/*
 * Copyright (C) 2009 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.internal.os;

import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.content.res.Resources;
import android.hardware.SensorManager;
import android.net.ConnectivityManager;
import android.os.BatteryStats;
import android.os.BatteryStats.Uid;
import android.os.Bundle;
import android.os.MemoryFile;
import android.os.Parcel;
import android.os.ParcelFileDescriptor;
import android.os.Process;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.os.SystemClock;
import android.os.UserHandle;
import android.text.format.DateUtils;
import android.util.ArrayMap;
import android.util.Log;
import android.util.SparseArray;
import android.util.SparseLongArray;

import com.android.internal.annotations.VisibleForTesting;
import com.android.internal.app.IBatteryStats;
import com.android.internal.os.BatterySipper.DrainType;
import com.android.internal.util.ArrayUtils;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Locale;

A helper class for retrieving the power usage information for all applications and services.
The caller must initialize this class as soon as activity object is ready to use (for example, in
onAttach() for Fragment), call create() in onCreate() and call destroy() in onDestroy().
/**
 * A helper class for retrieving the power usage information for all applications and services.
 *
 * The caller must initialize this class as soon as activity object is ready to use (for example, in
 * onAttach() for Fragment), call create() in onCreate() and call destroy() in onDestroy().
 */
public class BatteryStatsHelper {
    static final boolean DEBUG = false;

    private static final String TAG = BatteryStatsHelper.class.getSimpleName();

    private static BatteryStats sStatsXfer;
    private static Intent sBatteryBroadcastXfer;
    private static ArrayMap<File, BatteryStats> sFileXfer = new ArrayMap<>();

    final private Context mContext;
    final private boolean mCollectBatteryBroadcast;
    final private boolean mWifiOnly;

    private IBatteryStats mBatteryInfo;
    private BatteryStats mStats;
    private Intent mBatteryBroadcast;
    private PowerProfile mPowerProfile;

    private String[] mSystemPackageArray;
    private String[] mServicepackageArray;
    private PackageManager mPackageManager;

    
List of apps using power.
/**
     * List of apps using power.
     */
    private final List<BatterySipper> mUsageList = new ArrayList<>();

    
List of apps using wifi power.
/**
     * List of apps using wifi power.
     */
    private final List<BatterySipper> mWifiSippers = new ArrayList<>();

    
List of apps using bluetooth power.
/**
     * List of apps using bluetooth power.
     */
    private final List<BatterySipper> mBluetoothSippers = new ArrayList<>();

    private final SparseArray<List<BatterySipper>> mUserSippers = new SparseArray<>();

    private final List<BatterySipper> mMobilemsppList = new ArrayList<>();

    private int mStatsType = BatteryStats.STATS_SINCE_CHARGED;

    long mRawRealtimeUs;
    long mRawUptimeUs;
    long mBatteryRealtimeUs;
    long mBatteryUptimeUs;
    long mTypeBatteryRealtimeUs;
    long mTypeBatteryUptimeUs;
    long mBatteryTimeRemainingUs;
    long mChargeTimeRemainingUs;

    private long mStatsPeriod = 0;

    // The largest entry by power.
    private double mMaxPower = 1;

    // The largest real entry by power (not undercounted or overcounted).
    private double mMaxRealPower = 1;

    // Total computed power.
    private double mComputedPower;
    private double mTotalPower;
    private double mMinDrainedPower;
    private double mMaxDrainedPower;

    PowerCalculator mCpuPowerCalculator;
    PowerCalculator mWakelockPowerCalculator;
    MobileRadioPowerCalculator mMobileRadioPowerCalculator;
    PowerCalculator mWifiPowerCalculator;
    PowerCalculator mBluetoothPowerCalculator;
    PowerCalculator mSensorPowerCalculator;
    PowerCalculator mCameraPowerCalculator;
    PowerCalculator mFlashlightPowerCalculator;
    PowerCalculator mMemoryPowerCalculator;
    PowerCalculator mMediaPowerCalculator;

    boolean mHasWifiPowerReporting = false;
    boolean mHasBluetoothPowerReporting = false;

    public static boolean checkWifiOnly(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(
                Context.CONNECTIVITY_SERVICE);
        if (cm == null) {
            return false;
        }
        return !cm.isNetworkSupported(ConnectivityManager.TYPE_MOBILE);
    }

    public static boolean checkHasWifiPowerReporting(BatteryStats stats, PowerProfile profile) {
        return stats.hasWifiActivityReporting() &&
                profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_IDLE) != 0 &&
                profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_RX) != 0 &&
                profile.getAveragePower(PowerProfile.POWER_WIFI_CONTROLLER_TX) != 0;
    }

    public static boolean checkHasBluetoothPowerReporting(BatteryStats stats,
            PowerProfile profile) {
        return stats.hasBluetoothActivityReporting() &&
                profile.getAveragePower(PowerProfile.POWER_BLUETOOTH_CONTROLLER_IDLE) != 0 &&
                profile.getAveragePower(PowerProfile.POWER_BLUETOOTH_CONTROLLER_RX) != 0 &&
                profile.getAveragePower(PowerProfile.POWER_BLUETOOTH_CONTROLLER_TX) != 0;
    }

