/*
 *  SPDX-FileCopyrightText: 2015 Marco Martin <mart@kde.org>
 *
 *  SPDX-License-Identifier: GPL-2.0-or-later
 */

import QtQuick 2.4
import QtQuick.Layouts 1.1
import QtQuick.Window 2.2
import QtGraphicalEffects 1.12

import org.kde.taskmanager 0.1 as TaskManager
import org.kde.plasma.plasmoid 2.0
import org.kde.plasma.core 2.0 as PlasmaCore
import org.kde.plasma.components 2.0 as PlasmaComponents
import org.kde.kquickcontrolsaddons 2.0

import org.kde.plasma.private.nanoshell 2.0 as NanoShell
import org.kde.plasma.private.mobileshell 1.0 as MobileShell
import org.kde.plasma.phone.taskpanel 1.0 as TaskPanel

PlasmaCore.ColorScope {
    id: root
    width: 600
    height: 480
    colorGroup: showingApp ? PlasmaCore.Theme.HeaderColorGroup : PlasmaCore.Theme.ComplementaryColorGroup

    Plasmoid.backgroundHints: PlasmaCore.Types.NoBackground

    readonly property color backgroundColor: NanoShell.StartupFeedback.visible ? NanoShell.StartupFeedback.backgroundColor : PlasmaCore.ColorScope.backgroundColor
    readonly property bool showingApp: !plasmoid.nativeInterface.allMinimized

    readonly property bool hasTasks: tasksModel.count > 0

    property QtObject taskSwitcher: taskSwitcherLoader.item ? taskSwitcherLoader.item : null
    Loader {
        id: taskSwitcherLoader
    }
    //FIXME: why it crashes on startup if TaskSwitcher is loaded immediately?
    Connections {
        target: plasmoid.nativeInterface
        function onAllMinimizedChanged() {
            MobileShell.HomeScreenControls.homeScreenVisible = plasmoid.nativeInterface.allMinimized
        }
    }
    Timer {
        running: true
        interval: 200
        onTriggered: {
            taskSwitcherLoader.setSource(Qt.resolvedUrl("TaskSwitcher.qml"), {"model": tasksModel});
        }
    }

    function minimizeAll() {
        for (var i = 0 ; i < tasksModel.count; i++) {
            var idx = tasksModel.makeModelIndex(i);
            if (!tasksModel.data(idx, TaskManager.AbstractTasksModel.IsMinimized)) {
                tasksModel.requestToggleMinimized(idx);
            }
        }
    }

    function restoreAll() {
        for (var i = 0 ; i < tasksModel.count; i++) {
            var idx = tasksModel.makeModelIndex(i);
            if (tasksModel.data(idx, TaskManager.AbstractTasksModel.IsMinimized)) {
                tasksModel.requestToggleMinimized(idx);
            }
        }
    }

    TaskManager.TasksModel {
        id: tasksModel
        groupMode: TaskManager.TasksModel.GroupDisabled

        screenGeometry: plasmoid.screenGeometry
        sortMode: TaskManager.TasksModel.SortAlpha

        virtualDesktop: virtualDesktopInfo.currentDesktop
        activity: activityInfo.currentActivity
        //FIXME: workaround
        Component.onCompleted: tasksModel.countChanged();
    }

    TaskManager.VirtualDesktopInfo {
        id: virtualDesktopInfo
    }

    TaskManager.ActivityInfo {
        id: activityInfo
    }

    MouseArea {
        id: mainMouseArea
        anchors.fill: parent
        property int oldMouseY: 0
        property int startMouseY: 0
        property int oldMouseX: 0
        property int startMouseX: 0
        property bool isDragging: false
        property bool opening: false
        drag.filterChildren: true
        property Button activeButton

        onPressed: {
            startMouseX = oldMouseX = mouse.y;
            startMouseY = oldMouseY = mouse.y;
            taskSwitcher.offset = -taskSwitcher.height;
            activeButton = icons.childAt(mouse.x, mouse.y);
        }
        onPositionChanged: {
            let newButton = icons.childAt(mouse.x, mouse.y);
            if (newButton != activeButton) {
                activeButton = null;
            }
            if (!isDragging && Math.abs(startMouseY - oldMouseY) < root.height) {
                oldMouseY = mouse.y;
                return;
            } else {
                isDragging = true;
            }

            taskSwitcher.offset = taskSwitcher.offset - (mouse.y - oldMouseY);
            opening = oldMouseY > mouse.y;

