// 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.

import Quickshell
import Quickshell.Wayland
import Quickshell.Services.Pipewire
import QtQuick

Scope {
    id: root

    // Milliseconds the OSD stays up after the last change.
    property int timeout: 1500

    readonly property PwNode sink: Pipewire.defaultAudioSink
    readonly property PwNode source: Pipewire.defaultAudioSource

    // Which one to draw: set by whichever node changed last.
    property PwNode active: null
    property bool isInput: false

    // Keeping the nodes bound is what makes volume/muted actually update.
    PwObjectTracker { objects: [root.sink, root.source].filter(n => n !== null) }

    // A node reports its initial volume while binding, before `ready` goes
    // true, so the `ready` check alone suppresses the startup values. Nothing
    // else may be swallowed: the next signal after that is the user's first
    // keypress, and eating it costs the OSD its first appearance.
    function show(node, input) {
        if (!node?.ready || !node.audio) return;
        root.active = node;
        root.isInput = input;
        hideTimer.restart();
    }

    Connections {
        target: root.sink?.audio ?? null
        function onVolumeChanged() { root.show(root.sink, false); }
        function onMutedChanged() { root.show(root.sink, false); }
    }

    // A track change shows the OSD as well, so the row is not something you
    // only see when you happen to touch the volume.
    Connections {
        target: Player.current ?? null
        function onTrackTitleChanged() { if (Player.title) root.showTrack(); }
        function onPlaybackStateChanged() { root.showTrack(); }
    }

    Connections {
        target: root.source?.audio ?? null
        function onVolumeChanged() { root.show(root.source, true); }
        function onMutedChanged() { root.show(root.source, true); }
    }

    function showTrack() {
        if (!Player.active) return;
        root.active = root.sink;
        root.isInput = false;
        hideTimer.restart();
    }

    // Hovering freezes the countdown so the transport buttons can be clicked;
    // leaving starts it again. Without a hover the OSD behaves exactly as it
    // did before there was anything clickable on it.
    property bool hovered: false

    // Only counts down while the OSD is up and the pointer is elsewhere.
    Timer {
        id: hideTimer
        running: root.active !== null && !root.hovered
        interval: root.timeout
        onTriggered: root.active = null
    }

    // Quickshell exits once no window is visible, and the OSD is hidden most
    // of the time, so a 1x1 transparent window holds the process open. Its
    // empty mask makes it click-through, so it cannot catch a stray click.
    PanelWindow {
        visible: true
        implicitWidth: 1
        implicitHeight: 1
        color: "transparent"
        exclusionMode: ExclusionMode.Ignore
        mask: Region {}
        WlrLayershell.keyboardFocus: WlrKeyboardFocus.None
    }

    PanelWindow {
        id: win

        visible: root.active !== null

        readonly property PwNode node: root.active
        readonly property real volume: node?.audio?.volume ?? 0
        readonly property bool muted: node?.audio?.muted ?? false

        // Bottom centre. Move the anchor to relocate.
        anchors.bottom: true
        margins.bottom: 120

        // Grows to fit the track row; the volume-only size is unchanged.
        implicitWidth: 360
        implicitHeight: Player.active ? 150 : 72
        color: "transparent"

        exclusionMode: ExclusionMode.Ignore
        WlrLayershell.layer: WlrLayer.Overlay
        WlrLayershell.namespace: "quickshell-volume-osd"
        // Still no keyboard focus: the transport buttons are pointer targets,
        // and the OSD must never take keys from the window being typed in.
        WlrLayershell.keyboardFocus: WlrKeyboardFocus.None

        Rectangle {
            anchors.fill: parent
            radius: 12
            // Translucent so the compositor's blur shows through. The frosting
            // itself is Hyprland's, applied by layerrule to this window's
            // namespace: see the README.
            color: Qt.alpha(Theme.base, 0.65)
            border.width: 1
            border.color: Qt.alpha(Theme.text, 0.12)

            // Tracks the pointer over the whole panel so the fade can pause.
            HoverHandler {
                onHoveredChanged: root.hovered = hovered
            }

            Column {
                anchors.fill: parent
                anchors.margins: 16
                spacing: 12

                Loader {
                    active: Player.active
                    width: parent.width
                    sourceComponent: trackRow
                }

