateresponse = itemdata.audiochat_autoresponse || false;
            log.debug('itemdata', itemdata);
            this.quizhelper = quizhelper;
            this.index = index;
            this.cantChat = !itemdata.canchat;
            this.init_strings();
            this.init_controls(quizhelper, itemdata);
            this.init_voice(itemdata.audiochat_voice);
            this.register_events(index, itemdata, quizhelper);
            this.renderUI();
        },

        init_strings: function() {
            var self = this;
            // Set up strings
            str.get_strings([
                { "key": "gradebywordcount", "component": "mod_minilesson" },
            ]).done(function (s) {
                var i = 0;
                self.strings.gradebywordcount = s[i++];
            });
        },

        next_question: function() {
            var self = this;
            var stepdata = {};
            stepdata.index = self.index;
            stepdata.hasgrade = true;
            stepdata.lessonitemid = self.itemdata.id;
            stepdata.totalitems = self.itemdata.totalmarks;
            stepdata.resultsdata = {'items': Object.values(self.items)};
            // Add grade and other results data
            stepdata= self.grade_activity(stepdata);
            stepdata.correctitems = Math.round((self.itemdata.totalmarks * stepdata.grade) / 100);
            self.quizhelper.do_next(stepdata);
        },

        count_words: function() {
            var self = this;
            var userTranscript = [];
            Object.values(self.items).forEach(item => {
                if (item.content) {
                    userTranscript.push(item.content);
                }
            });
            var wordCount = userTranscript.join(' ').split(/\s+/).length;
            return wordCount;
        },

        toggle_autocreate_response: function() {
            var self = this;
            self.autocreateresponse = !self.autocreateresponse;
            self.timebased_vad.create_response = self.autocreateresponse;
            log.debug("Autocreate response toggled:", self.autocreateresponse);
            self.dc.send(JSON.stringify({
                type: "session.update",
                session: {
                    turn_detection: self.timebased_vad,
                }
            }));
        },

        grade_activity: function(stepdata) {
            //loop through items and form a complete user transcript
            var self = this;

            //count words in the transcript
            var wordcount = self.count_words();

            if(self.gradingData && self.gradingData.score !== undefined) {
                log.debug("Using grading data from AI:", self.gradingData);
                // If grading data is available, use it
                stepdata.grade = self.gradingData.score;

                //If target word count is greater then 0, we lower the grade if it is lower then that target word count
                if(typeof stepdata.grade === 'number' &&
                    typeof wordcount === 'number' &&
                    self.itemdata.targetwordcount > 0 &&
                     wordcount < self.itemdata.targetwordcount) {
                    stepdata.grade = Math.round(stepdata.grade * (wordcount / self.itemdata.targetwordcount));
                }


                stepdata.resultsdata.aifeedback = self.gradingData.feedback || "";
                stepdata.resultsdata.gradeexplanation = self.gradingData.gradeexplanation || "";

            } else {
                //Otherwise we default to counting words
                log.debug("No grading data from AI: counting words", self.gradingData);
                stepdata.resultsdata.gradeexplanation = self.strings.gradebywordcount;
                if(self.itemdata.countwords === false || self.itemdata.targetwordcount === 0){
                    stepdata.grade =  100;
                }



                // Calculate grade based on word count
                stepdata.grade = Math.min(wordcount / self.itemdata.targetwordcount, 1) * 100;

            }

            // return stepdata
            return stepdata;

        },

        register_events: function(index, itemdata, quizhelper) {

            var self = this;

            // Event Listeners
            self.controls.startSessionBtn.addEventListener("click", self.startSession.bind(this));
            self.controls.stopSessionBtn.addEventListener("click", self.stopSession.bind(this));
            self.controls.retrySessionBtn.addEventListener("click", self.resetSession.bind(this));
            self.controls.autocreateresponseCheckbox.addEventListener("change", self.toggle_autocreate_response.bind(self));
            self.controls.cancelStartSessionBtn.addEventListener("click", () => {
                log.debug("Cancelling session start");
                self.abortcontroller.abort();
                self.abortcontroller = new AbortController();
            });

            $(self.controls.nextbutton).on('click', function() {
                self.next_question();
            });

            var container = $(self.controls.container);
            container.on('showElement', () => {
                if (itemdata.timelimit > 0) {
                    container.find(".progress-container").show();
                    container.find(".progress-container i").show();
                    container.find(".progress-container #progresstimer").progressTimer({
                        height: '5px',
                        timeLimit: itemdata.timelimit,
                        onFinish: function() {
                            nextbutton.trigger('click');
                        }
                    });
                }
            });


            if (self.controls.toggleMicBtn) {
                self.controls.toggleMicBtn.addEventListener("click", self.toggleMute.bind(self))
            }
        },

        init_voice: function(voice) {
            var self = this;
            var voices = ['alloy', 'ash', 'ballad', 'coral', 'echo', 'sage', 'shimmer', 'verse', 'marin', 'cedar'];
            if (voice && voices.includes(voice)) {
                self.audiochat_voice = voice;
            } else {
                self.audiochat_voice = 'alloy'; // Default voice
            }
            log.debug("AudioChat voice set to:", this.audiochat_voice);
        },

