package com.android.server.am;

import static android.app.ActivityManager.START_SUCCESS;
import static android.app.ActivityManager.START_TASK_TO_FRONT;
import static android.app.ActivityManager.processStateAmToProto;
import static android.app.ActivityManagerInternal.APP_TRANSITION_TIMEOUT;
import static android.app.WindowConfiguration.WINDOWING_MODE_FREEFORM;
import static android.app.WindowConfiguration.WINDOWING_MODE_FULLSCREEN;
import static android.app.WindowConfiguration.WINDOWING_MODE_PINNED;
import static android.app.WindowConfiguration.WINDOWING_MODE_SPLIT_SCREEN_PRIMARY;
import static android.app.WindowConfiguration.WINDOWING_MODE_SPLIT_SCREEN_SECONDARY;
import static android.app.WindowConfiguration.WINDOWING_MODE_UNDEFINED;

import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.ACTION_ACTIVITY_START;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.APP_TRANSITION;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.APP_TRANSITION_BIND_APPLICATION_DELAY_MS;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.APP_TRANSITION_CALLING_PACKAGE_NAME;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.APP_TRANSITION_CANCELLED;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.APP_TRANSITION_DELAY_MS;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.APP_TRANSITION_DEVICE_UPTIME_SECONDS;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.APP_TRANSITION_IS_EPHEMERAL;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.APP_TRANSITION_PROCESS_RUNNING;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.APP_TRANSITION_REPORTED_DRAWN;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.APP_TRANSITION_REPORTED_DRAWN_MS;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.APP_TRANSITION_STARTING_WINDOW_DELAY_MS;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.APP_TRANSITION_WINDOWS_DRAWN_DELAY_MS;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_FLAGS;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_IS_FULLSCREEN;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_IS_NO_DISPLAY;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_IS_VISIBLE;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_IS_VISIBLE_IGNORING_KEYGUARD;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_LAUNCH_MODE;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_MILLIS_SINCE_LAST_LAUNCH;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_MILLIS_SINCE_LAST_VISIBLE;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_PROCESS_NAME;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_REAL_ACTIVITY;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_RESULT_TO_PKG_NAME;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_RESULT_TO_SHORT_COMPONENT_NAME;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_SHORT_COMPONENT_NAME;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_ACTIVITY_RECORD_TARGET_ACTIVITY;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_CALLING_PACKAGE_NAME;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_CALLING_UID;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_CALLING_UID_HAS_ANY_VISIBLE_WINDOW;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_CALLING_UID_PROC_STATE;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_CLASS_NAME;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_COMING_FROM_PENDING_INTENT;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_INSTANT_APP_LAUNCH_TOKEN;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_INTENT_ACTION;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_PROCESS_RECORD_CUR_PROC_STATE;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_PROCESS_RECORD_HAS_CLIENT_ACTIVITIES;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_PROCESS_RECORD_HAS_FOREGROUND_ACTIVITIES;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_PROCESS_RECORD_HAS_FOREGROUND_SERVICES;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_PROCESS_RECORD_HAS_OVERLAY_UI;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_PROCESS_RECORD_HAS_TOP_UI;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_PROCESS_RECORD_MILLIS_SINCE_FG_INTERACTION;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_PROCESS_RECORD_MILLIS_SINCE_LAST_INTERACTION_EVENT;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_PROCESS_RECORD_MILLIS_SINCE_UNIMPORTANT;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_PROCESS_RECORD_PENDING_UI_CLEAN;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_PROCESS_RECORD_PROCESS_NAME;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_REAL_CALLING_UID;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_REAL_CALLING_UID_HAS_ANY_VISIBLE_WINDOW;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_REAL_CALLING_UID_PROC_STATE;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_TARGET_PACKAGE_NAME;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_TARGET_SHORT_COMPONENT_NAME;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_TARGET_UID;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_TARGET_UID_HAS_ANY_VISIBLE_WINDOW;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_TARGET_UID_PROC_STATE;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.FIELD_TARGET_WHITELIST_TAG;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.PACKAGE_OPTIMIZATION_COMPILATION_FILTER;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.PACKAGE_OPTIMIZATION_COMPILATION_REASON;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.TYPE_TRANSITION_COLD_LAUNCH;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.TYPE_TRANSITION_HOT_LAUNCH;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.TYPE_TRANSITION_REPORTED_DRAWN_NO_BUNDLE;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.TYPE_TRANSITION_REPORTED_DRAWN_WITH_BUNDLE;
import static com.android.internal.logging.nano.MetricsProto.MetricsEvent.TYPE_TRANSITION_WARM_LAUNCH;
import static com.android.server.am.ActivityManagerDebugConfig.DEBUG_METRICS;
import static com.android.server.am.ActivityManagerDebugConfig.TAG_AM;
import static com.android.server.am.ActivityManagerDebugConfig.TAG_WITH_CLASS_NAME;
import static com.android.server.am.EventLogTags.AM_ACTIVITY_LAUNCH_TIME;
import static com.android.server.am.MemoryStatUtil.MemoryStat;
import static com.android.server.am.MemoryStatUtil.readMemoryStatFromFilesystem;

import android.content.Context;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.dex.ArtManagerInternal;
import android.content.pm.dex.PackageOptimizationInfo;
import android.metrics.LogMaker;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.os.SystemClock;
import android.os.Trace;
import android.util.EventLog;
import android.util.Log;
import android.util.Slog;
import android.util.SparseArray;
import android.util.SparseIntArray;
import android.util.StatsLog;
import android.util.TimeUtils;

import com.android.internal.logging.MetricsLogger;
import com.android.internal.os.BackgroundThread;
import com.android.internal.os.SomeArgs;
import com.android.server.LocalServices;

import java.util.ArrayList;

