tiramisu/tiramisu/value.py

# -*- coding: utf-8 -*-
"takes care of the option's values and multi values"
# Copyright (C) 2013-2018 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 Lesser General Public License as published by the
# Free Software Foundation, either version 3 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 Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
# ____________________________________________________________
import weakref
from .error import ConfigError, PropertiesOptionError
from .setting import owners, expires_time, undefined, forbidden_owners, OptionBag, ConfigBag
from .autolib import carry_out_calculation
from .i18n import _


class Values(object):
    """The `Config`'s root is indeed  in charge of the `Option()`'s values,
    but the values are physicaly located here, in `Values`, wich is also
    responsible of a caching utility.
    """
    __slots__ = ('context',
                 '_p_',
                 '__weakref__')

    def __init__(self,
                 context,
                 storage):
        """
        Initializes the values's dict.

        :param context: the context is the home config's values
        :param storage: where values or owners are stored

        """
        self.context = weakref.ref(context)
        # store the storage
        self._p_ = storage

    #______________________________________________________________________
    # get context

    def _getcontext(self):
        """context is a weakref so context could be None, we need to test it
        context is None only if all reference to `Config` object is deleted
        (for example we delete a `Config` and we manipulate a reference to
        old `SubConfig`, `Values`, `Multi` or `Settings`)
        """
        context = self.context()
        if context is None:  # pragma: no cover
            raise ConfigError(_('the context does not exist anymore'))
        return context

    #______________________________________________________________________
    # get value

    def get_cached_value(self,
                         option_bag):
        """get value directly in cache if set
        otherwise calculated value and set it in cache

        :param opt: the `Option` that we want to get value
        :param path: the path of the `Option`
        :param validate: the value must be valid
        :param force_permissive: force permissive when check properties
        :param setting_properties: global properties
        :param self_properties: properties for this `Option`
        :param index: index for a slave `Option`
        :param display_warnings: display warnings or not

        :returns: value
        """
        # try to retrive value in cache
        setting_properties = option_bag.config_bag.setting_properties
        is_cached, value = self._p_.getcache(option_bag.path,
                                             expires_time,
                                             option_bag.index,
                                             setting_properties,
                                             option_bag.properties,
                                             'value')

        if not is_cached:
            # no cached value so get value
            value = self.getvalue(option_bag)
        # validate value
        context = self._getcontext()
        opt = option_bag.option
        opt.impl_validate(value,
                          option_bag,
                          context=context,
                          check_error=True)
        if setting_properties and 'warnings' in setting_properties:
            opt.impl_validate(value,
                              option_bag,
                              context=context,
                              check_error=False)
        # store value in cache
        if not is_cached:
            self._p_.setcache(option_bag.path,
                              option_bag.index,
                              value,
                              setting_properties,
                              option_bag.properties)
        if isinstance(value, list):
            # return a copy, so value cannot be modified
            return value.copy()
        # and return it
        return value

    def getvalue(self,
                 option_bag):
        """actually retrieves the value

        :param path: the path of the `Option`
        :param index: index for a slave `Option`

        :returns: value
        """
        # get owner and value from store
        # index allowed only for slave
        index = option_bag.index
        is_slave = option_bag.option.impl_is_master_slaves('slave')
        if index is None or not is_slave:
            _index = None
        else:
            _index = index
        owner, value = self._p_.getowner(option_bag.path,
                                         owners.default,
                                         index=_index,
                                         with_value=True)

        if owner != owners.default:
            # if a value is store in storage, check if not frozen + force_default_on_freeze
            # if frozen + force_default_on_freeze => force default value
            if not ('frozen' in option_bag.properties and \
                    'force_default_on_freeze' in option_bag.properties):
                if index is not None and not is_slave:
                    if len(value) > index:
                        return value[index]
                    #value is smaller than expected
                    #so return default value
                else:
                    return value
        return self.getdefaultvalue(option_bag)

    def getdefaultvalue(self,
                        option_bag):
        """get default value:
        - get meta config value or
        - get calculated value or
        - get default value
        :param opt: the `option.Option()` object
        :param path: path for `option.Option()` object
        :type path: str
        :param index: index of a multi/submulti
        :type index: int
        :returns: default value
        """
        context = self._getcontext()
        config_bag = option_bag.config_bag
        opt = option_bag.option
        index = option_bag.index
        def _reset_cache(_value):
            is_cache, cache_value = self._p_.getcache(option_bag.path,
                                                      expires_time,
                                                      index,
                                                      config_bag.setting_properties,
                                                      option_bag.properties,
                                                      'value')
            if is_cache and cache_value == _value:
                # calculation return same value as previous value,
                # so do not invalidate cache
                return
            # calculated value is a new value, so reset cache
            context.cfgimpl_reset_cache(option_bag)