    public BatteryStatsHelper(Context context) {
        this(context, true);
    }

    public BatteryStatsHelper(Context context, boolean collectBatteryBroadcast) {
        this(context, collectBatteryBroadcast, checkWifiOnly(context));
    }

    public BatteryStatsHelper(Context context, boolean collectBatteryBroadcast, boolean wifiOnly) {
        mContext = context;
        mCollectBatteryBroadcast = collectBatteryBroadcast;
        mWifiOnly = wifiOnly;
        mPackageManager = context.getPackageManager();

        final Resources resources = context.getResources();
        mSystemPackageArray = resources.getStringArray(
                com.android.internal.R.array.config_batteryPackageTypeSystem);
        mServicepackageArray = resources.getStringArray(
                com.android.internal.R.array.config_batteryPackageTypeService);
    }

    public void storeStatsHistoryInFile(String fname) {
        synchronized (sFileXfer) {
            File path = makeFilePath(mContext, fname);
            sFileXfer.put(path, this.getStats());
            FileOutputStream fout = null;
            try {
                fout = new FileOutputStream(path);
                Parcel hist = Parcel.obtain();
                getStats().writeToParcelWithoutUids(hist, 0);
                byte[] histData = hist.marshall();
                fout.write(histData);
            } catch (IOException e) {
                Log.w(TAG, "Unable to write history to file", e);
            } finally {
                if (fout != null) {
                    try {
                        fout.close();
                    } catch (IOException e) {
                    }
                }
            }
        }
    }

    public static BatteryStats statsFromFile(Context context, String fname) {
        synchronized (sFileXfer) {
            File path = makeFilePath(context, fname);
            BatteryStats stats = sFileXfer.get(path);
            if (stats != null) {
                return stats;
            }
            FileInputStream fin = null;
            try {
                fin = new FileInputStream(path);
                byte[] data = readFully(fin);
                Parcel parcel = Parcel.obtain();
                parcel.unmarshall(data, 0, data.length);
                parcel.setDataPosition(0);
                return com.android.internal.os.BatteryStatsImpl.CREATOR.createFromParcel(parcel);
            } catch (IOException e) {
                Log.w(TAG, "Unable to read history to file", e);
            } finally {
                if (fin != null) {
                    try {
                        fin.close();
                    } catch (IOException e) {
                    }
                }
            }
        }
        return getStats(IBatteryStats.Stub.asInterface(
                ServiceManager.getService(BatteryStats.SERVICE_NAME)));
    }

    public static void dropFile(Context context, String fname) {
        makeFilePath(context, fname).delete();
    }

    private static File makeFilePath(Context context, String fname) {
        return new File(context.getFilesDir(), fname);
    }

    
Clears the current stats and forces recreating for future use. /** Clears the current stats and forces recreating for future use. */
    public void clearStats() {
        mStats = null;
    }

    public BatteryStats getStats() {
        if (mStats == null) {
            load();
        }
        return mStats;
    }

    public Intent getBatteryBroadcast() {
        if (mBatteryBroadcast == null && mCollectBatteryBroadcast) {
            load();
        }
        return mBatteryBroadcast;
    }

    public PowerProfile getPowerProfile() {
        return mPowerProfile;
    }

    public void create(BatteryStats stats) {
        mPowerProfile = new PowerProfile(mContext);
        mStats = stats;
    }

    public void create(Bundle icicle) {
        if (icicle != null) {
            mStats = sStatsXfer;
            mBatteryBroadcast = sBatteryBroadcastXfer;
        }
        mBatteryInfo = IBatteryStats.Stub.asInterface(
                ServiceManager.getService(BatteryStats.SERVICE_NAME));
        mPowerProfile = new PowerProfile(mContext);
    }

    public void storeState() {
        sStatsXfer = mStats;
        sBatteryBroadcastXfer = mBatteryBroadcast;
    }

    public static String makemAh(double power) {
        if (power == 0) return "0";

        final String format;
        if (power < .00001) {
            format = "%.8f";
        } else if (power < .0001) {
            format = "%.7f";
        } else if (power < .001) {
            format = "%.6f";
        } else if (power < .01) {
            format = "%.5f";
        } else if (power < .1) {
            format = "%.4f";
        } else if (power < 1) {
            format = "%.3f";
        } else if (power < 10) {
            format = "%.2f";
        } else if (power < 100) {
            format = "%.1f";
        } else {
            format = "%.0f";
        }

        // Use English locale because this is never used in UI (only in checkin and dump).
        return String.format(Locale.ENGLISH, format, power);
    }

    
Refreshes the power usage list.
/**
     * Refreshes the power usage list.
     */
    public void refreshStats(int statsType, int asUser) {
        SparseArray<UserHandle> users = new SparseArray<>(1);
        users.put(asUser, new UserHandle(asUser));
        refreshStats(statsType, users);
    }

