/*
 * Copyright (C) 2021 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.android.launcher3.taskbar;

import static com.android.window.flags.Flags.enableDesktopWindowingMode;
import static com.android.window.flags.Flags.enableDesktopWindowingTaskbarRunningApps;

import android.util.SparseArray;
import android.view.View;

import androidx.annotation.UiThread;

import com.android.launcher3.LauncherSettings.Favorites;
import com.android.launcher3.model.BgDataModel;
import com.android.launcher3.model.BgDataModel.FixedContainerItems;
import com.android.launcher3.model.data.AppInfo;
import com.android.launcher3.model.data.ItemInfo;
import com.android.launcher3.model.data.WorkspaceItemInfo;
import com.android.launcher3.statehandlers.DesktopVisibilityController;
import com.android.launcher3.util.ComponentKey;
import com.android.launcher3.util.IntArray;
import com.android.launcher3.util.IntSet;
import com.android.launcher3.util.ItemInfoMatcher;
import com.android.launcher3.util.LauncherBindableItemsContainer;
import com.android.launcher3.util.PackageUserKey;
import com.android.launcher3.util.Preconditions;
import com.android.quickstep.LauncherActivityInterface;
import com.android.quickstep.RecentsModel;

import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.Predicate;

/**
 * Launcher model Callbacks for rendering taskbar.
 */
public class TaskbarModelCallbacks implements
        BgDataModel.Callbacks, LauncherBindableItemsContainer, RecentsModel.RunningTasksListener {

    private final SparseArray<ItemInfo> mHotseatItems = new SparseArray<>();
    private List<ItemInfo> mPredictedItems = Collections.emptyList();

    private final TaskbarActivityContext mContext;
    private final TaskbarView mContainer;

    // Initialized in init.
    protected TaskbarControllers mControllers;

    // Used to defer any UI updates during the SUW unstash animation.
    private boolean mDeferUpdatesForSUW;
    private Runnable mDeferredUpdates;
    private final DesktopVisibilityController.DesktopVisibilityListener mDesktopVisibilityListener =
            visible -> updateRunningApps();

    public TaskbarModelCallbacks(
            TaskbarActivityContext context, TaskbarView container) {
        mContext = context;
        mContainer = container;
    }

    public void init(TaskbarControllers controllers) {
        mControllers = controllers;
        if (mControllers.taskbarRecentAppsController.getCanShowRunningApps()) {
            RecentsModel.INSTANCE.get(mContext).registerRunningTasksListener(this);

            if (shouldShowRunningAppsInDesktopMode()) {
                DesktopVisibilityController desktopVisibilityController =
                        LauncherActivityInterface.INSTANCE.getDesktopVisibilityController();
                if (desktopVisibilityController != null) {
                    desktopVisibilityController.registerDesktopVisibilityListener(
                            mDesktopVisibilityListener);
                }
            }
        }
    }

    /**
     * Unregisters listeners in this class.
     */
    public void unregisterListeners() {
        RecentsModel.INSTANCE.get(mContext).unregisterRunningTasksListener();

        if (shouldShowRunningAppsInDesktopMode()) {
            DesktopVisibilityController desktopVisibilityController =
                    LauncherActivityInterface.INSTANCE.getDesktopVisibilityController();
            if (desktopVisibilityController != null) {
                desktopVisibilityController.unregisterDesktopVisibilityListener(
                        mDesktopVisibilityListener);
            }
        }
    }

    private boolean shouldShowRunningAppsInDesktopMode() {
        // TODO(b/335401172): unify DesktopMode checks in Launcher
        return enableDesktopWindowingMode() && enableDesktopWindowingTaskbarRunningApps();
    }

    @Override
    public void startBinding() {
        mContext.setBindingItems(true);
        mHotseatItems.clear();
        mPredictedItems = Collections.emptyList();
    }

    @Override
    public void finishBindingItems(IntSet pagesBoundFirst) {
        mContext.setBindingItems(false);
        commitItemsToUI();
    }

    @Override
    public void bindAppsAdded(IntArray newScreens, ArrayList<ItemInfo> addNotAnimated,
            ArrayList<ItemInfo> addAnimated) {
        boolean add1 = handleItemsAdded(addNotAnimated);
        boolean add2 = handleItemsAdded(addAnimated);
        if (add1 || add2) {
            commitItemsToUI();
        }
    }

    @Override
    public void bindItems(List<ItemInfo> shortcuts, boolean forceAnimateIcons) {
        if (handleItemsAdded(shortcuts)) {
            commitItemsToUI();
        }
    }

    private boolean handleItemsAdded(List<ItemInfo> items) {
        boolean modified = false;
        for (ItemInfo item : items) {
            if (item.container == Favorites.CONTAINER_HOTSEAT) {
                mHotseatItems.put(item.screenId, item);
                modified = true;
            }
        }
        return modified;
    }


    @Override
    public void bindWorkspaceItemsChanged(List<WorkspaceItemInfo> updated) {
        updateWorkspaceItems(updated, mContext);
    }

    @Override
    public void bindRestoreItemsChange(HashSet<ItemInfo> updates) {
        updateRestoreItems(updates, mContext);
    }

    @Override
    public void mapOverItems(ItemOperator op) {
        final int itemCount = mContainer.getChildCount();
        for (int itemIdx = 0; itemIdx < itemCount; itemIdx++) {
            View item = mContainer.getChildAt(itemIdx);
            if (op.evaluate((ItemInfo) item.getTag(), item)) {
                return;
            }
        }
    }