/**
 * Listens to activity launches, transitions, visibility changes and window drawn callbacks to
 * determine app launch times and draw delays. Source of truth for activity metrics and provides
 * data for Tron, logcat, event logs and {@link android.app.WaitResult}.
 *
 * Tests:
 * atest CtsActivityManagerDeviceTestCases:ActivityMetricsLoggerTests
 */
class ActivityMetricsLogger {

    private static final String TAG = TAG_WITH_CLASS_NAME ? "ActivityMetricsLogger" : TAG_AM;

    // Window modes we are interested in logging. If we ever introduce a new type, we need to add
    // a value here and increase the {@link #TRON_WINDOW_STATE_VARZ_STRINGS} array.
    private static final int WINDOW_STATE_STANDARD = 0;
    private static final int WINDOW_STATE_SIDE_BY_SIDE = 1;
    private static final int WINDOW_STATE_FREEFORM = 2;
    private static final int WINDOW_STATE_ASSISTANT = 3;
    private static final int WINDOW_STATE_INVALID = -1;

    private static final long INVALID_START_TIME = -1;
    private static final int INVALID_DELAY = -1;
    private static final int INVALID_TRANSITION_TYPE = -1;

    private static final int MSG_CHECK_VISIBILITY = 0;

    // Preallocated strings we are sending to tron, so we don't have to allocate a new one every
    // time we log.
    private static final String[] TRON_WINDOW_STATE_VARZ_STRINGS = {
            "window_time_0", "window_time_1", "window_time_2", "window_time_3"};

    private int mWindowState = WINDOW_STATE_STANDARD;
    private long mLastLogTimeSecs;
    private final ActivityStackSupervisor mSupervisor;
    private final Context mContext;
    private final MetricsLogger mMetricsLogger = new MetricsLogger();

    private long mCurrentTransitionStartTime = INVALID_START_TIME;
    private long mLastTransitionStartTime = INVALID_START_TIME;

    private int mCurrentTransitionDeviceUptime;
    private int mCurrentTransitionDelayMs;
    private boolean mLoggedTransitionStarting;

    private final SparseArray<WindowingModeTransitionInfo> mWindowingModeTransitionInfo =
            new SparseArray<>();
    private final SparseArray<WindowingModeTransitionInfo> mLastWindowingModeTransitionInfo =
            new SparseArray<>();
    private final H mHandler;

    private ArtManagerInternal mArtManagerInternal;
    private boolean mDrawingTraceActive;
    private final StringBuilder mStringBuilder = new StringBuilder();

    private final class H extends Handler {

        public H(Looper looper) {
            super(looper);
        }

        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MSG_CHECK_VISIBILITY:
                    final SomeArgs args = (SomeArgs) msg.obj;
                    checkVisibility((TaskRecord) args.arg1, (ActivityRecord) args.arg2);
                    break;
            }
        }
    }

    private final class WindowingModeTransitionInfo {
        private ActivityRecord launchedActivity;
        private int startResult;
        private boolean currentTransitionProcessRunning;
        /** Elapsed time from when we launch an activity to when its windows are drawn. */
        private int windowsDrawnDelayMs;
        private int startingWindowDelayMs = INVALID_DELAY;
        private int bindApplicationDelayMs = INVALID_DELAY;
        private int reason = APP_TRANSITION_TIMEOUT;
        private boolean loggedWindowsDrawn;
        private boolean loggedStartingWindowDrawn;
        private boolean launchTraceActive;
    }

    final class WindowingModeTransitionInfoSnapshot {
        final private ApplicationInfo applicationInfo;
        final private ProcessRecord processRecord;
        final String packageName;
        final String launchedActivityName;
        final private String launchedActivityLaunchedFromPackage;
        final private String launchedActivityLaunchToken;
        final private String launchedActivityAppRecordRequiredAbi;
        final String launchedActivityShortComponentName;
        final private String processName;
        final private int reason;
        final private int startingWindowDelayMs;
        final private int bindApplicationDelayMs;
        final int windowsDrawnDelayMs;
        final int type;
        final int userId;
        /**
         * Elapsed time from when we launch an activity to when the app reported it was
         * fully drawn. If this is not reported then the value is set to INVALID_DELAY.
         */
        final int windowsFullyDrawnDelayMs;
        final int activityRecordIdHashCode;

        private WindowingModeTransitionInfoSnapshot(WindowingModeTransitionInfo info) {
            this(info, info.launchedActivity);
        }

        private WindowingModeTransitionInfoSnapshot(WindowingModeTransitionInfo info,
                ActivityRecord launchedActivity) {
            this(info, launchedActivity, INVALID_DELAY);
        }

        private WindowingModeTransitionInfoSnapshot(WindowingModeTransitionInfo info,
                ActivityRecord launchedActivity, int windowsFullyDrawnDelayMs) {
            applicationInfo = launchedActivity.appInfo;
            packageName = launchedActivity.packageName;
            launchedActivityName = launchedActivity.info.name;
            launchedActivityLaunchedFromPackage = launchedActivity.launchedFromPackage;
            launchedActivityLaunchToken = launchedActivity.info.launchToken;
            launchedActivityAppRecordRequiredAbi = launchedActivity.app == null
                    ? null
                    : launchedActivity.app.requiredAbi;
            reason = info.reason;
            startingWindowDelayMs = info.startingWindowDelayMs;
            bindApplicationDelayMs = info.bindApplicationDelayMs;
            windowsDrawnDelayMs = info.windowsDrawnDelayMs;
            type = getTransitionType(info);
            processRecord = findProcessForActivity(launchedActivity);
            processName = launchedActivity.processName;
            userId = launchedActivity.userId;
            launchedActivityShortComponentName = launchedActivity.shortComponentName;
            activityRecordIdHashCode = System.identityHashCode(launchedActivity);
            this.windowsFullyDrawnDelayMs = windowsFullyDrawnDelayMs;
        }
    }