    
Refreshes the power usage list.
/**
     * Refreshes the power usage list.
     */
    public void refreshStats(int statsType, List<UserHandle> asUsers) {
        final int n = asUsers.size();
        SparseArray<UserHandle> users = new SparseArray<>(n);
        for (int i = 0; i < n; ++i) {
            UserHandle userHandle = asUsers.get(i);
            users.put(userHandle.getIdentifier(), userHandle);
        }
        refreshStats(statsType, users);
    }

    
Refreshes the power usage list.
/**
     * Refreshes the power usage list.
     */
    public void refreshStats(int statsType, SparseArray<UserHandle> asUsers) {
        refreshStats(statsType, asUsers, SystemClock.elapsedRealtime() * 1000,
                SystemClock.uptimeMillis() * 1000);
    }

    public void refreshStats(int statsType, SparseArray<UserHandle> asUsers, long rawRealtimeUs,
            long rawUptimeUs) {
        // Initialize mStats if necessary.
        getStats();

        mMaxPower = 0;
        mMaxRealPower = 0;
        mComputedPower = 0;
        mTotalPower = 0;

        mUsageList.clear();
        mWifiSippers.clear();
        mBluetoothSippers.clear();
        mUserSippers.clear();
        mMobilemsppList.clear();

        if (mStats == null) {
            return;
        }

        if (mCpuPowerCalculator == null) {
            mCpuPowerCalculator = new CpuPowerCalculator(mPowerProfile);
        }
        mCpuPowerCalculator.reset();

        if (mMemoryPowerCalculator == null) {
            mMemoryPowerCalculator = new MemoryPowerCalculator(mPowerProfile);
        }
        mMemoryPowerCalculator.reset();

        if (mWakelockPowerCalculator == null) {
            mWakelockPowerCalculator = new WakelockPowerCalculator(mPowerProfile);
        }
        mWakelockPowerCalculator.reset();

        if (mMobileRadioPowerCalculator == null) {
            mMobileRadioPowerCalculator = new MobileRadioPowerCalculator(mPowerProfile, mStats);
        }
        mMobileRadioPowerCalculator.reset(mStats);

        // checkHasWifiPowerReporting can change if we get energy data at a later point, so
        // always check this field.
        final boolean hasWifiPowerReporting = checkHasWifiPowerReporting(mStats, mPowerProfile);
        if (mWifiPowerCalculator == null || hasWifiPowerReporting != mHasWifiPowerReporting) {
            mWifiPowerCalculator = hasWifiPowerReporting ?
                    new WifiPowerCalculator(mPowerProfile) :
                    new WifiPowerEstimator(mPowerProfile);
            mHasWifiPowerReporting = hasWifiPowerReporting;
        }
        mWifiPowerCalculator.reset();

        final boolean hasBluetoothPowerReporting = checkHasBluetoothPowerReporting(mStats,
                mPowerProfile);
        if (mBluetoothPowerCalculator == null ||
                hasBluetoothPowerReporting != mHasBluetoothPowerReporting) {
            mBluetoothPowerCalculator = new BluetoothPowerCalculator(mPowerProfile);
            mHasBluetoothPowerReporting = hasBluetoothPowerReporting;
        }
        mBluetoothPowerCalculator.reset();

        mSensorPowerCalculator = new SensorPowerCalculator(mPowerProfile,
                (SensorManager) mContext.getSystemService(Context.SENSOR_SERVICE),
                mStats, rawRealtimeUs, statsType);
        mSensorPowerCalculator.reset();

        if (mCameraPowerCalculator == null) {
            mCameraPowerCalculator = new CameraPowerCalculator(mPowerProfile);
        }
        mCameraPowerCalculator.reset();

        if (mFlashlightPowerCalculator == null) {
            mFlashlightPowerCalculator = new FlashlightPowerCalculator(mPowerProfile);
        }
        mFlashlightPowerCalculator.reset();

        if (mMediaPowerCalculator == null) {
            mMediaPowerCalculator = new MediaPowerCalculator(mPowerProfile);
        }
        mMediaPowerCalculator.reset();

        mStatsType = statsType;
        mRawUptimeUs = rawUptimeUs;
        mRawRealtimeUs = rawRealtimeUs;
        mBatteryUptimeUs = mStats.getBatteryUptime(rawUptimeUs);
        mBatteryRealtimeUs = mStats.getBatteryRealtime(rawRealtimeUs);
        mTypeBatteryUptimeUs = mStats.computeBatteryUptime(rawUptimeUs, mStatsType);
        mTypeBatteryRealtimeUs = mStats.computeBatteryRealtime(rawRealtimeUs, mStatsType);
        mBatteryTimeRemainingUs = mStats.computeBatteryTimeRemaining(rawRealtimeUs);
        mChargeTimeRemainingUs = mStats.computeChargeTimeRemaining(rawRealtimeUs);

        if (DEBUG) {
            Log.d(TAG, "Raw time: realtime=" + (rawRealtimeUs / 1000) + " uptime="
                    + (rawUptimeUs / 1000));
            Log.d(TAG, "Battery time: realtime=" + (mBatteryRealtimeUs / 1000) + " uptime="
                    + (mBatteryUptimeUs / 1000));
            Log.d(TAG, "Battery type time: realtime=" + (mTypeBatteryRealtimeUs / 1000) + " uptime="
                    + (mTypeBatteryUptimeUs / 1000));
        }
        mMinDrainedPower = (mStats.getLowDischargeAmountSinceCharge()
                * mPowerProfile.getBatteryCapacity()) / 100;
        mMaxDrainedPower = (mStats.getHighDischargeAmountSinceCharge()
                * mPowerProfile.getBatteryCapacity()) / 100;

        processAppUsage(asUsers);

