Controller.py

"""Controller class for geomag algorithms"""
from __future__ import absolute_import, print_function
from builtins import str as unicode

import argparse
import sys
from io import BytesIO
from obspy.core import Stream, UTCDateTime
from .algorithm import algorithms, AlgorithmException
from .PlotTimeseriesFactory import PlotTimeseriesFactory
from .StreamTimeseriesFactory import StreamTimeseriesFactory
from . import TimeseriesUtility, Util

# factory packages
from . import binlog
from . import edge
from . import iaga2002
from . import imfjson
from . import pcdcp
from . import imfv122
from . import imfv283
from . import temperature
from . import vbf


class Controller(object):
    """Controller for geomag algorithms.

    Parameters
    ----------
    inputFactory: TimeseriesFactory
        the factory that will read in timeseries data
    outputFactory: TimeseriesFactory
        the factory that will output the timeseries data
    algorithm: Algorithm
        the algorithm(s) that will procees the timeseries data

    Notes
    -----
    Has 2 basic modes.
    Run simply sends all the data in a stream to edge. If a startime/endtime is
        provided, it will send the data from the stream that is within that
        time span.
    Update will update any data that has changed between the source, and
        the target during a given timeframe. It will also attempt to
        recursively backup so it can update all missing data.
    """

    def __init__(self, inputFactory, outputFactory, algorithm):
        self._inputFactory = inputFactory
        self._algorithm = algorithm
        self._outputFactory = outputFactory

    def _get_input_timeseries(self, observatory, channels, starttime, endtime):
        """Get timeseries from the input factory for requested options.

        Parameters
        ----------
        observatory : array_like
            observatories to request.
        channels : array_like
            channels to request.
        starttime : obspy.core.UTCDateTime
            time of first sample to request.
        endtime : obspy.core.UTCDateTime
            time of last sample to request.
        renames : array_like
            list of channels to rename
            each list item should be array_like:
                the first element is the channel to rename,
                the last element is the new channel name

        Returns
        -------
        timeseries : obspy.core.Stream
        """
        timeseries = Stream()
        for obs in observatory:
            # get input interval for observatory
            # do this per observatory in case an
            # algorithm needs different amounts of data
            input_start, input_end = self._algorithm.get_input_interval(
                    start=starttime,
                    end=endtime,
                    observatory=obs,
                    channels=channels)
            if input_start is None or input_end is None:
                continue
            timeseries += self._inputFactory.get_timeseries(
                    observatory=obs,
                    starttime=input_start,
                    endtime=input_end,
                    channels=channels)
        return timeseries

    def _rename_channels(self, timeseries, renames):
        """Rename trace channel names.

        Parameters
        ----------
        timeseries : obspy.core.Stream
            stream with channels to rename
        renames : array_like
            list of channels to rename
            each list item should be array_like:
                the first element is the channel to rename,
                the last element is the new channel name

        Returns
        -------
        timeseries : obspy.core.Stream
        """
        for r in renames:
            from_name, to_name = r[0], r[-1]
            for t in timeseries.select(channel=from_name):
                t.stats.channel = to_name
        return timeseries

    def _get_output_timeseries(self, observatory, channels, starttime,
            endtime):
        """Get timeseries from the output factory for requested options.

        Parameters
        ----------
        observatory : array_like
            observatories to request.
        channels : array_like
            channels to request.
        starttime : obspy.core.UTCDateTime
            time of first sample to request.
        endtime : obspy.core.UTCDateTime
            time of last sample to request.

        Returns
        -------
        timeseries : obspy.core.Stream
        """
        timeseries = Stream()
        for obs in observatory:
            timeseries += self._outputFactory.get_timeseries(
                observatory=obs,
                starttime=starttime,
                endtime=endtime,
                channels=channels)
        return timeseries