        init_controls: async function() {
            var self = this;
            var container = document.getElementById(self.itemdata.uniqueid + "_container");
            self.controls = {
                hiddenaudio: container.querySelector('.ml_ac_hiddenaudio'),
                nextbutton: container.querySelector('.minilesson_nextbutton'),
                cantChatWarning: container.querySelector(".ml_ac_cantchat"),
                startSessionBtn: container.querySelector(".ml_ac_start-session-btn"),
                stopSessionBtn: container.querySelector(".ml_ac_stop-session-btn"),
                loadingIndicator: container.querySelector(".ml_ac_loading-indicator"),
                aiAvatarSection: container.querySelector(".ml_ac_ai-avatar-section"),
                chatActiveMessage: container.querySelector(".ml_ac_chat-active-message"),
                conversationSection: container.querySelector(".ml_ac_conversation-section"),
                messagesContainer: container.querySelector(".ml_ac_messages-container"),
                micButtonContainer: container.querySelector(".mic-button-container"),
                toggleMicBtn: container.querySelector(".toggle-mic-btn"),
                micIcon: container.querySelector(".mic-icon"),
                micWaveformCanvas: container.querySelector(".mic-waveform-canvas"),
                micSelect: container.querySelector('.ml_ac_micselect'),
                finishMessage: container.querySelector('.ml_ac_finished-message'),
                retrySessionBtn: container.querySelector('.ml_ac_retrybtn'),
                cancelStartSessionBtn: container.querySelector('.ml_ac_cancel-start-session-btn'),
                autocreateresponseCheckbox: container.querySelector('.ml_ac_autoresponse-checkbox'),
                resultscontainer: container.querySelector('.ml_ac_results_container'),
                resultscontent: container.querySelector('.ml_ac_results_content'),
                autocreateresponseToggle: container.querySelector('.ml_ac_autoresponse-toggle'),

                clicktosendlabel: container.querySelector('.ml_ac_clicktosend'),
                mainWrapper: container.querySelector('.minilesson_audiochat_box .ml_unique_mainwrapper'),
            };
            self.canvasCtx = !self.controls.micWaveformCanvas ? null :
                self.controls.micWaveformCanvas.getContext("2d");

            // Initial render
            await self.populateMicList();

        },

        scrollToBottom: function() {
            var self = this;
            self.controls.conversationSection.firstElementChild.scrollIntoViewIfNeeded();
            self.controls.conversationSection.firstElementChild.scrollTop = self.controls.conversationSection.firstElementChild.scrollHeight;
        },

        scrollMicButtonIntoView: function() {
            var self = this;
            if (self.controls.micButtonContainer) {
                self.controls.micButtonContainer.scrollIntoView({behavior: "smooth", block: "center"});
            }
        },

        renderUI: function() {
            var self = this;
            // Session Controls
            self.controls.startSessionBtn.classList.toggle("hidden", self.isSessionActive || self.isLoading || self.isSessionStarted || self.cantChat);
            self.controls.cantChatWarning.classList.toggle("hidden", !self.cantChat);
            self.controls.loadingIndicator.classList.toggle("hidden", !self.isLoading);
            self.controls.stopSessionBtn.classList.toggle("hidden", !self.isSessionActive);
            self.controls.micButtonContainer.classList.toggle("hidden", !self.isSessionActive);
            var endScreen = self.isSessionStarted && self.isSessionStopped;
            self.controls.resultscontainer.classList.toggle("hidden", !endScreen && self.quizhelper.showitemreview);
            self.controls.finishMessage.classList.toggle("hidden", !endScreen);
            self.controls.retrySessionBtn.classList.toggle("hidden", !endScreen && self.itemdata.allowretry);
            // We no longer show the cancel button. It does not work after changes we made to icegathering.
            // If we set abortcontroller.signal to work with it will work, but it is complex
            //self.controls.cancelStartSessionBtn.classList.toggle('hidden', !(self.isLoading && !self.isSessionActive));
            self.controls.autocreateresponseToggle.classList.toggle("hidden", !self.isSessionActive);
            if (self.controls.micSelect) {
                //how many options are in micselect
                var mics = self.controls.micSelect.querySelectorAll('option');
                var noshowmics = mics.length < 2;
                self.controls.micSelect.parentElement.classList.toggle(
                    'hidden',
                    noshowmics || self.isSessionStarted || self.isLoading || self.controls.micSelect.disabled
                );
            }

            var orderedItems = [];
            var idMap = new Map();
            var previousMap = new Map();
            var currentItem;
            Object.values(self.items).forEach(item => {
                idMap.set(item.id, item);
                previousMap.set(item.previous_item_id, item);
                if (item.previous_item_id === null) {
                    currentItem = item;
                }
            });
            while (currentItem) {
                orderedItems.push(currentItem);
                currentItem = previousMap.get(currentItem.id);
            }

            // The cute dog avatar
            self.controls.aiAvatarSection.classList.toggle("hidden", self.isSessionStarted || self.isSessionActive || self.isSessionStopped);
            //The chat session is active message
            self.controls.chatActiveMessage.classList.toggle("hidden", !self.isSessionActive);
            // The conversation area
            self.controls.conversationSection.classList.toggle("hidden", !(self.isSessionActive || self.isSessionStopped));

            // Render messages
            self.controls.messagesContainer.innerHTML = ""; // Clear existing messages

            orderedItems.forEach((message) => {
                if (!message.content) {
                    return;
                }
                var messageDiv = document.createElement("div");
                messageDiv.className = `flex ${message.usertype === "user" ? "justify-end" : "justify-start"} ml_unique_ordered_message_${message.usertype === "user" ? "user" : "assistant"}`;

                var contentDiv = document.createElement("div");
                contentDiv.className = `max-w-xs lg:max-w-md px-4 py-2 rounded-lg ${
                        message.usertype === "user" ? "bg-blue-500 text-white" : "bg-gray-200 text-gray-800"
                    } ml_unique_content_${
                        message.usertype === "user" ? "user" : "assistant"
                    }`;

                var headerDiv = document.createElement("div");
                headerDiv.className = "flex items-center text-xs font-medium mb-1 ml_unique_headerdiv";
                if (message.usertype === "assistant") {
                    var pictureDiv = document.createElement('div');
                    pictureDiv.innerHTML = `
                        <img src="${self.itemdata.avatarimage}?themerev=${M.cfg.themerev}" 
                        alt="AI Assistant" class="mr-2 rounded-circle shadow-lg ml_unique_assistant_img">
                        `;
                    headerDiv.appendChild(pictureDiv);
                }
                headerDiv.innerHTML += message.usertype === "user" ? "Student" : "AI Assistant";
                contentDiv.appendChild(headerDiv);

