/*
 * 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.job;

import static android.util.TimeUtils.formatDuration;

import android.annotation.NonNull;
import android.annotation.Nullable;
import android.content.ComponentName;
import android.net.Uri;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.PersistableBundle;
import android.util.Log;

import java.util.ArrayList;
import java.util.Objects;

/**
 * Container of data passed to the {@link android.app.job.JobScheduler} fully encapsulating the
 * parameters required to schedule work against the calling application. These are constructed
 * using the {@link JobInfo.Builder}.
 * You must specify at least one sort of constraint on the JobInfo object that you are creating.
 * The goal here is to provide the scheduler with high-level semantics about the work you want to
 * accomplish. Doing otherwise with throw an exception in your app.
 */
public class JobInfo implements Parcelable {
    private static String TAG = "JobInfo";
    /** Default. */
    public static final int NETWORK_TYPE_NONE = 0;
    /** This job requires network connectivity. */
    public static final int NETWORK_TYPE_ANY = 1;
    /** This job requires network connectivity that is unmetered. */
    public static final int NETWORK_TYPE_UNMETERED = 2;
    /** This job requires network connectivity that is not roaming. */
    public static final int NETWORK_TYPE_NOT_ROAMING = 3;

    /**
     * Amount of backoff a job has initially by default, in milliseconds.
     */
    public static final long DEFAULT_INITIAL_BACKOFF_MILLIS = 30000L;  // 30 seconds.

    /**
     * Maximum backoff we allow for a job, in milliseconds.
     */
    public static final long MAX_BACKOFF_DELAY_MILLIS = 5 * 60 * 60 * 1000;  // 5 hours.

    /**
     * Linearly back-off a failed job. See
     * {@link android.app.job.JobInfo.Builder#setBackoffCriteria(long, int)}
     * retry_time(current_time, num_failures) =
     *     current_time + initial_backoff_millis * num_failures, num_failures >= 1
     */
    public static final int BACKOFF_POLICY_LINEAR = 0;

    /**
     * Exponentially back-off a failed job. See
     * {@link android.app.job.JobInfo.Builder#setBackoffCriteria(long, int)}
     *
     * retry_time(current_time, num_failures) =
     *     current_time + initial_backoff_millis * 2 ^ (num_failures - 1), num_failures >= 1
     */
    public static final int BACKOFF_POLICY_EXPONENTIAL = 1;

    /* Minimum interval for a periodic job, in milliseconds. */
    private static final long MIN_PERIOD_MILLIS = 15 * 60 * 1000L;   // 15 minutes

    /* Minimum flex for a periodic job, in milliseconds. */
    private static final long MIN_FLEX_MILLIS = 5 * 60 * 1000L; // 5 minutes

    /**
     * Query the minimum interval allowed for periodic scheduled jobs.  Attempting
     * to declare a smaller period that this when scheduling a job will result in a
     * job that is still periodic, but will run with this effective period.
     *
     * @return The minimum available interval for scheduling periodic jobs, in milliseconds.
     */
    public static final long getMinPeriodMillis() {
        return MIN_PERIOD_MILLIS;
    }

    /**
     * Query the minimum flex time allowed for periodic scheduled jobs.  Attempting
     * to declare a shorter flex time than this when scheduling such a job will
     * result in this amount as the effective flex time for the job.
     *
     * @return The minimum available flex time for scheduling periodic jobs, in milliseconds.
     */
    public static final long getMinFlexMillis() {
        return MIN_FLEX_MILLIS;
    }

    /**
     * Default type of backoff.
     * @hide
     */
    public static final int DEFAULT_BACKOFF_POLICY = BACKOFF_POLICY_EXPONENTIAL;

    /**
     * Default of {@link #getPriority}.
     * @hide
     */
    public static final int PRIORITY_DEFAULT = 0;

    /**
     * Value of {@link #getPriority} for expedited syncs.
     * @hide
     */
    public static final int PRIORITY_SYNC_EXPEDITED = 10;

    /**
     * Value of {@link #getPriority} for first time initialization syncs.
     * @hide
     */
    public static final int PRIORITY_SYNC_INITIALIZATION = 20;