        // Before aggregating apps in to users, collect all apps to sort by their ms per packet.
        for (int i = 0; i < mUsageList.size(); i++) {
            BatterySipper bs = mUsageList.get(i);
            bs.computeMobilemspp();
            if (bs.mobilemspp != 0) {
                mMobilemsppList.add(bs);
            }
        }

        for (int i = 0; i < mUserSippers.size(); i++) {
            List<BatterySipper> user = mUserSippers.valueAt(i);
            for (int j = 0; j < user.size(); j++) {
                BatterySipper bs = user.get(j);
                bs.computeMobilemspp();
                if (bs.mobilemspp != 0) {
                    mMobilemsppList.add(bs);
                }
            }
        }
        Collections.sort(mMobilemsppList, new Comparator<BatterySipper>() {
            @Override
            public int compare(BatterySipper lhs, BatterySipper rhs) {
                return Double.compare(rhs.mobilemspp, lhs.mobilemspp);
            }
        });

        processMiscUsage();

        Collections.sort(mUsageList);

        // At this point, we've sorted the list so we are guaranteed the max values are at the top.
        // We have only added real powers so far.
        if (!mUsageList.isEmpty()) {
            mMaxRealPower = mMaxPower = mUsageList.get(0).totalPowerMah;
            final int usageListCount = mUsageList.size();
            for (int i = 0; i < usageListCount; i++) {
                mComputedPower += mUsageList.get(i).totalPowerMah;
            }
        }

        if (DEBUG) {
            Log.d(TAG, "Accuracy: total computed=" + makemAh(mComputedPower) + ", min discharge="
                    + makemAh(mMinDrainedPower) + ", max discharge=" + makemAh(mMaxDrainedPower));
        }

        mTotalPower = mComputedPower;
        if (mStats.getLowDischargeAmountSinceCharge() > 1) {
            if (mMinDrainedPower > mComputedPower) {
                double amount = mMinDrainedPower - mComputedPower;
                mTotalPower = mMinDrainedPower;
                BatterySipper bs = new BatterySipper(DrainType.UNACCOUNTED, null, amount);

                // Insert the BatterySipper in its sorted position.
                int index = Collections.binarySearch(mUsageList, bs);
                if (index < 0) {
                    index = -(index + 1);
                }
                mUsageList.add(index, bs);
                mMaxPower = Math.max(mMaxPower, amount);
            } else if (mMaxDrainedPower < mComputedPower) {
                double amount = mComputedPower - mMaxDrainedPower;

                // Insert the BatterySipper in its sorted position.
                BatterySipper bs = new BatterySipper(DrainType.OVERCOUNTED, null, amount);
                int index = Collections.binarySearch(mUsageList, bs);
                if (index < 0) {
                    index = -(index + 1);
                }
                mUsageList.add(index, bs);
                mMaxPower = Math.max(mMaxPower, amount);
            }
        }

        // Smear it!
        final double hiddenPowerMah = removeHiddenBatterySippers(mUsageList);
        final double totalRemainingPower = getTotalPower() - hiddenPowerMah;
        if (Math.abs(totalRemainingPower) > 1e-3) {
            for (int i = 0, size = mUsageList.size(); i < size; i++) {
                final BatterySipper sipper = mUsageList.get(i);
                if (!sipper.shouldHide) {
                    sipper.proportionalSmearMah = hiddenPowerMah
                            * ((sipper.totalPowerMah + sipper.screenPowerMah)
                            / totalRemainingPower);
                    sipper.sumPower();
                }
            }
        }
    }

    private void processAppUsage(SparseArray<UserHandle> asUsers) {
        final boolean forAllUsers = (asUsers.get(UserHandle.USER_ALL) != null);
        mStatsPeriod = mTypeBatteryRealtimeUs;

        BatterySipper osSipper = null;
        final SparseArray<? extends Uid> uidStats = mStats.getUidStats();
        final int NU = uidStats.size();
        for (int iu = 0; iu < NU; iu++) {
            final Uid u = uidStats.valueAt(iu);
            final BatterySipper app = new BatterySipper(BatterySipper.DrainType.APP, u, 0);

