// file: frontend/main.ts

import { invoke } from "@tauri-apps/api/core";
import { AvStartResponse } from './ts/bindings/AvStartResponse';
import { AvStopResponse } from './ts/bindings/AvStopResponse';
import { RtcSnapshot } from './ts/bindings/RtcSnapshot';

type Mode = "idle" | "audio" | "video" | "av";

const startAudioBtn = document.querySelector<HTMLButtonElement>("#start-audio-btn");
const stopAudioBtn = document.querySelector<HTMLButtonElement>("#stop-audio-btn");
const audioStatus = document.querySelector<HTMLElement>("#audio-status");

const startVideoBtn = document.querySelector<HTMLButtonElement>("#start-video-btn");
const stopVideoBtn = document.querySelector<HTMLButtonElement>("#stop-video-btn");
const videoStatus = document.querySelector<HTMLElement>("#video-status");

const startAvBtn = document.querySelector<HTMLButtonElement>("#start-av-btn");
const stopAvBtn = document.querySelector<HTMLButtonElement>("#stop-av-btn");
const avStatus = document.querySelector<HTMLElement>("#av-status");

const previewElement = document.querySelector<HTMLImageElement>("#video-preview");

const rtcServerUrlInput = document.querySelector<HTMLInputElement>("#rtc-server-url");
const rtcDisplayNameInput = document.querySelector<HTMLInputElement>("#rtc-display-name");
const rtcConnectBtn = document.querySelector<HTMLButtonElement>("#rtc-connect-btn");
const rtcDisconnectBtn = document.querySelector<HTMLButtonElement>("#rtc-disconnect-btn");

const rtcPeers = document.querySelector<HTMLElement>("#rtc-peers");
const rtcLogs = document.querySelector<HTMLElement>("#rtc-logs");

const rtcChatInput = document.querySelector<HTMLInputElement>("#rtc-chat-input");
const rtcChatSendBtn = document.querySelector<HTMLButtonElement>("#rtc-chat-send-btn");
const rtcChatMessages = document.querySelector<HTMLElement>("#rtc-chat-messages");

const rtcTargetPeerIdInput = document.querySelector<HTMLInputElement>("#rtc-target-peer-id");
const rtcStartOfferBtn = document.querySelector<HTMLButtonElement>("#rtc-start-offer-btn");
const rtcClosePeerBtn = document.querySelector<HTMLButtonElement>("#rtc-close-peer-btn");
const rtcStatus = document.querySelector<HTMLElement>("#rtc-status");

const rtcDirectMessageInput = document.querySelector<HTMLInputElement>("#rtc-direct-message-input");
const rtcDirectSendBtn = document.querySelector<HTMLButtonElement>("#rtc-direct-send-btn");
const rtcDirectMessages = document.querySelector<HTMLElement>("#rtc-direct-messages");

let currentMode: Mode = "idle";

let previewTimer: number | null = null;
let previewRequestInFlight = false;
let previewObjectUrl: string | null = null;

let rtcSnapshotTimer: number | null = null;
let rtcSnapshotRequestInFlight = false;
let rtcPollingPaused = false;

function setAudioStatus(message: string): void {
    if (audioStatus) {
        audioStatus.textContent = message;
    }
}

function setVideoStatus(message: string): void {
    if (videoStatus) {
        videoStatus.textContent = message;
    }
}

function setAvStatus(message: string): void {
    if (avStatus) {
        avStatus.textContent = message;
    }
}

function setAudioButtons(isRecording: boolean): void {
    if (startAudioBtn) {
        startAudioBtn.disabled = isRecording;
    }

    if (stopAudioBtn) {
        stopAudioBtn.disabled = !isRecording;
    }
}

function setVideoButtons(isRecording: boolean): void {
    if (startVideoBtn) {
        startVideoBtn.disabled = isRecording;
    }

    if (stopVideoBtn) {
        stopVideoBtn.disabled = !isRecording;
    }
}

function setAvButtons(isRecording: boolean): void {
    if (startAvBtn) {
        startAvBtn.disabled = isRecording;
    }

    if (stopAvBtn) {
        stopAvBtn.disabled = !isRecording;
    }
}

function setAllButtonsForMode(mode: Mode): void {
    if (mode === "idle") {
        setAudioButtons(false);
        setVideoButtons(false);
        setAvButtons(false);
        return;
    }

    setAudioButtons(mode === "audio");
    setVideoButtons(mode === "video");
    setAvButtons(mode === "av");

    if (mode !== "audio") {
        if (stopAudioBtn) {
            stopAudioBtn.disabled = true;
        }
        if (startAudioBtn) {
            startAudioBtn.disabled = true;
        }
    }