    def run(self, options, input_timeseries=None):
        """run controller
        Parameters
        ----------
        options: dictionary
            The dictionary of all the command line arguments. Could in theory
            contain other options passed in by the controller.
        input_timeseries : obspy.core.Stream
            Used by run_as_update to save a double input read, since it has
            already read the input to confirm data can be produced.
        """
        algorithm = self._algorithm
        input_channels = options.inchannels or \
                algorithm.get_input_channels()
        output_channels = options.outchannels or \
                algorithm.get_output_channels()
        starttime = algorithm.get_starttime() or options.starttime
        endtime = options.endtime
        # input
        timeseries = input_timeseries or self._get_input_timeseries(
                observatory=options.observatory,
                starttime=starttime,
                endtime=endtime,
                channels=input_channels)
        if timeseries.count() == 0:
            return
        # process
        if options.rename_input_channel:
            timeseries = self._rename_channels(
                    timeseries=timeseries,
                    renames=options.rename_input_channel)
        processed = algorithm.process(timeseries)
        # trim if --no-trim is not set
        if not options.no_trim:
            processed.trim(starttime=starttime,
                    endtime=endtime)
        if options.rename_output_channel:
            processed = self._rename_channels(
                    timeseries=processed,
                    renames=options.rename_output_channel)
        # output
        self._outputFactory.put_timeseries(
                timeseries=processed,
                starttime=starttime,
                endtime=endtime,
                channels=output_channels)

    def run_as_update(self, options, update_count=0):
        """Updates data.
        Parameters
        ----------
        options: dictionary
            The dictionary of all the command line arguments. Could in theory
            contain other options passed in by the controller.

        Notes
        -----
        Finds gaps in the target data, and if there's new data in the input
            source, calls run with the start/end time of a given gap to fill
            in.
        It checks the start of the target data, and if it's missing, and
            there's new data available, it backs up the starttime/endtime,
            and recursively calls itself, to check the previous period, to see
            if new data is available there as well. Calls run for each new
            period, oldest to newest.
        """
        # If an update_limit is set, make certain we don't step past it.
        if options.update_limit != 0:
            if update_count >= options.update_limit:
                return
        algorithm = self._algorithm
        if algorithm.get_starttime() is not None:
            raise AlgorithmException(
                    'Stateful algorithms cannot use run_as_update')
        input_channels = options.inchannels or \
                algorithm.get_input_channels()
        output_observatory = options.output_observatory
        output_channels = options.outchannels or \
                algorithm.get_output_channels()
        print('checking gaps', options.starttime, options.endtime,
                output_observatory, output_channels,
                file=sys.stderr)
        # request output to see what has already been generated
        output_timeseries = self._get_output_timeseries(
                observatory=options.output_observatory,
                starttime=options.starttime,
                endtime=options.endtime,
                channels=output_channels)
        if len(output_timeseries) > 0:
            # find gaps in output, so they can be updated
            output_gaps = TimeseriesUtility.get_merged_gaps(
                    TimeseriesUtility.get_stream_gaps(output_timeseries))
        else:
            output_gaps = [[
                options.starttime,
                options.endtime,
                # next sample time not used
                None
            ]]
        for output_gap in output_gaps:
            input_timeseries = self._get_input_timeseries(
                    observatory=options.observatory,
                    starttime=output_gap[0],
                    endtime=output_gap[1],
                    channels=input_channels)
            if not algorithm.can_produce_data(
                    starttime=output_gap[0],
                    endtime=output_gap[1],
                    stream=input_timeseries):
                continue
            # check for fillable gap at start
            if output_gap[0] == options.starttime:
                # found fillable gap at start, recurse to previous interval
                interval = options.endtime - options.starttime
                starttime = options.starttime - interval
                endtime = options.starttime - 1
                options.starttime = starttime
                options.endtime = endtime
                self.run_as_update(options, update_count + 1)
            # fill gap
            options.starttime = output_gap[0]
            options.endtime = output_gap[1]
            print('processing', options.starttime, options.endtime,
                    output_observatory, output_channels,
                    file=sys.stderr)
            self.run(options, input_timeseries)


def get_input_factory(args):
    """Parse input factory arguments.

    Parameters
    ----------
    args : argparse.Namespace
        arguments

    Returns
    -------
    TimeseriesFactory
        input timeseries factory
    """
    input_factory = None
    input_factory_args = None
    input_stream = None

