let peerConnection = null;
let localStream = null;
let currentUsername = null;
let currentChannelId = null;
let availableCameras = [];
let availableMics = [];
let candidateQueue = [];
const configuration = {
    iceServers:[
        {
            urls:[
                'stun:stun1.l.google.com:19302',
                'stun:stun2.l.google.com:19302',
            ],
        },
    ],
    iceCandidatePoolSize: 10,
}

window.setUsername = function(name) {
    currentUsername = name;
    LogMessage("Username set to: " + currentUsername);
};
window.setChannelId = function(channelId) {
    currentChannelId = channelId;
    LogMessage("Channel set to: " + currentChannelId);
};

function LogMessage(msg) {
    const messageLog = document.getElementById("messageLog");
    messageLog.value += '\r\n' + msg;
    messageLog.scrollTop = messageLog.scrollHeight;
}

function hasVideoTrack() {
    return !!localStream && localStream.getVideoTracks().length > 0;
}

function hasAudioTrack() {
    return !!localStream && localStream.getAudioTracks().length > 0;
}

async function ensurePeerConnection() {
    if (peerConnection) return;

    peerConnection = new RTCPeerConnection({
        iceServers: [{ urls: "stun:stun.l.google.com:19302" }]
    });

    peerConnection.onicecandidate = (event) => {
        if (event.candidate) {
            LogMessage("ICE candidate gathered");
        }
    };

    peerConnection.ontrack = (event) => {
        LogMessage("Remote track received");

        const remoteVideo = document.getElementById("remoteVideo");
        const remoteVideoStatus = document.getElementById("remoteVideoStatus");
        const remoteMediaStatus = document.getElementById("remoteMediaStatus");

        const stream = event.streams[0];
        const hasVideo = stream.getVideoTracks().length > 0;
        const hasAudio = stream.getAudioTracks().length > 0;

        if (hasVideo) {
            remoteVideo.srcObject = stream;
        } else {
            remoteVideo.srcObject = null;
        }

        if (remoteVideoStatus) {
            remoteVideoStatus.textContent = hasVideo
                ? "Remote video: active"
                : "Remote video: unavailable";
        }

        if (remoteMediaStatus) {
            remoteMediaStatus.textContent = `Remote media: audio=${hasAudio} video=${hasVideo}`;
        }
    };

    peerConnection.onconnectionstatechange = () => {
        LogMessage("Connection state: " + peerConnection.connectionState);
        const remoteMediaStatus = document.getElementById("remoteMediaStatus");
        if (remoteMediaStatus && peerConnection.connectionState === "connected") {
            remoteMediaStatus.textContent += " | connected";
        }
    };

    peerConnection.oniceconnectionstatechange = () => {
        LogMessage("ICE connection state: " + peerConnection.iceConnectionState);
    };

    peerConnection.onicegatheringstatechange = () => {
        LogMessage("ICE gathering state: " + peerConnection.iceGatheringState);
    };
} //Remove?
async function ensureLocalMedia(forceReload = false) {
    const localMediaStatus = document.getElementById("localMediaStatus");
    const localVideoStatus = document.getElementById("localVideoStatus");
    const localVideo = document.getElementById("localVideo");
    const cameraSelect = document.getElementById("cameraSelect");
    const micSelect = document.getElementById("micSelect");

    if (localStream && !forceReload) {
        return;
    }

    if (localStream) {
        localStream.getTracks().forEach(track => track.stop());
        localStream = null;
    }

    let selectedCameraId = cameraSelect ? cameraSelect.value : "";
    let selectedMicId = micSelect ? micSelect.value : "";

    const videoConstraint = selectedCameraId
        ? { deviceId: { exact: selectedCameraId } }
        : false;

    const audioConstraint = selectedMicId
        ? { deviceId: { exact: selectedMicId } }
        : true;

    try {
        localStream = await navigator.mediaDevices.getUserMedia({
            video: videoConstraint,
            audio: audioConstraint
        });

        LogMessage("Local media initialized");
    } catch (err) {
        LogMessage("selected media failed: " + err);

        try {
            localStream = await navigator.mediaDevices.getUserMedia({
                video: false,
                audio: audioConstraint
            });

