/**
 * Copyright (C) 2014 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 android.app.usage;

import android.app.usage.UsageStatsManager.StandbyBuckets;
import android.content.ComponentName;
import android.content.res.Configuration;

import java.util.List;

/**
 * UsageStatsManager local system service interface.
 *
 * {@hide} Only for use within the system server.
 */
public abstract class UsageStatsManagerInternal {

    /**
     * Reports an event to the UsageStatsManager.
     *
     * @param component The component for which this event occurred.
     * @param userId The user id to which the component belongs to.
     * @param eventType The event that occurred. Valid values can be found at
     * {@link UsageEvents}
     */
    public abstract void reportEvent(ComponentName component, int userId, int eventType);

    /**
     * Reports an event to the UsageStatsManager.
     *
     * @param packageName The package for which this event occurred.
     * @param userId The user id to which the component belongs to.
     * @param eventType The event that occurred. Valid values can be found at
     * {@link UsageEvents}
     */
    public abstract void reportEvent(String packageName, int userId, int eventType);

    /**
     * Reports a configuration change to the UsageStatsManager.
     *
     * @param config The new device configuration.
     */
    public abstract void reportConfigurationChange(Configuration config, int userId);

    /**
     * Reports that an action equivalent to a ShortcutInfo is taken by the user.
     *
     * @param packageName The package name of the shortcut publisher
     * @param shortcutId The ID of the shortcut in question
     * @param userId The user in which the content provider was accessed.
     *
     * @see android.content.pm.ShortcutManager#reportShortcutUsed(String)
     */
    public abstract void reportShortcutUsage(String packageName, String shortcutId, int userId);

    /**
     * Reports that a content provider has been accessed by a foreground app.
     * @param name The authority of the content provider
     * @param pkgName The package name of the content provider
     * @param userId The user in which the content provider was accessed.
     */
    public abstract void reportContentProviderUsage(String name, String pkgName, int userId);

    /**
     * Prepares the UsageStatsService for shutdown.
     */
    public abstract void prepareShutdown();

    /**
     * Returns true if the app has not been used for a certain amount of time. How much time?
     * Could be hours, could be days, who knows?
     *
     * @param packageName
     * @param uidForAppId The uid of the app, which will be used for its app id
     * @param userId
     * @return
     */
    public abstract boolean isAppIdle(String packageName, int uidForAppId, int userId);

    /**
     * Returns the app standby bucket that the app is currently in.  This accessor does
     * <em>not</em> obfuscate instant apps.
     *
     * @param packageName
     * @param userId
     * @param nowElapsed The current time, in the elapsedRealtime time base
     * @return the AppStandby bucket code the app currently resides in.  If the app is
     *     unknown in the given user, STANDBY_BUCKET_NEVER is returned.
     */
    @StandbyBuckets public abstract int getAppStandbyBucket(String packageName, int userId,
            long nowElapsed);

    /**
     * Returns all of the uids for a given user where all packages associating with that uid
     * are in the app idle state -- there are no associated apps that are not idle.  This means
     * all of the returned uids can be safely considered app idle.
     */
    public abstract int[] getIdleUidsForUser(int userId);

    /**
     * @return True if currently app idle parole mode is on.  This means all idle apps are allow to
     * run for a short period of time.
     */
    public abstract boolean isAppIdleParoleOn();

    /**
     * Sets up a listener for changes to packages being accessed.
     * @param listener A listener within the system process.
     */
    public abstract void addAppIdleStateChangeListener(
            AppIdleStateChangeListener listener);

    /**
     * Removes a listener that was previously added for package usage state changes.
     * @param listener The listener within the system process to remove.
     */
    public abstract void removeAppIdleStateChangeListener(
            AppIdleStateChangeListener listener);

    public static abstract class AppIdleStateChangeListener {

        /** Callback to inform listeners that the idle state has changed to a new bucket. */
        public abstract void onAppIdleStateChanged(String packageName, int userId, boolean idle,
                                                   int bucket);

        /**
         * Callback to inform listeners that the parole state has changed. This means apps are
         * allowed to do work even if they're idle or in a low bucket.
         */
        public abstract void onParoleStateChanged(boolean isParoleOn);
    }

    /*  Backup/Restore API */
    public abstract byte[] getBackupPayload(int user, String key);

    public abstract void applyRestoredPayload(int user, String key, byte[] payload);

    /**
     * Return usage stats.
     *
     * @param obfuscateInstantApps whether instant app package names need to be obfuscated in the
     *     result.
     */
    public abstract List<UsageStats> queryUsageStatsForUser(
            int userId, int interval, long beginTime, long endTime, boolean obfuscateInstantApps);
}