        if opt.impl_is_master_slaves('slave'):
            index_ = index
        else:
            index_ = None
        if option_bag.index != index_:
            moption_bag = OptionBag()
            moption_bag.set_option(opt,
                                   option_bag.path,
                                   index_,
                                   config_bag)
            moption_bag.fromconsistency = option_bag.fromconsistency.copy()
        else:
            moption_bag = option_bag
        if self._is_meta(moption_bag):
            meta = context.cfgimpl_get_meta()
            # retrieved value from meta config
            try:
                # FIXME could have different property!
                value = meta.getattr(moption_bag.path,
                                     moption_bag)
            except PropertiesOptionError:
                # if properties error, return an other default value
                # unexpected error, should not happened
                pass
            else:
                return value

        if opt.impl_has_callback():
            # if value has callback, calculate value
            callback, callback_params = opt.impl_get_callback()
            value = carry_out_calculation(opt,
                                          context=context,
                                          callback=callback,
                                          callback_params=callback_params,
                                          index=index,
                                          option_bag=option_bag)
            if isinstance(value, list) and index is not None:
                # if value is a list and index is set
                if opt.impl_is_submulti() and (value == [] or not isinstance(value[0], list)):
                    # return value only if it's a submulti and not a list of list
                    _reset_cache(value)
                    return value

                if len(value) > index:
                    # return the value for specified index if found
                    _reset_cache(value[index])
                    return value[index]
                # there is no calculate value for this index,
                # so return an other default value
            else:
                if opt.impl_is_submulti():
                    if isinstance(value, list):
                        # value is a list, but no index specified
                        if (value != [] and not isinstance(value[0], list)):
                            # if submulti, return a list of value
                            value = [value]
                    elif index is not None:
                        # if submulti, return a list of value
                        value = [value]
                    else:
                        # return a list of list for a submulti
                        value = [[value]]
                elif opt.impl_is_multi() and not isinstance(value, list) and index is None:
                    # return a list for a multi
                    value = [value]
                _reset_cache(value)
                return value

        # now try to get default value:
        # - if opt is a submulti, return a list a list
        # - if opt is a multi, return a list
        # - default value
        value = opt.impl_getdefault()
        if opt.impl_is_multi() and index is not None:
            # if index, must return good value for this index
            if len(value) > index:
                value = value[index]
            else:
                # no value for this index, retrieve default multi value
                # default_multi is already a list for submulti
                value = opt.impl_getdefault_multi()
        return value

    def isempty(self,
                opt,
                value,
                force_allow_empty_list=False,
                index=None):
        "convenience method to know if an option is empty"
        empty = opt._empty
        if index in [None, undefined] and opt.impl_is_multi():
            if force_allow_empty_list:
                allow_empty_list = True
            else:
                allow_empty_list = opt.impl_allow_empty_list()
                if allow_empty_list is undefined:
                    allow_empty_list = opt.impl_is_master_slaves('slave')
            isempty = value is None or (not allow_empty_list and value == []) or \
                None in value or empty in value
        else:
            isempty = value is None or value == empty
        return isempty

    #______________________________________________________________________
    # set value

    def setvalue(self,
                 value,
                 option_bag,
                 _commit):

        context = self._getcontext()
        owner = context.cfgimpl_get_settings().getowner()
        if 'validator' in option_bag.config_bag.setting_properties:
            if option_bag.index is not None or option_bag.option._has_consistencies(context):
                # set value to a fake config when option has dependency
                # validation will be complet in this case (consistency, ...)
                tested_context = context._gen_fake_values()
                option_bag.config_bag.remove_validation()
                try:
                    tested_context.cfgimpl_get_values().setvalue(value,
                                                                 option_bag,
                                                                 True)
                    option_bag.config_bag.restore_validation()
                    tested_context.getattr(option_bag.path,
                                           option_bag)
                except Exception as exc:
                    option_bag.config_bag.restore_validation()
                    raise exc
            else:
                self.setvalue_validation(value,
                                         option_bag)

        self._setvalue(option_bag,
                       value,
                       owner,
                       commit=_commit)

    def setvalue_validation(self,
                            value,
                            option_bag):

        context = self._getcontext()
        settings = context.cfgimpl_get_settings()
        # First validate properties with this value
        opt = option_bag.option
        settings.validate_frozen(option_bag)
        settings.validate_mandatory(value,
                                    option_bag)
        # Value must be valid for option
        opt.impl_validate(value,
                          option_bag,
                          context,
                          check_error=True)
        if option_bag.config_bag.setting_properties and \
                'warnings' in option_bag.config_bag.setting_properties:
            # No error found so emit warnings
            opt.impl_validate(value,
                              option_bag,
                              context,
                              check_error=False)