    /**
     * Value of {@link #getPriority} for a foreground app (overrides the supplied
     * JobInfo priority if it is smaller).
     * @hide
     */
    public static final int PRIORITY_FOREGROUND_APP = 30;

    /**
     * Value of {@link #getPriority} for the current top app (overrides the supplied
     * JobInfo priority if it is smaller).
     * @hide
     */
    public static final int PRIORITY_TOP_APP = 40;

    /**
     * Adjustment of {@link #getPriority} if the app has often (50% or more of the time)
     * been running jobs.
     * @hide
     */
    public static final int PRIORITY_ADJ_OFTEN_RUNNING = -40;

    /**
     * Adjustment of {@link #getPriority} if the app has always (90% or more of the time)
     * been running jobs.
     * @hide
     */
    public static final int PRIORITY_ADJ_ALWAYS_RUNNING = -80;

    /**
     * Indicates that the implementation of this job will be using
     * {@link JobService#startForeground(int, android.app.Notification)} to run
     * in the foreground.
     * <p>
     * When set, the internal scheduling of this job will ignore any background
     * network restrictions for the requesting app. Note that this flag alone
     * doesn't actually place your {@link JobService} in the foreground; you
     * still need to post the notification yourself.
     * <p>
     * To use this flag, the caller must hold the
     * {@link android.Manifest.permission#CONNECTIVITY_INTERNAL} permission.
     *
     * @hide
     */
    public static final int FLAG_WILL_BE_FOREGROUND = 1 << 0;

    private final int jobId;
    private final PersistableBundle extras;
    private final ComponentName service;
    private final boolean requireCharging;
    private final boolean requireDeviceIdle;
    private final TriggerContentUri[] triggerContentUris;
    private final long triggerContentUpdateDelay;
    private final long triggerContentMaxDelay;
    private final boolean hasEarlyConstraint;
    private final boolean hasLateConstraint;
    private final int networkType;
    private final long minLatencyMillis;
    private final long maxExecutionDelayMillis;
    private final boolean isPeriodic;
    private final boolean isPersisted;
    private final long intervalMillis;
    private final long flexMillis;
    private final long initialBackoffMillis;
    private final int backoffPolicy;
    private final int priority;
    private final int flags;

    /**
     * Unique job id associated with this application (uid).  This is the same job ID
     * you supplied in the {@link Builder} constructor.
     */
    public int getId() {
        return jobId;
    }

    /**
     * Bundle of extras which are returned to your application at execution time.
     */
    public PersistableBundle getExtras() {
        return extras;
    }

    /**
     * Name of the service endpoint that will be called back into by the JobScheduler.
     */
    public ComponentName getService() {
        return service;
    }

    /** @hide */
    public int getPriority() {
        return priority;
    }

    /** @hide */
    public int getFlags() {
        return flags;
    }

    /**
     * Whether this job needs the device to be plugged in.
     */
    public boolean isRequireCharging() {
        return requireCharging;
    }

    /**
     * Whether this job needs the device to be in an Idle maintenance window.
     */
    public boolean isRequireDeviceIdle() {
        return requireDeviceIdle;
    }

    /**
     * Which content: URIs must change for the job to be scheduled.  Returns null
     * if there are none required.
     */
    @Nullable
    public TriggerContentUri[] getTriggerContentUris() {
        return triggerContentUris;
    }

    /**
     * When triggering on content URI changes, this is the delay from when a change
     * is detected until the job is scheduled.
     */
    public long getTriggerContentUpdateDelay() {
        return triggerContentUpdateDelay;
    }

    /**
     * When triggering on content URI changes, this is the maximum delay we will
     * use before scheduling the job.
     */
    public long getTriggerContentMaxDelay() {
        return triggerContentMaxDelay;
    }

    /**
     * One of {@link android.app.job.JobInfo#NETWORK_TYPE_ANY},
     * {@link android.app.job.JobInfo#NETWORK_TYPE_NONE},
     * {@link android.app.job.JobInfo#NETWORK_TYPE_UNMETERED}, or
     * {@link android.app.job.JobInfo#NETWORK_TYPE_NOT_ROAMING}.
     */
    public int getNetworkType() {
        return networkType;
    }

