tiramisu/tiramisu/config.py

# -*- coding: utf-8 -*-
"pretty small and local configuration management tool"
# Copyright (C) 2012-2013 Team tiramisu (see AUTHORS for all contributors)
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# The original `Config` design model is unproudly borrowed from
# the rough pypy's guys: http://codespeak.net/svn/pypy/dist/pypy/config/
# the whole pypy projet is under MIT licence
# ____________________________________________________________
#from inspect import getmembers, ismethod
from tiramisu.error import PropertiesOptionError
from tiramisu.option import OptionDescription, Option, SymLinkOption
from tiramisu.setting import groups, Setting
from tiramisu.value import Values
from tiramisu.i18n import _


class SubConfig(object):
    "sub configuration management entry"
    __slots__ = ('_cfgimpl_descr', '_cfgimpl_context')

    def __init__(self, descr, context):
        """ Configuration option management master class

        :param descr: describes the configuration schema
        :type descr: an instance of ``option.OptionDescription``
        :param context: the current root config
        :type context: `Config`
        """
        # main option description
        if not isinstance(descr, OptionDescription):
            raise ValueError(_('descr must be an optiondescription, not {0}').format(type(descr)))
        self._cfgimpl_descr = descr
        # sub option descriptions
        self._cfgimpl_context = context

    def cfgimpl_get_context(self):
        return self._cfgimpl_context

    def cfgimpl_get_settings(self):
        return self._cfgimpl_context._cfgimpl_settings

    def cfgimpl_get_values(self):
        return self._cfgimpl_context._cfgimpl_values

    def cfgimpl_get_consistancies(self):
        return self.cfgimpl_get_context().cfgimpl_get_description()._consistancies

    def cfgimpl_get_description(self):
        return self._cfgimpl_descr

    def cfgimpl_reset_cache(self, only_expired=False, only=('values', 'settings')):
        self.cfgimpl_get_context().cfgimpl_reset_cache(only_expired, only)

    # ____________________________________________________________
    # attribute methods
    def __setattr__(self, name, value):
        "attribute notation mechanism for the setting of the value of an option"
        if name.startswith('_cfgimpl_'):
            #self.__dict__[name] = value
            object.__setattr__(self, name, value)
            return
        self._setattr(name, value)

    def _setattr(self, name, value, force_permissive=False):
        if '.' in name:
            homeconfig, name = self.cfgimpl_get_home_by_path(name)
            return homeconfig.__setattr__(name, value)
        child = getattr(self._cfgimpl_descr, name)
        if not isinstance(child, SymLinkOption):
            self.cfgimpl_get_values().setitem(child, value,
                                              force_permissive=force_permissive)
        else:
            context = self.cfgimpl_get_context()
            path = context.cfgimpl_get_description().optimpl_get_path_by_opt(child._opt)
            context._setattr(path, value, force_permissive=force_permissive)

    def __delattr__(self, name):
        child = getattr(self._cfgimpl_descr, name)
        del(self.cfgimpl_get_values()[child])

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

    def _getattr(self, name, force_permissive=False, force_properties=None,
                 validate=True):
        """
        attribute notation mechanism for accessing the value of an option
        :param name: attribute name
        :return: option's value if name is an option name, OptionDescription
                 otherwise
        """
        # attribute access by passing a path,
        # for instance getattr(self, "creole.general.family.adresse_ip_eth0")
        if '.' in name:
            homeconfig, name = self.cfgimpl_get_home_by_path(name,
                                                             force_permissive=force_permissive,
                                                             force_properties=force_properties)
            return homeconfig._getattr(name, force_permissive=force_permissive,
                                       force_properties=force_properties,
                                       validate=validate)
        # special attributes
        if name.startswith('_cfgimpl_') or name.startswith('cfgimpl_'):
            # if it were in __dict__ it would have been found already
            object.__getattr__(self, name)
        opt_or_descr = getattr(self.cfgimpl_get_description(), name)
        # symlink options
        if isinstance(opt_or_descr, SymLinkOption):
            context = self.cfgimpl_get_context()
            path = context.cfgimpl_get_description().optimpl_get_path_by_opt(opt_or_descr._opt)
            return context._getattr(path, validate=validate,
                                    force_properties=force_properties,
                                    force_permissive=force_permissive)
        elif isinstance(opt_or_descr, OptionDescription):
            self.cfgimpl_get_settings().validate_properties(opt_or_descr,
                                                            True, False,
                                                            force_permissive=force_permissive,
                                                            force_properties=force_properties)
            return SubConfig(opt_or_descr, self._cfgimpl_context)
        else:
            return self.cfgimpl_get_values().getitem(opt_or_descr,
                                                     validate=validate,
                                                     force_properties=force_properties,
                                                     force_permissive=force_permissive)

    def cfgimpl_get_home_by_path(self, path, force_permissive=False, force_properties=None):
        """:returns: tuple (config, name)"""
        path = path.split('.')
        for step in path[:-1]:
            self = self._getattr(step,
                                 force_permissive=force_permissive,
                                 force_properties=force_properties)
        return self, path[-1]

    def __hash__(self):
        return hash(self.cfgimpl_get_description().optimpl_getkey(self))

    def __eq__(self, other):
        "Config comparison"
        if not isinstance(other, Config):
            return False
        return self.cfgimpl_get_description().optimpl_getkey(self) == \
            other.cfgimpl_get_description().optimpl_getkey(other)

    def __ne__(self, other):
        "Config comparison"
        if not isinstance(other, Config):
            return False
        return not self == other

