/*
 * 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.settings;

import android.app.Application;
import android.database.ContentObserver;
import android.net.Uri;
import android.provider.Settings;
import android.util.FeatureFlagUtils;

import androidx.window.embedding.SplitController;

import com.android.settings.activityembedding.ActivityEmbeddingRulesController;
import com.android.settings.homepage.SettingsHomepageActivity;
import com.android.settings.spa.SettingsSpaEnvironment;
import com.android.settingslib.applications.AppIconCacheManager;
import com.android.settingslib.spa.framework.common.SpaEnvironmentFactory;

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

import java.lang.ref.WeakReference;

/** Settings application which sets up activity embedding rules for the large screen device. */
public class SettingsApplication extends Application {

    private WeakReference<SettingsHomepageActivity> mHomeActivity = new WeakReference<>(null);

    @Override
    public void onCreate() {
        super.onCreate();

        // Set Spa environment.
        setSpaEnvironment();

        if (FeatureFlagUtils.isEnabled(this, FeatureFlagUtils.SETTINGS_SUPPORT_LARGE_SCREEN)
                && SplitController.getInstance().isSplitSupported()) {
            if (WizardManagerHelper.isUserSetupComplete(this)) {
                new ActivityEmbeddingRulesController(this).initRules();
            } else {
                new DeviceProvisionedObserver().registerContentObserver();
            }
        }
    }

    /**
     * Set the spa environment instance.
     * Override this function to set different spa environment for different Settings app.
     */
    protected void setSpaEnvironment() {
        SpaEnvironmentFactory.INSTANCE.reset(new SettingsSpaEnvironment(this));
    }

    public void setHomeActivity(SettingsHomepageActivity homeActivity) {
        mHomeActivity = new WeakReference<>(homeActivity);
    }

    public SettingsHomepageActivity getHomeActivity() {
        return mHomeActivity.get();
    }

    @Override
    public void onLowMemory() {
        super.onLowMemory();
        AppIconCacheManager.getInstance().release();
    }

    private class DeviceProvisionedObserver extends ContentObserver {
        private final Uri mDeviceProvisionedUri = Settings.Secure.getUriFor(
                Settings.Secure.USER_SETUP_COMPLETE);

        DeviceProvisionedObserver() {
            super(null /* handler */);
        }

        @Override
        public void onChange(boolean selfChange, Uri uri, int flags) {
            if (!mDeviceProvisionedUri.equals(uri)) {
                return;
            }

            SettingsApplication.this.getContentResolver().unregisterContentObserver(this);
            new ActivityEmbeddingRulesController(SettingsApplication.this).initRules();
        }

        public void registerContentObserver() {
            SettingsApplication.this.getContentResolver().registerContentObserver(
                    mDeviceProvisionedUri,
                    false /* notifyForDescendants */,
                    this);
        }
    }
}