/*
    SPDX-FileCopyrightText: 2012-2016 Eike Hein <hein@kde.org>

    SPDX-License-Identifier: GPL-2.0-or-later
*/
pragma ComponentBehavior: Bound

import QtQuick
import QtQuick.Layouts

import org.kde.plasma.plasmoid
import org.kde.plasma.components as PlasmaComponents3
import org.kde.plasma.core as PlasmaCore
import org.kde.ksvg as KSvg
import org.kde.plasma.private.mpris as Mpris
import org.kde.kirigami as Kirigami

import org.kde.plasma.workspace.trianglemousefilter

import org.kde.taskmanager as TaskManager
import plasma.applet.org.kde.plasma.taskmanager as TaskManagerApplet
import org.kde.plasma.workspace.dbus as DBus

PlasmoidItem {
    id: tasks

    // For making a bottom to top layout since qml flow can't do that.
    // We just hang the task manager upside down to achieve that.
    // This mirrors the tasks and group dialog as well, so we un-rotate them
    // to fix that (see Task.qml and GroupDialog.qml).
    rotation: Plasmoid.configuration.reverseMode && Plasmoid.formFactor === PlasmaCore.Types.Vertical ? 180 : 0

    readonly property bool shouldShrinkToZero: tasksModel.count === 0
    readonly property bool vertical: Plasmoid.formFactor === PlasmaCore.Types.Vertical
    readonly property bool iconsOnly: Plasmoid.pluginName === "org.kde.plasma.icontasks"

    property Task toolTipOpenedByClick
    property Task toolTipAreaItem

    readonly property Component pulseAudioComponent: Qt.createComponent("PulseAudio.qml")

    property alias taskList: taskList

    preferredRepresentation: fullRepresentation

    Plasmoid.constraintHints: Plasmoid.CanFillArea

    Plasmoid.onUserConfiguringChanged: {
        if (Plasmoid.userConfiguring && groupDialog !== null) {
            groupDialog.visible = false;
        }
    }

    Layout.fillWidth: vertical ? true : Plasmoid.configuration.fill
    Layout.fillHeight: !vertical ? true : Plasmoid.configuration.fill
    Layout.minimumWidth: {
        if (shouldShrinkToZero) {
            return Kirigami.Units.gridUnit; // For edit mode
        }
        return vertical ? 0 : TaskManagerApplet.LayoutMetrics.preferredMinWidth();
    }
    Layout.minimumHeight: {
        if (shouldShrinkToZero) {
            return Kirigami.Units.gridUnit; // For edit mode
        }
        return !vertical ? 0 : TaskManagerApplet.LayoutMetrics.preferredMinHeight();
    }

//BEGIN TODO: this is not precise enough: launchers are smaller than full tasks
    Layout.preferredWidth: {
        if (shouldShrinkToZero) {
            return 0.01;
        }
        if (vertical) {
            return Kirigami.Units.gridUnit * 10;
        }
        return taskList.Layout.maximumWidth
    }
    Layout.preferredHeight: {
        if (shouldShrinkToZero) {
            return 0.01;
        }
        if (vertical) {
            return taskList.Layout.maximumHeight
        }
        return Kirigami.Units.gridUnit * 2;
    }
//END TODO

    property Item dragSource
    property var hoveredWinIds

    signal requestLayout

    onDragSourceChanged: {
        if (dragSource === null) {
            tasksModel.syncLaunchers();
        }
    }

    function windowsHovered(winIds: var, hovered: bool): DBus.DBusPendingReply {
        if (!Plasmoid.configuration.highlightWindows) {
            return;
        }
        // If the hover leave event comes after something else was already hovered, don't cancel the new highlight
        if (!hovered && !(winIds.every(winId => hoveredWinIds.includes(winId)) &&
                          hoveredWinIds.every(winId => winIds.includes(winId)))) {
            return
        }
        hoveredWinIds = winIds

        return DBus.SessionBus.asyncCall({service: "org.kde.KWin.HighlightWindow", path: "/org/kde/KWin/HighlightWindow", iface: "org.kde.KWin.HighlightWindow", member: "highlightWindows", arguments: [hovered ? winIds : []], signature: "(as)"});
    }

    function cancelHighlightWindows(): DBus.DBusPendingReply {
        return DBus.SessionBus.asyncCall({service: "org.kde.KWin.HighlightWindow", path: "/org/kde/KWin/HighlightWindow", iface: "org.kde.KWin.HighlightWindow", member: "highlightWindows", arguments: [[]], signature: "(as)"});
    }