    /**
     * Set for a job that does not recur periodically, to specify a delay after which the job
     * will be eligible for execution. This value is not set if the job recurs periodically.
     */
    public long getMinLatencyMillis() {
        return minLatencyMillis;
    }

    /**
     * See {@link Builder#setOverrideDeadline(long)}. This value is not set if the job recurs
     * periodically.
     */
    public long getMaxExecutionDelayMillis() {
        return maxExecutionDelayMillis;
    }

    /**
     * Track whether this job will repeat with a given period.
     */
    public boolean isPeriodic() {
        return isPeriodic;
    }

    /**
     * @return Whether or not this job should be persisted across device reboots.
     */
    public boolean isPersisted() {
        return isPersisted;
    }

    /**
     * Set to the interval between occurrences of this job. This value is <b>not</b> set if the
     * job does not recur periodically.
     */
    public long getIntervalMillis() {
        return intervalMillis >= getMinPeriodMillis() ? intervalMillis : getMinPeriodMillis();
    }

    /**
     * Flex time for this job. Only valid if this is a periodic job.  The job can
     * execute at any time in a window of flex length at the end of the period.
     */
    public long getFlexMillis() {
        long interval = getIntervalMillis();
        long percentClamp = 5 * interval / 100;
        long clampedFlex = Math.max(flexMillis, Math.max(percentClamp, getMinFlexMillis()));
        return clampedFlex <= interval ? clampedFlex : interval;
    }

    /**
     * The amount of time the JobScheduler will wait before rescheduling a failed job. This value
     * will be increased depending on the backoff policy specified at job creation time. Defaults
     * to 5 seconds.
     */
    public long getInitialBackoffMillis() {
        return initialBackoffMillis;
    }

    /**
     * One of either {@link android.app.job.JobInfo#BACKOFF_POLICY_EXPONENTIAL}, or
     * {@link android.app.job.JobInfo#BACKOFF_POLICY_LINEAR}, depending on which criteria you set
     * when creating this job.
     */
    public int getBackoffPolicy() {
        return backoffPolicy;
    }

    /**
     * User can specify an early constraint of 0L, which is valid, so we keep track of whether the
     * function was called at all.
     * @hide
     */
    public boolean hasEarlyConstraint() {
        return hasEarlyConstraint;
    }

    /**
     * User can specify a late constraint of 0L, which is valid, so we keep track of whether the
     * function was called at all.
     * @hide
     */
    public boolean hasLateConstraint() {
        return hasLateConstraint;
    }

    private JobInfo(Parcel in) {
        jobId = in.readInt();
        extras = in.readPersistableBundle();
        service = in.readParcelable(null);
        requireCharging = in.readInt() == 1;
        requireDeviceIdle = in.readInt() == 1;
        triggerContentUris = in.createTypedArray(TriggerContentUri.CREATOR);
        triggerContentUpdateDelay = in.readLong();
        triggerContentMaxDelay = in.readLong();
        networkType = in.readInt();
        minLatencyMillis = in.readLong();
        maxExecutionDelayMillis = in.readLong();
        isPeriodic = in.readInt() == 1;
        isPersisted = in.readInt() == 1;
        intervalMillis = in.readLong();
        flexMillis = in.readLong();
        initialBackoffMillis = in.readLong();
        backoffPolicy = in.readInt();
        hasEarlyConstraint = in.readInt() == 1;
        hasLateConstraint = in.readInt() == 1;
        priority = in.readInt();
        flags = in.readInt();
    }