    ActivityMetricsLogger(ActivityStackSupervisor supervisor, Context context, Looper looper) {
        mLastLogTimeSecs = SystemClock.elapsedRealtime() / 1000;
        mSupervisor = supervisor;
        mContext = context;
        mHandler = new H(looper);
    }

    void logWindowState() {
        final long now = SystemClock.elapsedRealtime() / 1000;
        if (mWindowState != WINDOW_STATE_INVALID) {
            // We log even if the window state hasn't changed, because the user might remain in
            // home/fullscreen move forever and we would like to track this kind of behavior
            // too.
            MetricsLogger.count(mContext, TRON_WINDOW_STATE_VARZ_STRINGS[mWindowState],
                    (int) (now - mLastLogTimeSecs));
        }
        mLastLogTimeSecs = now;

        mWindowState = WINDOW_STATE_INVALID;
        ActivityStack stack = mSupervisor.getFocusedStack();
        if (stack.isActivityTypeAssistant()) {
            mWindowState = WINDOW_STATE_ASSISTANT;
            return;
        }

        int windowingMode = stack.getWindowingMode();
        if (windowingMode == WINDOWING_MODE_PINNED) {
            stack = mSupervisor.findStackBehind(stack);
            windowingMode = stack.getWindowingMode();
        }
        switch (windowingMode) {
            case WINDOWING_MODE_FULLSCREEN:
                mWindowState = WINDOW_STATE_STANDARD;
                break;
            case WINDOWING_MODE_SPLIT_SCREEN_PRIMARY:
            case WINDOWING_MODE_SPLIT_SCREEN_SECONDARY:
                mWindowState = WINDOW_STATE_SIDE_BY_SIDE;
                break;
            case WINDOWING_MODE_FREEFORM:
                mWindowState = WINDOW_STATE_FREEFORM;
                break;
            default:
                if (windowingMode != WINDOWING_MODE_UNDEFINED) {
                    throw new IllegalStateException("Unknown windowing mode for stack=" + stack
                            + " windowingMode=" + windowingMode);
                }
        }
    }

    /**
     * Notifies the tracker at the earliest possible point when we are starting to launch an
     * activity.
     */
    void notifyActivityLaunching() {
        if (!isAnyTransitionActive()) {
            if (DEBUG_METRICS) Slog.i(TAG, "notifyActivityLaunching");
            mCurrentTransitionStartTime = SystemClock.uptimeMillis();
            mLastTransitionStartTime = mCurrentTransitionStartTime;
        }
    }

    /**
     * Notifies the tracker that the activity is actually launching.
     *
     * @param resultCode one of the ActivityManager.START_* flags, indicating the result of the
     *                   launch
     * @param launchedActivity the activity that is being launched
     */
    void notifyActivityLaunched(int resultCode, ActivityRecord launchedActivity) {
        final ProcessRecord processRecord = findProcessForActivity(launchedActivity);
        final boolean processRunning = processRecord != null;

        // We consider this a "process switch" if the process of the activity that gets launched
        // didn't have an activity that was in started state. In this case, we assume that lot
        // of caches might be purged so the time until it produces the first frame is very
        // interesting.
        final boolean processSwitch = processRecord == null
                || !hasStartedActivity(processRecord, launchedActivity);

        notifyActivityLaunched(resultCode, launchedActivity, processRunning, processSwitch);
    }

    private boolean hasStartedActivity(ProcessRecord record, ActivityRecord launchedActivity) {
        final ArrayList<ActivityRecord> activities = record.activities;
        for (int i = activities.size() - 1; i >= 0; i--) {
            final ActivityRecord activity = activities.get(i);
            if (launchedActivity == activity) {
                continue;
            }
            if (!activity.stopped) {
                return true;
            }
        }
        return false;
    }

    /**
     * Notifies the tracker the the activity is actually launching.
     *
     * @param resultCode one of the ActivityManager.START_* flags, indicating the result of the
     *                   launch
     * @param launchedActivity the activity being launched
     * @param processRunning whether the process that will contains the activity is already running
     * @param processSwitch whether the process that will contain the activity didn't have any
     *                      activity that was stopped, i.e. the started activity is "switching"
     *                      processes
     */
    private void notifyActivityLaunched(int resultCode, ActivityRecord launchedActivity,
            boolean processRunning, boolean processSwitch) {

        if (DEBUG_METRICS) Slog.i(TAG, "notifyActivityLaunched"
                + " resultCode=" + resultCode
                + " launchedActivity=" + launchedActivity
                + " processRunning=" + processRunning
                + " processSwitch=" + processSwitch);

        final int windowingMode = launchedActivity != null
                ? launchedActivity.getWindowingMode()
                : WINDOWING_MODE_UNDEFINED;
        final WindowingModeTransitionInfo info = mWindowingModeTransitionInfo.get(windowingMode);
        if (mCurrentTransitionStartTime == INVALID_START_TIME) {
            // No transition is active ignore this launch.
            return;
        }