            mCpuPowerCalculator.calculateApp(app, u, mRawRealtimeUs, mRawUptimeUs, mStatsType);
            mWakelockPowerCalculator.calculateApp(app, u, mRawRealtimeUs, mRawUptimeUs, mStatsType);
            mMobileRadioPowerCalculator.calculateApp(app, u, mRawRealtimeUs, mRawUptimeUs,
                    mStatsType);
            mWifiPowerCalculator.calculateApp(app, u, mRawRealtimeUs, mRawUptimeUs, mStatsType);
            mBluetoothPowerCalculator.calculateApp(app, u, mRawRealtimeUs, mRawUptimeUs,
                    mStatsType);
            mSensorPowerCalculator.calculateApp(app, u, mRawRealtimeUs, mRawUptimeUs, mStatsType);
            mCameraPowerCalculator.calculateApp(app, u, mRawRealtimeUs, mRawUptimeUs, mStatsType);
            mFlashlightPowerCalculator.calculateApp(app, u, mRawRealtimeUs, mRawUptimeUs,
                    mStatsType);
            mMediaPowerCalculator.calculateApp(app, u, mRawRealtimeUs, mRawUptimeUs, mStatsType);

            final double totalPower = app.sumPower();
            if (DEBUG && totalPower != 0) {
                Log.d(TAG, String.format("UID %d: total power=%s", u.getUid(),
                        makemAh(totalPower)));
            }

            // Add the app to the list if it is consuming power.
            if (totalPower != 0 || u.getUid() == 0) {
                //
                // Add the app to the app list, WiFi, Bluetooth, etc, or into "Other Users" list.
                //
                final int uid = app.getUid();
                final int userId = UserHandle.getUserId(uid);
                if (uid == Process.WIFI_UID) {
                    mWifiSippers.add(app);
                } else if (uid == Process.BLUETOOTH_UID) {
                    mBluetoothSippers.add(app);
                } else if (!forAllUsers && asUsers.get(userId) == null
                        && UserHandle.getAppId(uid) >= Process.FIRST_APPLICATION_UID) {
                    // We are told to just report this user's apps as one large entry.
                    List<BatterySipper> list = mUserSippers.get(userId);
                    if (list == null) {
                        list = new ArrayList<>();
                        mUserSippers.put(userId, list);
                    }
                    list.add(app);
                } else {
                    mUsageList.add(app);
                }

                if (uid == 0) {
                    osSipper = app;
                }
            }
        }

        if (osSipper != null) {
            // The device has probably been awake for longer than the screen on
            // time and application wake lock time would account for.  Assign
            // this remainder to the OS, if possible.
            mWakelockPowerCalculator.calculateRemaining(osSipper, mStats, mRawRealtimeUs,
                    mRawUptimeUs, mStatsType);
            osSipper.sumPower();
        }
    }

    private void addPhoneUsage() {
        long phoneOnTimeMs = mStats.getPhoneOnTime(mRawRealtimeUs, mStatsType) / 1000;
        double phoneOnPower = mPowerProfile.getAveragePower(PowerProfile.POWER_RADIO_ACTIVE)
                * phoneOnTimeMs / (60 * 60 * 1000);
        if (phoneOnPower != 0) {
            addEntry(BatterySipper.DrainType.PHONE, phoneOnTimeMs, phoneOnPower);
        }
    }

    
Screen power is the additional power the screen takes while the device is running.
/**
     * Screen power is the additional power the screen takes while the device is running.
     */
    private void addScreenUsage() {
        double power = 0;
        long screenOnTimeMs = mStats.getScreenOnTime(mRawRealtimeUs, mStatsType) / 1000;
        power += screenOnTimeMs * mPowerProfile.getAveragePower(PowerProfile.POWER_SCREEN_ON);
        final double screenFullPower =
                mPowerProfile.getAveragePower(PowerProfile.POWER_SCREEN_FULL);
        for (int i = 0; i < BatteryStats.NUM_SCREEN_BRIGHTNESS_BINS; i++) {
            double screenBinPower = screenFullPower * (i + 0.5f)
                    / BatteryStats.NUM_SCREEN_BRIGHTNESS_BINS;
            long brightnessTime = mStats.getScreenBrightnessTime(i, mRawRealtimeUs, mStatsType)
                    / 1000;
            double p = screenBinPower * brightnessTime;
            if (DEBUG && p != 0) {
                Log.d(TAG, "Screen bin #" + i + ": time=" + brightnessTime
                        + " power=" + makemAh(p / (60 * 60 * 1000)));
            }
            power += p;
        }
        power /= (60 * 60 * 1000); // To hours
        if (power != 0) {
            addEntry(BatterySipper.DrainType.SCREEN, screenOnTimeMs, power);
        }
    }

    
Ambient display power is the additional power the screen takes while in ambient display/ screen doze/ always-on display (interchangeable terms) mode. Ambient display power should be hidden shouldHideSipper(BatterySipper), but should not be included in smearing removeHiddenBatterySippers(List<BatterySipper>). /**
     * Ambient display power is the additional power the screen takes while in ambient display/
     * screen doze/ always-on display (interchangeable terms) mode. Ambient display power should
     * be hidden {@link #shouldHideSipper(BatterySipper)}, but should not be included in smearing
     * {@link #removeHiddenBatterySippers(List)}.
     */
    private void addAmbientDisplayUsage() {
        long ambientDisplayMs = mStats.getScreenDozeTime(mRawRealtimeUs, mStatsType) / 1000;
        double power = mPowerProfile.getAveragePower(PowerProfile.POWER_AMBIENT_DISPLAY)
                * ambientDisplayMs / (60 * 60 * 1000);
        if (power > 0) {
            addEntry(DrainType.AMBIENT_DISPLAY, ambientDisplayMs, power);
        }
    }