                var textDiv = document.createElement("div");
                textDiv.className = "text-sm ml_unique_textsmall";
                textDiv.textContent = message.content;
                contentDiv.appendChild(textDiv);

                if (self.loadingMessages.has(message.id)) {
                    var loaderDiv = document.createElement("div");
                    loaderDiv.className = "flex items-center space-x-1 py-1 message-loader ml_unique_loadingmessage";
                    loaderDiv.innerHTML = `
                        <div class="flex space-x-1 ml_unique_loader">
                            <div class="w-2 h-2 bg-current rounded-full ml_unique_loader_dot"></div>
                            <div class="w-2 h-2 bg-current rounded-full ml_unique_loader_dot"></div>
                            <div class="w-2 h-2 bg-current rounded-full ml_unique_loader_dot"></div>
                        </div>
                        <span class="text-xs opacity-70 ml_unique_loader_text">AI is thinking...</span>
                    `;
                    contentDiv.appendChild(loaderDiv);
                }

                messageDiv.appendChild(contentDiv);
                self.controls.messagesContainer.appendChild(messageDiv);
            });

            self.scrollToBottom();
           // self.scrollMicButtonIntoView();

            // Update mic button container and canvas visibility
            if (self.controls.micButtonContainer) {
                self.controls.micButtonContainer.classList.toggle("active", self.isMicActive);
                self.controls.micButtonContainer.classList.toggle("bg-blue-500", self.isMicActive); // Active background color
                self.controls.micButtonContainer.classList.toggle("text-white", self.isMicActive); // Active icon color
                self.controls.micButtonContainer.classList.toggle("bg-gray-200", !self.isMicActive); // Inactive background color
                self.controls.micButtonContainer.classList.toggle("text-gray-800", !self.isMicActive); // Inactive icon color
            }


            if (self.controls.micWaveformCanvas) {
                self.controls.micWaveformCanvas.classList.toggle("active", self.isMicActive);
            }

            if (self.controls.micIcon) {
                // Set icon based on mic state
                self.controls.micIcon.innerHTML = self.isMicActive
                    ? `<rect id="primary" x="2" y="2" width="20" height="20" rx="2" style="fill: rgb(0, 0, 0);"></rect>` // Mic On icon
                    : `<path id="secondary" d="M12,15h0a4,4,0,0,1-4-4V7a4,4,0,0,1,4-4h0a4,4,0,0,1,4,4v4A4,4,0,0,1,12,15Z" style="fill: rgb(44, 169, 188); stroke-width: 2;"></path><path id="primary" d="M18.24,16A8,8,0,0,1,5.76,16" style="fill: none; stroke: rgb(0, 0, 0); stroke-linecap: round; stroke-linejoin: round; stroke-width: 2;"></path><path id="primary-2" data-name="primary" d="M12,19v2m4-10V7a4,4,0,0,0-4-4h0A4,4,0,0,0,8,7v4a4,4,0,0,0,4,4h0A4,4,0,0,0,16,11Z" style="fill: none; stroke: rgb(0, 0, 0); stroke-linecap: round; stroke-linejoin: round; stroke-width: 2;"></path>`; // Mic Off icon
            }

            //show or not show clicktosendlabel
            if (self.isMicActive && !self.autocreateresponse) {
                self.controls.clicktosendlabel.classList.remove("hidden");
            } else {
                self.controls.clicktosendlabel.classList.add("hidden");
            }

        },

        //setter for datainputbuffer
        setDataInputBuffer: function(value, source) {
            var self = this;
            self.datainputbuffer = value;
            log.debug("Data in input buffer set to:", value);
            log.debug("Data input buffer set source:", source);
        },

        resetSession: function() {
            log.debug("reset  session");
            var self = this;
            self.isLoading = false;
            self.isSessionActive = false;
            self.isSessionStopped = false;
            self.isSessionStarted = false;
            self.renderUI();
        },

        startSession: async function() {
            var self = this;
            var twoletterlang = self.itemdata.language.substr(0, 2);
            var hiddenaudio = self.controls.hiddenaudio;
            log.debug("Session starting");
            self.isLoading = true;
            self.items = [];
            self.renderUI();
            // Open the RTC PeerConnection via Stun and ICE servers
            log.debug("Opening peer connection...");
            self.pc = new RTCPeerConnection({
                iceServers: [{
                    urls: "stun:stun.l.google.com:19302"
                }]
            });

            // Create a DataChannel for sending events (text and audio)
            log.debug("creating data channel...");
            self.dc = self.pc.createDataChannel("oai-events");

            // Handle incoming messages on the DataChannel
            self.dc.onmessage = (e) => {
                self.eventlogs.push(e.data);
                //log.debug("DataChannel message:", e.data);
                try {
                    var lines = e.data.split("\n").filter(Boolean);
                    for (var line of lines) {
                        self.handleRTCEvent.call(self, JSON.parse(line));
                    }
                } catch (err) {
                    log.debug("Failed to parse", err);
                }
            };
            self.dc.onopen = () => {
                log.debug("DataChannel open");

                //Turn detection - semantic is good for native speakers, but awful for language learners
                // time based we give 1.5s of silence detection before posting
                var semantic_vad ={
                    type: "semantic_vad",
                    eagerness: "low",
                };

                // Set the auto turn detection, or manual submit flag
                self.timebased_vad.create_response = self.autocreateresponse;

                log.debug(self.itemdata.audiochatinstructions);
                var updateinstructions = self.itemdata.audiochatinstructions;
                Fragment.loadFragment(
                    'mod_minilesson',
                    'audiochat_fetchstudentsubmission',
                    M.cfg.contextid,
                    {
                        itemid: self.itemdata.id
                    }
                ).done(function(studentsubmission) {
                    log.debug("Loaded audio chat studentsubmission:", studentsubmission);
                    if(studentsubmission) {
                        // Replace "{student submission}" placeholder with actual submission
                        updateinstructions = updateinstructions.replace('{student submission}', studentsubmission);
                        