    # standard arguments
    input_factory_args = {}
    input_factory_args['interval'] = args.interval
    input_factory_args['observatory'] = args.observatory
    input_factory_args['type'] = args.type
    # stream/url arguments
    if args.input_file is not None:
        input_stream = open(args.input_file, 'r')
    elif args.input_stdin:
        input_stream = sys.stdin
    elif args.input_url is not None:
        if '{' in args.input_url:
            input_factory_args['urlInterval'] = args.input_url_interval
            input_factory_args['urlTemplate'] = args.input_url
        else:
            input_stream = BytesIO(Util.read_url(args.input_url))
    input_type = args.input
    if input_type == 'edge':
        input_factory = edge.EdgeFactory(
                host=args.input_host,
                port=args.input_port,
                locationCode=args.locationcode,
                **input_factory_args)
    elif input_type == 'goes':
        # TODO: deal with other goes arguments
        input_factory = imfv283.GOESIMFV283Factory(
                directory=args.input_goes_directory,
                getdcpmessages=args.input_goes_getdcpmessages,
                password=args.input_goes_password,
                server=args.input_goes_server,
                user=args.input_goes_user,
                **input_factory_args)
    else:
        # stream compatible factories
        if input_type == 'iaga2002':
            input_factory = iaga2002.IAGA2002Factory(**input_factory_args)
        elif input_type == 'imfv122':
            input_factory = imfv122.IMFV122Factory(**input_factory_args)
        elif input_type == 'imfv283':
            input_factory = imfv283.IMFV283Factory(**input_factory_args)
        elif input_type == 'pcdcp':
            input_factory = pcdcp.PCDCPFactory(**input_factory_args)
        # wrap stream
        if input_stream is not None:
            input_factory = StreamTimeseriesFactory(
                    factory=input_factory,
                    stream=input_stream)
    return input_factory


def get_output_factory(args):
    """Parse output factory arguments.

    Parameters
    ----------
    args : argparse.Namespace
        arguments

    Returns
    -------
    TimeseriesFactory
        output timeseries factory
    """
    output_factory = None
    output_factory_args = None
    output_stream = None
    output_url = None

    # standard arguments
    output_factory_args = {}
    output_factory_args['interval'] = args.interval
    output_factory_args['observatory'] = args.output_observatory
    output_factory_args['type'] = args.type
    # stream/url arguments
    if args.output_file is not None:
        output_stream = open(args.output_file, 'wb')
    elif args.output_stdout:
        try:
            # python 3
            output_stream = sys.stdout.buffer
        except AttributeError:
            # python 2
            output_stream = sys.stdout
    elif args.output_url is not None:
        output_url = args.output_url
        output_factory_args['urlInterval'] = args.output_url_interval
        output_factory_args['urlTemplate'] = output_url

    output_type = args.output
    if output_type == 'edge':
        # TODO: deal with other edge arguments
        locationcode = args.outlocationcode or args.locationcode or None
        output_factory = edge.EdgeFactory(
                host=args.output_host,
                port=args.output_edge_read_port,
                write_port=args.output_port,
                locationCode=locationcode,
                tag=args.output_edge_tag,
                forceout=args.output_edge_forceout,
                **output_factory_args)
    elif output_type == 'plot':
        output_factory = PlotTimeseriesFactory()
    else:
        # stream compatible factories
        if output_type == 'binlog':
            output_factory = binlog.BinLogFactory(**output_factory_args)
        elif output_type == 'iaga2002':
            output_factory = iaga2002.IAGA2002Factory(**output_factory_args)
        elif output_type == 'imfjson':
            output_factory = imfjson.IMFJSONFactory(**output_factory_args)
        elif output_type == 'pcdcp':
            output_factory = pcdcp.PCDCPFactory(**output_factory_args)
        elif output_type == 'temperature':
            output_factory = temperature.TEMPFactory(**output_factory_args)
        elif output_type == 'vbf':
            output_factory = vbf.VBFFactory(**output_factory_args)
        # wrap stream
        if output_stream is not None:
            output_factory = StreamTimeseriesFactory(
                    factory=output_factory,
                    stream=output_stream)
    return output_factory


def main(args):
    """command line factory for geomag algorithms

    Inputs
    ------
    use geomag.py --help to see inputs, or see parse_args.

    Notes
    -----
    parses command line options using argparse, then calls the controller
    with instantiated I/O factories, and algorithm(s)
    """