    private void addRadioUsage() {
        BatterySipper radio = new BatterySipper(BatterySipper.DrainType.CELL, null, 0);
        mMobileRadioPowerCalculator.calculateRemaining(radio, mStats, mRawRealtimeUs, mRawUptimeUs,
                mStatsType);
        radio.sumPower();
        if (radio.totalPowerMah > 0) {
            mUsageList.add(radio);
        }
    }

    private void aggregateSippers(BatterySipper bs, List<BatterySipper> from, String tag) {
        for (int i = 0; i < from.size(); i++) {
            BatterySipper wbs = from.get(i);
            if (DEBUG) Log.d(TAG, tag + " adding sipper " + wbs + ": cpu=" + wbs.cpuTimeMs);
            bs.add(wbs);
        }
        bs.computeMobilemspp();
        bs.sumPower();
    }

    
Calculate the baseline power usage for the device when it is in suspend and idle.
The device is drawing POWER_CPU_SUSPEND power at its lowest power state.
The device is drawing POWER_CPU_SUSPEND + POWER_CPU_IDLE power when a wakelock is held.
/**
     * Calculate the baseline power usage for the device when it is in suspend and idle.
     * The device is drawing POWER_CPU_SUSPEND power at its lowest power state.
     * The device is drawing POWER_CPU_SUSPEND + POWER_CPU_IDLE power when a wakelock is held.
     */
    private void addIdleUsage() {
        final double suspendPowerMaMs = (mTypeBatteryRealtimeUs / 1000) *
                mPowerProfile.getAveragePower(PowerProfile.POWER_CPU_SUSPEND);
        final double idlePowerMaMs = (mTypeBatteryUptimeUs / 1000) *
                mPowerProfile.getAveragePower(PowerProfile.POWER_CPU_IDLE);
        final double totalPowerMah = (suspendPowerMaMs + idlePowerMaMs) / (60 * 60 * 1000);
        if (DEBUG && totalPowerMah != 0) {
            Log.d(TAG, "Suspend: time=" + (mTypeBatteryRealtimeUs / 1000)
                    + " power=" + makemAh(suspendPowerMaMs / (60 * 60 * 1000)));
            Log.d(TAG, "Idle: time=" + (mTypeBatteryUptimeUs / 1000)
                    + " power=" + makemAh(idlePowerMaMs / (60 * 60 * 1000)));
        }

        if (totalPowerMah != 0) {
            addEntry(BatterySipper.DrainType.IDLE, mTypeBatteryRealtimeUs / 1000, totalPowerMah);
        }
    }

    
We do per-app blaming of WiFi activity. If energy info is reported from the controller,
then only the WiFi process gets blamed here since we normalize power calculations and
assign all the power drain to apps. If energy info is not reported, we attribute the
difference between total running time of WiFi for all apps and the actual running time
of WiFi to the WiFi subsystem.
/**
     * We do per-app blaming of WiFi activity. If energy info is reported from the controller,
     * then only the WiFi process gets blamed here since we normalize power calculations and
     * assign all the power drain to apps. If energy info is not reported, we attribute the
     * difference between total running time of WiFi for all apps and the actual running time
     * of WiFi to the WiFi subsystem.
     */
    private void addWiFiUsage() {
        BatterySipper bs = new BatterySipper(DrainType.WIFI, null, 0);
        mWifiPowerCalculator.calculateRemaining(bs, mStats, mRawRealtimeUs, mRawUptimeUs,
                mStatsType);
        aggregateSippers(bs, mWifiSippers, "WIFI");
        if (bs.totalPowerMah > 0) {
            mUsageList.add(bs);
        }
    }

    
Bluetooth usage is not attributed to any apps yet, so the entire blame goes to the
Bluetooth Category.
/**
     * Bluetooth usage is not attributed to any apps yet, so the entire blame goes to the
     * Bluetooth Category.
     */
    private void addBluetoothUsage() {
        BatterySipper bs = new BatterySipper(BatterySipper.DrainType.BLUETOOTH, null, 0);
        mBluetoothPowerCalculator.calculateRemaining(bs, mStats, mRawRealtimeUs, mRawUptimeUs,
                mStatsType);
        aggregateSippers(bs, mBluetoothSippers, "Bluetooth");
        if (bs.totalPowerMah > 0) {
            mUsageList.add(bs);
        }
    }

    private void addUserUsage() {
        for (int i = 0; i < mUserSippers.size(); i++) {
            final int userId = mUserSippers.keyAt(i);
            BatterySipper bs = new BatterySipper(DrainType.USER, null, 0);
            bs.userId = userId;
            aggregateSippers(bs, mUserSippers.valueAt(i), "User");
            mUsageList.add(bs);
        }
    }

