/*
 *  SPDX-FileCopyrightText: 2019 Marco Martin <mart@kde.org>
 *
 *   SPDX-License-Identifier: LGPL-2.0-or-later
 */

import QtQuick 2.12
import QtQuick.Window 2.12
import QtQuick.Layouts 1.1
import QtGraphicalEffects 1.0

import org.kde.plasma.plasmoid 2.0
import org.kde.plasma.core 2.0 as PlasmaCore
import org.kde.plasma.components 3.0 as PlasmaComponents
import org.kde.draganddrop 2.0 as DragDrop

import "launcher" as Launcher
//TODO: everything using this will eventually move in Launcher
import "launcher/private" as LauncherPrivate

import org.kde.plasma.private.containmentlayoutmanager 1.0 as ContainmentLayoutManager 

import org.kde.phone.homescreen 1.0

import org.kde.plasma.private.mobileshell 1.0 as MobileShell

FocusScope {
    id: root
    width: 640
    height: 480

    property Item toolBox

//BEGIN functions

    function recalculateMaxFavoriteCount() {
        if (!componentComplete) {
            return;
        }

        plasmoid.nativeInterface.applicationListModel.maxFavoriteCount = Math.max(4, Math.floor(Math.min(width, height) / appletsLayout.cellWidth));
    }

//END functions


    property bool componentComplete: false
    onWidthChanged: recalculateMaxFavoriteCount()
    onHeightChanged:recalculateMaxFavoriteCount()
    Component.onCompleted: {
        if (plasmoid.screen == 0) {
            MobileShell.HomeScreenControls.homeScreen = root
            MobileShell.HomeScreenControls.homeScreenWindow = root.Window.window
        }
        componentComplete = true;
        recalculateMaxFavoriteCount()
    }

    Plasmoid.onScreenChanged: {
        if (plasmoid.screen == 0) {
            MobileShell.HomeScreenControls.homeScreen = root
            MobileShell.HomeScreenControls.homeScreenWindow = root.Window.window
        }
    }
    Window.onWindowChanged: {
        if (plasmoid.screen == 0) {
            MobileShell.HomeScreenControls.homeScreenWindow = root.Window.window
        }
    }

    Connections {
        property real lastRequestedPosition: 0
        target: MobileShell.HomeScreenControls
        function onResetHomeScreenPosition() {
            scrollAnim.to = 0;
            scrollAnim.restart();
            appDrawer.close();
        }
        function onSnapHomeScreenPosition() {
            if (lastRequestedPosition > 0) {
                appDrawer.open();
            } else {
                appDrawer.close();
            }
        }
        function onRequestHomeScreenPosition(y) {
            appDrawer.offset += y;
            lastRequestedPosition = y;
        }
    }

    Connections {
        target: plasmoid
        function onEditModeChanged() {
            appletsLayout.editMode = plasmoid.editMode
        }
    }

    Launcher.LauncherDragManager {
        id: launcherDragManager
        anchors.fill: parent
        z: 2
        appletsLayout: appletsLayout
        favoriteStrip: favoriteStrip
    }

    Launcher.FlickablePages {
        id: mainFlickable

        anchors {
            fill: parent
            topMargin: plasmoid.availableScreenRect.y
            bottomMargin: favoriteStrip.height + plasmoid.screenGeometry.height - plasmoid.availableScreenRect.height - plasmoid.availableScreenRect.y
        }

        appDrawer: appDrawer
        contentWidth: Math.max(width, width * Math.ceil(appletsLayout.childrenRect.width/width)) + (launcherDragManager.active ? width : 0)

