/**
 * Copyright (C) 2018 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.settings.core;

import android.annotation.LayoutRes;
import android.annotation.Nullable;
import android.app.ActivityManager;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.content.res.TypedArray;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.ArraySet;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.Toolbar;

import androidx.fragment.app.FragmentActivity;

import com.android.settings.R;
import com.android.settings.SubSettings;
import com.android.settings.dashboard.CategoryManager;
import com.android.settingslib.drawer.Tile;

import com.google.android.setupcompat.util.WizardManagerHelper;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class SettingsBaseActivity extends FragmentActivity {

    protected static final boolean DEBUG_TIMING = false;
    private static final String TAG = "SettingsBaseActivity";
    private static final String DATA_SCHEME_PKG = "package";

    // Serves as a temporary list of tiles to ignore until we heard back from the PM that they
    // are disabled.
    private static ArraySet<ComponentName> sTileBlacklist = new ArraySet<>();

    private final PackageReceiver mPackageReceiver = new PackageReceiver();
    private final List<CategoryListener> mCategoryListeners = new ArrayList<>();
    private int mCategoriesUpdateTaskCount;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (isLockTaskModePinned() && !isSettingsRunOnTop()) {
            Log.w(TAG, "Devices lock task mode pinned.");
            finish();
        }
        final long startTime = System.currentTimeMillis();
        getLifecycle().addObserver(new HideNonSystemOverlayMixin(this));

        final TypedArray theme = getTheme().obtainStyledAttributes(android.R.styleable.Theme);
        if (!theme.getBoolean(android.R.styleable.Theme_windowNoTitle, false)) {
            requestWindowFeature(Window.FEATURE_NO_TITLE);
        }
        // Apply SetupWizard light theme during setup flow. This is for SubSettings pages.
        if (WizardManagerHelper.isAnySetupWizard(getIntent()) && this instanceof SubSettings) {
            setTheme(R.style.LightTheme_SubSettings_SetupWizard);
        }
        super.setContentView(R.layout.settings_base_layout);

        final Toolbar toolbar = findViewById(R.id.action_bar);
        if (theme.getBoolean(android.R.styleable.Theme_windowNoTitle, false)) {
            toolbar.setVisibility(View.GONE);
            return;
        }
        setActionBar(toolbar);

        if (DEBUG_TIMING) {
            Log.d(TAG, "onCreate took " + (System.currentTimeMillis() - startTime)
                    + " ms");
        }
    }

    @Override
    public boolean onNavigateUp() {
        if (!super.onNavigateUp()) {
            finish();
        }
        return true;
    }

    @Override
    protected void onResume() {
        super.onResume();
        final IntentFilter filter = new IntentFilter(Intent.ACTION_PACKAGE_ADDED);
        filter.addAction(Intent.ACTION_PACKAGE_REMOVED);
        filter.addAction(Intent.ACTION_PACKAGE_CHANGED);
        filter.addAction(Intent.ACTION_PACKAGE_REPLACED);
        filter.addDataScheme(DATA_SCHEME_PKG);
        registerReceiver(mPackageReceiver, filter);

        updateCategories();
    }

    @Override
    protected void onPause() {
        unregisterReceiver(mPackageReceiver);
        super.onPause();
    }

    public void addCategoryListener(CategoryListener listener) {
        mCategoryListeners.add(listener);
    }

    public void remCategoryListener(CategoryListener listener) {
        mCategoryListeners.remove(listener);
    }

    @Override
    public void setContentView(@LayoutRes int layoutResID) {
        final ViewGroup parent = findViewById(R.id.content_frame);
        if (parent != null) {
            parent.removeAllViews();
        }
        LayoutInflater.from(this).inflate(layoutResID, parent);
    }

    @Override
    public void setContentView(View view) {
        ((ViewGroup) findViewById(R.id.content_frame)).addView(view);
    }

    @Override
    public void setContentView(View view, ViewGroup.LayoutParams params) {
        ((ViewGroup) findViewById(R.id.content_frame)).addView(view, params);
    }

    private void onCategoriesChanged(Set<String> categories) {
        final int N = mCategoryListeners.size();
        for (int i = 0; i < N; i++) {
            mCategoryListeners.get(i).onCategoriesChanged(categories);
        }
    }

    private boolean isLockTaskModePinned() {
        final ActivityManager activityManager =
                getApplicationContext().getSystemService(ActivityManager.class);
        return activityManager.getLockTaskModeState() == ActivityManager.LOCK_TASK_MODE_PINNED;
    }

    private boolean isSettingsRunOnTop() {
        final ActivityManager activityManager =
                getApplicationContext().getSystemService(ActivityManager.class);
        final String taskPkgName = activityManager.getRunningTasks(1 /* maxNum */)
                .get(0 /* index */).baseActivity.getPackageName();
        return TextUtils.equals(getPackageName(), taskPkgName);
    }