    # TODO: remove argument mapping in future version
    # map legacy input arguments
    usingDeprecated = False
    if args.input_edge is not None:
        args.input = 'edge'
        args.input_host = args.input_edge
        args.input_port = args.input_edge_port
        usingDeprecated = True
    elif args.input_iaga_file is not None:
        args.input = 'iaga2002'
        args.input_file = args.input_iaga_file
        usingDeprecated = True
    elif args.input_iaga_stdin:
        args.input = 'iaga2002'
        args.input_stdin = True
        usingDeprecated = True
    elif args.input_iaga_url is not None:
        args.input = 'iaga2002'
        args.input_url = args.input_iaga_url
        usingDeprecated = True
    elif args.input_imfv283_file is not None:
        args.input = 'imfv283'
        args.input_file = args.input_imfv283_file
        usingDeprecated = True
    elif args.input_imfv283_url is not None:
        args.input = 'imfv283'
        args.input_url = args.input_imfv283_url
        usingDeprecated = True
    elif args.input_imfv283_goes:
        args.input = 'goes'
        usingDeprecated = True
    # map legacy output arguments
    if args.output_edge is not None:
        args.output = 'edge'
        args.output_host = args.output_edge
        args.output_port = args.edge_write_port
        usingDeprecated = True
    elif args.output_iaga_file is not None:
        args.output = 'iaga2002'
        args.output_file = args.output_iaga_file
        usingDeprecated = True
    elif args.output_iaga_stdout:
        args.output = 'iaga2002'
        args.output_stdout = True
        usingDeprecated = True
    elif args.output_iaga_url is not None:
        args.output = 'iaga2002'
        args.output_url = args.output_iaga_url
        usingDeprecated = True
    elif args.output_pcdcp_file is not None:
        args.output = 'pcdcp'
        args.output_file = args.output_pcdcp_file
        usingDeprecated = True
    elif args.output_pcdcp_stdout:
        args.output = 'pcdcp'
        args.output_stdout = True
        usingDeprecated = True
    elif args.output_pcdcp_url is not None:
        args.output = 'pcdcp'
        args.output_url = args.output_pcdcp_url
        usingDeprecated = True
    elif args.output_plot:
        args.output = 'plot'
        usingDeprecated = True

    if usingDeprecated:
        print('WARNING: you are using deprecated arguments,' +
              ' please update your usage', file=sys.stderr)
    # TODO check for unused arguments.

    # make sure observatory is a tuple
    if isinstance(args.observatory, (str, unicode)):
        args.observatory = (args.observatory,)

    if args.output_observatory is None:
        args.output_observatory = args.observatory
    elif args.observatory_foreach:
        raise Exception("Cannot specify" +
             " --output-observatory and --observatory-foreach")

    if args.observatory_foreach:
        observatory = args.observatory
        observatory_exception = None
        for obs in observatory:
            args.observatory = (obs,)
            args.output_observatory = (obs,)
            try:
                _main(args)
            except Exception as e:
                print("Exception processing observatory {}".format(obs),
                        str(e),
                        file=sys.stderr)
        if observatory_exception:
            print("Exceptions occurred during processing", file=sys.stderr)
            sys.exit(1)

    else:
        _main(args)


def _main(args):
    """Actual main method logic, called by main

    Parameters
    ----------
    args : argparse.Namespace
        command line arguments
    """
    # create controller
    input_factory = get_input_factory(args)
    output_factory = get_output_factory(args)
    algorithm = algorithms[args.algorithm]()
    algorithm.configure(args)
    controller = Controller(input_factory, output_factory, algorithm)

    if args.realtime:
        now = UTCDateTime()
        args.endtime = UTCDateTime(now.year, now.month, now.day,
                now.hour, now.minute)
        if args.realtime is True:
            if args.interval == 'minute':
                args.starttime = args.endtime - 3600
            else:
                args.starttime = args.endtime - 600
        else:
            args.starttime = args.endtime - args.realtime
    if args.update:
        controller.run_as_update(args)
    else:
        controller.run(args)


def parse_args(args):
    """parse input arguments

    Parameters
    ----------
    args : list of strings

    Returns
    -------
    argparse.Namespace
        dictionary like object containing arguments.
    """
    parser = argparse.ArgumentParser(
        description='Use @ to read commands from a file.',
        fromfile_prefix_chars='@',)

    parser.add_argument('--starttime',
            type=UTCDateTime,
            default=None,
            help='UTC date YYYY-MM-DD HH:MM:SS')
    parser.add_argument('--endtime',
            type=UTCDateTime,
            default=None,
            help='UTC date YYYY-MM-DD HH:MM:SS')