        // TODO: span on multiple pages
        DragDrop.DropArea {
            id: dropArea
            width: mainFlickable.width * 100
            //width: Math.max(mainFlickable.width, mainFlickable.width * Math.ceil(appletsLayout.childrenRect.width/mainFlickable.width))
            height: mainFlickable.height + favoriteStrip.height + units.gridUnit

            onDragEnter: {
                event.accept(event.proposedAction);
                launcherDragManager.active = true;
            }
            onDragMove: {
                let posInFavorites = favoriteStrip.mapFromItem(this, event.x, event.y);
                if (posInFavorites.y > 0) {
                    if (plasmoid.nativeInterface.applicationListModel.favoriteCount >= plasmoid.nativeInterface.applicationListModel.maxFavoriteCount ) {
                        launcherDragManager.hideSpacer();
                    } else {
                        launcherDragManager.showSpacerAtPos(event.x, event.y, favoriteStrip);
                    }
                    appletsLayout.hidePlaceHolder();
                } else {
                    appletsLayout.showPlaceHolderAt(
                        Qt.rect(event.x - appletsLayout.defaultItemWidth / 2,
                        event.y - appletsLayout.defaultItemHeight / 2,
                        appletsLayout.defaultItemWidth,
                        appletsLayout.defaultItemHeight)
                    );
                    launcherDragManager.hideSpacer();

                    //SCROLL LEFT
                    if (event.x < units.gridUnit) {
                        mainFlickable.scrollLeft();
                    //SCROLL RIGHT
                    } else if (event.x > mainFlickable.width - units.gridUnit) {
                        mainFlickable.scrollRight();
                    //DON't SCROLL
                    } else {
                        mainFlickable.stopScroll();
                    }
                }
            }

            onDragLeave: {
                appletsLayout.hidePlaceHolder();
                launcherDragManager.active = false;
            }

            preventStealing: true

            onDrop: {
                launcherDragManager.active = false;
                if (event.mimeData.formats[0] === "text/x-plasma-phone-homescreen-launcher") {
                    let storageId = event.mimeData.getDataAsByteArray("text/x-plasma-phone-homescreen-launcher");

                    let posInFavorites = favoriteStrip.flow.mapFromItem(this, event.x, event.y);
                    if (posInFavorites.y > 0) {
                        if (plasmoid.nativeInterface.applicationListModel.favoriteCount >= plasmoid.nativeInterface.applicationListModel.maxFavoriteCount ) {
                            return;
                        }

                        let pos = Math.min(plasmoid.nativeInterface.applicationListModel.count, Math.floor(posInFavorites.x/favoriteStrip.cellWidth))
                        plasmoid.nativeInterface.applicationListModel.addFavorite(storageId, pos, ApplicationListModel.Favorites)
                        let item = launcherRepeater.itemAt(pos);

                        if (item) {
                            item.x = posInFavorites.x;
                            item.y = 0//posInFavorites.y;

                            //launcherDragManager.showSpacer(item, item.width/2, item.height/2);
                            launcherDragManager.dropItem(item, item.width/2, item.height/2);
                        }

                        return;
                    }


                    let pos = plasmoid.nativeInterface.applicationListModel.count;
                    plasmoid.nativeInterface.applicationListModel.addFavorite(storageId, pos, ApplicationListModel.Desktop)
                    let item = launcherRepeater.itemAt(pos);

                    event.accept(event.proposedAction);
                    if (item) {
                        item.x = appletsLayout.placeHolder.x;
                        item.y = appletsLayout.placeHolder.y;
                        appletsLayout.hidePlaceHolder();
                        launcherDragManager.dropItem(item, appletsLayout.placeHolder.x + appletsLayout.placeHolder.width/2, appletsLayout.placeHolder.y + appletsLayout.placeHolder.height/2);
                    }
                    appletsLayout.hidePlaceHolder();
                } else {
                    plasmoid.processMimeData(event.mimeData,
                                event.x - appletsLayout.placeHolder.width / 2, event.y - appletsLayout.placeHolder.height / 2);
                    event.accept(event.proposedAction);
                    appletsLayout.hidePlaceHolder();
                }
            }

            PlasmaCore.Svg {
                id: arrowsSvg
                imagePath: "widgets/arrows"
                colorGroup: PlasmaCore.Theme.ComplementaryColorGroup
            }