                        // Replace student submission in grade instructions too
                        self.itemdata.audiochatgradeinstructions = self.itemdata.audiochatgradeinstructions.replace('{student submission}', studentsubmission);

                        // Save student submission in itemdata for later use
                        self.itemdata.studentsubmission = studentsubmission;
                    }

                    self.sendEvent({
                        type: "session.update",
                        session: {
                            instructions: updateinstructions,
                            input_audio_format: "pcm16", // Ensure correct audio encoding
                            input_audio_transcription: {
                                language: twoletterlang,
                                model: "whisper-1" // "gpt-4o-mini-transcribe"  // Use a transcription model
                            },
                            turn_detection: self.timebased_vad,
                            speed: 0.9,
                            voice: self.audiochat_voice,
                            modalities: ["text", "audio"],
                        }
                    });

                    // Send the first message to tell AI to say something
                    // the response create function overrides the session instructions, so we need to double up here
                    var firstmessageinstructions =  "Please introduce yourself to the student and explain todays topic.";
                        self.sendEvent({
                        type: "response.create",
                        response: {
                            modalities: ["audio", "text"],
                            instructions:  updateinstructions + " " + firstmessageinstructions,
                            voice: self.audiochat_voice
                        }
                    });
                });
            };

            // Set up the audio element to play incoming audio.
            self.pc.ontrack = (event) => {
                hiddenaudio.srcObject = event.streams[0];
            };

            // Set up the Mic stream.
            self.mediaStream = await navigator.mediaDevices.getUserMedia({audio: true});
            self.mediaStream.getTracks().forEach((track) => {
                track.enabled = false;
                self.pc.addTrack(track, self.mediaStream);
            });

            // Set up the RTC Connection by bouncing our request off the Moodle server
            var offer = await self.pc.createOffer({
                offerToReceiveAudio: true
            });
            await self.pc.setLocalDescription(offer);
            // Search for server candidates for relaying messages, may take 15s
            await self.waitForIceGathering(self.pc);

            try {
                var sdpResponse = await fetch(M.cfg.wwwroot + "/mod/minilesson/openairtc.php", {
                    method: "POST",
                    headers: {
                        "Content-Type": "application/sdp"
                    },
                    body: self.pc.localDescription.sdp,
                    signal: self.abortcontroller.signal
                });
                if (!sdpResponse.ok) {
                    log.debug("Failed /rtc:", await sdpResponse.text());
                    return;
                }
                log.debug("Received SDP answer from server");
                var answer = await sdpResponse.text();
                log.debug(answer);
                await self.pc.setRemoteDescription({
                    type: "answer",
                    sdp: answer
                });
                log.debug("Session started");
            } catch(e) {

                if (e.name === 'AbortError') {
                    log.debug("Session start aborted by user.");
                    // Reset UI and state as needed
                    self.isLoading = false;
                    self.renderUI();
                    return;
                }

                // Close data channel if open
                if (self.dc) {
                    self.dc.close();
                }
                // Close peer connection if open
                if (self.pc) {
                    self.pc.close();
                }
                if (self.mediaStream) {
                    self.mediaStream.getTracks().forEach((track) => track.stop());
                }
                self.isLoading = false;
                self.renderUI();
                return;
            }

            self.isLoading = false;
            self.isSessionActive = true;
            self.isSessionStarted = true;
            self.isSessionStopped = false;
            self.renderUI();
        },

        sendGradingRequest: function() {
            var self = this;
            // Send a final message to tell AI to grade the session and give feedback
            var gradingInstructions = "Please provide a percentage score for the session, an explanation of the score (for teachers), and feedback (for the student). " +
                 self.itemdata.audiochatgradeinstructions +
                "Return the response as JSON in the format: {\"score\": \"the score  ( 0-100 ) \", \"gradeexplanation\": \"the explanation\", \"feedback\": \"the feedback\"}.";

            var responsedata = {
                // The response is out of band and not be added to the default conversation
                conversation: "none",
                modalities: ["text"],
                instructions: gradingInstructions,
                // Add the gradingrequest tag to make handltertc life easier
                metadata: { tag: self.gradingrequesttag},
                max_output_tokens: 500, // Keeps it tight
                temperature: 0.6, // Optional: makes grading more deterministic
            };

            //If we wanted to reutrn an audio response (but lets not)
            //responsedata.voice = self.audiochat_voice;

            self.sendEvent({
                type: "response.create",
                response: responsedata,
            });
        },

        stopSession: function() {
            var self = this;

            log.debug("Session stopping...");
            self.isSessionActive = false;
            self.isSessionStopped = true;
            self.loadingMessages.clear();

            // Release mic resources when session ends
            self.releaseMicResources();
            self.renderUI();

            // request grading information
            // after that response, we will close the data channel and peer connection
            //but shut it down after 2s just in case there is an error or something
            if(self.itemdata.audiochatgradeinstructions && self.itemdata.audiochatgradeinstructions !== "") {
                self.sendGradingRequest();

                //add a spinner to the results content
                //if we are not showing item review we do not need this, but in that case it is hidden anyway
                self.controls.resultscontent.innerHTML = `<i class="fa fa-spinner fa-spin fa-2x"></i>`;

                setTimeout(() => {
                    //now show the results content if that is what we are doing
                    if(self.quizhelper.showitemreview) {
                        self.showResults();
                    }
                    log.debug("Closing session resources...");
                    self.closeDataChannel();
                }, 7000);
            }else{
                log.debug("Closing session resources...");
                self.closeDataChannel();
            }
            log.debug("Session stopped");
        },

        closeDataChannel: function() {
            var self = this;
            // Tidy up the data channel and peer connection
            if (typeof self.dc !== 'undefined' && self.dc) {
                self.dc.close();
                self.dc = null;
            }
            if (typeof self.pc !== 'undefined' && self.pc) {
                self.pc.close();
                self.pc = null;
            }
        },

        showResults: function(){
            var self = this;
            var tdata = {};
            tdata.resultsdata = {'items': Object.values(self.items)};
            // Add grade and other results data
            tdata = self.grade_activity(tdata);