        if (launchedActivity != null && launchedActivity.drawn) {
            // Launched activity is already visible. We cannot measure windows drawn delay.
            reset(true /* abort */, info);
            return;
        }

        if (launchedActivity != null && info != null) {
            // If we are already in an existing transition, only update the activity name, but not
            // the other attributes.
            info.launchedActivity = launchedActivity;
            return;
        }

        final boolean otherWindowModesLaunching =
                mWindowingModeTransitionInfo.size() > 0 && info == null;
        if ((!isLoggableResultCode(resultCode) || launchedActivity == null || !processSwitch
                || windowingMode == WINDOWING_MODE_UNDEFINED) && !otherWindowModesLaunching) {
            // Failed to launch or it was not a process switch, so we don't care about the timing.
            reset(true /* abort */, info);
            return;
        } else if (otherWindowModesLaunching) {
            // Don't log this windowing mode but continue with the other windowing modes.
            return;
        }

        if (DEBUG_METRICS) Slog.i(TAG, "notifyActivityLaunched successful");

        final WindowingModeTransitionInfo newInfo = new WindowingModeTransitionInfo();
        newInfo.launchedActivity = launchedActivity;
        newInfo.currentTransitionProcessRunning = processRunning;
        newInfo.startResult = resultCode;
        mWindowingModeTransitionInfo.put(windowingMode, newInfo);
        mLastWindowingModeTransitionInfo.put(windowingMode, newInfo);
        mCurrentTransitionDeviceUptime = (int) (SystemClock.uptimeMillis() / 1000);
        startTraces(newInfo);
    }

    /**
     * @return True if we should start logging an event for an activity start that returned
     *         {@code resultCode} and that we'll indeed get a windows drawn event.
     */
    private boolean isLoggableResultCode(int resultCode) {
        return resultCode == START_SUCCESS || resultCode == START_TASK_TO_FRONT;
    }

    /**
     * Notifies the tracker that all windows of the app have been drawn.
     */
    WindowingModeTransitionInfoSnapshot notifyWindowsDrawn(int windowingMode, long timestamp) {
        if (DEBUG_METRICS) Slog.i(TAG, "notifyWindowsDrawn windowingMode=" + windowingMode);

        final WindowingModeTransitionInfo info = mWindowingModeTransitionInfo.get(windowingMode);
        if (info == null || info.loggedWindowsDrawn) {
            return null;
        }
        info.windowsDrawnDelayMs = calculateDelay(timestamp);
        info.loggedWindowsDrawn = true;
        final WindowingModeTransitionInfoSnapshot infoSnapshot =
                new WindowingModeTransitionInfoSnapshot(info);
        if (allWindowsDrawn() && mLoggedTransitionStarting) {
            reset(false /* abort */, info);
        }
        return infoSnapshot;
    }

    /**
     * Notifies the tracker that the starting window was drawn.
     */
    void notifyStartingWindowDrawn(int windowingMode, long timestamp) {
        final WindowingModeTransitionInfo info = mWindowingModeTransitionInfo.get(windowingMode);
        if (info == null || info.loggedStartingWindowDrawn) {
            return;
        }
        info.loggedStartingWindowDrawn = true;
        info.startingWindowDelayMs = calculateDelay(timestamp);
    }

    /**
     * Notifies the tracker that the app transition is starting.
     *
     * @param windowingModeToReason A map from windowing mode to a reason integer, which must be on
     *                              of ActivityTaskManagerInternal.APP_TRANSITION_* reasons.
     */
    void notifyTransitionStarting(SparseIntArray windowingModeToReason, long timestamp) {
        if (!isAnyTransitionActive() || mLoggedTransitionStarting) {
            return;
        }
        if (DEBUG_METRICS) Slog.i(TAG, "notifyTransitionStarting");
        mCurrentTransitionDelayMs = calculateDelay(timestamp);
        mLoggedTransitionStarting = true;
        for (int index = windowingModeToReason.size() - 1; index >= 0; index--) {
            final int windowingMode = windowingModeToReason.keyAt(index);
            final WindowingModeTransitionInfo info = mWindowingModeTransitionInfo.get(
                    windowingMode);
            if (info == null) {
                continue;
            }
            info.reason = windowingModeToReason.valueAt(index);
        }
        if (allWindowsDrawn()) {
            reset(false /* abort */, null /* WindowingModeTransitionInfo */);
        }
    }

    /**
     * Notifies the tracker that the visibility of an app is changing.
     *
     * @param activityRecord the app that is changing its visibility
     */
    void notifyVisibilityChanged(ActivityRecord activityRecord) {
        final WindowingModeTransitionInfo info = mWindowingModeTransitionInfo.get(
                activityRecord.getWindowingMode());
        if (info == null) {
            return;
        }
        if (info.launchedActivity != activityRecord) {
            return;
        }
        final TaskRecord t = activityRecord.getTask();
        final SomeArgs args = SomeArgs.obtain();
        args.arg1 = t;
        args.arg2 = activityRecord;
        mHandler.obtainMessage(MSG_CHECK_VISIBILITY, args).sendToTarget();
    }

    private void checkVisibility(TaskRecord t, ActivityRecord r) {
        synchronized (mSupervisor.mService) {

            final WindowingModeTransitionInfo info = mWindowingModeTransitionInfo.get(
                    r.getWindowingMode());

            // If we have an active transition that's waiting on a certain activity that will be
            // invisible now, we'll never get onWindowsDrawn, so abort the transition if necessary.
            if (info != null && !t.isVisible()) {
                if (DEBUG_METRICS) Slog.i(TAG, "notifyVisibilityChanged to invisible"
                        + " activity=" + r);
                logAppTransitionCancel(info);
                mWindowingModeTransitionInfo.remove(r.getWindowingMode());
                if (mWindowingModeTransitionInfo.size() == 0) {
                    reset(true /* abort */, info);
                }
                stopFullyDrawnTraceIfNeeded();
            }
        }
    }