    function activateWindowView(winIds: var): DBus.DBusPendingReply {
        if (!effectWatcher.registered) {
            return;
        }
        cancelHighlightWindows();
        return DBus.SessionBus.asyncCall({service: "org.kde.KWin.Effect.WindowView1", path: "/org/kde/KWin/Effect/WindowView1", iface: "org.kde.KWin.Effect.WindowView1", member: "activate", arguments: [winIds.map(s => String(s))], signature: "(as)"});
    }

    function publishIconGeometries(taskItems: /*list<Item>*/var): void {
        if (TaskManagerApplet.TaskTools.taskManagerInstanceCount >= 2) {
            return;
        }
        for (let i = 0; i < taskItems.length - 1; ++i) {
            const task = taskItems[i];

            if (!task.model.IsLauncher && !task.model.IsStartup) {
                tasksModel.requestPublishDelegateGeometry(tasksModel.makeModelIndex(task.index),
                    backend.globalRect(task), task);
            }
        }
    }

    readonly property TaskManager.TasksModel tasksModel: TaskManager.TasksModel {
        id: tasksModel

        readonly property int logicalLauncherCount: {
            if (Plasmoid.configuration.separateLaunchers) {
                return launcherCount;
            }

            let startupsWithLaunchers = 0;

            for (let i = 0; i < taskRepeater.count; ++i) {
                const item = taskRepeater.itemAt(i) as Task;

                // During destruction required properties such as item.model can go null for a while,
                // so in paths that can trigger on those moments, they need to be guarded
                if (item?.model?.IsStartup && item.model.HasLauncher) {
                    ++startupsWithLaunchers;
                }
            }

            return launcherCount + startupsWithLaunchers;
        }

        screenGeometry: Plasmoid.containment.screenGeometry
        activity: activityInfo.currentActivity

        filterByCurrentVirtualDesktop: Plasmoid.configuration.showOnlyCurrentDesktop
        filterByScreen: Plasmoid.configuration.showOnlyCurrentScreen
        filterByActivity: Plasmoid.configuration.showOnlyCurrentActivity
        filterNotMinimized: Plasmoid.configuration.showOnlyMinimized

        hideActivatedLaunchers: tasks.iconsOnly || Plasmoid.configuration.hideLauncherOnStart
        sortMode: sortModeEnumValue(Plasmoid.configuration.sortingStrategy)
        launchInPlace: tasks.iconsOnly && Plasmoid.configuration.sortingStrategy === 1
        separateLaunchers: {
            if (!tasks.iconsOnly && !Plasmoid.configuration.separateLaunchers
                && Plasmoid.configuration.sortingStrategy === 1) {
                return false;
            }

            return true;
        }

        groupMode: groupModeEnumValue(Plasmoid.configuration.groupingStrategy)
        groupInline: !Plasmoid.configuration.groupPopups && !tasks.iconsOnly
        groupingWindowTasksThreshold: (Plasmoid.configuration.onlyGroupWhenFull && !tasks.iconsOnly
            ? TaskManagerApplet.LayoutMetrics.optimumCapacity(tasks.width, tasks.height) + 1 : -1)

        onLauncherListChanged: {
            Plasmoid.configuration.launchers = launcherList;
        }

        onGroupingAppIdBlacklistChanged: {
            Plasmoid.configuration.groupingAppIdBlacklist = groupingAppIdBlacklist;
        }

        onGroupingLauncherUrlBlacklistChanged: {
            Plasmoid.configuration.groupingLauncherUrlBlacklist = groupingLauncherUrlBlacklist;
        }

        function sortModeEnumValue(index: int): /*TaskManager.TasksModel.SortMode*/ int {
            switch (index) {
            case 0:
                return TaskManager.TasksModel.SortDisabled;
            case 1:
                return TaskManager.TasksModel.SortManual;
            case 2:
                return TaskManager.TasksModel.SortAlpha;
            case 3:
                return TaskManager.TasksModel.SortVirtualDesktop;
            case 4:
                return TaskManager.TasksModel.SortActivity;
            // 5 is SortLastActivated, skipped
            case 6:
                return TaskManager.TasksModel.SortWindowPositionHorizontal;
            default:
                return TaskManager.TasksModel.SortDisabled;
            }
        }

        function groupModeEnumValue(index: int): /*TaskManager.TasksModel.GroupMode*/ int {
            switch (index) {
            case 0:
                return TaskManager.TasksModel.GroupDisabled;
            case 1:
                return TaskManager.TasksModel.GroupApplications;
            }
        }