    private void addMemoryUsage() {
        BatterySipper memory = new BatterySipper(DrainType.MEMORY, null, 0);
        mMemoryPowerCalculator.calculateRemaining(memory, mStats, mRawRealtimeUs, mRawUptimeUs,
                mStatsType);
        memory.sumPower();
        if (memory.totalPowerMah > 0) {
            mUsageList.add(memory);
        }
    }

    private void processMiscUsage() {
        addUserUsage();
        addPhoneUsage();
        addScreenUsage();
        addAmbientDisplayUsage();
        addWiFiUsage();
        addBluetoothUsage();
        addMemoryUsage();
        addIdleUsage(); // Not including cellular idle power
        // Don't compute radio usage if it's a wifi-only device
        if (!mWifiOnly) {
            addRadioUsage();
        }
    }

    private BatterySipper addEntry(DrainType drainType, long time, double power) {
        BatterySipper bs = new BatterySipper(drainType, null, 0);
        bs.usagePowerMah = power;
        bs.usageTimeMs = time;
        bs.sumPower();
        mUsageList.add(bs);
        return bs;
    }

    public List<BatterySipper> getUsageList() {
        return mUsageList;
    }

    public List<BatterySipper> getMobilemsppList() {
        return mMobilemsppList;
    }

    public long getStatsPeriod() {
        return mStatsPeriod;
    }

    public int getStatsType() {
        return mStatsType;
    }

    public double getMaxPower() {
        return mMaxPower;
    }

    public double getMaxRealPower() {
        return mMaxRealPower;
    }

    public double getTotalPower() {
        return mTotalPower;
    }

    public double getComputedPower() {
        return mComputedPower;
    }

    public double getMinDrainedPower() {
        return mMinDrainedPower;
    }

    public double getMaxDrainedPower() {
        return mMaxDrainedPower;
    }

    public static byte[] readFully(FileInputStream stream) throws java.io.IOException {
        return readFully(stream, stream.available());
    }

    public static byte[] readFully(FileInputStream stream, int avail) throws java.io.IOException {
        int pos = 0;
        byte[] data = new byte[avail];
        while (true) {
            int amt = stream.read(data, pos, data.length - pos);
            //Log.i("foo", "Read " + amt + " bytes at " + pos
            //        + " of avail " + data.length);
            if (amt <= 0) {
                //Log.i("foo", "**** FINISHED READING: pos=" + pos
                //        + " len=" + data.length);
                return data;
            }
            pos += amt;
            avail = stream.available();
            if (avail > data.length - pos) {
                byte[] newData = new byte[pos + avail];
                System.arraycopy(data, 0, newData, 0, pos);
                data = newData;
            }
        }
    }

    
Mark the BatterySipper that we should hide and smear the screen usage based on foreground activity time. 
Params:
sippers – sipper list that need to check and remove
Returns:
the total power of the hidden items of BatterySipper for proportional smearing/**
     * Mark the {@link BatterySipper} that we should hide and smear the screen usage based on
     * foreground activity time.
     *
     * @param sippers sipper list that need to check and remove
     * @return the total power of the hidden items of {@link BatterySipper}
     * for proportional smearing
     */
    public double removeHiddenBatterySippers(List<BatterySipper> sippers) {
        double proportionalSmearPowerMah = 0;
        BatterySipper screenSipper = null;
        for (int i = sippers.size() - 1; i >= 0; i--) {
            final BatterySipper sipper = sippers.get(i);
            sipper.shouldHide = shouldHideSipper(sipper);
            if (sipper.shouldHide) {
                if (sipper.drainType != DrainType.OVERCOUNTED
                        && sipper.drainType != DrainType.SCREEN
                        && sipper.drainType != DrainType.AMBIENT_DISPLAY
                        && sipper.drainType != DrainType.UNACCOUNTED
                        && sipper.drainType != DrainType.BLUETOOTH
                        && sipper.drainType != DrainType.WIFI
                        && sipper.drainType != DrainType.IDLE) {
                    // Don't add it if it is overcounted, unaccounted or screen
                    proportionalSmearPowerMah += sipper.totalPowerMah;
                }
            }

            if (sipper.drainType == BatterySipper.DrainType.SCREEN) {
                screenSipper = sipper;
            }
        }

        smearScreenBatterySipper(sippers, screenSipper);

        return proportionalSmearPowerMah;
    }

    
Smear the screen on power usage among sippers, based on ratio of foreground activity time. /**
     * Smear the screen on power usage among {@code sippers}, based on ratio of foreground activity
     * time.
     */
    public void smearScreenBatterySipper(List<BatterySipper> sippers, BatterySipper screenSipper) {
        long totalActivityTimeMs = 0;
        final SparseLongArray activityTimeArray = new SparseLongArray();
        for (int i = 0, size = sippers.size(); i < size; i++) {
            final BatteryStats.Uid uid = sippers.get(i).uidObj;
            if (uid != null) {
                final long timeMs = getProcessForegroundTimeMs(uid,
                        BatteryStats.STATS_SINCE_CHARGED);
                activityTimeArray.put(uid.getUid(), timeMs);
                totalActivityTimeMs += timeMs;
            }
        }

        if (screenSipper != null && totalActivityTimeMs >= 10 * DateUtils.MINUTE_IN_MILLIS) {
            final double screenPowerMah = screenSipper.totalPowerMah;
            for (int i = 0, size = sippers.size(); i < size; i++) {
                final BatterySipper sipper = sippers.get(i);
                sipper.screenPowerMah = screenPowerMah * activityTimeArray.get(sipper.getUid(), 0)
                        / totalActivityTimeMs;
            }
        }
    }