    if (mode !== "video") {
        if (stopVideoBtn) {
            stopVideoBtn.disabled = true;
        }
        if (startVideoBtn) {
            startVideoBtn.disabled = true;
        }
    }

    if (mode !== "av") {
        if (stopAvBtn) {
            stopAvBtn.disabled = true;
        }
        if (startAvBtn) {
            startAvBtn.disabled = true;
        }
    }
}

function setCurrentMode(mode: Mode): void {
    currentMode = mode;
    setAllButtonsForMode(mode);
}

function setRtcConnected(
    signallingConnected: boolean,
    dataChannelOpen: boolean,
    activeRemotePeerId: string | null,
): void {
    const rtcBusy = dataChannelOpen || activeRemotePeerId !== null;

    if (rtcConnectBtn) {
        rtcConnectBtn.disabled = signallingConnected;
    }

    if (rtcDisconnectBtn) {
        rtcDisconnectBtn.disabled = !signallingConnected;
    }

    if (rtcChatSendBtn) {
        rtcChatSendBtn.disabled = !signallingConnected;
    }

    if (rtcStartOfferBtn) {
        rtcStartOfferBtn.disabled = !signallingConnected || rtcBusy;
    }
}

function setRtcDataChannelOpen(open: boolean): void {
    if (rtcDirectSendBtn) {
        rtcDirectSendBtn.disabled = !open;
    }

    if (rtcClosePeerBtn) {
        rtcClosePeerBtn.disabled = !open;
    }
}

function base64ToUint8Array(base64: string): Uint8Array {
    const binary = window.atob(base64);
    const bytes = new Uint8Array(binary.length);

    let index = 0;
    while (index < binary.length) {
        bytes[index] = binary.charCodeAt(index);
        index += 1;
    }

    return bytes;
}

function updatePreviewImageFromBase64(encoded: string): void {
    if (!previewElement) {
        return;
    }

    const bytes = base64ToUint8Array(encoded);
    const copied = new Uint8Array(bytes.byteLength);
    copied.set(bytes);

    const blob = new Blob([copied.buffer], { type: "image/jpeg" });
    const objectUrl = URL.createObjectURL(blob);

    if (previewObjectUrl !== null) {
        URL.revokeObjectURL(previewObjectUrl);
    }

    previewObjectUrl = objectUrl;
    previewElement.src = objectUrl;
}

async function refreshPreviewFrame(): Promise<void> {
    if (previewRequestInFlight) {
        return;
    }

    if (currentMode !== "video" && currentMode !== "av") {
        return;
    }

    previewRequestInFlight = true;

    try {
        const encoded = await invoke<string | null>("get_video_preview_frame_base64");

        if (encoded !== null && encoded.length > 0) {
            updatePreviewImageFromBase64(encoded);
        }
    } catch (error) {
        console.error("preview refresh failed", error);
    } finally {
        previewRequestInFlight = false;
    }
}

function startPreviewPolling(): void {
    if (previewTimer !== null) {
        return;
    }

    window.setTimeout(() => {
        void refreshPreviewFrame();
    }, 120);

    previewTimer = window.setInterval(() => {
        void refreshPreviewFrame();
    }, 200);
}

function stopPreviewPolling(): void {
    if (previewTimer !== null) {
        window.clearInterval(previewTimer);
        previewTimer = null;
    }

    previewRequestInFlight = false;

    if (previewObjectUrl !== null) {
        URL.revokeObjectURL(previewObjectUrl);
        previewObjectUrl = null;
    }

    if (previewElement) {
        previewElement.removeAttribute("src");
    }
}

function renderRtcSnapshot(snapshot: RtcSnapshot): void {
    const peersText = JSON.stringify(snapshot.peers, null, 2);
    if (rtcPeers && rtcPeers.textContent !== peersText) {
        rtcPeers.textContent = peersText;
    }

    const logsText = snapshot.logs.join("\n");
    if (rtcLogs && rtcLogs.textContent !== logsText) {
        rtcLogs.textContent = logsText;
    }

    const chatMessagesText = snapshot.chat_messages.join("\n");
    if (rtcChatMessages && rtcChatMessages.textContent !== chatMessagesText) {
        rtcChatMessages.textContent = chatMessagesText;
    }

    const directMessagesText = snapshot.rtc_messages.join("\n");
    if (rtcDirectMessages && rtcDirectMessages.textContent !== directMessagesText) {
        rtcDirectMessages.textContent = directMessagesText;
    }

    if (rtcStatus && rtcStatus.textContent !== snapshot.rtc_status) {
        rtcStatus.textContent = snapshot.rtc_status;
    }