        Component.onCompleted: {
            launcherList = Plasmoid.configuration.launchers;
            groupingAppIdBlacklist = Plasmoid.configuration.groupingAppIdBlacklist;
            groupingLauncherUrlBlacklist = Plasmoid.configuration.groupingLauncherUrlBlacklist;

            // Only hook up view only after the above churn is done.
            taskRepeater.model = tasksModel;
        }
    }

    readonly property TaskManagerApplet.Backend backend: TaskManagerApplet.Backend {
        id: backend

        screen: Plasmoid.screen ?? -1
        hasActiveTask: tasksModel.count > 0 && tasksModel.activeTask.valid
        showsOnlyCurrentScreen: Plasmoid.configuration.showOnlyCurrentScreen

        onAddLauncher: url => {
            tasks.addLauncher(url);
        }

        onActivateTaskAtIndexRequested: index => {
            tasks.activateTaskAtIndex(index);
        }

        onActivatePreviousTaskRequested: () => {
            tasks.activatePreviousTask();
        }

        onActivateNextTaskRequested: () => {
            tasks.activateNextTask();
        }

        onMoveActiveTaskBackwardRequested: () => {
            tasks.moveActiveTaskBackward();
        }

        onMoveActiveTaskForwardRequested: () => {
            tasks.moveActiveTaskForward();
        }
    }

    DBus.DBusServiceWatcher {
        id: effectWatcher
        busType: DBus.BusType.Session
        watchedService: "org.kde.KWin.Effect.WindowView1"
    }

    readonly property Component taskInitComponent: Component {
        Timer {
            interval: 200
            running: true

            onTriggered: {
                const task = parent as Task;
                if (task) {
                    tasks.tasksModel.requestPublishDelegateGeometry(task.modelIndex(), tasks.backend.globalRect(task), task);
                }
                destroy();
            }
        }
    }

    Connections {
        target: Plasmoid

        function onLocationChanged(): void {
            if (TaskManagerApplet.TaskTools.taskManagerInstanceCount >= 2) {
                return;
            }
            // This is on a timer because the panel may not have
            // settled into position yet when the location prop-
            // erty updates.
            iconGeometryTimer.start();
        }
    }

    Connections {
        target: Plasmoid.containment

        function onScreenGeometryChanged(): void {
            iconGeometryTimer.start();
        }
    }

    Mpris.Mpris2Model {
        id: mpris2Source
    }

    Component {
        id: contextMenuComponent
        ContextMenu {}
    }

    Item {
        anchors.fill: parent

        TaskManager.VirtualDesktopInfo {
            id: virtualDesktopInfo
        }

        TaskManager.ActivityInfo {
            id: activityInfo
            readonly property string nullUuid: "00000000-0000-0000-0000-000000000000"
        }

        Loader {
            id: pulseAudio
            sourceComponent: tasks.pulseAudioComponent
            active: tasks.pulseAudioComponent.status === Component.Ready
        }

        Timer {
            id: iconGeometryTimer

            interval: 500
            repeat: false

            onTriggered: {
                tasks.publishIconGeometries(taskList.children, tasks);
            }
        }

        Binding {
            target: Plasmoid
            property: "status"
            value: (tasksModel.anyTaskDemandsAttention && Plasmoid.configuration.unhideOnAttention
                ? PlasmaCore.Types.NeedsAttentionStatus : PlasmaCore.Types.PassiveStatus)
            restoreMode: Binding.RestoreBinding
        }

        Connections {
            target: Plasmoid.configuration

            function onLaunchersChanged(): void {
                tasksModel.launcherList = Plasmoid.configuration.launchers
            }
            function onGroupingAppIdBlacklistChanged(): void {
                tasksModel.groupingAppIdBlacklist = Plasmoid.configuration.groupingAppIdBlacklist;
            }
            function onGroupingLauncherUrlBlacklistChanged(): void {
                tasksModel.groupingLauncherUrlBlacklist = Plasmoid.configuration.groupingLauncherUrlBlacklist;
            }
        }

        Component {
            id: busyIndicator
            PlasmaComponents3.BusyIndicator {}
        }

        // Save drag data
        Item {
            id: dragHelper

            Drag.dragType: Drag.Automatic
            Drag.supportedActions: Qt.CopyAction | Qt.MoveAction | Qt.LinkAction
            Drag.onDragFinished: dropAction => {
                tasks.dragSource = null;
            }
        }