            LogMessage("Local media initialized with audio only fallback");
        } catch (audioErr) {
            LogMessage("audio-only failed: " + audioErr);

            if (localMediaStatus) localMediaStatus.textContent = "Local media failed";
            if (localVideoStatus) localVideoStatus.textContent = "Local video: unavailable";
            if (localVideo) localVideo.srcObject = null;

            throw audioErr;
        }
    }

    const hasVideo = localStream.getVideoTracks().length > 0;
    const hasAudio = localStream.getAudioTracks().length > 0;

    localVideo.srcObject = hasVideo ? localStream : null;

    if (localVideoStatus) {
        localVideoStatus.textContent = hasVideo
            ? "Local video: active"
            : "Local video: unavailable";
    }

    if (localMediaStatus) {
        localMediaStatus.textContent = `Local media: audio=${hasAudio} video=${hasVideo}`;
    }

    if (!hasVideo) {
        LogMessage("No camera available, continuing without video");
    }
}

async function applyLocalStreamToPeerConnection() {
    if (!peerConnection || !localStream) return;

    const senders = peerConnection.getSenders();

    const audioTrack = localStream.getAudioTracks()[0] || null;
    const videoTrack = localStream.getVideoTracks()[0] || null;

    const audioSender = senders.find(s => s.track && s.track.kind === "audio");
    const videoSender = senders.find(s => s.track && s.track.kind === "video");

    if (audioSender) {
        await audioSender.replaceTrack(audioTrack);
        LogMessage("Replaced audio track on peer connection");
    } else if (audioTrack) {
        peerConnection.addTrack(audioTrack, localStream);
        LogMessage("Added audio track to peer connection");
    }

    if (videoSender) {
        await videoSender.replaceTrack(videoTrack);
        LogMessage("Replaced video track on peer connection");
    } else if (videoTrack) {
        peerConnection.addTrack(videoTrack, localStream);
        LogMessage("Added video track to peer connection");
    }
}

async function refreshDevicesAndPreview() {
    await loadDevices();
    await ensureLocalMedia(true);

    if (peerConnection) {
        await applyLocalStreamToPeerConnection();
    }
}

async function joinChannelCall() {
    LogMessage("Current username: " + currentUsername);
    LogMessage("Current channel: " + currentChannelId);
    // LogMessage("Joining RTCChannel");
    let active = await window.HybridWebView.InvokeDotNet("JoinRtcChannel");
    await channelCallJoin(active);
    // LogMessage("Joined RTCChannel");
    // return;
    // try {
    //     if (!currentChannelId) {
    //         LogMessage("No current channel set.");
    //         return;
    //     }
    //
    //     await ensurePeerConnection();
    //     await ensureLocalMedia();
    //
    //     LogMessage(`Joining call with media: audio=${hasAudioTrack()} video=${hasVideoTrack()}`);
    //
    //     const payload = {
    //         type: "rtc_join",
    //         from: currentUsername,
    //         channelId: currentChannelId
    //     };
    //
    //     LogMessage("Requesting join for channel " + currentChannelId);
    //     await window.HybridWebView.InvokeDotNet("SendRtcSignal", [JSON.stringify(payload)]);
    // } catch (err) {
    //     LogMessage("joinChannelCall failed: " + err);
    // }
} //Combine with channelCallJoin

async function ensurePeerConnection2()
{
    if (peerConnection) return;
    peerConnection = new RTCPeerConnection(configuration);

    peerConnection.onicegatheringstatechange = () => {
        console.log(`ICE gathering state changed: ${peerConnection.iceGatheringState}`);
    };
    peerConnection.onconnectionstatechange = () => {
        console.log(`Connection state change: ${peerConnection.connectionState}`);
    };
    peerConnection.onsignalingstatechange = () => {
        console.log(`Signaling state change: ${peerConnection.signalingState}`);
    };
    peerConnection.oniceconnectionstatechange = () => {
        console.log(`ICE connection state change: ${peerConnection.iceConnectionState}`); 
    };
    
    peerConnection.onicecandidate = async (event) => {
        console.log(`Ice Candidate: ${JSON.stringify(event.candidate)}`);
        LogMessage(`Ice Candidate: ${JSON.stringify(event.candidate)}`);
        await window.HybridWebView.InvokeDotNet("WriteIceCandidate", [JSON.stringify(event.candidate)]);
        await IceCandidateAdded(event.candidate);
    };
    
    peerConnection.ontrack = (event) => {
        LogMessage("Remote track received");