    private JobInfo(JobInfo.Builder b) {
        jobId = b.mJobId;
        extras = b.mExtras;
        service = b.mJobService;
        requireCharging = b.mRequiresCharging;
        requireDeviceIdle = b.mRequiresDeviceIdle;
        triggerContentUris = b.mTriggerContentUris != null
                ? b.mTriggerContentUris.toArray(new TriggerContentUri[b.mTriggerContentUris.size()])
                : null;
        triggerContentUpdateDelay = b.mTriggerContentUpdateDelay;
        triggerContentMaxDelay = b.mTriggerContentMaxDelay;
        networkType = b.mNetworkType;
        minLatencyMillis = b.mMinLatencyMillis;
        maxExecutionDelayMillis = b.mMaxExecutionDelayMillis;
        isPeriodic = b.mIsPeriodic;
        isPersisted = b.mIsPersisted;
        intervalMillis = b.mIntervalMillis;
        flexMillis = b.mFlexMillis;
        initialBackoffMillis = b.mInitialBackoffMillis;
        backoffPolicy = b.mBackoffPolicy;
        hasEarlyConstraint = b.mHasEarlyConstraint;
        hasLateConstraint = b.mHasLateConstraint;
        priority = b.mPriority;
        flags = b.mFlags;
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel out, int flags) {
        out.writeInt(jobId);
        out.writePersistableBundle(extras);
        out.writeParcelable(service, flags);
        out.writeInt(requireCharging ? 1 : 0);
        out.writeInt(requireDeviceIdle ? 1 : 0);
        out.writeTypedArray(triggerContentUris, flags);
        out.writeLong(triggerContentUpdateDelay);
        out.writeLong(triggerContentMaxDelay);
        out.writeInt(networkType);
        out.writeLong(minLatencyMillis);
        out.writeLong(maxExecutionDelayMillis);
        out.writeInt(isPeriodic ? 1 : 0);
        out.writeInt(isPersisted ? 1 : 0);
        out.writeLong(intervalMillis);
        out.writeLong(flexMillis);
        out.writeLong(initialBackoffMillis);
        out.writeInt(backoffPolicy);
        out.writeInt(hasEarlyConstraint ? 1 : 0);
        out.writeInt(hasLateConstraint ? 1 : 0);
        out.writeInt(priority);
        out.writeInt(this.flags);
    }

    public static final Creator<JobInfo> CREATOR = new Creator<JobInfo>() {
        @Override
        public JobInfo createFromParcel(Parcel in) {
            return new JobInfo(in);
        }

        @Override
        public JobInfo[] newArray(int size) {
            return new JobInfo[size];
        }
    };

    @Override
    public String toString() {
        return "(job:" + jobId + "/" + service.flattenToShortString() + ")";
    }

    /**
     * Information about a content URI modification that a job would like to
     * trigger on.
     */
    public static final class TriggerContentUri implements Parcelable {
        private final Uri mUri;
        private final int mFlags;

        /**
         * Flag for trigger: also trigger if any descendants of the given URI change.
         * Corresponds to the <var>notifyForDescendants</var> of
         * {@link android.content.ContentResolver#registerContentObserver}.
         */
        public static final int FLAG_NOTIFY_FOR_DESCENDANTS = 1<<0;

        /**
         * Create a new trigger description.
         * @param uri The URI to observe.  Must be non-null.
         * @param flags Optional flags for the observer, either 0 or
         * {@link #FLAG_NOTIFY_FOR_DESCENDANTS}.
         */
        public TriggerContentUri(@NonNull Uri uri, int flags) {
            mUri = uri;
            mFlags = flags;
        }

        /**
         * Return the Uri this trigger was created for.
         */
        public Uri getUri() {
            return mUri;
        }

        /**
         * Return the flags supplied for the trigger.
         */
        public int getFlags() {
            return mFlags;
        }

        @Override
        public boolean equals(Object o) {
            if (!(o instanceof TriggerContentUri)) {
                return false;
            }
            TriggerContentUri t = (TriggerContentUri) o;
            return Objects.equals(t.mUri, mUri) && t.mFlags == mFlags;
        }

        @Override
        public int hashCode() {
            return (mUri == null ? 0 : mUri.hashCode()) ^ mFlags;
        }

        private TriggerContentUri(Parcel in) {
            mUri = Uri.CREATOR.createFromParcel(in);
            mFlags = in.readInt();
        }

        @Override
        public int describeContents() {
            return 0;
        }

        @Override
        public void writeToParcel(Parcel out, int flags) {
            mUri.writeToParcel(out, flags);
            out.writeInt(mFlags);
        }

        public static final Creator<TriggerContentUri> CREATOR = new Creator<TriggerContentUri>() {
            @Override
            public TriggerContentUri createFromParcel(Parcel in) {
                return new TriggerContentUri(in);
            }