    if (
        rtcTargetPeerIdInput &&
        snapshot.active_remote_peer_id !== null &&
        document.activeElement !== rtcTargetPeerIdInput &&
        rtcTargetPeerIdInput.value !== snapshot.active_remote_peer_id
    ) {
        rtcTargetPeerIdInput.value = snapshot.active_remote_peer_id;
    }

    if (
        rtcServerUrlInput &&
        snapshot.server_url.length > 0 &&
        document.activeElement !== rtcServerUrlInput &&
        rtcServerUrlInput.value !== snapshot.server_url
    ) {
        rtcServerUrlInput.value = snapshot.server_url;
    }

    if (
        rtcDisplayNameInput &&
        snapshot.display_name.length > 0 &&
        document.activeElement !== rtcDisplayNameInput &&
        rtcDisplayNameInput.value !== snapshot.display_name
    ) {
        rtcDisplayNameInput.value = snapshot.display_name;
    }

    setRtcConnected(
        snapshot.signalling_connected,
        snapshot.data_channel_open,
        snapshot.active_remote_peer_id,
    );
}

async function refreshRtcSnapshot(): Promise<void> {
    if (rtcSnapshotRequestInFlight) {
        return;
    }

    if (rtcPollingPaused) {
        return;
    }

    rtcSnapshotRequestInFlight = true;

    try {
        const snapshot = await invoke<RtcSnapshot>("rtc_get_snapshot");
        renderRtcSnapshot(snapshot);
    } catch (error) {
        console.error("rtc snapshot refresh failed", error);
    } finally {
        rtcSnapshotRequestInFlight = false;
    }
}

async function refreshRtcSnapshotForced(): Promise<void> {
    if (rtcSnapshotRequestInFlight) {
        return;
    }

    rtcSnapshotRequestInFlight = true;

    try {
        const snapshot = await invoke<RtcSnapshot>("rtc_get_snapshot");
        renderRtcSnapshot(snapshot);
    } catch (error) {
        console.error("rtc snapshot forced refresh failed", error);
    } finally {
        rtcSnapshotRequestInFlight = false;
    }
}

function startRtcSnapshotPolling(): void {
    if (rtcSnapshotTimer !== null) {
        return;
    }

    window.setTimeout(() => {
        void refreshRtcSnapshot();
    }, 100);

    rtcSnapshotTimer = window.setInterval(() => {
        void refreshRtcSnapshot();
    }, 1000);
}

if (startAudioBtn) {
    startAudioBtn.addEventListener("click", async () => {
        if (currentMode !== "idle") {
            setAudioStatus("Another mode is already running.");
            return;
        }

        setCurrentMode("audio");

        try {
            const path = await invoke<string>("start_audio_recording");
            setAudioStatus(`Audio recording started.\nOutput: ${path}`);
        } catch (error) {
            setAudioStatus(`Start audio failed.\n${String(error)}`);
            setCurrentMode("idle");
        }
    });
}

if (stopAudioBtn) {
    stopAudioBtn.addEventListener("click", async () => {
        if (currentMode !== "audio") {
            setAudioStatus("Audio mode is not running.");
            return;
        }

        stopAudioBtn.disabled = true;

        try {
            const path = await invoke<string>("stop_audio_recording");
            setAudioStatus(`Audio recording stopped.\nSaved file: ${path}`);
            setCurrentMode("idle");
        } catch (error) {
            setAudioStatus(`Stop audio failed.\n${String(error)}`);
            setCurrentMode("audio");
        }
    });
}

if (startVideoBtn) {
    startVideoBtn.addEventListener("click", async () => {
        if (currentMode !== "idle") {
            setVideoStatus("Another mode is already running.");
            return;
        }

        setCurrentMode("video");

        try {
            const path = await invoke<string>("start_video_recording");
            setVideoStatus(`Video recording started.\nOutput: ${path}`);
            startPreviewPolling();
        } catch (error) {
            setVideoStatus(`Start video failed.\n${String(error)}`);
            stopPreviewPolling();
            setCurrentMode("idle");
        }
    });
}

if (stopVideoBtn) {
    stopVideoBtn.addEventListener("click", async () => {
        if (currentMode !== "video") {
            setVideoStatus("Video mode is not running.");
            return;
        }

        stopVideoBtn.disabled = true;

        try {
            const path = await invoke<string>("stop_video_recording");
            setVideoStatus(`Video recording stopped.\nSaved file: ${path}`);
            stopPreviewPolling();
            setCurrentMode("idle");
        } catch (error) {
            setVideoStatus(`Stop video failed.\n${String(error)}`);
            setCurrentMode("video");
        }
    });
}

