# Source code for tornado.options

    #!/usr/bin/env python
    #
    # Copyright 2009 Facebook
    #
    # 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.

    """A command line parsing module that lets modules define their own options.

    Each module defines its own options which are added to the global
    option namespace, e.g.::

        from tornado4.options import define, options

        define("mysql_host", default="127.0.0.1:3306", help="Main user DB")
        define("memcache_hosts", default="127.0.0.1:11011", multiple=True,
               help="Main user memcache servers")

        def connect():
            db = database.Connection(options.mysql_host)
            ...

    The ``main()`` method of your application does not need to be aware of all of
    the options used throughout your program; they are all automatically loaded
    when the modules are loaded.  However, all modules that define options
    must have been imported before the command line is parsed.

    Your ``main()`` method can parse the command line or parse a config file with
    either::

        tornado4.options.parse_command_line()
        # or
        tornado4.options.parse_config_file("/etc/server.conf")

    .. note:

       When using tornado4.options.parse_command_line or
       tornado4.options.parse_config_file, the only options that are set are
       ones that were previously defined with tornado4.options.define.

    Command line formats are what you would expect (``--myoption=myvalue``).
    Config files are just Python files. Global names become options, e.g.::

        myoption = "myvalue"
        myotheroption = "myothervalue"

    We support `datetimes <datetime.datetime>`, `timedeltas
    <datetime.timedelta>`, ints, and floats (just pass a ``type`` kwarg to
    `define`). We also accept multi-value options. See the documentation for
    `define()` below.

    `tornado4.options.options` is a singleton instance of `OptionParser`, and
    the top-level functions in this module (`define`, `parse_command_line`, etc)
    simply call methods on it.  You may create additional `OptionParser`
    instances to define isolated sets of options, such as for subcommands.

    .. note::

       By default, several options are defined that will configure the
       standard `logging` module when `parse_command_line` or `parse_config_file`
       are called.  If you want Tornado to leave the logging configuration
       alone so you can manage it yourself, either pass ``--logging=none``
       on the command line or do the following to disable it in code::

           from tornado4.options import options, parse_command_line
           options.logging = None
           parse_command_line()

    .. versionchanged:: 4.3
       Dashes and underscores are fully interchangeable in option names;
       options can be defined, set, and read with any mix of the two.
       Dashes are typical for command-line usage while config files require
       underscores.
    """

    from __future__ import absolute_import, division, print_function

    import datetime
    import numbers
    import re
    import sys
    import os
    import textwrap

    from tornado4.escape import _unicode, native_str
    from tornado4.log import define_logging_options
    from tornado4 import stack_context
    from tornado4.util import basestring_type, exec_in

    class Error(Exception):
        """Exception raised by errors in the options module."""
        pass

    class OptionParser(object):
        """A collection of options, a dictionary with object-like access.

        Normally accessed via static functions in the `tornado4.options` module,
        which reference a global instance.
        """
        def __init__(self):
            # we have to use self.__dict__ because we override setattr.
            self.__dict__['_options'] = {}
            self.__dict__['_parse_callbacks'] = []
            self.define("help", type=bool, help="show this help information",
                        callback=self._help_callback)

        def _normalize_name(self, name):
            return name.replace('_', '-')

        def __getattr__(self, name):
            name = self._normalize_name(name)
            if isinstance(self._options.get(name), _Option):
                return self._options[name].value()
            raise AttributeError("Unrecognized option %r" % name)

        def __setattr__(self, name, value):
            name = self._normalize_name(name)
            if isinstance(self._options.get(name), _Option):
                return self._options[name].set(value)
            raise AttributeError("Unrecognized option %r" % name)

        def __iter__(self):
            return (opt.name for opt in self._options.values())

        def __contains__(self, name):
            name = self._normalize_name(name)
            return name in self._options

        def __getitem__(self, name):
            return self.__getattr__(name)

        def __setitem__(self, name, value):
            return self.__setattr__(name, value)

        def items(self):
            """A sequence of (name, value) pairs.

            .. versionadded:: 3.1
            """
            return [(opt.name, opt.value()) for name, opt in self._options.items()]

        def groups(self):
            """The set of option-groups created by ``define``.

            .. versionadded:: 3.1
            """
            return set(opt.group_name for opt in self._options.values())

        def group_dict(self, group):
            """The names and values of options in a group.