    # ______________________________________________________________________
    def __iter__(self):
        """Pythonesque way of parsing group's ordered options.
        iteration only on Options (not OptionDescriptions)"""
        for child in self.cfgimpl_get_description().optimpl_getchildren():
            if not isinstance(child, OptionDescription):
                try:
                    yield child._name, getattr(self, child._name)
                except GeneratorExit:
                    raise StopIteration
                except PropertiesOptionError:
                    pass  # option with properties

    def iter_all(self):
        """A way of parsing options **and** groups.
        iteration on Options and OptionDescriptions."""
        for child in self.cfgimpl_get_description().optimpl_getchildren():
            try:
                yield child._name, getattr(self, child._name)
            except GeneratorExit:
                raise StopIteration
            except PropertiesOptionError:
                pass  # option with properties

    def iter_groups(self, group_type=None):
        """iteration on groups objects only.
        All groups are returned if `group_type` is `None`, otherwise the groups
        can be filtered by categories (families, or whatever).

        :param group_type: if defined, is an instance of `groups.GroupType`
                           or `groups.MasterGroupType` that lives in
                           `setting.groups`

        """
        if group_type is not None:
            if not isinstance(group_type, groups.GroupType):
                raise TypeError(_("unknown group_type: {0}").format(group_type))
        for child in self.cfgimpl_get_description().optimpl_getchildren():
            if isinstance(child, OptionDescription):
                try:
                    if group_type is None or (group_type is not None and
                                              child.optimpl_get_group_type() == group_type):
                        yield child._name, getattr(self, child._name)
                except GeneratorExit:
                    raise StopIteration
                except PropertiesOptionError:
                    pass
    # ______________________________________________________________________

    def __str__(self):
        "Config's string representation"
        lines = []
        for name, grp in self.iter_groups():
            lines.append("[%s]" % name)
        for name, value in self:
            try:
                lines.append("%s = %s" % (name, value))
            except PropertiesOptionError:
                pass
        return '\n'.join(lines)

    __repr__ = __str__

    def cfgimpl_get_path(self):
        descr = self.cfgimpl_get_description()
        context_descr = self.cfgimpl_get_context().cfgimpl_get_description()
        return context_descr.optimpl_get_path_by_opt(descr)

    def find(self, bytype=None, byname=None, byvalue=None, type_='option'):
        """
            finds a list of options recursively in the config

            :param bytype: Option class (BoolOption, StrOption, ...)
            :param byname: filter by Option._name
            :param byvalue: filter by the option's value
            :returns: list of matching Option objects
        """
        return self.cfgimpl_get_context()._find(bytype, byname, byvalue,
                                                first=False,
                                                type_=type_,
                                                _subpath=self.cfgimpl_get_path())

    def find_first(self, bytype=None, byname=None, byvalue=None, type_='option'):
        """
            finds an option recursively in the config

            :param bytype: Option class (BoolOption, StrOption, ...)
            :param byname: filter by Option._name
            :param byvalue: filter by the option's value
            :returns: list of matching Option objects
        """
        return self.cfgimpl_get_context()._find(bytype, byname, byvalue,
                                                first=True,
                                                type_=type_,
                                                _subpath=self.cfgimpl_get_path())

    def make_dict(self, flatten=False, _currpath=None, withoption=None, withvalue=None):
        """export the whole config into a `dict`
        :returns: dict of Option's name (or path) and values"""
        pathsvalues = []
        if _currpath is None:
            _currpath = []
        if withoption is None and withvalue is not None:
            raise ValueError(_("make_dict can't filtering with value without option"))
        if withoption is not None:
            mypath = self.cfgimpl_get_path()
            for path in self.cfgimpl_get_context()._find(bytype=Option,
                                                         byname=withoption,
                                                         byvalue=withvalue,
                                                         first=False,
                                                         type_='path',
                                                         _subpath=mypath):
                path = '.'.join(path.split('.')[:-1])
                opt = self.cfgimpl_get_context().cfgimpl_get_description().optimpl_get_opt_by_path(path)
                if mypath is not None:
                    if mypath == path:
                        withoption = None
                        withvalue = None
                        break
                    else:
                        tmypath = mypath + '.'
                        if not path.startswith(tmypath):
                            raise AttributeError(_('unexpected path {0}, '
                                                 'should start with {1}').format(path, mypath))
                        path = path[len(tmypath):]
                self._make_sub_dict(opt, path, pathsvalues, _currpath, flatten)
        #withoption can be set to None below !
        if withoption is None:
            for opt in self.cfgimpl_get_description().optimpl_getchildren():
                path = opt._name
                self._make_sub_dict(opt, path, pathsvalues, _currpath, flatten)
        if _currpath == []:
            options = dict(pathsvalues)
            return options
        return pathsvalues

    def _make_sub_dict(self, opt, path, pathsvalues, _currpath, flatten):
        if isinstance(opt, OptionDescription):
            pathsvalues += getattr(self, path).make_dict(flatten,
                                                         _currpath + path.split('.'))
        else:
            try:
                value = self._getattr(opt._name)
                if flatten:
                    name = opt._name
                else:
                    name = '.'.join(_currpath + [opt._name])
                pathsvalues.append((name, value))
            except PropertiesOptionError:
                pass  # this just a hidden or disabled option


