def present(name,
            retention_hours=None,
            enhanced_monitoring=None,
            num_shards=None,
            do_reshard=True,
            region=None,
            key=None,
            keyid=None,
            profile=None):
    '''
    Ensure the kinesis stream is properly configured and scaled.

    name (string)
        Stream name

    retention_hours (int)
        Retain data for this many hours.
        AWS allows minimum 24 hours, maximum 168 hours.

    enhanced_monitoring (list of string)
        Turn on enhanced monitoring for the specified shard-level metrics.
        Pass in ['ALL'] or True for all metrics, [] or False for no metrics.
        Turn on individual metrics by passing in a list: ['IncomingBytes', 'OutgoingBytes']
        Note that if only some metrics are supplied, the remaining metrics will be turned off.

    num_shards (int)
        Reshard stream (if necessary) to this number of shards
        !!!!! Resharding is expensive! Each split or merge can take up to 30 seconds,
        and the reshard method balances the partition space evenly.
        Resharding from N to N+1 can require 2N operations.
        Resharding is much faster with powers of 2 (e.g. 2^N to 2^N+1) !!!!!

    do_reshard (boolean)
        If set to False, this script will NEVER reshard the stream,
        regardless of other input. Useful for testing.

    region (string)
        Region to connect to.

    key (string)
        Secret key to be used.

    keyid (string)
        Access key to be used.

    profile (dict)
        A dict with region, key and keyid, or a pillar key (string)
        that contains a dict with region, key and keyid.
    '''

    ret = {'name': name, 'result': True, 'comment': '', 'changes': {}}

    comments = []
    changes_old = {}
    changes_new = {}

    # Ensure stream exists
    exists = __salt__['boto_kinesis.exists'](
        name,
        region,
        key,
        keyid,
        profile
    )
    if exists['result'] is False:
        if __opts__['test']:
            ret['result'] = None
            comments.append('Kinesis stream {0} would be created'.format(name))
            _add_changes(ret, changes_old, changes_new, comments)
            return ret
        else:
            is_created = __salt__['boto_kinesis.create_stream'](
                name,
                num_shards,
                region,
                key,
                keyid,
                profile
            )
            if 'error' in is_created:
                ret['result'] = False
                comments.append('Failed to create stream {0}: {1}'.format(name, is_created['error']))
                _add_changes(ret, changes_old, changes_new, comments)
                return ret

            comments.append('Kinesis stream {0} successfully created'.format(name))
            changes_new['name'] = name
            changes_new['num_shards'] = num_shards
    else:
        comments.append('Kinesis stream {0} already exists'.format(name))

    stream_response = __salt__['boto_kinesis.get_stream_when_active'](
        name,
        region,
        key,
        keyid,
        profile
    )
    if 'error' in stream_response:
        ret['result'] = False
        comments.append('Kinesis stream {0}: error getting description: {1}'
                        .format(name, stream_response['error']))
        _add_changes(ret, changes_old, changes_new, comments)
        return ret

    stream_details = stream_response['result']["StreamDescription"]

    # Configure retention hours
    if retention_hours is not None:
        old_retention_hours = stream_details["RetentionPeriodHours"]
        retention_matches = (old_retention_hours == retention_hours)
        if not retention_matches:
            if __opts__['test']:
                ret['result'] = None
                comments.append('Kinesis stream {0}: retention hours would be updated to {1}'
                                .format(name, retention_hours))
            else:
                if old_retention_hours > retention_hours:
                    retention_updated = __salt__['boto_kinesis.decrease_stream_retention_period'](
                        name,
                        retention_hours,
                        region,
                        key,
                        keyid,
                        profile
                    )
                else:
                    retention_updated = __salt__['boto_kinesis.increase_stream_retention_period'](
                        name,
                        retention_hours,
                        region,
                        key,
                        keyid,
                        profile
                    )

                if 'error' in retention_updated:
                    ret['result'] = False
                    comments.append('Kinesis stream {0}: failed to update retention hours: {1}'
                                    .format(name, retention_updated['error']))
                    _add_changes(ret, changes_old, changes_new, comments)
                    return ret

                comments.append('Kinesis stream {0}: retention hours was successfully updated'.format(name))
                changes_old['retention_hours'] = old_retention_hours
                changes_new['retention_hours'] = retention_hours

                # wait until active again, otherwise it will log a lot of ResourceInUseExceptions
                # note that this isn't required below; reshard() will itself handle waiting
                stream_response = __salt__['boto_kinesis.get_stream_when_active'](
                    name,
                    region,
                    key,
                    keyid,
                    profile
                )
                if 'error' in stream_response:
                    ret['result'] = False
                    comments.append('Kinesis stream {0}: error getting description: {1}'
                                    .format(name, stream_response['error']))
                    _add_changes(ret, changes_old, changes_new, comments)
                    return ret

                stream_details = stream_response['result']["StreamDescription"]
        else:
            comments.append('Kinesis stream {0}: retention hours did not require change, already set at {1}'
                            .format(name, old_retention_hours))
    else:
        comments.append('Kinesis stream {0}: did not configure retention hours'.format(name))