            //calculate stars from grade
            const stars = [];
            const maxStars = 5;
            // if tdata grade is NAn or undefined, set it to 0
            if (typeof tdata.grade === 'undefined' || isNaN(tdata.grade) || tdata.grade === null || tdata.grade === "") {
                tdata.grade = 0;
            }

            const filledStars = Math.round((tdata.grade / 100) * maxStars);
            for (let i = 0; i < maxStars; i++) {
                stars.push({ filled: i < filledStars });
            }
            tdata.stars = stars;

            templates.render('mod_minilesson/audiochatimmediatefeedback', tdata).then(
                function(html, js) {
                    self.controls.resultscontent.innerHTML = html;
                }
            );
        },

        waitForIceGathering: function(pc, timeout = 15000) {
            return new Promise((resolve) => {
                let timer;

                function checkState() {
                    if (pc.iceGatheringState === "complete") {
                        clearTimeout(timer);
                        pc.removeEventListener("icegatheringstatechange", checkState);
                        resolve();
                    }
                }

                pc.addEventListener("icegatheringstatechange", checkState);

                // Timeout to resolve with current state
                timer = setTimeout(() => {
                    pc.removeEventListener("icegatheringstatechange", checkState);
                    resolve(); // Resolve with as many candidates as gathered so far
                }, timeout);
            });
        },

        sendEvent: function(obj) {
            var self = this;
            if (self.dc && self.dc.readyState === "open") {
                self.dc.send(JSON.stringify(obj));
            }
        },

        handleRTCEvent: function(msg) {
            var self = this;
            log.debug("Received event:");

            // Check if its the final grading message, which we don't want to enter "items"
            if (msg.type === "response.done" &&
                msg.response.metadata?.tag === self.gradingrequesttag) {
                // Check if the response corresponds to the grading event
                log.debug("It is a grading event:");
                    try {
                        var jsonresponse = msg.response.output[0].content[0].text;
                        if(!jsonresponse || jsonresponse === "") {
                            log.debug("No valid grading data received .. msg is ..");
                            log.debug(msg);
                            self.closeDataChannel();
                            return;
                        }

                        self.gradingData = JSON.parse(jsonresponse);
                        log.debug("Grading and Feedback:", self.gradingData);

                    } catch (err) {
                        self.gradingData = false;
                        log.debug("Failed to parse grading feedback:", err);
                        log.debug(jsonresponse);
                    }
                    return;

            }

            // log.debug(msg);
            var msgresponse_id = msg.response ? msg.response.id : msg.response_id;
            var msgitem_id = msg.item ? msg.item.id : msg.item_id;
            if (msgresponse_id) {
                self.responses[msgresponse_id] = self.responses[msgresponse_id] || {
                    id: msgresponse_id,
                    itemid: msgitem_id,
                    stack: []
                };
            }
            if (msgitem_id) {
                if (typeof self.items[msgitem_id] === 'undefined') {
                    self.scrollToBottom();
                }
                self.items[msgitem_id] = self.items[msgitem_id] || {
                    id: msgitem_id,
                    events: [],
                    responses: null,
                    content: ''
                };
                if (msgresponse_id) {
                    self.items[msgitem_id].responses = self.responses[msgresponse_id];
                }
            }

            msg.time = Date.now().toString();