    /**
     * Notifies the tracker that we called immediately before we call bindApplication on the client.
     *
     * @param app The client into which we'll call bindApplication.
     */
    void notifyBindApplication(ProcessRecord app) {
        for (int i = mWindowingModeTransitionInfo.size() - 1; i >= 0; i--) {
            final WindowingModeTransitionInfo info = mWindowingModeTransitionInfo.valueAt(i);

            // App isn't attached to record yet, so match with info.
            if (info.launchedActivity.appInfo == app.info) {
                info.bindApplicationDelayMs = calculateCurrentDelay();
            }
        }
    }

    private boolean allWindowsDrawn() {
        for (int index = mWindowingModeTransitionInfo.size() - 1; index >= 0; index--) {
            if (!mWindowingModeTransitionInfo.valueAt(index).loggedWindowsDrawn) {
                return false;
            }
        }
        return true;
    }

    private boolean isAnyTransitionActive() {
        return mCurrentTransitionStartTime != INVALID_START_TIME
                && mWindowingModeTransitionInfo.size() > 0;
    }

    private void reset(boolean abort, WindowingModeTransitionInfo info) {
        if (DEBUG_METRICS) Slog.i(TAG, "reset abort=" + abort);
        if (!abort && isAnyTransitionActive()) {
            logAppTransitionMultiEvents();
        }
        stopLaunchTrace(info);
        mCurrentTransitionStartTime = INVALID_START_TIME;
        mCurrentTransitionDelayMs = INVALID_DELAY;
        mLoggedTransitionStarting = false;
        mWindowingModeTransitionInfo.clear();
    }

    private int calculateCurrentDelay() {
        // Shouldn't take more than 25 days to launch an app, so int is fine here.
        return (int) (SystemClock.uptimeMillis() - mCurrentTransitionStartTime);
    }

    private int calculateDelay(long timestamp) {
        // Shouldn't take more than 25 days to launch an app, so int is fine here.
        return (int) (timestamp - mCurrentTransitionStartTime);
    }

    private void logAppTransitionCancel(WindowingModeTransitionInfo info) {
        final int type = getTransitionType(info);
        if (type == INVALID_TRANSITION_TYPE) {
            return;
        }
        final LogMaker builder = new LogMaker(APP_TRANSITION_CANCELLED);
        builder.setPackageName(info.launchedActivity.packageName);
        builder.setType(type);
        builder.addTaggedData(FIELD_CLASS_NAME, info.launchedActivity.info.name);
        mMetricsLogger.write(builder);
        StatsLog.write(
                StatsLog.APP_START_CANCELED,
                info.launchedActivity.appInfo.uid,
                info.launchedActivity.packageName,
                convertAppStartTransitionType(type),
                info.launchedActivity.info.name);
    }

    private void logAppTransitionMultiEvents() {
        if (DEBUG_METRICS) Slog.i(TAG, "logging transition events");
        for (int index = mWindowingModeTransitionInfo.size() - 1; index >= 0; index--) {
            final WindowingModeTransitionInfo info = mWindowingModeTransitionInfo.valueAt(index);
            final int type = getTransitionType(info);
            if (type == INVALID_TRANSITION_TYPE) {
                return;
            }

            // Take a snapshot of the transition info before sending it to the handler for logging.
            // This will avoid any races with other operations that modify the ActivityRecord.
            final WindowingModeTransitionInfoSnapshot infoSnapshot =
                    new WindowingModeTransitionInfoSnapshot(info);
            final int currentTransitionDeviceUptime = mCurrentTransitionDeviceUptime;
            final int currentTransitionDelayMs = mCurrentTransitionDelayMs;
            BackgroundThread.getHandler().post(() -> logAppTransition(
                    currentTransitionDeviceUptime, currentTransitionDelayMs, infoSnapshot));
            BackgroundThread.getHandler().post(() -> logAppDisplayed(infoSnapshot));