        KSvg.FrameSvgItem {
            id: taskFrame

            visible: false

            imagePath: "widgets/tasks"
            prefix: TaskManagerApplet.TaskTools.taskPrefix("normal", Plasmoid.location)
        }

        MouseHandler {
            id: mouseHandler

            anchors.fill: parent

            target: taskList

            onUrlsDropped: urls => {
                // If all dropped URLs point to application desktop files, we'll add a launcher for each of them.
                const createLaunchers = urls.every(item => tasks.backend.isApplication(item));

                if (createLaunchers) {
                    urls.forEach(item => addLauncher(item));
                    return;
                }

                if (!hoveredItem) {
                    return;
                }

                // Otherwise we'll just start a new instance of the application with the URLs as argument,
                // as you probably don't expect some of your files to open in the app and others to spawn launchers.
                tasksModel.requestOpenUrls((hoveredItem as Task).modelIndex(), urls);
            }
        }

        ToolTipDelegate {
            id: openWindowToolTipDelegate
            visible: false
        }

        ToolTipDelegate {
            id: pinnedAppToolTipDelegate
            visible: false
        }

        TriangleMouseFilter {
            id: tmf
            filterTimeOut: 300
            active: tasks.toolTipAreaItem && tasks.toolTipAreaItem.toolTipOpen
            blockFirstEnter: false

            edge: {
                switch (Plasmoid.location) {
                case PlasmaCore.Types.BottomEdge:
                    return Qt.TopEdge;
                case PlasmaCore.Types.TopEdge:
                    return Qt.BottomEdge;
                case PlasmaCore.Types.LeftEdge:
                    return Qt.RightEdge;
                case PlasmaCore.Types.RightEdge:
                    return Qt.LeftEdge;
                default:
                    return Qt.TopEdge;
                }
            }

            LayoutMirroring.enabled: tasks.shouldBeMirrored(Plasmoid.configuration.reverseMode, Application.layoutDirection, tasks.vertical)
            anchors {
                left: parent.left
                top: parent.top
            }

            height: taskList.height
            width: taskList.width

            TaskList {
                id: taskList

                LayoutMirroring.enabled: tasks.shouldBeMirrored(Plasmoid.configuration.reverseMode, Application.layoutDirection, tasks.vertical)
                anchors {
                    left: parent.left
                    top: parent.top
                }

                count: tasksModel.count

                readonly property real widthOccupation: taskRepeater.count / columns
                readonly property real heightOccupation: taskRepeater.count / rows

                Layout.maximumWidth: {
                    const totalMaxWidth = children.reduce((accumulator, child) => {
                            if (!isFinite(child.Layout.maximumWidth)) {
                                return accumulator;
                            }
                            return accumulator + child.Layout.maximumWidth
                        }, 0);
                    return Math.round(totalMaxWidth / widthOccupation);
                }
                Layout.maximumHeight: {
                    const totalMaxHeight = children.reduce((accumulator, child) => {
                            if (!isFinite(child.Layout.maximumHeight)) {
                                return accumulator;
                            }
                            return accumulator + child.Layout.maximumHeight
                        }, 0);
                    return Math.round(totalMaxHeight / heightOccupation);
                }
                width: {
                    if (tasks.shouldShrinkToZero) {
                        return 0;
                    }
                    if (tasks.vertical) {
                        return tasks.width * Math.min(1, widthOccupation);
                    } else {
                        return Math.min(tasks.width, Layout.maximumWidth);
                    }
                }
                height: {
                    if (tasks.shouldShrinkToZero) {
                        return 0;
                    }
                    if (tasks.vertical) {
                        return Math.min(tasks.height, Layout.maximumHeight);
                    } else {
                        return tasks.height * Math.min(1, heightOccupation);
                    }
                }

                flow: {
                    if (tasks.vertical) {
                        return Plasmoid.configuration.forceStripes ? Grid.LeftToRight : Grid.TopToBottom
                    }
                    return Plasmoid.configuration.forceStripes ? Grid.TopToBottom : Grid.LeftToRight
                }

                onAnimatingChanged: {
                    if (!animating) {
                        tasks.publishIconGeometries(children, tasks);
                    }
                }