            Useful for copying options into Application settings::

                from tornado4.options import define, parse_command_line, options

                define('template_path', group='application')
                define('static_path', group='application')

                parse_command_line()

                application = Application(
                    handlers, **options.group_dict('application'))

            .. versionadded:: 3.1
            """
            return dict(
                (opt.name, opt.value()) for name, opt in self._options.items()
                if not group or group == opt.group_name)

        def as_dict(self):
            """The names and values of all options.

            .. versionadded:: 3.1
            """
            return dict(
                (opt.name, opt.value()) for name, opt in self._options.items())

        def define(self, name, default=None, type=None, help=None, metavar=None,
                   multiple=False, group=None, callback=None):
            """Defines a new command line option.

            If ``type`` is given (one of str, float, int, datetime, or timedelta)
            or can be inferred from the ``default``, we parse the command line
            arguments based on the given type. If ``multiple`` is True, we accept
            comma-separated values, and the option value is always a list.

            For multi-value integers, we also accept the syntax ``x:y``, which
            turns into ``range(x, y)`` - very useful for long integer ranges.

            ``help`` and ``metavar`` are used to construct the
            automatically generated command line help string. The help
            message is formatted like::

               --name=METAVAR      help string

            ``group`` is used to group the defined options in logical
            groups. By default, command line options are grouped by the
            file in which they are defined.

            Command line option names must be unique globally. They can be parsed
            from the command line with `parse_command_line` or parsed from a
            config file with `parse_config_file`.

            If a ``callback`` is given, it will be run with the new value whenever
            the option is changed.  This can be used to combine command-line
            and file-based options::

                define("config", type=str, help="path to config file",
                       callback=lambda path: parse_config_file(path, final=False))

            With this definition, options in the file specified by ``--config`` will
            override options set earlier on the command line, but can be overridden
            by later flags.
            """
            normalized = self._normalize_name(name)
            if normalized in self._options:
                raise Error("Option %r already defined in %s" %
                            (normalized, self._options[normalized].file_name))
            frame = sys._getframe(0)
            options_file = frame.f_code.co_filename

            # Can be called directly, or through top level define() fn, in which
            # case, step up above that frame to look for real caller.
            if (frame.f_back.f_code.co_filename == options_file and
                    frame.f_back.f_code.co_name == 'define'):
                frame = frame.f_back

            file_name = frame.f_back.f_code.co_filename
            if file_name == options_file:
                file_name = ""
            if type is None:
                if not multiple and default is not None:
                    type = default.__class__
                else:
                    type = str
            if group:
                group_name = group
            else:
                group_name = file_name
            option = _Option(name, file_name=file_name,
                             default=default, type=type, help=help,
                             metavar=metavar, multiple=multiple,
                             group_name=group_name,
                             callback=callback)
            self._options[normalized] = option

        def parse_command_line(self, args=None, final=True):
            """Parses all options given on the command line (defaults to
            `sys.argv`).

            Note that ``args[0]`` is ignored since it is the program name
            in `sys.argv`.

            We return a list of all arguments that are not parsed as options.

            If ``final`` is ``False``, parse callbacks will not be run.
            This is useful for applications that wish to combine configurations
            from multiple sources.
            """
            if args is None:
                args = sys.argv
            remaining = []
            for i in range(1, len(args)):
                # All things after the last option are command line arguments
                if not args[i].startswith("-"):
                    remaining = args[i:]
                    break
                if args[i] == "--":
                    remaining = args[i + 1:]
                    break
                arg = args[i].lstrip("-")
                name, equals, value = arg.partition("=")
                name = self._normalize_name(name)
                if name not in self._options:
                    self.print_help()
                    raise Error('Unrecognized command line option: %r' % name)
                option = self._options[name]
                if not equals:
                    if option.type == bool:
                        value = "true"
                    else:
                        raise Error('Option %r requires a value' % name)
                option.parse(value)

            if final:
                self.run_parse_callbacks()

            return remaining

        def parse_config_file(self, path, final=True):
            """Parses and loads the Python config file at the given path.

            If ``final`` is ``False``, parse callbacks will not be run.
            This is useful for applications that wish to combine configurations
            from multiple sources.

            .. versionchanged:: 4.1
               Config files are now always interpreted as utf-8 instead of
               the system default encoding.