            switch (msg.type) {
                case "response.created": {
/*```
{
    "type": "response.created",
    "event_id": "event_Bzbmm1vOdUpYK5LcKMPAU",
    "response": {
        "object": "realtime.response",
        "id": "resp_BzbmmfvbvyUuYz2hvigPm",
        "status": "in_progress",
        "status_details": null,
        "output": [],
        "conversation_id": "conv_BzbmjU4iAZBReV6QpTbKH",
        "modalities": [
            "audio",
            "text"
        ],
        "voice": "alloy",
        "output_audio_format": "pcm16",
        "temperature": 0.8,
        "max_output_tokens": "inf",
        "usage": null,
        "metadata": null
    }
}
```*/
                    self.responses[msg.response.id].stack.push(msg);
                    break;
                }
                case "response.output_item.added": {
/*```
{
    "type": "response.output_item.added",
    "event_id": "event_BzbmnNUVJeqok4KqSLSVl",
    "response_id": "resp_BzbmmfvbvyUuYz2hvigPm",
    "output_index": 0,
    "item": {
        "id": "item_BzbmmIsy7p3YZXC9HroUp",
        "object": "realtime.item",
        "type": "message",
        "status": "in_progress",
        "role": "assistant",
        "content": []
    }
}
```*/
                    self.responses[msg.response_id].stack.push(msg);
                    break;
                }
                case "conversation.item.created": {
/*```
{
    "type": "conversation.item.created",
    "event_id": "event_BzbmnttqDhvU3h2he1tK7",
    "previous_item_id": "item_BzbmmcBxU60HVn8xvCWA2",
    "item": {
        "id": "item_BzbmmIsy7p3YZXC9HroUp",
        "object": "realtime.item",
        "type": "message",
        "status": "in_progress",
        "role": "assistant",
        "content": []
    }
}
```*/
                    self.items[msg.item.id].previous_item_id = msg.previous_item_id;
                    self.items[msg.item.id].usertype = msg.item.role;
                    self.items[msg.item.id].events.push(msg);
                    if (msg.item.role === 'assistant') {
                        self.loadingMessages.add(msgitem_id);
                    }
                    break;
                }
                case "response.content_part.added": {
/*```
{
    "type": "response.content_part.added",
    "event_id": "event_Bzbmn7lA1i7fOfFq8ju3F",
    "response_id": "resp_BzbmmfvbvyUuYz2hvigPm",
    "item_id": "item_BzbmmIsy7p3YZXC9HroUp",
    "output_index": 0,
    "content_index": 0,
    "part": {
        "type": "audio",
        "transcript": ""
    }
}
```*/
                    self.enableMic();// Let's enable mic
                    self.responses[msg.response_id].stack.push(msg);
                    break;
                }
                case "response.audio_transcript.delta": {
/*```
{
    "type": "response.audio_transcript.delta",
    "event_id": "event_BzbmnpxUmLA0zAnR5mRy3",
    "response_id": "resp_BzbmmfvbvyUuYz2hvigPm",
    "item_id": "item_BzbmmIsy7p3YZXC9HroUp",
    "output_index": 0,
    "content_index": 0,
    "delta": "Hi"
}
```*/
                    self.responses[msg.response_id].stack.push(msg);
                    self.items[msg.item_id].content += msg.delta;
                    break;
                }

                case "output_audio_buffer.cleared": {
/*```
{
    "type": "output_audio_buffer.cleared",
    "event_id": "event_f7273193069b4938",
    "response_id": "resp_BzbmmfvbvyUuYz2hvigPm"
}
```*/
                    self.responses[msg.response_id].stack.push(msg);
                    break;
                }
                case "response.audio.done": {
/*```
{
    "type": "response.audio.done",
    "event_id": "event_Bzbmn7aEtTnprkzqE9i6X",
    "response_id": "resp_BzbmmfvbvyUuYz2hvigPm",
    "item_id": "item_BzbmmIsy7p3YZXC9HroUp",
    "output_index": 0,
    "content_index": 0
}
```*/
                    self.responses[msg.response_id].stack.push(msg);
                    break;
                }
                case "response.audio_transcript.done": {
/*```
{
    "type": "response.audio_transcript.done",
    "event_id": "event_BzbmnNGRs7797nz1Qh7em",
    "response_id": "resp_BzbmmfvbvyUuYz2hvigPm",
    "item_id": "item_BzbmmIsy7p3YZXC9HroUp",
    "output_index": 0,
    "content_index": 0,
    "transcript": "Hi! How are you today? What did you do today?"
}
```*/
                    self.responses[msg.response_id].stack.push(msg);
                    self.items[msg.item_id].content = msg.transcript;
                    break;
                }
                case "response.content_part.done": {
/*```
{
    "type": "response.content_part.done",
    "event_id": "event_BzbmnYdAvAKMU7ti311Vj",
    "response_id": "resp_BzbmmfvbvyUuYz2hvigPm",
    "item_id": "item_BzbmmIsy7p3YZXC9HroUp",
    "output_index": 0,
    "content_index": 0,
    "part": {
        "type": "audio",
        "transcript": "Hi! How are you today? What did you do today?"
    }
}
```*/
                    self.responses[msg.response_id].stack.push(msg);
                    break;
                }
                case "response.output_item.done": {
/*```
{
    "type": "response.output_item.done",
    "event_id": "event_BzbmnhD5RdLxAOnko94Z1",
    "response_id": "resp_BzbmmfvbvyUuYz2hvigPm",
    "output_index": 0,
    "item": {
        "id": "item_BzbmmIsy7p3YZXC9HroUp",
        "object": "realtime.item",
        "type": "message",
        "status": "incomplete",
        "role": "assistant",
        "content": [
            {
                "type": "audio",
                "transcript": "Hi! How are you today? What did you do today?"
            }
        ]
    }
}
```*/
                    self.responses[msg.response_id].stack.push(msg);
                    self.loadingMessages.delete(msg.item.id);
                    break;
                }
                case "response.done": {
/*```
{
    "type": "response.done",
    "event_id": "event_Bzbmn8bIaGB59d6qG7LQS",
    "response": {
        "object": "realtime.response",
        "id": "resp_BzbmmfvbvyUuYz2hvigPm",
        "status": "cancelled",
        "status_details": {
            "type": "cancelled",
            "reason": "turn_detected"
        },
        "output": [
            {
                "id": "item_BzbmmIsy7p3YZXC9HroUp",
                "object": "realtime.item",
                "type": "message",
                "status": "incomplete",
                "role": "assistant",
                "content": [
                    {
                        "type": "audio",
                        "transcript": "Hi! How are you today? What did you do today?"
                    }
                ]
            }
        ],
        "conversation_id": "conv_BzbmjU4iAZBReV6QpTbKH",
        "modalities": [
            "audio",
            "text"
        ],
        "voice": "alloy",
        "output_audio_format": "pcm16",
        "temperature": 0.8,
        "max_output_tokens": "inf",
        "usage": {
            "total_tokens": 170,
            "input_tokens": 94,
            "output_tokens": 76,
            "input_token_details": {
                "text_tokens": 87,
                "audio_tokens": 7,
                "cached_tokens": 0,
                "cached_tokens_details": {
                    "text_tokens": 0,
                    "audio_tokens": 0
                }
            },
            "output_token_details": {
                "text_tokens": 23,
                "audio_tokens": 53
            }
        },
        "metadata": null
    }
}
```*/
                    self.responses[msg.response.id].stack.push(msg);
                    break;
                }
                case "output_audio_buffer.stopped": {
/*```
{
    "type":"output_audio_buffer.stopped",
    "event_id":"event_0ebd8495b5a945e5",
    "response_id":"resp_C17PJbWxcyg7tgQBVTAaL"
}
```*/
                    if (!self.isMicActive) {
                        self.toggleMute();