if (startAvBtn) {
    startAvBtn.addEventListener("click", async () => {
        if (currentMode !== "idle") {
            setAvStatus("Another mode is already running.");
            return;
        }

        setCurrentMode("av");

        try {
            const result = await invoke<AvStartResponse>("start_av_recording");
            setAvStatus(
                `AV recording started.\nAudio: ${result.audio_path}\nVideo: ${result.video_path}`
            );
            startPreviewPolling();
        } catch (error) {
            setAvStatus(`Start AV failed.\n${String(error)}`);
            stopPreviewPolling();
            setCurrentMode("idle");
        }
    });
}

if (stopAvBtn) {
    stopAvBtn.addEventListener("click", async () => {
        if (currentMode !== "av") {
            setAvStatus("AV mode is not running.");
            return;
        }

        stopAvBtn.disabled = true;

        try {
            const result = await invoke<AvStopResponse>("stop_av_recording");
            setAvStatus(
                `AV recording stopped.\nAudio: ${result.audio_path}\nVideo: ${result.video_path}`
            );
            stopPreviewPolling();
            setCurrentMode("idle");
        } catch (error) {
            setAvStatus(`Stop AV failed.\n${String(error)}`);
            setCurrentMode("av");
        }
    });
}

if (rtcConnectBtn) {
    rtcConnectBtn.addEventListener("click", async () => {
        const serverUrl = (rtcServerUrlInput?.value || "").trim() || "ws://127.0.0.1:3012";
        const displayName = (rtcDisplayNameInput?.value || "").trim() || "anonymous";

        rtcPollingPaused = true;

        try {
            await invoke("rtc_connect_signalling", {
                serverUrl,
                displayName,
            });
            await refreshRtcSnapshotForced();
        } catch (error) {
            console.error("rtc_connect_signalling failed", error);
        } finally {
            rtcPollingPaused = false;
        }
    });
}

if (rtcDisconnectBtn) {
    rtcDisconnectBtn.addEventListener("click", async () => {
        rtcPollingPaused = true;

        try {
            await invoke("rtc_disconnect_signalling");
            await refreshRtcSnapshotForced();
        } catch (error) {
            console.error("rtc_disconnect_signalling failed", error);
        } finally {
            rtcPollingPaused = false;
        }
    });
}

if (rtcChatSendBtn) {
    rtcChatSendBtn.addEventListener("click", async () => {
        const text = (rtcChatInput?.value || "").trim();
        if (text.length === 0) {
            return;
        }

        rtcPollingPaused = true;

        try {
            await invoke("rtc_send_chat_message", { text });

            if (rtcChatInput) {
                rtcChatInput.value = "";
            }

            await refreshRtcSnapshotForced();
        } catch (error) {
            console.error("rtc_send_chat_message failed", error);
        } finally {
            rtcPollingPaused = false;
        }
    });
}

if (rtcStartOfferBtn) {
    rtcStartOfferBtn.addEventListener("click", async () => {
        const targetPeerId = (rtcTargetPeerIdInput?.value || "").trim();
        if (targetPeerId.length === 0) {
            return;
        }

        rtcPollingPaused = true;

        if (rtcStartOfferBtn) {
            rtcStartOfferBtn.disabled = true;
        }

        try {
            await invoke("rtc_start_offer", { targetPeerId });
            await refreshRtcSnapshotForced();
        } catch (error) {
            console.error("rtc_start_offer failed", error);
        } finally {
            rtcPollingPaused = false;
        }
    });
}

if (rtcClosePeerBtn) {
    rtcClosePeerBtn.addEventListener("click", async () => {
        rtcPollingPaused = true;

        try {
            await invoke("rtc_close_peer");
            await refreshRtcSnapshotForced();
        } catch (error) {
            console.error("rtc_close_peer failed", error);
        } finally {
            rtcPollingPaused = false;
        }
    });
}

if (rtcDirectSendBtn) {
    rtcDirectSendBtn.addEventListener("click", async () => {
        const text = (rtcDirectMessageInput?.value || "").trim();
        if (text.length === 0) {
            return;
        }

        rtcPollingPaused = true;

        try {
            await invoke("rtc_send_data_message", { text });

            if (rtcDirectMessageInput) {
                rtcDirectMessageInput.value = "";
            }

            await refreshRtcSnapshotForced();
        } catch (error) {
            console.error("rtc_send_data_message failed", error);
        } finally {
            rtcPollingPaused = false;
        }
    });
}

setCurrentMode("idle");
setRtcConnected(false, false, null);
setRtcDataChannelOpen(false);
startRtcSnapshotPolling();