            .. versionchanged:: 4.4
               The special variable ``__file__`` is available inside config
               files, specifying the absolute path to the config file itself.
            """
            config = {'__file__': os.path.abspath(path)}
            with open(path, 'rb') as f:
                exec_in(native_str(f.read()), config, config)
            for name in config:
                normalized = self._normalize_name(name)
                if normalized in self._options:
                    self._options[normalized].set(config[name])

            if final:
                self.run_parse_callbacks()

        def print_help(self, file=None):
            """Prints all the command line options to stderr (or another file)."""
            if file is None:
                file = sys.stderr
            print("Usage: %s [OPTIONS]" % sys.argv[0], file=file)
            print("\nOptions:\n", file=file)
            by_group = {}
            for option in self._options.values():
                by_group.setdefault(option.group_name, []).append(option)

            for filename, o in sorted(by_group.items()):
                if filename:
                    print("\n%s options:\n" % os.path.normpath(filename), file=file)
                o.sort(key=lambda option: option.name)
                for option in o:
                    # Always print names with dashes in a CLI context.
                    prefix = self._normalize_name(option.name)
                    if option.metavar:
                        prefix += "=" + option.metavar
                    description = option.help or ""
                    if option.default is not None and option.default != '':
                        description += " (default %s)" % option.default
                    lines = textwrap.wrap(description, 79 - 35)
                    if len(prefix) > 30 or len(lines) == 0:
                        lines.insert(0, '')
                    print("  --%-30s %s" % (prefix, lines[0]), file=file)
                    for line in lines[1:]:
                        print("%-34s %s" % (' ', line), file=file)
            print(file=file)

        def _help_callback(self, value):
            if value:
                self.print_help()
                sys.exit(0)

        def add_parse_callback(self, callback):
            """Adds a parse callback, to be invoked when option parsing is done."""
            self._parse_callbacks.append(stack_context.wrap(callback))

        def run_parse_callbacks(self):
            for callback in self._parse_callbacks:
                callback()

        def mockable(self):
            """Returns a wrapper around self that is compatible with
            `mock.patch <unittest.mock.patch>`.

            The `mock.patch <unittest.mock.patch>` function (included in
            the standard library `unittest.mock` package since Python 3.3,
            or in the third-party ``mock`` package for older versions of
            Python) is incompatible with objects like ``options`` that
            override ``__getattr__`` and ``__setattr__``.  This function
            returns an object that can be used with `mock.patch.object
            <unittest.mock.patch.object>` to modify option values::

                with mock.patch.object(options.mockable(), 'name', value):
                    assert options.name == value
            """
            return _Mockable(self)

    class _Mockable(object):
        """`mock.patch` compatible wrapper for `OptionParser`.

        As of ``mock`` version 1.0.1, when an object uses ``__getattr__``
        hooks instead of ``__dict__``, ``patch.__exit__`` tries to delete
        the attribute it set instead of setting a new one (assuming that
        the object does not catpure ``__setattr__``, so the patch
        created a new attribute in ``__dict__``).

        _Mockable's getattr and setattr pass through to the underlying
        OptionParser, and delattr undoes the effect of a previous setattr.
        """
        def __init__(self, options):
            # Modify __dict__ directly to bypass __setattr__
            self.__dict__['_options'] = options
            self.__dict__['_originals'] = {}

        def __getattr__(self, name):
            return getattr(self._options, name)

        def __setattr__(self, name, value):
            assert name not in self._originals, "don't reuse mockable objects"
            self._originals[name] = getattr(self._options, name)
            setattr(self._options, name, value)

        def __delattr__(self, name):
            setattr(self._options, name, self._originals.pop(name))

    class _Option(object):
        UNSET = object()

        def __init__(self, name, default=None, type=basestring_type, help=None,
                     metavar=None, multiple=False, file_name=None, group_name=None,
                     callback=None):
            if default is None and multiple:
                default = []
            self.name = name
            self.type = type
            self.help = help
            self.metavar = metavar
            self.multiple = multiple
            self.file_name = file_name
            self.group_name = group_name
            self.callback = callback
            self.default = default
            self._value = _Option.UNSET

        def value(self):
            return self.default if self._value is _Option.UNSET else self._value