                Repeater {
                    id: taskRepeater

                    delegate: Task {
                        tasksRoot: tasks
                    }
                }
            }
        }
    }

    readonly property Component groupDialogComponent: Qt.createComponent("GroupDialog.qml")
    property GroupDialog groupDialog

    readonly property bool supportsLaunchers: true

    function hasLauncher(url: url): bool {
        return tasksModel.launcherPosition(url) !== -1;
    }

    function addLauncher(url: url): void {
        if (Plasmoid.immutability !== PlasmaCore.Types.SystemImmutable) {
            tasksModel.requestAddLauncher(url);
        }
    }

    function removeLauncher(url: url): void {
        if (Plasmoid.immutability !== PlasmaCore.Types.SystemImmutable) {
            tasksModel.requestRemoveLauncher(url);
        }
    }

    function activateTaskAtIndex(index: int): void {
        const task = taskRepeater.itemAt(index) as Task;
        if (task) {
            TaskManagerApplet.TaskTools.activateTask(task.modelIndex(), task.model, null, task, Plasmoid, this, effectWatcher.registered);
        }
    }

    // Shared helpers for activatePreviousTask/activateNextTask.

    function buildFlatTaskList() {
        const count = taskRepeater.count;
        if (count === 0) return [];

        let taskIndexList = [];
        for (let i = 0; i < count; ++i) {
            const item = taskRepeater.itemAt(i);
            if (!item || item.model.IsLauncher || item.model.IsStartup) continue;

            if (item.model.IsGroupParent) {
                for (let j = 0; j < tasksModel.rowCount(item.modelIndex()); ++j) {
                    taskIndexList.push(tasksModel.makeModelIndex(i, j));
                }
            } else if (item.model.IsWindow) {
                taskIndexList.push(item.modelIndex());
            }
        }
        return taskIndexList;
    }

    function findActivePosition(taskIndexList): int {
        for (let i = 0; i < taskIndexList.length; ++i) {
            if (tasksModel.data(taskIndexList[i], TaskManager.AbstractTasksModel.IsActive)) {
                return i;
            }
        }
        return -1;
    }

    function activatePreviousTask(): void {
        const taskIndexList = buildFlatTaskList();
        if (taskIndexList.length === 0) return;

        const activePos = findActivePosition(taskIndexList);
        if (activePos < 0) return;

        const prevPos = (activePos - 1 + taskIndexList.length) % taskIndexList.length;
        tasksModel.requestActivate(taskIndexList[prevPos]);
    }

    function activateNextTask(): void {
        const taskIndexList = buildFlatTaskList();
        if (taskIndexList.length === 0) return;

        const activePos = findActivePosition(taskIndexList);
        if (activePos < 0) return;

        const nextPos = (activePos + 1) % taskIndexList.length;
        tasksModel.requestActivate(taskIndexList[nextPos]);
    }

    // Shared helper for moveActiveTaskBackward/moveActiveTaskForward.

    function getActiveRow(): int {
        if (tasksModel.count === 0) return -1;

        // Switch to manual sorting via the config so the binding and the
        // settings UI stay in sync.
        Plasmoid.configuration.sortingStrategy = 1; // Manual

        // Find the active task's top-level row from the now-resorted model.
        const activeModelIndex = tasksModel.activeTask;
        if (!activeModelIndex.valid) return -1;

        // If the active task is a group child, find its parent's row.
        const parentIndex = activeModelIndex.parent;
        return parentIndex.valid ? parentIndex.row : activeModelIndex.row;
    }

    function moveActiveTaskBackward(): void {
        const activeRow = getActiveRow();
        if (activeRow <= 0) return; // Already leftmost

        tasksModel.move(activeRow, activeRow - 1);
    }

    function moveActiveTaskForward(): void {
        const activeRow = getActiveRow();
        if (activeRow < 0 || activeRow >= tasksModel.count - 1) return; // Already rightmost

        tasksModel.move(activeRow, activeRow + 1);
    }

    function createContextMenu(rootTask, modelIndex, args = {}) {
        const initialArgs = Object.assign(args, {
            visualParent: rootTask,
            modelIndex,
            mpris2Source,
            backend,
        });
        return contextMenuComponent.createObject(rootTask, initialArgs);
    }

    function shouldBeMirrored(reverseMode, layoutDirection, vertical): bool {
        // LayoutMirroring is only horizontal
        if (vertical) {
            return layoutDirection === Qt.RightToLeft;
        }

        if (layoutDirection === Qt.LeftToRight) {
            return reverseMode;
        }
        return !reverseMode;
    }

    Component.onCompleted: {
        TaskManagerApplet.TaskTools.taskManagerInstanceCount += 1;
        requestLayout.connect(iconGeometryTimer.restart);
    }

    Component.onDestruction: {
        TaskManagerApplet.TaskTools.taskManagerInstanceCount -= 1;
    }
}