                    }
                    self.responses[msg.response.id].stack.push(msg);
                    break;
                }
                case "conversation.item.truncated": {
/*```
{
    "type": "conversation.item.truncated",
    "event_id": "event_BzbmnGqfHdq1hy2Wr2fnA",
    "item_id": "item_BzbmmIsy7p3YZXC9HroUp",
    "content_index": 0,
    "audio_end_ms": 261
}
```*/
                    self.items[msg.item_id].events.push(msg);
                    break;
                }
                // User events.
                case "input_audio_buffer.speech_started": {
/*```
{
    "type": "input_audio_buffer.speech_started",
    "event_id": "event_Bzbmm9FJ5oCTmCpng9tem",
    "audio_start_ms": 820,
    "item_id": "item_BzbmmcBxU60HVn8xvCWA2"
}
```*/
                    log.debug("Input audio buffer speech started");
                    self.setDataInputBuffer(true, 'audiobufferstarted');
                    self.items[msg.item_id].events.push(msg);
                    break;
                }
                case "input_audio_buffer.speech_stopped": {
/*```
{
    "type": "input_audio_buffer.speech_stopped",
    "event_id": "event_BzbmmUgLX2JKgJr1eMx0l",
    "audio_end_ms": 1568,
    "item_id": "item_BzbmmcBxU60HVn8xvCWA2"
}
```*/
                    if (self.isMicActive) {
                        // Only auto-toggle mic if autocreateresponse is true
                        if (self.autocreateresponse) {
                            self.toggleMute();
                            self.disableMic();
                        }
                    }
                    self.items[msg.item_id].events.push(msg);
                    break;
                }
                case "input_audio_buffer.committed": {
/*```
{
    "type": "input_audio_buffer.committed",
    "event_id": "event_BzbmmOICFLRU8vnGEJ6vM",
    "previous_item_id": null,
    "item_id": "item_BzbmmcBxU60HVn8xvCWA2"
}
```*/               log.debug("Input audio buffer committed");
                    self.setDataInputBuffer(false, 'audiobuffercommitted');
                    self.items[msg.item_id].events.push(msg);
                    break;
                }
                case "conversation.item.created": {
/*```
{
    "type": "conversation.item.created",
    "event_id": "event_BzbmmiskBBbCkRSHvUVrL",
    "previous_item_id": null,
    "item": {
        "id": "item_BzbmmcBxU60HVn8xvCWA2",
        "object": "realtime.item",
        "type": "message",
        "status": "completed",
        "role": "user",
        "content": [
            {
                "type": "input_audio",
                "transcript": null
            }
        ]
    }
}
```*/
                    self.items[msg.item.id].events.push(msg);
                    break;
                }
                case "conversation.item.input_audio_transcription.delta": {
/*```
{
    "type": "conversation.item.input_audio_transcription.delta",
    "event_id": "event_BzbmonQuYXZ7QxUCOLlZd",
    "item_id": "item_BzbmmcBxU60HVn8xvCWA2",
    "content_index": 0,
    "delta": "Hey."
}
```*/
                    self.items[msg.item_id].events.push(msg);
                    self.items[msg.item_id].content += msg.delta;
                    break;
                }
                case "conversation.item.input_audio_transcription.completed": {
/*```
{
    "type": "conversation.item.input_audio_transcription.completed",
    "event_id": "event_BzbmotVIjHphgHjViNkZk",
    "item_id": "item_BzbmmcBxU60HVn8xvCWA2",
    "content_index": 0,
    "transcript": "Hey.",
    "usage": {
        "type": "duration",
        "seconds": 1
    }
}
```*/
                    self.items[msg.item_id].events.push(msg);
                    self.items[msg.item_id].content = msg.transcript;
                    self.loadingMessages.delete(msg.item_id);
                    break;
                }
            }
            self.renderUI();
        },

        enableMic: function() {
            var self = this;
            if (self.controls.toggleMicBtn) {
                log.debug('Enabling mic');
                self.controls.toggleMicBtn.parentElement.classList.remove('disabled');
            }
        },

        disableMic: function() {
            var self = this;
            if (self.controls.toggleMicBtn) {
                log.debug('Disabling mic');
                self.controls.toggleMicBtn.parentElement.classList.add('disabled');
            }
        },

        initializeMicStream: async function() {
            var self = this;
            try {
                self.audioContext = new (window.AudioContext || window.webkitAudioContext)();
                self.analyser = self.audioContext.createAnalyser();
                self.analyser.fftSize = 2048;
                const bufferLength = self.analyser.frequencyBinCount;
                self.dataArray = new Uint8Array(bufferLength);

                self.sourceNode = self.audioContext.createMediaStreamSource(self.mediaStream);
                // Source is connected/disconnected in toggleMute
                self.isMicInitialized = true;
                return true;
            } catch (err) {
                log.debug("Error accessing microphone:", err);
                self.isMicInitialized = false;
                log.debug("Could not access microphone. Please ensure it's connected and permissions are granted.");
                return false;
            }
        },

        // Toggles mute/unmute state of the mic
        toggleMute: async function() {
            var self = this;
            if (!self.isMicInitialized) {
                const success = await self.initializeMicStream();
                if (!success) {
                    return;
                } // If initialization failed, stop here
            }

            if (self.isMicActive) {
                // Mute mic: Disconnect source from analyser
                if (self.sourceNode && self.analyser) {
                    self.sourceNode.disconnect(self.analyser);
                }
                if (self.animationFrameId) {
                    cancelAnimationFrame(self.animationFrameId);
                    self.animationFrameId = null;
                }
                if (self.pc) {
                    self.mediaStream.getTracks().forEach((track) => {
                        track.enabled = false;
                    });
                }
                if (self.canvasCtx) {
                    self.canvasCtx.clearRect(0, 0, self.controls.micWaveformCanvas.width, self.controls.micWaveformCanvas.height); // Clear canvas
                }
                self.isMicActive = false;

                // Send response event when mic is disabled and autocreateresponse is false
                if (!self.autocreateresponse) {
                    if(!self.datainputbuffer){
                        log.debug(" sending response.create");
                        self.sendEvent({
                            type: "response.create",
                            response: {
                                modalities: ["audio", "text"],
                                instructions: self.itemdata.audiochatinstructions,
                                voice: self.audiochat_voice
                            }
                        });
                    } else {
                        //set a recurring 500ms timeout that will send the response.create event if self.datainputbuffer is false
                        log.debug("Waiting for input audio buffer to commit before sending response.create");
                        let attempts = 0;
                        if (self.inputBufferInterval) {
                            clearInterval(self.inputBufferInterval);
                            self.inputBufferInterval = null;
                        }
                        const maxAttempts = 3;
                        self.inputBufferInterval = setInterval(() => {