            @Override
            public TriggerContentUri[] newArray(int size) {
                return new TriggerContentUri[size];
            }
        };
    }

    /** Builder class for constructing {@link JobInfo} objects. */
    public static final class Builder {
        private final int mJobId;
        private final ComponentName mJobService;
        private PersistableBundle mExtras = PersistableBundle.EMPTY;
        private int mPriority = PRIORITY_DEFAULT;
        private int mFlags;
        // Requirements.
        private boolean mRequiresCharging;
        private boolean mRequiresDeviceIdle;
        private int mNetworkType;
        private ArrayList<TriggerContentUri> mTriggerContentUris;
        private long mTriggerContentUpdateDelay = -1;
        private long mTriggerContentMaxDelay = -1;
        private boolean mIsPersisted;
        // One-off parameters.
        private long mMinLatencyMillis;
        private long mMaxExecutionDelayMillis;
        // Periodic parameters.
        private boolean mIsPeriodic;
        private boolean mHasEarlyConstraint;
        private boolean mHasLateConstraint;
        private long mIntervalMillis;
        private long mFlexMillis;
        // Back-off parameters.
        private long mInitialBackoffMillis = DEFAULT_INITIAL_BACKOFF_MILLIS;
        private int mBackoffPolicy = DEFAULT_BACKOFF_POLICY;
        /** Easy way to track whether the client has tried to set a back-off policy. */
        private boolean mBackoffPolicySet = false;

        /**
         * Initialize a new Builder to construct a {@link JobInfo}.
         *
         * @param jobId Application-provided id for this job. Subsequent calls to cancel, or
         * jobs created with the same jobId, will update the pre-existing job with
         * the same id.  This ID must be unique across all clients of the same uid
         * (not just the same package).  You will want to make sure this is a stable
         * id across app updates, so probably not based on a resource ID.
         * @param jobService The endpoint that you implement that will receive the callback from the
         * JobScheduler.
         */
        public Builder(int jobId, ComponentName jobService) {
            mJobService = jobService;
            mJobId = jobId;
        }

        /** @hide */
        public Builder setPriority(int priority) {
            mPriority = priority;
            return this;
        }

        /** @hide */
        public Builder setFlags(int flags) {
            mFlags = flags;
            return this;
        }

        /**
         * Set optional extras. This is persisted, so we only allow primitive types.
         * @param extras Bundle containing extras you want the scheduler to hold on to for you.
         */
        public Builder setExtras(PersistableBundle extras) {
            mExtras = extras;
            return this;
        }

        /**
         * Set some description of the kind of network type your job needs to have.
         * Not calling this function means the network is not necessary, as the default is
         * {@link #NETWORK_TYPE_NONE}.
         * Bear in mind that calling this function defines network as a strict requirement for your
         * job. If the network requested is not available your job will never run. See
         * {@link #setOverrideDeadline(long)} to change this behaviour.
         */
        public Builder setRequiredNetworkType(int networkType) {
            mNetworkType = networkType;
            return this;
        }

        /**
         * Specify that to run this job, the device needs to be plugged in. This defaults to
         * false.
         * @param requiresCharging Whether or not the device is plugged in.
         */
        public Builder setRequiresCharging(boolean requiresCharging) {
            mRequiresCharging = requiresCharging;
            return this;
        }

        /**
         * Specify that to run, the job needs the device to be in idle mode. This defaults to
         * false.
         * <p>Idle mode is a loose definition provided by the system, which means that the device
         * is not in use, and has not been in use for some time. As such, it is a good time to
         * perform resource heavy jobs. Bear in mind that battery usage will still be attributed
         * to your application, and surfaced to the user in battery stats.</p>
         * @param requiresDeviceIdle Whether or not the device need be within an idle maintenance
         *                           window.
         */
        public Builder setRequiresDeviceIdle(boolean requiresDeviceIdle) {
            mRequiresDeviceIdle = requiresDeviceIdle;
            return this;
        }

