// Copyright (C) 2026 Danilo M. <danix@danix.xyz>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2 as
// published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

pragma Singleton

import Quickshell
import Quickshell.Io
import QtQuick
import QtWebSockets
import "Logic.js" as Logic

// OBS Studio over obs-websocket v5. Connected means OBS is running with
// its server enabled, so nothing checks for the process. State follows
// OBS's events; actions only send requests and never set state
// optimistically.
Singleton {
    id: root

    property bool connected: false
    property bool recording: false
    property bool paused: false
    property real duration: 0
    property var scenes: []
    property string scene: ""
    // The webcam: the first v4l2_input item in the current scene, -1 for none.
    // ponytail: a webcam inside a group or nested scene is not found; walk
    // GetGroupSceneItemList if one ever is.
    property int camId: -1
    property bool camOn: false
    property real camW: 0
    property real camH: 0
    // The global "Desktop Audio" input's name, "" when none is configured.
    property string desktopAudio: ""
    property bool desktopMuted: false
    property real baseWidth: 0
    property real baseHeight: 0

    function toggleRecord() { request("ToggleRecord"); }
    function togglePause() { request("ToggleRecordPause"); }
    function setScene(name) { if (name) request("SetCurrentProgramScene", { sceneName: name }); }
    function toggleCam() {
        if (camId >= 0)
            request("SetSceneItemEnabled", { sceneName: scene, sceneItemId: camId, sceneItemEnabled: !camOn });
    }
    function toggleAudio() {
        if (desktopAudio)
            request("SetInputMute", { inputName: desktopAudio, inputMuted: !desktopMuted });
    }
    // The corner math assumes the webcam item is top-left aligned (alignment 5).
    function moveCam(corner) {
        if (camId < 0 || baseWidth <= 0 || camW <= 0 || camH <= 0) return;
        const p = Logic.cornerPos(corner, baseWidth, baseHeight, camW, camH, 16);
        request("SetSceneItemTransform", { sceneName: scene, sceneItemId: camId,
            sceneItemTransform: { positionX: p.x, positionY: p.y } });
    }

    // --- config -----------------------------------------------------------

    // OBS's own file, so no copy of the password exists anywhere else.
    FileView {
        id: cfg
        path: `${Quickshell.env("XDG_CONFIG_HOME") || Quickshell.env("HOME") + "/.config"}/obs-studio/plugin_config/obs-websocket/config.json`
        watchChanges: true
        onFileChanged: reload()
    }

    function config() {
        try { return JSON.parse(cfg.text()); } catch (e) { return null; }
    }

    // --- socket -----------------------------------------------------------

    property bool warned: false
    property bool wasOpen: false

    WebSocket {
        id: sock
        onStatusChanged: {
            if (status === WebSocket.Open) { root.wasOpen = true; return; }
            if (status === WebSocket.Connecting) return;
            // QML's WebSocket hides the close code, so a wrong password
            // (4009) and OBS quitting look the same. Say it once per run.
            if (root.wasOpen && !root.connected && !root.warned) {
                console.warn("obs: closed before Identified, wrong password?");
                root.warned = true;
            }
            root.reset();
        }
        onTextMessageReceived: message => {
            try { root.receive(JSON.parse(message)); }
            catch (e) { console.warn(`obs: bad message: ${e}`); }
        }
    }

    function reset() {
        connected = false; wasOpen = false;
        recording = false; paused = false; duration = 0;
        scenes = []; scene = ""; camId = -1; camOn = false;
        camW = 0; camH = 0;
        desktopAudio = ""; desktopMuted = false;
        baseWidth = 0; baseHeight = 0;
    }

    // Retry while not connected; a closed or failed socket is reopened by
    // toggling active.
    Timer {
        interval: 3000
        repeat: true
        running: !root.connected
        triggeredOnStart: true
        onTriggered: {
            if (sock.status === WebSocket.Open || sock.status === WebSocket.Connecting) return;
            const c = root.config();
            if (!c || !c.server_enabled) return;
            sock.active = false;
            sock.url = `ws://127.0.0.1:${c.server_port}`;
            sock.active = true;
        }
    }