        const remoteVideo = document.getElementById("remoteVideo");
        const remoteVideoStatus = document.getElementById("remoteVideoStatus");
        const remoteMediaStatus = document.getElementById("remoteMediaStatus");

        const stream = event.streams[0];
        const hasVideo = stream.getVideoTracks().length > 0;
        const hasAudio = stream.getAudioTracks().length > 0;

        if (hasVideo) {
            remoteVideo.srcObject = stream;
        } else {
            remoteVideo.srcObject = null;
        }

        if (remoteVideoStatus) {
            remoteVideoStatus.textContent = hasVideo
                ? "Remote video: active"
                : "Remote video: unavailable";
        }

        if (remoteMediaStatus) {
            remoteMediaStatus.textContent = `Remote media: audio=${hasAudio} video=${hasVideo}`;
        }
    };
}
async function channelCallJoin(activeCall)
{
    // LogMessage("Active call: " + activeCall);
    await ensurePeerConnection2();
    await ensureLocalMedia();
    await applyLocalStreamToPeerConnection();
    
    if (activeCall)
    {
        const rawJson = await window.HybridWebView.InvokeDotNet("GetRtcOffer");
        const offer = typeof rawJson === "string" ? JSON.parse(rawJson) : rawJson;
        await peerConnection.setRemoteDescription(offer);
        const answer = await peerConnection.createAnswer();
        await peerConnection.setLocalDescription(answer);

        // LogMessage("Joining call with media answer: " + JSON.stringify(answer));
        // LogMessage("Calling C# WriteRtcAnswer with: " + JSON.stringify(answer));
        await window.HybridWebView.InvokeDotNet("WriteRtcAnswer", [JSON.stringify(answer)]);
        LogMessage("C# WriteRtcAnswer invoked");
        //TODO: Update offer in SurrealDB to include answer
    }
    else
    {
        const offer = await peerConnection.createOffer();
        await peerConnection.setLocalDescription(offer);
        
        await window.HybridWebView.InvokeDotNet("WriteRtcOffer", [JSON.stringify(offer)]);
        LogMessage(`Joining call with media offer: ${JSON.stringify(offer)}`);
    }
}
async function AnswerCallbackJS(answer)
{
    answer.sdp = answer.sdp.replaceAll("(rn)", "\r\n");
    // LogMessage("Answer: " + JSON.stringify(answer));
    
    // LogMessage("RemoteDescription: " + peerConnection.currentRemoteDescription);
    
    if (!peerConnection.currentRemoteDescription && answer)
    {
        LogMessage("Current answer: " + JSON.stringify(answer));
        const desc = new RTCSessionDescription(answer);
        await peerConnection.setRemoteDescription(desc);
        for (const candidate of candidateQueue) {
            await peerConnection.addIceCandidate(candidate);
        }
    }
}
async function IceCandidateAdded(candidate)
{
    if (peerConnection.currentRemoteDescription) {
        await peerConnection.addIceCandidate(candidate);
        LogMessage("ICE CANDIDATE ADDED: " + JSON.stringify(candidate));
    }
    else {
        LogMessage("RemoteDescription Missing")
        candidateQueue.push(candidate);
        
    }
}

async function RtcLeaveCall()
{}
async function handleRtcSignal(rawJson) {
    try {
        const msg = typeof rawJson === "string" ? JSON.parse(rawJson) : rawJson;

        LogMessage("Received signal: " + msg.type + " from " + msg.from + " in " + msg.channelId);

        await ensurePeerConnection();

        if (msg.type === "rtc_join_state") {
            if (msg.isInitiator) {
                LogMessage("No active call found. Becoming initiator.");

                const offer = await peerConnection.createOffer();
                await peerConnection.setLocalDescription(offer);
                // await waitForIceGatheringComplete(peerConnection);

                const payload = {
                    type: "rtc_offer",
                    from: currentUsername,
                    channelId: currentChannelId,
                    sdp: peerConnection.localDescription.sdp
                };

                LogMessage("Sending offer to channel " + currentChannelId);
                await window.HybridWebView.InvokeDotNet("SendRtcSignal", [JSON.stringify(payload)]);
            } else {
                LogMessage("Active call exists. Waiting for stored offer.");
            }

            return;
        }

        if (msg.type === "rtc_offer") {
            LogMessage("Incoming channel call offer from " + msg.from);
            await ensureLocalMedia();