    def _setvalue(self,
                  option_bag,
                  value,
                  owner,
                  commit=True):

        self._getcontext().cfgimpl_reset_cache(option_bag)
        if isinstance(value, list):
            # copy
            value = value.copy()
        self._p_.setvalue(option_bag.path,
                          value,
                          owner,
                          option_bag.index,
                          commit)

    def _is_meta(self,
                 option_bag,
                 force_owner_is_default=False):

        if not force_owner_is_default and self._p_.hasvalue(option_bag.path,
                                                            index=option_bag.index):
            # has already a value, so not meta
            return False
        context = self._getcontext()
        meta = context.cfgimpl_get_meta()
        if meta is None:
            return False
        opt = option_bag.option
        if opt.impl_is_master_slaves('slave'):
            master = opt.impl_get_master_slaves().getmaster()
            masterp = master.impl_getpath(context)
            # slave could be a "meta" only if master hasn't value
            if self._p_.hasvalue(masterp,
                                 index=None):
                return False
        return not meta.cfgimpl_get_values().is_default_owner(option_bag)


    #______________________________________________________________________
    # owner

    def is_default_owner(self,
                         option_bag,
                         validate_meta=undefined):
        return self.getowner(option_bag,
                             validate_meta=validate_meta,
                             only_default=True) == owners.default

    def getowner(self,
                 option_bag,
                 validate_meta=True,
                 only_default=False):
        """
        retrieves the option's owner

        :param opt: the `option.Option` object
        :param force_permissive: behaves as if the permissive property
                                 was present
        :returns: a `setting.owners.Owner` object
        """
        context = self._getcontext()
        opt = option_bag.option
        if opt.impl_is_symlinkoption():
            option_bag.ori_option = opt
            opt = opt.impl_getopt()
            option_bag.option = opt
            option_bag.path = opt.impl_getpath(context)
        self_properties = option_bag.properties
        settings = context.cfgimpl_get_settings()
        settings.validate_properties(option_bag)
        if 'frozen' in self_properties and 'force_default_on_freeze' in self_properties:
            return owners.default
        if only_default:
            if self._p_.hasvalue(option_bag.path,
                                 option_bag.index):
                owner = undefined
            else:
                owner = owners.default
        else:
            owner = self._p_.getowner(option_bag.path,
                                      owners.default,
                                      index=option_bag.index)
        if owner is owners.default and validate_meta is not False:
            meta = context.cfgimpl_get_meta()
            if meta is not None and self._is_meta(option_bag):
                owner = meta.cfgimpl_get_values().getowner(option_bag,
                                                           only_default=only_default)
        return owner

    def setowner(self,
                 owner,
                 option_bag):
        """
        sets a owner to an option

        :param opt: the `option.Option` object
        :param owner: a valid owner, that is a `setting.owners.Owner` object
        """
        opt = option_bag.option
        if opt.impl_is_symlinkoption():
            raise ConfigError(_("can't set owner for the symlinkoption \"{}\""
                                "").format(opt.impl_get_display_name()))
        if owner in forbidden_owners:
            raise ConfigError(_('set owner "{0}" is forbidden').format(str(owner)))

        if not self._p_.hasvalue(option_bag.path):
            raise ConfigError(_('no value for {0} cannot change owner to {1}'
                                '').format(option_bag.path, owner))
        self._getcontext().cfgimpl_get_settings().validate_frozen(option_bag)
        self._p_.setowner(option_bag.path,
                          owner,
                          index=option_bag.index)
    #______________________________________________________________________
    # reset

    def reset(self,
              option_bag,
              _commit=True):

        context = self._getcontext()
        setting = context.cfgimpl_get_settings()
        hasvalue = self._p_.hasvalue(option_bag.path)

        if hasvalue and 'validator' in option_bag.config_bag.setting_properties:
            option_bag.config_bag.remove_validation()
            fake_context = context._gen_fake_values()
            fake_value = fake_context.cfgimpl_get_values()
            fake_value.reset(option_bag)
            option_bag.config_bag.restore_validation()
            value = fake_value.getdefaultvalue(option_bag)
            fake_value.setvalue_validation(value,
                                           option_bag)
        opt = option_bag.option
        if opt.impl_is_master_slaves('master'):
            opt.impl_get_master_slaves().reset(self,
                                               option_bag,
                                               _commit=_commit)
        if hasvalue:
            if 'force_store_value' in option_bag.properties:
                value = self.getdefaultvalue(option_bag)