            info.launchedActivity.info.launchToken = null;
        }
    }

    // This gets called on a background thread without holding the activity manager lock.
    private void logAppTransition(int currentTransitionDeviceUptime, int currentTransitionDelayMs,
            WindowingModeTransitionInfoSnapshot info) {
        final LogMaker builder = new LogMaker(APP_TRANSITION);
        builder.setPackageName(info.packageName);
        builder.setType(info.type);
        builder.addTaggedData(FIELD_CLASS_NAME, info.launchedActivityName);
        final boolean isInstantApp = info.applicationInfo.isInstantApp();
        if (info.launchedActivityLaunchedFromPackage != null) {
            builder.addTaggedData(APP_TRANSITION_CALLING_PACKAGE_NAME,
                    info.launchedActivityLaunchedFromPackage);
        }
        String launchToken = info.launchedActivityLaunchToken;
        if (launchToken != null) {
            builder.addTaggedData(FIELD_INSTANT_APP_LAUNCH_TOKEN, launchToken);
        }
        builder.addTaggedData(APP_TRANSITION_IS_EPHEMERAL, isInstantApp ? 1 : 0);
        builder.addTaggedData(APP_TRANSITION_DEVICE_UPTIME_SECONDS,
                currentTransitionDeviceUptime);
        builder.addTaggedData(APP_TRANSITION_DELAY_MS, currentTransitionDelayMs);
        builder.setSubtype(info.reason);
        if (info.startingWindowDelayMs != INVALID_DELAY) {
            builder.addTaggedData(APP_TRANSITION_STARTING_WINDOW_DELAY_MS,
                    info.startingWindowDelayMs);
        }
        if (info.bindApplicationDelayMs != INVALID_DELAY) {
            builder.addTaggedData(APP_TRANSITION_BIND_APPLICATION_DELAY_MS,
                    info.bindApplicationDelayMs);
        }
        builder.addTaggedData(APP_TRANSITION_WINDOWS_DRAWN_DELAY_MS, info.windowsDrawnDelayMs);
        final ArtManagerInternal artManagerInternal = getArtManagerInternal();
        final PackageOptimizationInfo packageOptimizationInfo =
                (artManagerInternal == null) || (info.launchedActivityAppRecordRequiredAbi == null)
                ? PackageOptimizationInfo.createWithNoInfo()
                : artManagerInternal.getPackageOptimizationInfo(
                        info.applicationInfo,
                        info.launchedActivityAppRecordRequiredAbi);
        builder.addTaggedData(PACKAGE_OPTIMIZATION_COMPILATION_REASON,
                packageOptimizationInfo.getCompilationReason());
        builder.addTaggedData(PACKAGE_OPTIMIZATION_COMPILATION_FILTER,
                packageOptimizationInfo.getCompilationFilter());
        mMetricsLogger.write(builder);
        StatsLog.write(
                StatsLog.APP_START_OCCURRED,
                info.applicationInfo.uid,
                info.packageName,
                convertAppStartTransitionType(info.type),
                info.launchedActivityName,
                info.launchedActivityLaunchedFromPackage,
                isInstantApp,
                currentTransitionDeviceUptime * 1000,
                info.reason,
                currentTransitionDelayMs,
                info.startingWindowDelayMs,
                info.bindApplicationDelayMs,
                info.windowsDrawnDelayMs,
                launchToken,
                packageOptimizationInfo.getCompilationReason(),
                packageOptimizationInfo.getCompilationFilter());
        logAppStartMemoryStateCapture(info);
    }

    private void logAppDisplayed(WindowingModeTransitionInfoSnapshot info) {
        if (info.type != TYPE_TRANSITION_WARM_LAUNCH && info.type != TYPE_TRANSITION_COLD_LAUNCH) {
            return;
        }

        EventLog.writeEvent(AM_ACTIVITY_LAUNCH_TIME,
                info.userId, info.activityRecordIdHashCode, info.launchedActivityShortComponentName,
                info.windowsDrawnDelayMs);

        StringBuilder sb = mStringBuilder;
        sb.setLength(0);
        sb.append("Displayed ");
        sb.append(info.launchedActivityShortComponentName);
        sb.append(": ");
        TimeUtils.formatDuration(info.windowsDrawnDelayMs, sb);
        Log.i(TAG, sb.toString());
    }

    private int convertAppStartTransitionType(int tronType) {
        if (tronType == TYPE_TRANSITION_COLD_LAUNCH) {
            return StatsLog.APP_START_OCCURRED__TYPE__COLD;
        }
        if (tronType == TYPE_TRANSITION_WARM_LAUNCH) {
            return StatsLog.APP_START_OCCURRED__TYPE__WARM;
        }
        if (tronType == TYPE_TRANSITION_HOT_LAUNCH) {
            return StatsLog.APP_START_OCCURRED__TYPE__HOT;
        }
        return StatsLog.APP_START_OCCURRED__TYPE__UNKNOWN;
     }

    WindowingModeTransitionInfoSnapshot logAppTransitionReportedDrawn(ActivityRecord r,
            boolean restoredFromBundle) {
        final WindowingModeTransitionInfo info = mLastWindowingModeTransitionInfo.get(
                r.getWindowingMode());
        if (info == null) {
            return null;
        }
        final LogMaker builder = new LogMaker(APP_TRANSITION_REPORTED_DRAWN);
        builder.setPackageName(r.packageName);
        builder.addTaggedData(FIELD_CLASS_NAME, r.info.name);
        long startupTimeMs = SystemClock.uptimeMillis() - mLastTransitionStartTime;
        builder.addTaggedData(APP_TRANSITION_REPORTED_DRAWN_MS, startupTimeMs);
        builder.setType(restoredFromBundle
                ? TYPE_TRANSITION_REPORTED_DRAWN_WITH_BUNDLE
                : TYPE_TRANSITION_REPORTED_DRAWN_NO_BUNDLE);
        builder.addTaggedData(APP_TRANSITION_PROCESS_RUNNING,
                info.currentTransitionProcessRunning ? 1 : 0);
        mMetricsLogger.write(builder);
        StatsLog.write(
                StatsLog.APP_START_FULLY_DRAWN,
                info.launchedActivity.appInfo.uid,
                info.launchedActivity.packageName,
                restoredFromBundle
                        ? StatsLog.APP_START_FULLY_DRAWN__TYPE__WITH_BUNDLE
                        : StatsLog.APP_START_FULLY_DRAWN__TYPE__WITHOUT_BUNDLE,
                info.launchedActivity.info.name,
                info.currentTransitionProcessRunning,
                startupTimeMs);
        stopFullyDrawnTraceIfNeeded();
        final WindowingModeTransitionInfoSnapshot infoSnapshot =
                new WindowingModeTransitionInfoSnapshot(info, r, (int) startupTimeMs);
        BackgroundThread.getHandler().post(() -> logAppFullyDrawn(infoSnapshot));
        return infoSnapshot;
    }

    private void logAppFullyDrawn(WindowingModeTransitionInfoSnapshot info) {
        if (info.type != TYPE_TRANSITION_WARM_LAUNCH && info.type != TYPE_TRANSITION_COLD_LAUNCH) {
            return;
        }