            if (taskSwitcher.visibility == Window.Hidden && taskSwitcher.offset > -taskSwitcher.height + units.gridUnit && taskSwitcher.tasksCount) {
                activeButton = null;
                taskSwitcher.showFullScreen();
            //no tasks, let's scroll up the homescreen instead
            } else if (taskSwitcher.tasksCount === 0) {
                MobileShell.HomeScreenControls.requestRelativeScroll(Qt.point(mouse.x - oldMouseX, mouse.y - oldMouseY));
            }
            oldMouseY = mouse.y;
            oldMouseY = mouse.y;
        }
        onReleased: {
            if (taskSwitcher.visibility == Window.Hidden) {
                if (taskSwitcher.tasksCount === 0) {
                    MobileShell.HomeScreenControls.snapHomeScreenPosition();
                }

                if (activeButton) {
                    activeButton.clicked();
                }
                return;
            }

            if (!isDragging) {
                return;
            }

            if (opening) {
                taskSwitcher.show();
            } else {
                taskSwitcher.hide();
            }
        }

        DropShadow {
            anchors.fill: icons
            visible: !showingApp
            cached: true
            horizontalOffset: 0
            verticalOffset: 1
            radius: 4.0
            samples: 17
            color: Qt.rgba(0,0,0,0.8)
            source: icons
        }
        Item {
            id: icons
            anchors.fill: parent

            visible: plasmoid.configuration.PanelButtonsVisible
            
            Rectangle {
                anchors.fill: parent
                gradient: Gradient {
                    GradientStop {
                        position: 0
                        color: showingApp ? root.backgroundColor : "transparent"
                    }
                    GradientStop {
                        position: 1
                        color: showingApp ? root.backgroundColor : Qt.rgba(0, 0, 0, 0.1)
                    }
                }
            }

            Button {
                anchors {
                    verticalCenter: parent.verticalCenter
                    left: parent.left
                    leftMargin: parent.width * 0.1
                }
                height: parent.height
                width: parent.width*0.8/3
                mouseArea: mainMouseArea
                enabled: root.hasTasks
                onClicked: {
                    if (!enabled) {
                        return;
                    }
                    plasmoid.nativeInterface.showDesktop = false;
                    taskSwitcher.visible ? taskSwitcher.hide() : taskSwitcher.show();
                }
                iconSizeFactor: 0.75
                iconSource: "mobile-task-switcher"
                colorGroup: root.showingApp ? PlasmaCore.Theme.NormalColorGroup : PlasmaCore.Theme.ComplementaryColorGroup
            }

            Button {
                id: showDesktopButton
                anchors {
                    verticalCenter: parent.verticalCenter
                    horizontalCenter: parent.horizontalCenter
                }
                height: parent.height
                width: parent.width*0.8/3
                mouseArea: mainMouseArea
                onClicked: {
                    if (!enabled) {
                        return;
                    }
                    root.minimizeAll();
                    MobileShell.HomeScreenControls.resetHomeScreenPosition();
                    plasmoid.nativeInterface.allMinimizedChanged();
                }
                iconSizeFactor: 1
                iconSource: "start-here-kde"
                colorGroup: root.showingApp ? PlasmaCore.Theme.NormalColorGroup : PlasmaCore.Theme.ComplementaryColorGroup
            }

            Button {
                anchors {
                    verticalCenter: parent.verticalCenter
                    right: parent.right
                    rightMargin: parent.width * 0.1
                }
                height: parent.height
                width: parent.width*0.8/3
                mouseArea: mainMouseArea
                enabled: TaskPanel.KWinVirtualKeyboard.active || (plasmoid.nativeInterface.hasCloseableActiveWindow && !taskSwitcher.visible)
                onClicked: {
                    if (!enabled) {
                        return
                    }
                    if (TaskPanel.KWinVirtualKeyboard.active) {
                        TaskPanel.KWinVirtualKeyboard.active = false
                        return;
                    }
                    if (!plasmoid.nativeInterface.hasCloseableActiveWindow) {
                        return;
                    }
                    var index = taskSwitcher.model.activeTask;
                    if (index) {
                        taskSwitcher.model.requestClose(index);
                    }
                }

                // mobile-close-app (from plasma-frameworks) seems to have less margins than icons from breeze-icons
                iconSizeFactor: TaskPanel.KWinVirtualKeyboard.active ? 1 : 0.75
                iconSource: TaskPanel.KWinVirtualKeyboard.active ? "go-down-symbolic" : "mobile-close-app"
                colorGroup: root.showingApp ? PlasmaCore.Theme.NormalColorGroup : PlasmaCore.Theme.ComplementaryColorGroup
            }
        }
    }
}