        /**
         * Add a new content: URI that will be monitored with a
         * {@link android.database.ContentObserver}, and will cause the job to execute if changed.
         * If you have any trigger content URIs associated with a job, it will not execute until
         * there has been a change report for one or more of them.
         * <p>Note that trigger URIs can not be used in combination with
         * {@link #setPeriodic(long)} or {@link #setPersisted(boolean)}.  To continually monitor
         * for content changes, you need to schedule a new JobInfo observing the same URIs
         * before you finish execution of the JobService handling the most recent changes.</p>
         * <p>Because because setting this property is not compatible with periodic or
         * persisted jobs, doing so will throw an {@link java.lang.IllegalArgumentException} when
         * {@link android.app.job.JobInfo.Builder#build()} is called.</p>
         *
         * <p>The following example shows how this feature can be used to monitor for changes
         * in the photos on a device.</p>
         *
         * {@sample development/samples/ApiDemos/src/com/example/android/apis/content/PhotosContentJob.java
         *      job}
         *
         * @param uri The content: URI to monitor.
         */
        public Builder addTriggerContentUri(@NonNull TriggerContentUri uri) {
            if (mTriggerContentUris == null) {
                mTriggerContentUris = new ArrayList<>();
            }
            mTriggerContentUris.add(uri);
            return this;
        }

        /**
         * Set the delay (in milliseconds) from when a content change is detected until
         * the job is scheduled.  If there are more changes during that time, the delay
         * will be reset to start at the time of the most recent change.
         * @param durationMs Delay after most recent content change, in milliseconds.
         */
        public Builder setTriggerContentUpdateDelay(long durationMs) {
            mTriggerContentUpdateDelay = durationMs;
            return this;
        }

        /**
         * Set the maximum total delay (in milliseconds) that is allowed from the first
         * time a content change is detected until the job is scheduled.
         * @param durationMs Delay after initial content change, in milliseconds.
         */
        public Builder setTriggerContentMaxDelay(long durationMs) {
            mTriggerContentMaxDelay = durationMs;
            return this;
        }

        /**
         * Specify that this job should recur with the provided interval, not more than once per
         * period. You have no control over when within this interval this job will be executed,
         * only the guarantee that it will be executed at most once within this interval.
         * Setting this function on the builder with {@link #setMinimumLatency(long)} or
         * {@link #setOverrideDeadline(long)} will result in an error.
         * @param intervalMillis Millisecond interval for which this job will repeat.
         */
        public Builder setPeriodic(long intervalMillis) {
            return setPeriodic(intervalMillis, intervalMillis);
        }

        /**
         * Specify that this job should recur with the provided interval and flex. The job can
         * execute at any time in a window of flex length at the end of the period.
         * @param intervalMillis Millisecond interval for which this job will repeat. A minimum
         *                       value of {@link #getMinPeriodMillis()} is enforced.
         * @param flexMillis Millisecond flex for this job. Flex is clamped to be at least
         *                   {@link #getMinFlexMillis()} or 5 percent of the period, whichever is
         *                   higher.
         */
        public Builder setPeriodic(long intervalMillis, long flexMillis) {
            mIsPeriodic = true;
            mIntervalMillis = intervalMillis;
            mFlexMillis = flexMillis;
            mHasEarlyConstraint = mHasLateConstraint = true;
            return this;
        }

        /**
         * Specify that this job should be delayed by the provided amount of time.
         * Because it doesn't make sense setting this property on a periodic job, doing so will
         * throw an {@link java.lang.IllegalArgumentException} when
         * {@link android.app.job.JobInfo.Builder#build()} is called.
         * @param minLatencyMillis Milliseconds before which this job will not be considered for
         *                         execution.
         */
        public Builder setMinimumLatency(long minLatencyMillis) {
            mMinLatencyMillis = minLatencyMillis;
            mHasEarlyConstraint = true;
            return this;
        }

        /**
         * Set deadline which is the maximum scheduling latency. The job will be run by this
         * deadline even if other requirements are not met. Because it doesn't make sense setting
         * this property on a periodic job, doing so will throw an
         * {@link java.lang.IllegalArgumentException} when
         * {@link android.app.job.JobInfo.Builder#build()} is called.
         */
        public Builder setOverrideDeadline(long maxExecutionDelayMillis) {
            mMaxExecutionDelayMillis = maxExecutionDelayMillis;
            mHasLateConstraint = true;
            return this;
        }