                self._setvalue(option_bag,
                               value,
                               owners.forced,
                               commit=_commit)
            else:
                self._p_.resetvalue(option_bag.path,
                                    _commit)
            if not opt.impl_is_master_slaves('master'):
                # if master, already reset behind
                pass
            context.cfgimpl_reset_cache(option_bag)

    def reset_slave(self,
                    option_bag):

        if self._p_.hasvalue(option_bag.path, index=option_bag.index):
            context = self._getcontext()
            if 'validator' in option_bag.config_bag.setting_properties:
                fake_context = context._gen_fake_values()
                fake_value = fake_context.cfgimpl_get_values()
                option_bag.config_bag.remove_validation()
                try:
                    fake_value.reset_slave(option_bag)
                    value = fake_value.getdefaultvalue(option_bag)
                    fake_value.setvalue_validation(value,
                                                   option_bag)
                    option_bag.config_bag.restore_validation()
                except Exception as err:
                    option_bag.config_bag.restore_validation()
                    raise err
            self._p_.resetvalue_index(option_bag.path, option_bag.index)
            context.cfgimpl_reset_cache(option_bag)

    def reset_master(self,
                     index,
                     option_bag,
                     subconfig):

        current_value = self.get_cached_value(option_bag)
        length = len(current_value)
        if index >= length:
            raise IndexError(_('index "{}" is higher than the length "{}" '
                               'for option "{}"').format(index,
                                                         length,
                                                         option_bag.option.impl_get_display_name()))
        current_value.pop(index)
        self.setvalue(current_value,
                      option_bag,
                      _commit=True)
        subconfig.cfgimpl_get_description().pop(self,
                                                index,
                                                option_bag)

    #______________________________________________________________________
    # information

    def set_information(self, key, value):
        """updates the information's attribute

        :param key: information's key (ex: "help", "doc"
        :param value: information's value (ex: "the help string")
        """
        self._p_.set_information(key, value)

    def get_information(self, key, default=undefined):
        """retrieves one information's item

        :param key: the item string (ex: "help")
        """
        return self._p_.get_information(key, default)

    def del_information(self, key, raises=True):
        self._p_.del_information(key, raises)

    #______________________________________________________________________
    # mandatory warnings
    def _mandatory_warnings(self,
                            context,
                            config_bag,
                            description,
                            currpath,
                            config,
                            od_setting_properties):
        settings = context.cfgimpl_get_settings()
#        for option in config.cfgimpl_get_children(self.config_bag):
        for option in description.impl_getchildren(config_bag, context):
            name = option.impl_getname()
            path = '.'.join(currpath + [name])

            if option.impl_is_optiondescription():
                ori_setting_properties = config_bag.setting_properties
                config_bag.setting_properties = od_setting_properties
                try:
                    option_bag = OptionBag()
                    option_bag.set_option(option,
                                          path,
                                          None,
                                          config_bag)
                    subconfig = config.get_subconfig(name,
                                                     option_bag)
                except PropertiesOptionError as err:
                    pass
                else:
                    config_bag.setting_properties = ori_setting_properties
                    for path in self._mandatory_warnings(context,
                                                         config_bag,
                                                         option,
                                                         currpath + [name],
                                                         subconfig,
                                                         od_setting_properties):
                        yield path
            elif not option.impl_is_symlinkoption():
                # don't verifying symlink
                try:
                    if not option.impl_is_master_slaves('slave'):
                        option_bag = OptionBag()
                        option_bag.set_option(option,
                                              path,
                                              None,
                                              config_bag)
                        if 'mandatory' in option_bag.properties or 'empty' in option_bag.properties:
                            config.getattr(name,
                                           option_bag)
                    else:
                        for index in range(config.cfgimpl_get_length()):
                            option_bag = OptionBag()
                            option_bag.set_option(option,
                                                  path,
                                                  index,
                                                  config_bag)
                            if 'mandatory' in option_bag.properties:
                                config.getattr(name,
                                               option_bag)
                except PropertiesOptionError as err:
                    if err.proptype == ['mandatory']:
                        yield path
                except ConfigError as err:
                    #assume that uncalculated value is an empty value
                    yield path

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

        :returns: generator of mandatory Option's path
        """
        context = self._getcontext()
        # copy
        od_setting_properties = config_bag.setting_properties - {'mandatory', 'empty'}
        setting_properties = set(config_bag.setting_properties) - {'warnings'}
        setting_properties.update(['mandatory', 'empty'])
        config_bag = ConfigBag(context=config_bag.context)
        config_bag.setting_properties = frozenset(setting_properties)
        config_bag.force_permissive = True

        descr = context.cfgimpl_get_description()
        return self._mandatory_warnings(context,
                                        config_bag,
                                        descr,
                                        [],
                                        context,
                                        od_setting_properties)