    /**
     * @return whether or not the enabled state actually changed.
     */
    public boolean setTileEnabled(ComponentName component, boolean enabled) {
        final PackageManager pm = getPackageManager();
        int state = pm.getComponentEnabledSetting(component);
        boolean isEnabled = state == PackageManager.COMPONENT_ENABLED_STATE_ENABLED;
        if (isEnabled != enabled || state == PackageManager.COMPONENT_ENABLED_STATE_DEFAULT) {
            if (enabled) {
                sTileBlacklist.remove(component);
            } else {
                sTileBlacklist.add(component);
            }
            pm.setComponentEnabledSetting(component, enabled
                            ? PackageManager.COMPONENT_ENABLED_STATE_ENABLED
                            : PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
                    PackageManager.DONT_KILL_APP);
            return true;
        }
        return false;
    }

    /**
     * Updates dashboard categories. Only necessary to call this after setTileEnabled
     */
    public void updateCategories() {
        updateCategories(false /* fromBroadcast */);
    }

    private void updateCategories(boolean fromBroadcast) {
        // Only allow at most 2 tasks existing at the same time since when the first one is
        // executing, there may be new data from the second update request.
        // Ignore the third update request because the second task is still waiting for the first
        // task to complete in a serial thread, which will get the latest data.
        if (mCategoriesUpdateTaskCount < 2) {
            new CategoriesUpdateTask().execute(fromBroadcast);
        }
    }

    public interface CategoryListener {
        /**
         * @param categories the changed categories that have to be refreshed, or null to force
         * refreshing all.
         */
        void onCategoriesChanged(@Nullable Set<String> categories);
    }

    private class CategoriesUpdateTask extends AsyncTask<Boolean, Void, Set<String>> {

        private final Context mContext;
        private final CategoryManager mCategoryManager;
        private Map<ComponentName, Tile> mPreviousTileMap;

        public CategoriesUpdateTask() {
            mCategoriesUpdateTaskCount++;
            mContext = SettingsBaseActivity.this;
            mCategoryManager = CategoryManager.get(mContext);
        }

        @Override
        protected Set<String> doInBackground(Boolean... params) {
            mPreviousTileMap = mCategoryManager.getTileByComponentMap();
            mCategoryManager.reloadAllCategories(mContext);
            mCategoryManager.updateCategoryFromBlacklist(sTileBlacklist);
            return getChangedCategories(params[0]);
        }

        @Override
        protected void onPostExecute(Set<String> categories) {
            if (categories == null || !categories.isEmpty()) {
                onCategoriesChanged(categories);
            }
            mCategoriesUpdateTaskCount--;
        }

        // Return the changed categories that have to be refreshed, or null to force refreshing all.
        private Set<String> getChangedCategories(boolean fromBroadcast) {
            if (!fromBroadcast) {
                // Always refresh for non-broadcast case.
                return null;
            }

            final Set<String> changedCategories = new ArraySet<>();
            final Map<ComponentName, Tile> currentTileMap =
                    mCategoryManager.getTileByComponentMap();
            currentTileMap.forEach((component, currentTile) -> {
                final Tile previousTile = mPreviousTileMap.get(component);
                // Check if the tile is newly added.
                if (previousTile == null) {
                    Log.i(TAG, "Tile added: " + component.flattenToShortString());
                    changedCategories.add(currentTile.getCategory());
                    return;
                }

                // Check if the title or summary has changed.
                if (!TextUtils.equals(currentTile.getTitle(mContext),
                        previousTile.getTitle(mContext))
                        || !TextUtils.equals(currentTile.getSummary(mContext),
                        previousTile.getSummary(mContext))) {
                    Log.i(TAG, "Tile changed: " + component.flattenToShortString());
                    changedCategories.add(currentTile.getCategory());
                }
            });

            // Check if any previous tile is removed.
            final Set<ComponentName> removal = new ArraySet(mPreviousTileMap.keySet());
            removal.removeAll(currentTileMap.keySet());
            removal.forEach(component -> {
                Log.i(TAG, "Tile removed: " + component.flattenToShortString());
                changedCategories.add(mPreviousTileMap.get(component).getCategory());
            });

            return changedCategories;
        }
    }

    private class PackageReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            updateCategories(true /* fromBroadcast */);
        }
    }
}