    
Check whether we should hide the battery sipper.
/**
     * Check whether we should hide the battery sipper.
     */
    public boolean shouldHideSipper(BatterySipper sipper) {
        final DrainType drainType = sipper.drainType;

        return drainType == DrainType.IDLE
                || drainType == DrainType.CELL
                || drainType == DrainType.SCREEN
                || drainType == DrainType.AMBIENT_DISPLAY
                || drainType == DrainType.UNACCOUNTED
                || drainType == DrainType.OVERCOUNTED
                || isTypeService(sipper)
                || isTypeSystem(sipper);
    }

    
Check whether sipper is type service /**
     * Check whether {@code sipper} is type service
     */
    public boolean isTypeService(BatterySipper sipper) {
        final String[] packages = mPackageManager.getPackagesForUid(sipper.getUid());
        if (packages == null) {
            return false;
        }

        for (String packageName : packages) {
            if (ArrayUtils.contains(mServicepackageArray, packageName)) {
                return true;
            }
        }

        return false;
    }

    
Check whether sipper is type system /**
     * Check whether {@code sipper} is type system
     */
    public boolean isTypeSystem(BatterySipper sipper) {
        final int uid = sipper.uidObj == null ? -1 : sipper.getUid();
        sipper.mPackages = mPackageManager.getPackagesForUid(uid);
        // Classify all the sippers to type system if the range of uid is 0...FIRST_APPLICATION_UID
        if (uid >= Process.ROOT_UID && uid < Process.FIRST_APPLICATION_UID) {
            return true;
        } else if (sipper.mPackages != null) {
            for (final String packageName : sipper.mPackages) {
                if (ArrayUtils.contains(mSystemPackageArray, packageName)) {
                    return true;
                }
            }
        }

        return false;
    }

    public long convertUsToMs(long timeUs) {
        return timeUs / 1000;
    }

    public long convertMsToUs(long timeMs) {
        return timeMs * 1000;
    }

    @VisibleForTesting
    public long getForegroundActivityTotalTimeUs(BatteryStats.Uid uid, long rawRealtimeUs) {
        final BatteryStats.Timer timer = uid.getForegroundActivityTimer();
        if (timer != null) {
            return timer.getTotalTimeLocked(rawRealtimeUs, BatteryStats.STATS_SINCE_CHARGED);
        }

        return 0;
    }

    @VisibleForTesting
    public long getProcessForegroundTimeMs(BatteryStats.Uid uid, int which) {
        final long rawRealTimeUs = convertMsToUs(SystemClock.elapsedRealtime());
        final int foregroundTypes[] = {BatteryStats.Uid.PROCESS_STATE_TOP};

        long timeUs = 0;
        for (int type : foregroundTypes) {
            final long localTime = uid.getProcessStateTime(type, rawRealTimeUs, which);
            timeUs += localTime;
        }

        // Return the min value of STATE_TOP time and foreground activity time, since both of these
        // time have some errors.
        return convertUsToMs(
                Math.min(timeUs, getForegroundActivityTotalTimeUs(uid, rawRealTimeUs)));
    }

    @VisibleForTesting
    public void setPackageManager(PackageManager packageManager) {
        mPackageManager = packageManager;
    }

    @VisibleForTesting
    public void setSystemPackageArray(String[] array) {
        mSystemPackageArray = array;
    }

    @VisibleForTesting
    public void setServicePackageArray(String[] array) {
        mServicepackageArray = array;
    }

    private void load() {
        if (mBatteryInfo == null) {
            return;
        }
        mStats = getStats(mBatteryInfo);
        if (mCollectBatteryBroadcast) {
            mBatteryBroadcast = mContext.registerReceiver(null,
                    new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
        }
    }

    private static BatteryStatsImpl getStats(IBatteryStats service) {
        try {
            ParcelFileDescriptor pfd = service.getStatisticsStream();
            if (pfd != null) {
                try (FileInputStream fis = new ParcelFileDescriptor.AutoCloseInputStream(pfd)) {
                    byte[] data = readFully(fis, MemoryFile.getSize(pfd.getFileDescriptor()));
                    Parcel parcel = Parcel.obtain();
                    parcel.unmarshall(data, 0, data.length);
                    parcel.setDataPosition(0);
                    BatteryStatsImpl stats = com.android.internal.os.BatteryStatsImpl.CREATOR
                            .createFromParcel(parcel);
                    return stats;
                } catch (IOException e) {
                    Log.w(TAG, "Unable to read statistics stream", e);
                }
            }
        } catch (RemoteException e) {
            Log.w(TAG, "RemoteException:", e);
        }
        return new BatteryStatsImpl();
    }
}