    # Configure enhanced monitoring
    if enhanced_monitoring is not None:
        if enhanced_monitoring is True or enhanced_monitoring == ['ALL']:
            # for ease of comparison; describe_stream will always return the full list of metrics, never 'ALL'
            enhanced_monitoring = [
                    "IncomingBytes",
                    "OutgoingRecords",
                    "IteratorAgeMilliseconds",
                    "IncomingRecords",
                    "ReadProvisionedThroughputExceeded",
                    "WriteProvisionedThroughputExceeded",
                    "OutgoingBytes"
                ]
        elif enhanced_monitoring is False or enhanced_monitoring == "None":
            enhanced_monitoring = []

        old_enhanced_monitoring = stream_details.get("EnhancedMonitoring")[0]["ShardLevelMetrics"]

        new_monitoring_set = set(enhanced_monitoring)
        old_monitoring_set = set(old_enhanced_monitoring)

        matching_metrics = new_monitoring_set.intersection(old_monitoring_set)
        enable_metrics = list(new_monitoring_set.difference(matching_metrics))
        disable_metrics = list(old_monitoring_set.difference(matching_metrics))

        if enable_metrics:
            if __opts__['test']:
                ret['result'] = None
                comments.append('Kinesis stream {0}: would enable enhanced monitoring for {1}'
                                .format(name, enable_metrics))
            else:

                metrics_enabled = __salt__['boto_kinesis.enable_enhanced_monitoring'](
                    name,
                    enable_metrics,
                    region,
                    key,
                    keyid,
                    profile
                )
                if 'error' in metrics_enabled:
                    ret['result'] = False
                    comments.append('Kinesis stream {0}: failed to enable enhanced monitoring: {1}'
                                    .format(name, metrics_enabled['error']))
                    _add_changes(ret, changes_old, changes_new, comments)
                    return ret

                comments.append('Kinesis stream {0}: enhanced monitoring was enabled for shard-level metrics {1}'
                                .format(name, enable_metrics))

        if disable_metrics:
            if __opts__['test']:
                ret['result'] = None
                comments.append('Kinesis stream {0}: would disable enhanced monitoring for {1}'
                                .format(name, disable_metrics))
            else:

                metrics_disabled = __salt__['boto_kinesis.disable_enhanced_monitoring'](
                    name,
                    disable_metrics,
                    region,
                    key,
                    keyid,
                    profile
                )
                if 'error' in metrics_disabled:
                    ret['result'] = False
                    comments.append('Kinesis stream {0}: failed to disable enhanced monitoring: {1}'
                                    .format(name, metrics_disabled['error']))
                    _add_changes(ret, changes_old, changes_new, comments)
                    return ret

                comments.append('Kinesis stream {0}: enhanced monitoring was disabled for shard-level metrics {1}'
                                .format(name, disable_metrics))

        if not disable_metrics and not enable_metrics:
            comments.append('Kinesis stream {0}: enhanced monitoring did not require change, already set at {1}'
                            .format(name, (old_enhanced_monitoring if old_enhanced_monitoring else "None")))
        elif not __opts__['test']:
            changes_old['enhanced_monitoring'] = (old_enhanced_monitoring if old_enhanced_monitoring
                                                  else "None")
            changes_new['enhanced_monitoring'] = (enhanced_monitoring if enhanced_monitoring
                                                  else "None")
    else:
        comments.append('Kinesis stream {0}: did not configure enhanced monitoring'.format(name))

    # Reshard stream if necessary
    min_hash_key, max_hash_key, full_stream_details = __salt__['boto_kinesis.get_info_for_reshard'](
        stream_details
    )
    old_num_shards = len(full_stream_details["OpenShards"])

    if num_shards is not None and do_reshard:
        num_shards_matches = (old_num_shards == num_shards)
        if not num_shards_matches:
            if __opts__['test']:
                ret['result'] = None
                comments.append('Kinesis stream {0}: would be resharded from {1} to {2} shards'
                                .format(name, old_num_shards, num_shards))
            else:
                log.info(
                    'Resharding stream from %s to %s shards, this could take '
                    'a while', old_num_shards, num_shards
                )
                # reshard returns True when a split/merge action is taken,
                # or False when no more actions are required
                continue_reshard = True
                while continue_reshard:
                    reshard_response = __salt__['boto_kinesis.reshard'](
                        name,
                        num_shards,
                        do_reshard,
                        region,
                        key,
                        keyid,
                        profile)

                    if 'error' in reshard_response:
                        ret['result'] = False
                        comments.append('Encountered error while resharding {0}: {1}'
                                        .format(name, reshard_response['error']))
                        _add_changes(ret, changes_old, changes_new, comments)
                        return ret

                    continue_reshard = reshard_response['result']

                comments.append('Kinesis stream {0}: successfully resharded to {1} shards'.format(name, num_shards))
                changes_old['num_shards'] = old_num_shards
                changes_new['num_shards'] = num_shards
        else:
            comments.append('Kinesis stream {0}: did not require resharding, remains at {1} shards'
                            .format(name, old_num_shards))
    else:
        comments.append('Kinesis stream {0}: did not reshard, remains at {1} shards'.format(name, old_num_shards))

    _add_changes(ret, changes_old, changes_new, comments)
    return ret