        /**
         * Set up the back-off/retry policy.
         * This defaults to some respectable values: {30 seconds, Exponential}. We cap back-off at
         * 5hrs.
         * Note that trying to set a backoff criteria for a job with
         * {@link #setRequiresDeviceIdle(boolean)} will throw an exception when you call build().
         * This is because back-off typically does not make sense for these types of jobs. See
         * {@link android.app.job.JobService#jobFinished(android.app.job.JobParameters, boolean)}
         * for more description of the return value for the case of a job executing while in idle
         * mode.
         * @param initialBackoffMillis Millisecond time interval to wait initially when job has
         *                             failed.
         * @param backoffPolicy is one of {@link #BACKOFF_POLICY_LINEAR} or
         * {@link #BACKOFF_POLICY_EXPONENTIAL}
         */
        public Builder setBackoffCriteria(long initialBackoffMillis, int backoffPolicy) {
            mBackoffPolicySet = true;
            mInitialBackoffMillis = initialBackoffMillis;
            mBackoffPolicy = backoffPolicy;
            return this;
        }

        /**
         * Set whether or not to persist this job across device reboots. This will only have an
         * effect if your application holds the permission
         * {@link android.Manifest.permission#RECEIVE_BOOT_COMPLETED}. Otherwise an exception will
         * be thrown.
         * @param isPersisted True to indicate that the job will be written to disk and loaded at
         *                    boot.
         */
        public Builder setPersisted(boolean isPersisted) {
            mIsPersisted = isPersisted;
            return this;
        }

        /**
         * @return The job object to hand to the JobScheduler. This object is immutable.
         */
        public JobInfo build() {
            // Allow jobs with no constraints - What am I, a database?
            if (!mHasEarlyConstraint && !mHasLateConstraint && !mRequiresCharging &&
                    !mRequiresDeviceIdle && mNetworkType == NETWORK_TYPE_NONE &&
                    mTriggerContentUris == null) {
                throw new IllegalArgumentException("You're trying to build a job with no " +
                        "constraints, this is not allowed.");
            }
            mExtras = new PersistableBundle(mExtras);  // Make our own copy.
            // Check that a deadline was not set on a periodic job.
            if (mIsPeriodic && (mMaxExecutionDelayMillis != 0L)) {
                throw new IllegalArgumentException("Can't call setOverrideDeadline() on a " +
                        "periodic job.");
            }
            if (mIsPeriodic && (mMinLatencyMillis != 0L)) {
                throw new IllegalArgumentException("Can't call setMinimumLatency() on a " +
                        "periodic job");
            }
            if (mIsPeriodic && (mTriggerContentUris != null)) {
                throw new IllegalArgumentException("Can't call addTriggerContentUri() on a " +
                        "periodic job");
            }
            if (mIsPersisted && (mTriggerContentUris != null)) {
                throw new IllegalArgumentException("Can't call addTriggerContentUri() on a " +
                        "persisted job");
            }
            if (mBackoffPolicySet && mRequiresDeviceIdle) {
                throw new IllegalArgumentException("An idle mode job will not respect any" +
                        " back-off policy, so calling setBackoffCriteria with" +
                        " setRequiresDeviceIdle is an error.");
            }
            JobInfo job = new JobInfo(this);
            if (job.isPeriodic()) {
                if (job.intervalMillis != job.getIntervalMillis()) {
                    StringBuilder builder = new StringBuilder();
                    builder.append("Specified interval for ")
                            .append(String.valueOf(mJobId))
                            .append(" is ");
                    formatDuration(mIntervalMillis, builder);
                    builder.append(". Clamped to ");
                    formatDuration(job.getIntervalMillis(), builder);
                    Log.w(TAG, builder.toString());
                }
                if (job.flexMillis != job.getFlexMillis()) {
                    StringBuilder builder = new StringBuilder();
                    builder.append("Specified flex for ")
                            .append(String.valueOf(mJobId))
                            .append(" is ");
                    formatDuration(mFlexMillis, builder);
                    builder.append(". Clamped to ");
                    formatDuration(job.getFlexMillis(), builder);
                    Log.w(TAG, builder.toString());
                }
            }
            return job;
        }
    }

}