        StringBuilder sb = mStringBuilder;
        sb.setLength(0);
        sb.append("Fully drawn ");
        sb.append(info.launchedActivityShortComponentName);
        sb.append(": ");
        TimeUtils.formatDuration(info.windowsFullyDrawnDelayMs, sb);
        Log.i(TAG, sb.toString());
    }

    void logActivityStart(Intent intent, ProcessRecord callerApp, ActivityRecord r,
            int callingUid, String callingPackage, int callingUidProcState,
            boolean callingUidHasAnyVisibleWindow,
            int realCallingUid, int realCallingUidProcState,
            boolean realCallingUidHasAnyVisibleWindow,
            int targetUid, String targetPackage, int targetUidProcState,
            boolean targetUidHasAnyVisibleWindow, String targetWhitelistTag,
            boolean comingFromPendingIntent) {

        final long nowElapsed = SystemClock.elapsedRealtime();
        final long nowUptime = SystemClock.uptimeMillis();
        final LogMaker builder = new LogMaker(ACTION_ACTIVITY_START);
        builder.setTimestamp(System.currentTimeMillis());
        builder.addTaggedData(FIELD_CALLING_UID, callingUid);
        builder.addTaggedData(FIELD_CALLING_PACKAGE_NAME, callingPackage);
        builder.addTaggedData(FIELD_CALLING_UID_PROC_STATE,
                processStateAmToProto(callingUidProcState));
        builder.addTaggedData(FIELD_CALLING_UID_HAS_ANY_VISIBLE_WINDOW,
                callingUidHasAnyVisibleWindow ? 1 : 0);
        builder.addTaggedData(FIELD_REAL_CALLING_UID, realCallingUid);
        builder.addTaggedData(FIELD_REAL_CALLING_UID_PROC_STATE,
                processStateAmToProto(realCallingUidProcState));
        builder.addTaggedData(FIELD_REAL_CALLING_UID_HAS_ANY_VISIBLE_WINDOW,
                realCallingUidHasAnyVisibleWindow ? 1 : 0);
        builder.addTaggedData(FIELD_TARGET_UID, targetUid);
        builder.addTaggedData(FIELD_TARGET_PACKAGE_NAME, targetPackage);
        builder.addTaggedData(FIELD_TARGET_UID_PROC_STATE,
                processStateAmToProto(targetUidProcState));
        builder.addTaggedData(FIELD_TARGET_UID_HAS_ANY_VISIBLE_WINDOW,
                targetUidHasAnyVisibleWindow ? 1 : 0);
        builder.addTaggedData(FIELD_TARGET_WHITELIST_TAG, targetWhitelistTag);
        builder.addTaggedData(FIELD_TARGET_SHORT_COMPONENT_NAME, r.shortComponentName);
        builder.addTaggedData(FIELD_COMING_FROM_PENDING_INTENT, comingFromPendingIntent ? 1 : 0);
        builder.addTaggedData(FIELD_INTENT_ACTION, intent.getAction());
        if (callerApp != null) {
            builder.addTaggedData(FIELD_PROCESS_RECORD_PROCESS_NAME, callerApp.processName);
            builder.addTaggedData(FIELD_PROCESS_RECORD_CUR_PROC_STATE,
                    processStateAmToProto(callerApp.curProcState));
            builder.addTaggedData(FIELD_PROCESS_RECORD_HAS_CLIENT_ACTIVITIES,
                    callerApp.hasClientActivities ? 1 : 0);
            builder.addTaggedData(FIELD_PROCESS_RECORD_HAS_FOREGROUND_SERVICES,
                    callerApp.hasForegroundServices() ? 1 : 0);
            builder.addTaggedData(FIELD_PROCESS_RECORD_HAS_FOREGROUND_ACTIVITIES,
                    callerApp.foregroundActivities ? 1 : 0);
            builder.addTaggedData(FIELD_PROCESS_RECORD_HAS_TOP_UI, callerApp.hasTopUi ? 1 : 0);
            builder.addTaggedData(FIELD_PROCESS_RECORD_HAS_OVERLAY_UI,
                    callerApp.hasOverlayUi ? 1 : 0);
            builder.addTaggedData(FIELD_PROCESS_RECORD_PENDING_UI_CLEAN,
                    callerApp.pendingUiClean ? 1 : 0);
            if (callerApp.interactionEventTime != 0) {
                builder.addTaggedData(FIELD_PROCESS_RECORD_MILLIS_SINCE_LAST_INTERACTION_EVENT,
                        (nowElapsed - callerApp.interactionEventTime));
            }
            if (callerApp.fgInteractionTime != 0) {
                builder.addTaggedData(FIELD_PROCESS_RECORD_MILLIS_SINCE_FG_INTERACTION,
                        (nowElapsed - callerApp.fgInteractionTime));
            }
            if (callerApp.whenUnimportant != 0) {
                builder.addTaggedData(FIELD_PROCESS_RECORD_MILLIS_SINCE_UNIMPORTANT,
                        (nowUptime - callerApp.whenUnimportant));
            }
        }
        builder.addTaggedData(FIELD_ACTIVITY_RECORD_LAUNCH_MODE, r.info.launchMode);
        builder.addTaggedData(FIELD_ACTIVITY_RECORD_TARGET_ACTIVITY, r.info.targetActivity);
        builder.addTaggedData(FIELD_ACTIVITY_RECORD_FLAGS, r.info.flags);
        builder.addTaggedData(FIELD_ACTIVITY_RECORD_REAL_ACTIVITY, r.realActivity.toShortString());
        builder.addTaggedData(FIELD_ACTIVITY_RECORD_SHORT_COMPONENT_NAME, r.shortComponentName);
        builder.addTaggedData(FIELD_ACTIVITY_RECORD_PROCESS_NAME, r.processName);
        builder.addTaggedData(FIELD_ACTIVITY_RECORD_IS_FULLSCREEN, r.fullscreen ? 1 : 0);
        builder.addTaggedData(FIELD_ACTIVITY_RECORD_IS_NO_DISPLAY, r.noDisplay ? 1 : 0);
        if (r.lastVisibleTime != 0) {
            builder.addTaggedData(FIELD_ACTIVITY_RECORD_MILLIS_SINCE_LAST_VISIBLE,
                    (nowUptime - r.lastVisibleTime));
        }
        if (r.resultTo != null) {
            builder.addTaggedData(FIELD_ACTIVITY_RECORD_RESULT_TO_PKG_NAME, r.resultTo.packageName);
            builder.addTaggedData(FIELD_ACTIVITY_RECORD_RESULT_TO_SHORT_COMPONENT_NAME,
                    r.resultTo.shortComponentName);
        }
        builder.addTaggedData(FIELD_ACTIVITY_RECORD_IS_VISIBLE, r.visible ? 1 : 0);
        builder.addTaggedData(FIELD_ACTIVITY_RECORD_IS_VISIBLE_IGNORING_KEYGUARD,
                r.visibleIgnoringKeyguard ? 1 : 0);
        if (r.lastLaunchTime != 0) {
            builder.addTaggedData(FIELD_ACTIVITY_RECORD_MILLIS_SINCE_LAST_LAUNCH,
                    (nowUptime - r.lastLaunchTime));
        }
        mMetricsLogger.write(builder);
    }