            ContainmentLayoutManager.AppletsLayout {
                id: appletsLayout

                anchors {
                    fill: parent
                    bottomMargin: favoriteStrip.height
                }

                signal appletsLayoutInteracted

                TapHandler {
                    target: mainFlickable
                    enabled: appDrawer.status !== Launcher.AppDrawer.Status.Open
                    onTapped: {
                        //Hides icons close button
                        appletsLayout.appletsLayoutInteracted();
                        appletsLayout.editMode = false;
                    }
                    onLongPressed: appletsLayout.editMode = true;
                    onPressedChanged: root.focus = true;
                }

                cellWidth: favoriteStrip.cellWidth
                cellHeight: Math.floor(height / Math.floor(height / favoriteStrip.cellHeight))

                configKey: width > height ? "ItemGeometriesHorizontal" : "ItemGeometriesVertical"
                containment: plasmoid
                editModeCondition: plasmoid.immutable
                        ? ContainmentLayoutManager.AppletsLayout.Manual
                        : ContainmentLayoutManager.AppletsLayout.AfterPressAndHold

                // Sets the containment in edit mode when we go in edit mode as well
                onEditModeChanged: plasmoid.editMode = editMode

                minimumItemWidth: units.gridUnit * 3
                minimumItemHeight: minimumItemWidth

                defaultItemWidth: units.gridUnit * 6
                defaultItemHeight: defaultItemWidth

                acceptsAppletCallback: function(applet, x, y) {
                    print("Applet: "+applet+" "+x+" "+y)
                    return true;
                }

                appletContainerComponent: ContainmentLayoutManager.BasicAppletContainer {
                    id: appletContainer
                    configOverlayComponent: ConfigOverlay {}

                    onEditModeChanged: {
                        launcherDragManager.active = dragActive || editMode;
                    }
                    onDragActiveChanged: {
                        launcherDragManager.active = dragActive || editMode;
                    }
                }

                placeHolder: ContainmentLayoutManager.PlaceHolder {}
                //FIXME: move
                PlasmaComponents.Label {
                        id: metrics
                        text: "M\nM"
                        visible: false
                        font.pointSize: theme.defaultFont.pointSize * 0.9
                    }
                Launcher.LauncherRepeater {
                    id: launcherRepeater
                    cellWidth: appletsLayout.cellWidth
                    cellHeight: appletsLayout.cellHeight
                    appletsLayout: appletsLayout
                    favoriteStrip: favoriteStrip
                    onScrollLeftRequested: mainFlickable.scrollLeft()
                    onScrollRightRequested: mainFlickable.scrollRight()
                    onStopScrollRequested: mainFlickable.stopScroll()
                }
            }
        }
    }

    Launcher.AppDrawer {
        id: appDrawer
        anchors.fill: parent

        topPadding: plasmoid.availableScreenRect.y
        bottomPadding: favoriteStrip.height + plasmoid.screenGeometry.height - plasmoid.availableScreenRect.height - plasmoid.availableScreenRect.y
    }

    Launcher.FavoriteStrip {
        id: favoriteStrip
        anchors {
            left: parent.left
            right: parent.right
            bottom: parent.bottom
            bottomMargin: plasmoid.screenGeometry.height - plasmoid.availableScreenRect.height - plasmoid.availableScreenRect.y
        }
        appletsLayout: appletsLayout

        LauncherPrivate.DragGestureHandler {
            target: favoriteStrip
            appDrawer: appDrawer
            mainFlickable: mainFlickable
            enabled: root.focus && appDrawer.status !== Launcher.AppDrawer.Status.Open && !appletsLayout.editMode && !plasmoid.editMode && !launcherDragManager.active
            onSnapPage: mainFlickable.snapPage();
        }
        TapHandler {
            target: favoriteStrip
            onTapped: {
                //Hides icons close button
                appletsLayout.appletsLayoutInteracted();
                appletsLayout.editMode = false;
            }
            onLongPressed: appletsLayout.editMode = true;
            onPressedChanged: root.focus = true;
        }
    }
}