        def parse(self, value):
            _parse = {
                datetime.datetime: self._parse_datetime,
                datetime.timedelta: self._parse_timedelta,
                bool: self._parse_bool,
                basestring_type: self._parse_string,
            }.get(self.type, self.type)
            if self.multiple:
                self._value = []
                for part in value.split(","):
                    if issubclass(self.type, numbers.Integral):
                        # allow ranges of the form X:Y (inclusive at both ends)
                        lo, _, hi = part.partition(":")
                        lo = _parse(lo)
                        hi = _parse(hi) if hi else lo
                        self._value.extend(range(lo, hi + 1))
                    else:
                        self._value.append(_parse(part))
            else:
                self._value = _parse(value)
            if self.callback is not None:
                self.callback(self._value)
            return self.value()

        def set(self, value):
            if self.multiple:
                if not isinstance(value, list):
                    raise Error("Option %r is required to be a list of %s" %
                                (self.name, self.type.__name__))
                for item in value:
                    if item is not None and not isinstance(item, self.type):
                        raise Error("Option %r is required to be a list of %s" %
                                    (self.name, self.type.__name__))
            else:
                if value is not None and not isinstance(value, self.type):
                    raise Error("Option %r is required to be a %s (%s given)" %
                                (self.name, self.type.__name__, type(value)))
            self._value = value
            if self.callback is not None:
                self.callback(self._value)

        # Supported date/time formats in our options
        _DATETIME_FORMATS = [
            "%a %b %d %H:%M:%S %Y",
            "%Y-%m-%d %H:%M:%S",
            "%Y-%m-%d %H:%M",
            "%Y-%m-%dT%H:%M",
            "%Y%m%d %H:%M:%S",
            "%Y%m%d %H:%M",
            "%Y-%m-%d",
            "%Y%m%d",
            "%H:%M:%S",
            "%H:%M",
        ]

        def _parse_datetime(self, value):
            for format in self._DATETIME_FORMATS:
                try:
                    return datetime.datetime.strptime(value, format)
                except ValueError:
                    pass
            raise Error('Unrecognized date/time format: %r' % value)

        _TIMEDELTA_ABBREV_DICT = {
            'h': 'hours',
            'm': 'minutes',
            'min': 'minutes',
            's': 'seconds',
            'sec': 'seconds',
            'ms': 'milliseconds',
            'us': 'microseconds',
            'd': 'days',
            'w': 'weeks',
        }

        _FLOAT_PATTERN = r'[-+]?(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][-+]?\d+)?'

        _TIMEDELTA_PATTERN = re.compile(
            r'\s*(%s)\s*(\w*)\s*' % _FLOAT_PATTERN, re.IGNORECASE)

        def _parse_timedelta(self, value):
            try:
                sum = datetime.timedelta()
                start = 0
                while start < len(value):
                    m = self._TIMEDELTA_PATTERN.match(value, start)
                    if not m:
                        raise Exception()
                    num = float(m.group(1))
                    units = m.group(2) or 'seconds'
                    units = self._TIMEDELTA_ABBREV_DICT.get(units, units)
                    sum += datetime.timedelta(**{units: num})
                    start = m.end()
                return sum
            except Exception:
                raise

        def _parse_bool(self, value):
            return value.lower() not in ("false", "0", "f")

        def _parse_string(self, value):
            return _unicode(value)

    options = OptionParser()
    """Global options object.

    All defined options are available as attributes on this object.
    """

    def define(name, default=None, type=None, help=None, metavar=None,
               multiple=False, group=None, callback=None):
        """Defines an option in the global namespace.

        See `OptionParser.define`.
        """
        return options.define(name, default=default, type=type, help=help,
                              metavar=metavar, multiple=multiple, group=group,
                              callback=callback)

    def parse_command_line(args=None, final=True):
        """Parses global options from the command line.

        See `OptionParser.parse_command_line`.
        """
        return options.parse_command_line(args, final=final)

    def parse_config_file(path, final=True):
        """Parses global options from a config file.

        See `OptionParser.parse_config_file`.
        """
        return options.parse_config_file(path, final=final)

    def print_help(file=None):
        """Prints all the command line options to stderr (or another file).

        See `OptionParser.print_help`.
        """
        return options.print_help(file)

    def add_parse_callback(callback):
        """Adds a parse callback, to be invoked when option parsing is done.

        See `OptionParser.add_parse_callback`
        """
        options.add_parse_callback(callback)

    # Default options
    define_logging_options(options)