    private int getTransitionType(WindowingModeTransitionInfo info) {
        if (info.currentTransitionProcessRunning) {
            if (info.startResult == START_SUCCESS) {
                return TYPE_TRANSITION_WARM_LAUNCH;
            } else if (info.startResult == START_TASK_TO_FRONT) {
                return TYPE_TRANSITION_HOT_LAUNCH;
            }
        } else if (info.startResult == START_SUCCESS) {
            return TYPE_TRANSITION_COLD_LAUNCH;
        }
        return INVALID_TRANSITION_TYPE;
    }

    private void logAppStartMemoryStateCapture(WindowingModeTransitionInfoSnapshot info) {
        if (info.processRecord == null) {
            if (DEBUG_METRICS) Slog.i(TAG, "logAppStartMemoryStateCapture processRecord null");
            return;
        }

        final int pid = info.processRecord.pid;
        final int uid = info.applicationInfo.uid;
        final MemoryStat memoryStat = readMemoryStatFromFilesystem(uid, pid);
        if (memoryStat == null) {
            if (DEBUG_METRICS) Slog.i(TAG, "logAppStartMemoryStateCapture memoryStat null");
            return;
        }

        StatsLog.write(
                StatsLog.APP_START_MEMORY_STATE_CAPTURED,
                uid,
                info.processName,
                info.launchedActivityName,
                memoryStat.pgfault,
                memoryStat.pgmajfault,
                memoryStat.rssInBytes,
                memoryStat.cacheInBytes,
                memoryStat.swapInBytes);
    }

    private ProcessRecord findProcessForActivity(ActivityRecord launchedActivity) {
        return launchedActivity != null
                ? mSupervisor.mService.mProcessNames.get(launchedActivity.processName,
                        launchedActivity.appInfo.uid)
                : null;
    }

    private ArtManagerInternal getArtManagerInternal() {
        if (mArtManagerInternal == null) {
            // Note that this may be null.
            // ArtManagerInternal is registered during PackageManagerService
            // initialization which happens after ActivityManagerService.
            mArtManagerInternal = LocalServices.getService(ArtManagerInternal.class);
        }
        return mArtManagerInternal;
    }

    /**
     * Starts traces for app launch and draw times. We stop the fully drawn trace if its already
     * active since the app may not have reported fully drawn in the previous launch.
     *
     * See {@link android.app.Activity#reportFullyDrawn()}
     *
     * @param info
     * */
    private void startTraces(WindowingModeTransitionInfo info) {
        if (info == null) {
            return;
        }
        stopFullyDrawnTraceIfNeeded();
        int transitionType = getTransitionType(info);
        if (!info.launchTraceActive && transitionType == TYPE_TRANSITION_WARM_LAUNCH
                || transitionType == TYPE_TRANSITION_COLD_LAUNCH) {
            Trace.asyncTraceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "launching: "
                    + info.launchedActivity.packageName, 0);
            Trace.asyncTraceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "drawing", 0);
            mDrawingTraceActive = true;
            info.launchTraceActive = true;
        }
    }

    private void stopLaunchTrace(WindowingModeTransitionInfo info) {
        if (info == null) {
            return;
        }
        if (info.launchTraceActive) {
            Trace.asyncTraceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER, "launching: "
                    + info.launchedActivity.packageName, 0);
            info.launchTraceActive = false;
        }
    }

    void stopFullyDrawnTraceIfNeeded() {
        if (mDrawingTraceActive) {
            Trace.asyncTraceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER, "drawing", 0);
            mDrawingTraceActive = false;
        }
    }
}