            LogMessage(`Answering call with media: audio=${hasAudioTrack()} video=${hasVideoTrack()}`);
            LogMessage("Applying remote offer");

            await peerConnection.setRemoteDescription({
                type: "offer",
                sdp: msg.sdp
            });

            const answer = await peerConnection.createAnswer();
            await peerConnection.setLocalDescription(answer);
            // await waitForIceGatheringComplete(peerConnection);

            const payload = {
                type: "rtc_answer",
                from: currentUsername,
                channelId: msg.channelId,
                sdp: peerConnection.localDescription.sdp
            };

            LogMessage("Sending answer to channel " + msg.channelId);
            await window.HybridWebView.InvokeDotNet("SendRtcSignal", [JSON.stringify(payload)]);
            return;
        }

        if (msg.type === "rtc_answer") {
            LogMessage("Applying remote answer");

            await peerConnection.setRemoteDescription({
                type: "answer",
                sdp: msg.sdp
            });

            LogMessage("Remote answer applied");
            return;
        }

        if (msg.type === "rtc_ice_candidate") {
            LogMessage("Applying remote ICE candidate");

            await peerConnection.addIceCandidate({
                candidate: msg.candidate,
                sdpMid: msg.sdpMid,
                sdpMLineIndex: msg.sdpMLineIndex
            });

            LogMessage("Remote ICE candidate applied");
            return;
        }

        LogMessage("Unhandled signal type: " + msg.type);
    } catch (err) {
        LogMessage("handleRtcSignal failed: " + err);
    }
} //Remove?

async function loadDevices() {
    try {
        const devices = await navigator.mediaDevices.enumerateDevices();

        availableCameras = devices.filter(d => d.kind === "videoinput");
        availableMics = devices.filter(d => d.kind === "audioinput");

        const cameraSelect = document.getElementById("cameraSelect");
        const micSelect = document.getElementById("micSelect");

        if (!cameraSelect || !micSelect) {
            LogMessage("Device dropdowns not found.");
            return;
        }

        cameraSelect.innerHTML = "";
        micSelect.innerHTML = "";

        const noCameraOption = document.createElement("option");
        noCameraOption.value = "";
        noCameraOption.text = "No camera / audio-only";
        cameraSelect.appendChild(noCameraOption);

        const noMicOption = document.createElement("option");
        noMicOption.value = "";
        noMicOption.text = "Default microphone";
        micSelect.appendChild(noMicOption);

        for (const cam of availableCameras) {
            const option = document.createElement("option");
            option.value = cam.deviceId;
            option.text = cam.label || `Camera ${cameraSelect.options.length}`;
            cameraSelect.appendChild(option);
        }

        for (const mic of availableMics) {
            const option = document.createElement("option");
            option.value = mic.deviceId;
            option.text = mic.label || `Microphone ${micSelect.options.length + 1}`;
            micSelect.appendChild(option);
        }

        LogMessage(`Loaded devices: ${availableCameras.length} cameras, ${availableMics.length} mics`);
    } catch (err) {
        LogMessage("loadDevices failed: " + err);
    }
}

function wireDeviceSelectors() {
    const cameraSelect = document.getElementById("cameraSelect");
    const micSelect = document.getElementById("micSelect");

    if (cameraSelect) {
        cameraSelect.onchange = async () => {
            LogMessage("Camera changed");
            await ensureLocalMedia(true);
            await applyLocalStreamToPeerConnection();
        };
    }

    if (micSelect) {
        micSelect.onchange = async () => {
            LogMessage("Microphone changed");
            await ensureLocalMedia(true);
            await applyLocalStreamToPeerConnection();
        };
    }
}

async function waitForIceGatheringComplete(pc) {
    if (pc.iceGatheringState === "complete") return;

    await new Promise(resolve => {
        function checkState() {
            if (pc.iceGatheringState === "complete") {
                pc.removeEventListener("icegatheringstatechange", checkState);
                resolve();
            }
        }

        pc.addEventListener("icegatheringstatechange", checkState);
    });
} //Remove?

// window.handleRtcSignal = handleRtcSignal;

window.addEventListener("HybridWebViewMessageReceived", function (e) {
    LogMessage("Raw message: " + e.detail.message);
});

window.addEventListener("load", async () => {
    LogMessage("RTC page loaded");
    window.HybridWebView.SendRawMessage("rtc_page_ready");
    await loadDevices();
    wireDeviceSelectors();
    await ensureLocalMedia(true);
});