    @Override
    public void bindWorkspaceComponentsRemoved(Predicate<ItemInfo> matcher) {
        if (handleItemsRemoved(matcher)) {
            commitItemsToUI();
        }
    }

    private boolean handleItemsRemoved(Predicate<ItemInfo> matcher) {
        boolean modified = false;
        for (int i = mHotseatItems.size() - 1; i >= 0; i--) {
            if (matcher.test(mHotseatItems.valueAt(i))) {
                modified = true;
                mHotseatItems.removeAt(i);
            }
        }
        return modified;
    }

    @Override
    public void bindItemsModified(List<ItemInfo> items) {
        boolean removed = handleItemsRemoved(ItemInfoMatcher.ofItems(items));
        boolean added = handleItemsAdded(items);
        if (removed || added) {
            commitItemsToUI();
        }
    }

    @Override
    public void bindExtraContainerItems(FixedContainerItems item) {
        if (item.containerId == Favorites.CONTAINER_HOTSEAT_PREDICTION) {
            mPredictedItems = item.items;
            commitItemsToUI();
        } else if (item.containerId == Favorites.CONTAINER_PREDICTION) {
            mControllers.taskbarAllAppsController.setPredictedApps(item.items);
        }
    }

    private void commitItemsToUI() {
        if (mContext.isBindingItems()) {
            return;
        }

        ItemInfo[] hotseatItemInfos =
                new ItemInfo[mContext.getDeviceProfile().numShownHotseatIcons];
        int predictionSize = mPredictedItems.size();
        int predictionNextIndex = 0;

        for (int i = 0; i < hotseatItemInfos.length; i++) {
            hotseatItemInfos[i] = mHotseatItems.get(i);
            if (hotseatItemInfos[i] == null && predictionNextIndex < predictionSize) {
                hotseatItemInfos[i] = mPredictedItems.get(predictionNextIndex);
                hotseatItemInfos[i].screenId = i;
                predictionNextIndex++;
            }
        }
        hotseatItemInfos = mControllers.taskbarRecentAppsController
                .updateHotseatItemInfos(hotseatItemInfos);
        Set<String> runningPackages = mControllers.taskbarRecentAppsController.getRunningApps();
        Set<String> minimizedPackages = mControllers.taskbarRecentAppsController.getMinimizedApps();

        if (mDeferUpdatesForSUW) {
            ItemInfo[] finalHotseatItemInfos = hotseatItemInfos;
            mDeferredUpdates = () ->
                    commitHotseatItemUpdates(finalHotseatItemInfos, runningPackages,
                            minimizedPackages);
        } else {
            commitHotseatItemUpdates(hotseatItemInfos, runningPackages, minimizedPackages);
        }
    }

    private void commitHotseatItemUpdates(ItemInfo[] hotseatItemInfos, Set<String> runningPackages,
            Set<String> minimizedPackages) {
        mContainer.updateHotseatItems(hotseatItemInfos);
        mControllers.taskbarViewController.updateIconViewsRunningStates(runningPackages,
                minimizedPackages);
    }

    /**
     * This is used to defer UI updates after SUW builds the unstash animation.
     * @param defer if true, defers updates to the UI
     *              if false, posts updates (if any) to the UI
     */
    public void setDeferUpdatesForSUW(boolean defer) {
        mDeferUpdatesForSUW = defer;

        if (!mDeferUpdatesForSUW) {
            if (mDeferredUpdates != null) {
                mContainer.post(mDeferredUpdates);
                mDeferredUpdates = null;
            }
        }
    }

    @Override
    public void onRunningTasksChanged() {
        updateRunningApps();
    }

    /** Called when there's a change in running apps to update the UI. */
    public void commitRunningAppsToUI() {
        commitItemsToUI();
    }

    /** Call TaskbarRecentAppsController to update running apps with mHotseatItems. */
    public void updateRunningApps() {
        mControllers.taskbarRecentAppsController.updateRunningApps();
    }

    @Override
    public void bindDeepShortcutMap(HashMap<ComponentKey, Integer> deepShortcutMapCopy) {
        mControllers.taskbarPopupController.setDeepShortcutMap(deepShortcutMapCopy);
    }

    @UiThread
    @Override
    public void bindAllApplications(AppInfo[] apps, int flags,
            Map<PackageUserKey, Integer> packageUserKeytoUidMap) {
        Preconditions.assertUIThread();
        mControllers.taskbarAllAppsController.setApps(apps, flags, packageUserKeytoUidMap);
        mControllers.taskbarRecentAppsController.setApps(apps);
    }

    protected void dumpLogs(String prefix, PrintWriter pw) {
        pw.println(prefix + "TaskbarModelCallbacks:");

        pw.println(String.format("%s\thotseat items count=%s", prefix, mHotseatItems.size()));
        if (mPredictedItems != null) {
            pw.println(
                    String.format("%s\tpredicted items count=%s", prefix, mPredictedItems.size()));
        }
        pw.println(String.format("%s\tmDeferUpdatesForSUW=%b", prefix, mDeferUpdatesForSUW));
        pw.println(String.format("%s\tupdates pending=%b", prefix, (mDeferredUpdates != null)));
    }
}