    parser.add_argument('--observatory',
            default=(None,),
            help='Observatory code ie BOU, CMO, etc.' +
                    ' CAUTION: Using multiple observatories is not' +
                    ' recommended in most cases; especially with' +
                    ' single observatory formats like IAGA and PCDCP.',
            nargs='*',
            type=str)
    parser.add_argument('--output-observatory',
            default=None,
            help='Defaults to valur of --observatory argument.' +
                    ' Observatory code ie BOU, CMO, etc.' +
                    ' CAUTION: Using multiple observatories is not' +
                    ' recommended in most cases; especially with' +
                    ' single observatory formats like IAGA and PCDCP.',
            nargs='*',
            type=str)
    parser.add_argument('--observatory-foreach',
            action='store_true',
            default=False,
            help='When specifying multiple observatories, process'
                    ' each observatory separately')
    parser.add_argument('--inchannels',
            nargs='*',
            help='Channels H, E, Z, etc')
    parser.add_argument('--outchannels',
            nargs='*',
            default=None,
            help='Channels H, E, Z, etc')
    parser.add_argument('--type',
            default='variation',
            choices=['variation',
                     'reported',
                     'provisional',
                     'adjusted',
                     'quasi-definitive',
                     'definitive'])
    parser.add_argument('--rename-input-channel',
            action='append',
            help='Rename an input channel after it is read',
            metavar=('FROM', 'TO'),
            nargs=2)
    parser.add_argument('--rename-output-channel',
            action='append',
            help='Rename an output channel before it is written',
            metavar=('FROM', 'TO'),
            nargs=2)
    parser.add_argument('--locationcode',
            help='EDGE location code, e.g. "R0", "R1"',
            type=edge.LocationCode)
    parser.add_argument('--outlocationcode',
            help='EDGE output location code'
                    ' (if different from --locationcode)',
            type=edge.LocationCode)
    parser.add_argument('--interval',
            default='minute',
            choices=['hourly', 'minute', 'second'])
    parser.add_argument('--update',
            action='store_true',
            default=False,
            help='Used to update data')
    parser.add_argument('--update-limit',
            type=int,
            default=0,
            help='Used to limit the number of iterations update will recurse')
    parser.add_argument('--no-trim',
            action='store_true',
            default=False,
            help='Ensures output data will not be trimmed down'),
    parser.add_argument('--input-edge-port',
            type=int,
            default=2060,
            help='deprecated. \
                Input port # for edge input, defaults to 2060')
    parser.add_argument('--output-edge-port',
            type=int,
            dest='edge_write_port',
            default=7981,
            help='deprecated. \
                Edge port for writing realtime data, defaults to 7981')
    parser.add_argument('--output-edge-cwb-port',
            type=int,
            dest='edge_write_port',
            default='7981',
            help='deprecated. \
                Edge port for writing older data. Not used by geomag.')
    parser.add_argument('--output-edge-read-port',
            type=int,
            default=2060,
            help='deprecated. \
                Edge port for reading output data, defaults to 2060')
    parser.add_argument('--output-edge-tag',
            default='GEOMAG',
            help='ID Tag for edge connections, defaults to GEOMAG')
    parser.add_argument('--output-edge-forceout',
            action='store_true',
            default=False,
            help='Flag to force data into miniseed blocks. Should only ' +
                    'be used when certain the data is self contained.')
    # parser.add_argument('--realtime',
    #         action='store_true',
    #         default=False,
    #         help='Flag to run the last hour if interval is minute, ' +
    #                 'or the last 10 minutes if interval is seconds')
    parser.add_argument('--realtime',
            default=False,
            const=True,
            type=int,
            nargs='?',
            help='Flag to run the last hour if interval is minute, ' +
                 'the last 10 minutes if interval is seconds, ' +
                 'or the last N seconds if integer N is specified.')
    parser.add_argument('--input-goes-directory',
            default='.',
            help='Directory for support files for goes input of imfv283 data')
    parser.add_argument('--input-goes-getdcpmessages',
            default='',
            help='Location of getDcpMessages.')
    parser.add_argument('--input-goes-password',
            default='',
            help='Password for goes user')
    parser.add_argument('--input-goes-server',
            nargs='*',
            help='The server name(s) to retrieve the GOES data from')
    parser.add_argument('--input-goes-user',
            default='GEOMAG',
            help='The user name to use to retrieve data from GOES')