                Rectangle {
                    visible: Player.active
                    width: parent.width
                    height: 1
                    color: Qt.alpha(Theme.text, 0.1)
                }

            Row {
                width: parent.width
                spacing: 14

                Text {
                    anchors.verticalCenter: parent.verticalCenter
                    width: 30
                    horizontalAlignment: Text.AlignHCenter
                    font.family: Theme.fontFamily
                    font.pixelSize: 24
                    color: win.muted ? Theme.red : Theme.accent
                    text: {
                        if (root.isInput) return win.muted ? "\uf131" : "\uf130";
                        if (win.muted || win.volume <= 0) return "\uf026";
                        return win.volume < 0.5 ? "\uf027" : "\uf028";
                    }
                }

                Column {
                    anchors.verticalCenter: parent.verticalCenter
                    width: parent.width - 30 - parent.spacing
                    spacing: 8

                    Item {
                        width: parent.width
                        height: label.implicitHeight

                        Text {
                            id: label
                            anchors.left: parent.left
                            font.family: Theme.fontFamily
                            font.pixelSize: Theme.fontSize
                            color: Theme.subtext
                            text: root.isInput ? "Input" : "Output"
                        }

                        Text {
                            anchors.right: parent.right
                            font.family: Theme.fontFamily
                            font.pixelSize: Theme.fontSize
                            color: Theme.text
                            text: win.muted ? "muted" : Math.round(win.volume * 100) + "%"
                        }
                    }

                    Rectangle {
                        width: parent.width
                        height: 6
                        radius: 3
                        color: Theme.surface

                        Rectangle {
                            height: parent.height
                            radius: parent.radius
                            // Volume can exceed 1.0; the bar stops at full.
                            width: parent.width * Math.min(win.volume, 1)
                            color: win.muted ? Theme.red : Theme.accent
                            opacity: win.muted ? 0.5 : 1
                            Behavior on width { NumberAnimation { duration: 100 } }
                        }
                    }
                }
            }
            }
        }
    }

    Component {
        id: trackRow

        Row {
            id: trackLine
            // A Row sizes to its children, so the panel width has to be
            // pushed in: the text column below subtracts from it.
            width: parent ? parent.width : 0
            spacing: 12

            // Players that extract embedded art reuse one temp path, so the
            // source carries a per-track suffix and caching is off.
            Rectangle {
                width: 46; height: 46; radius: 6
                color: Qt.alpha(Theme.surface, 0.8)
                clip: true

                Image {
                    anchors.fill: parent
                    source: Player.artUrl
                    cache: false
                    asynchronous: true
                    fillMode: Image.PreserveAspectCrop
                    visible: status === Image.Ready
                }
                Text {
                    anchors.centerIn: parent
                    visible: Player.artUrl === "" || parent.children[0].status !== Image.Ready
                    text: ""
                    font { family: Theme.fontFamily; pixelSize: 20 }
                    color: Theme.overlay
                }
            }

            Column {
                anchors.verticalCenter: parent.verticalCenter
                // Whatever the art and transport buttons leave: a fixed width
                // here overflowed the panel and pushed `next` past its edge.
                width: trackLine.width - 46 - transport.width - 2 * trackLine.spacing
                spacing: 3

                Text {
                    width: parent.width
                    elide: Text.ElideRight
                    text: Player.title || "Nothing playing"
                    font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 1; bold: true }
                    color: Theme.text
                }
                Text {
                    width: parent.width
                    elide: Text.ElideRight
                    visible: Player.artist !== ""
                    text: Player.artist
                    font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 3 }
                    color: Theme.subtext
                }
            }

            Row {
                id: transport
                anchors.verticalCenter: parent.verticalCenter
                spacing: 2
                TransportButton {
                    glyph: ""
                    enabled: Player.current?.canGoPrevious ?? false
                    onClicked: Player.current?.previous()
                }
                TransportButton {
                    glyph: Player.playing ? "" : ""
                    enabled: Player.current?.canTogglePlaying ?? false
                    onClicked: Player.current?.togglePlaying()
                }
                TransportButton {
                    glyph: ""
                    enabled: Player.current?.canGoNext ?? false
                    onClicked: Player.current?.next()
                }
            }
        }
    }
}