    // --- protocol -----------------------------------------------------------

    property int seq: 0

    function send(op, d) { sock.sendTextMessage(JSON.stringify({ op: op, d: d })); }

    function request(type, data) {
        if (!connected) return;
        send(6, { requestType: type, requestId: String(++seq), requestData: data || {} });
    }

    function identify(token) {
        const d = { rpcVersion: 1, eventSubscriptions: 4 | 8 | 64 | 128 }; // Scenes | Inputs | Outputs | SceneItems
        if (token) d.authentication = token;
        send(1, d);
    }

    Process {
        id: auth
        command: ["sh", `${Quickshell.shellDir}/island/obs-auth.sh`]
        stdinEnabled: true
        property string data: ""
        onStarted: { auth.write(auth.data); auth.stdinEnabled = false; }
        stdout: StdioCollector { onStreamFinished: root.identify(text.trim()) }
    }

    function receive(m) {
        switch (m.op) {
        case 0: { // Hello
            const a = m.d.authentication;
            if (!a) { identify(""); break; }
            const c = config();
            auth.data = `${c ? c.server_password : ""}${a.salt}\n${a.challenge}\n`;
            auth.stdinEnabled = true;
            auth.running = false;
            auth.running = true;
            break;
        }
        case 2: // Identified
            connected = true;
            warned = false;
            request("GetRecordStatus");
            request("GetSceneList");
            request("GetSpecialInputs");
            request("GetVideoSettings");
            break;
        case 5:
            event(m.d.eventType, m.d.eventData || {});
            break;
        case 7:
            response(m.d);
            break;
        }
    }

    function event(type, d) {
        switch (type) {
        case "RecordStateChanged":
            recording = d.outputActive;
            paused = d.outputState === "OBS_WEBSOCKET_OUTPUT_PAUSED";
            if (!recording) duration = 0;
            break;
        case "CurrentProgramSceneChanged":
            scene = d.sceneName;
            request("GetSceneItemList", { sceneName: scene });
            break;
        case "SceneListChanged":
        case "SceneItemCreated":
        case "SceneItemRemoved":
            request("GetSceneList");
            break;
        case "SceneItemEnableStateChanged":
            if (d.sceneName === scene && d.sceneItemId === camId) camOn = d.sceneItemEnabled;
            break;
        case "InputMuteStateChanged":
            if (d.inputName === desktopAudio) desktopMuted = d.inputMuted;
            break;
        }
    }

    function response(d) {
        if (!d.requestStatus.result) {
            console.warn(`obs: ${d.requestType} failed: ${d.requestStatus.comment ?? d.requestStatus.code}`);
            return;
        }
        const r = d.responseData || {};
        switch (d.requestType) {
        case "GetRecordStatus":
            recording = r.outputActive;
            paused = r.outputPaused;
            duration = r.outputDuration;
            break;
        case "GetSceneList":
            // obs-websocket lists scenes bottom-up; reversed is OBS's own order.
            scenes = r.scenes.slice().reverse().map(s => s.sceneName);
            scene = r.currentProgramSceneName;
            request("GetSceneItemList", { sceneName: scene });
            break;
        case "GetSceneItemList": {
            const it = r.sceneItems.find(i => i.inputKind === "v4l2_input");
            camId = it ? it.sceneItemId : -1;
            camOn = !!it && it.sceneItemEnabled;
            camW = it ? it.sceneItemTransform.width : 0;
            camH = it ? it.sceneItemTransform.height : 0;
            break;
        }
        case "GetSpecialInputs":
            desktopAudio = r.desktop1 || "";
            if (desktopAudio) request("GetInputMute", { inputName: desktopAudio });
            break;
        case "GetVideoSettings":
            baseWidth = r.baseWidth;
            baseHeight = r.baseHeight;
            break;
        case "GetInputMute":
            desktopMuted = r.inputMuted;
            break;
        }
    }

    // OBS owns the clock, so pausing freezes it with no local bookkeeping.
    // ponytail: one local request a second, only while recording.
    Timer {
        interval: 1000
        repeat: true
        running: root.recording && !root.paused
        onTriggered: root.request("GetRecordStatus")
    }
}