    # Input group
    input_group = parser.add_mutually_exclusive_group(required=True)
    input_group.add_argument('--input',
            help='Input format',
            choices=(
                'edge',
                'goes',
                'iaga2002',
                'imfv122',
                'imfv283',
                'pcdcp'))

    parser.add_argument('--input-file',
            help='Read from specified file')
    parser.add_argument('--input-host',
            default='cwbpub.cr.usgs.gov',
            help='Hostname or IP address')
    parser.add_argument('--input-port',
            default=2060,
            help='Port number',
            type=int)
    parser.add_argument('--input-stdin',
            action='store_true',
            default=False,
            help='Read from standard input')
    parser.add_argument('--input-url',
            help='Read from a url pattern')
    parser.add_argument('--input-url-interval',
            default=86400,
            help='Read url interval in seconds',
            type=int)

    input_group.add_argument('--input-edge',
            help='deprecated. \
                Host IP #, see --input-edge-port for optional args')
    input_group.add_argument('--input-iaga-file',
            help='deprecated. Reads from the specified file.')
    input_group.add_argument('--input-iaga-stdin',
            action='store_true',
            default=False,
            help='deprecated. \
                Pass in an iaga file using redirection from stdin.')
    input_group.add_argument('--input-iaga-url',
            help='deprecated. \
                Example: file://./%%(obs)s%%(ymd)s%%(t)s%%(i)s.%%(i)s')
    input_group.add_argument('--input-imfv283-file',
            help='deprecated. Reads from the specified file.')
    input_group.add_argument('--input-imfv283-stdin',
            action='store_true',
            default=False,
            help='deprecated. \
                Pass in a file using redirection from stdin')
    input_group.add_argument('--input-imfv283-url',
            help='deprecated. Example file://./')
    input_group.add_argument('--input-imfv283-goes',
            action='store_true',
            default=False,
            help='deprecated. \
                Retrieves data directly from a goes server to read')
    input_group.add_argument('--input-pcdcp-file',
            help='deprecated. Reads from the specified file.')
    input_group.add_argument('--input-pcdcp-stdin',
            action='store_true',
            default=False,
            help='deprecated. \
                Pass in an pcdcp file using redirection from stdin.')
    input_group.add_argument('--input-pcdcp-url',
            help='deprecated. Example: file://./%%(obs)s%%(Y)s%%(j)s.%%(i)s')

    # Output group
    output_group = parser.add_mutually_exclusive_group(required=True)

    output_group.add_argument('--output-iaga-file',
            help='deprecated. Write to a single iaga file.')
    output_group.add_argument('--output-iaga-stdout',
            action='store_true', default=False,
            help='deprecated. Write to stdout.')
    output_group.add_argument('--output-iaga-url',
            help='deprecated. \
                Example: file://./%%(obs)s%%(ymd)s%%(t)s%%(i)s.%%(i)s')
    output_group.add_argument('--output-pcdcp-file',
            help='deprecated. Write to a single pcdcp file.')
    output_group.add_argument('--output-pcdcp-stdout',
            action='store_true', default=False,
            help='deprecated. Write to stdout.')
    output_group.add_argument('--output-pcdcp-url',
            help='deprecated. Example: file://./%%(obs)s%%(Y)s%%(j)s.%%(i)s')
    output_group.add_argument('--output-edge',
            help='deprecated. \
                Edge IP #. See --output-edge-* for other optional arguments')
    output_group.add_argument('--output-plot',
            action='store_true',
            default=False,
            help='deprecated. Plot the algorithm output using matplotlib')

    # output arguments
    output_group.add_argument('--output',
            choices=(
                'binlog',
                'edge',
                'iaga2002',
                'imfjson',
                'pcdcp',
                'plot',
                'temperature',
                'vbf'
            ),
            # TODO: set default to 'iaga2002'
            help='Output format')

    parser.add_argument('--output-file',
            help='Write to specified file')
    parser.add_argument('--output-host',
            default='cwbpub.cr.usgs.gov',
            help='Write to specified host')
    parser.add_argument('--output-port',
            default=7981,
            help='Write to specified port',
            type=int)
    parser.add_argument('--output-stdout',
            action='store_true',
            default=False,
            help='Write to standard output')
    parser.add_argument('--output-url',
            help='Write to a file:// url pattern')
    parser.add_argument('--output-url-interval',
            default=86400,
            help='Output interval in seconds',
            type=int)

    # Algorithms group
    parser.add_argument('--algorithm',
            choices=[k for k in algorithms],
            default='identity')

    for k in algorithms:
        algorithms[k].add_arguments(parser)

    return parser.parse_args(args)