                            log.debug("Checking input buffer status, attempt:", attempts);
                            if (!self.datainputbuffer || attempts >= maxAttempts) {
                                clearInterval(self.inputBufferInterval);
                                self.setDataInputBuffer(false, 'setInterval:' + attempts);
                                log.debug(" sending response.create");
                                self.sendEvent({
                                    type: "response.create",
                                    response: {
                                        modalities: ["audio", "text"],
                                        instructions: self.itemdata.audiochatinstructions,
                                        voice: self.audiochat_voice
                                    }
                                });
                            }
                            attempts++;
                        }, 1500);
                    }
                }
            } else {
                // Unmute mic: Connect source to analyser
                if (self.sourceNode && self.analyser) {
                    self.sourceNode.connect(self.analyser);
                }

                if (self.pc) {
                    self.mediaStream.getTracks().forEach((track) => {
                        track.enabled = true;
                    });
                }
                self.isMicActive = true;
                self.drawWave(); // Start drawing waveform
            }
            self.renderUI(); // Update UI
        },

        releaseMicResources: function() {
            var self = this;
            if (self.animationFrameId) {
                cancelAnimationFrame(self.animationFrameId);
                self.animationFrameId = null;
            }
            if (self.mediaStream) {
                self.mediaStream.getTracks().forEach((track) => {
                    if (typeof self.pc !== 'undefined' && self.pc) {
                        // Find the RTCRtpSender associated with the track
                        const sender = self.pc.getSenders().find(s => s.track === track);
                        // Remove the sender if it exists
                        if (sender) {
                            self.pc.removeTrack(sender);
                        }
                    }
                    track.stop();
                });
                self.mediaStream = null;
            }
            if (self.sourceNode) {
                self.sourceNode.disconnect();
                self.sourceNode = null;
            }
            if (self.audioContext) {
                self.audioContext.close();
                self.audioContext = null;
            }
            self.isMicActive = false;
            self.isMicInitialized = false;
            if (self.canvasCtx) {
                self.canvasCtx.clearRect(0, 0, self.controls.micWaveformCanvas.width, self.controls.micWaveformCanvas.height); // Clear canvas
            }
            self.renderUI(); // Update UI to show mic inactive
        },

        drawWave: function() {
            var self = this;
            if (!self.canvasCtx || !self.analyser || !self.dataArray || !self.isMicActive) {
                self.animationFrameId = null; // Stop animation if conditions are not met
                return;
            }

            const WIDTH = self.controls.micWaveformCanvas.width;
            const HEIGHT = self.controls.micWaveformCanvas.height;

            self.animationFrameId = requestAnimationFrame(self.drawWave.bind(self));

            self.analyser.getByteTimeDomainData(self.dataArray); // Get waveform data

            self.canvasCtx.clearRect(0, 0, WIDTH, HEIGHT); // Clear previous drawing
            self.canvasCtx.lineWidth = 2;
            self.canvasCtx.strokeStyle = "rgb(255, 255, 255)"; // White color for wave on blue background

            self.canvasCtx.beginPath();

            const sliceWidth = (WIDTH * 1.0) / self.dataArray.length;
            let x = 0;

            for (let i = 0; i < self.dataArray.length; i++) {
                const v = self.dataArray[i] / 128.0; // Normalize to 0-2
                const y = (v * HEIGHT) / 2;

                if (i === 0) {
                    self.canvasCtx.moveTo(x, y);
                } else {
                    self.canvasCtx.lineTo(x, y);
                }

                x += sliceWidth;
            }

            self.canvasCtx.lineTo(WIDTH, HEIGHT / 2);
            self.canvasCtx.stroke();
        },

        populateMicList: async function() {
            var self = this;
            try {
                const devices = await navigator.mediaDevices.enumerateDevices();
                const mics = devices.filter(device => device.kind === "audioinput");
                const select = self.controls.micSelect;

                select.innerHTML = ""; // Clear existing options

                // Group by groupId to remove duplicates
                const uniqueMics = [];
                const seenGroups = new Set();

                for (const mic of mics) {
                    if (!seenGroups.has(mic.groupId)) {
                        uniqueMics.push(mic);
                        seenGroups.add(mic.groupId);
                    }
                }

                if (uniqueMics.length <= 1) {
                    select.disabled = true;
                    return;
                }
                uniqueMics.forEach((mic, index) => {
                    const option = document.createElement("option");
                    option.value = mic.deviceId;
                    option.text = mic.label || `Microphone ${index + 1}`;
                    select.appendChild(option);
                });
                select.parentElement.classList.remove('hidden');

                // Set change listener
                select.addEventListener("change", async(e) => {
                    const deviceId = e.target.value;
                    await self.switchMic(deviceId);
                });
            } catch (err) {
                log.debug("Failed to get microphone list:", err);
            }
        },

        switchMic: async function(deviceId) {
            var self = this;

            // Stop and release current mic
            if (self.mediaStream) {
                self.mediaStream.getTracks().forEach(track => track.stop());
            }

            try {
                // Get new media stream from selected device
                self.mediaStream = await navigator.mediaDevices.getUserMedia({
                    audio: {deviceId: {exact: deviceId}}
                });

                // Replace tracks in PeerConnection
                if (self.pc) {
                    const senders = self.pc.getSenders();
                    const audioTrack = self.mediaStream.getAudioTracks()[0];
                    const audioSender = senders.find(sender => sender.track.kind === 'audio');
                    if (audioSender) {
                        audioSender.replaceTrack(audioTrack);
                    }
                }

                // Reinitialize mic stream and waveform
                await self.initializeMicStream();
                if (self.isMicInitialized) {
                    self.sourceNode.connect(self.analyser);
                    self.mediaStream.getTracks().forEach((track) => {
                        track.enabled = self.isMicActive;
                    });
                    if (self.isMicActive) {
                        self.drawWave();
                    }
                }

                log.debug("Switched microphone to:" + deviceId);
            } catch (err) {
                log.debug("Failed to switch microphone:");
                log.debug(err);
            }
        },

    }; // End of return object.
});