# ____________________________________________________________
class Config(SubConfig):
    "main configuration management entry"
    __slots__ = ('_cfgimpl_settings', '_cfgimpl_values')

    def __init__(self, descr):
        """ Configuration option management master class

        :param descr: describes the configuration schema
        :type descr: an instance of ``option.OptionDescription``
        :param context: the current root config
        :type context: `Config`
        """
        self._cfgimpl_settings = Setting(self)
        self._cfgimpl_values = Values(self)
        super(Config, self).__init__(descr, self)  # , slots)
        self._cfgimpl_build_all_paths()

    def _cfgimpl_build_all_paths(self):
        self._cfgimpl_descr.optimpl_build_cache()

    def read_only(self):
        self.cfgimpl_get_settings().read_only()

    def read_write(self):
        self.cfgimpl_get_settings().read_write()

    def getowner(self, path):
        opt = self.cfgimpl_get_description().optimpl_get_opt_by_path(path)
        return self.cfgimpl_get_values().getowner(opt)

    def cfgimpl_reset_cache(self, only_expired=False, only=('values', 'settings')):
        if 'values' in only:
            self.cfgimpl_get_values().reset_cache(only_expired=only_expired)
        if 'settings' in only:
            self.cfgimpl_get_settings().reset_cache(only_expired=only_expired)

    def unwrap_from_path(self, path):
        """convenience method to extract and Option() object from the Config()
        and it is **fast**: finds the option directly in the appropriate
        namespace

        :returns: Option()
        """
        if '.' in path:
            homeconfig, path = self.cfgimpl_get_home_by_path(path)
            return getattr(homeconfig._cfgimpl_descr, path)
        return getattr(self._cfgimpl_descr, path)

    def cfgimpl_get_path(self):
        return None

    def _find(self, bytype, byname, byvalue, first, type_='option',
              _subpath=None):
        """
        convenience method for finding an option that lives only in the subtree

        :param first: return only one option if True, a list otherwise
        :return: find list or an exception if nothing has been found
        """
        def _filter_by_name():
            if byname is None:
                return True
            if path == byname or path.endswith('.' + byname):
                return True
            else:
                return False

        def _filter_by_value():
            if byvalue is None:
                return True
            try:
                value = getattr(self, path)
                if value == byvalue:
                    return True
            except PropertiesOptionError:  # a property restricts the access of the value
                pass
            return False

        def _filter_by_type():
            if bytype is None:
                return True
            if isinstance(option, bytype):
                return True
            return False

        #def _filter_by_attrs():
        #    if byattrs is None:
        #        return True
        #    for key, val in byattrs.items():
        #        print "----", path, key
        #        if path == key or path.endswith('.' + key):
        #            if value == val:
        #                return True
        #            else:
        #                return False
        #    return False
        if type_ not in ('option', 'path', 'value'):
            raise ValueError(_('unknown type_ type {0} for _find').format(type_))
        find_results = []
        opts, paths = self.cfgimpl_get_description()._cache_paths
        for index in range(0, len(paths)):
            option = opts[index]
            if isinstance(option, OptionDescription):
                continue
            path = paths[index]
            if _subpath is not None and not path.startswith(_subpath + '.'):
                continue
            if not _filter_by_name():
                continue
            if not _filter_by_value():
                continue
            #remove option with propertyerror, ...
            try:
                value = getattr(self, path)
            except PropertiesOptionError:  # a property restricts the access of the value
                continue
            if not _filter_by_type():
                continue
            #if not _filter_by_attrs():
            #    continue
            if type_ == 'value':
                retval = value
            elif type_ == 'path':
                retval = path
            else:
                retval = option
            if first:
                return retval
            else:
                find_results.append(retval)
        if find_results == []:
            raise AttributeError(_("no option found in config with these criteria"))
        else:
            return find_results


def mandatory_warnings(config):
    """convenience function to trace Options that are mandatory and
    where no value has been set

    :returns: generator of mandatory Option's path
    """
    #if value in cache, properties are not calculated
    config.cfgimpl_reset_cache(only=('values',))
    for path in config.cfgimpl_get_description().optimpl_getpaths(include_groups=True):
        try:
            config._getattr(path, force_properties=('mandatory',))
        except PropertiesOptionError, err:
            if err.proptype == ['mandatory']:
                yield path
    config.cfgimpl_reset_cache(only=('values',))