# -*- coding: utf-8 -*-
# Copyright (C) 2014-2018 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/>.
#
# 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 copy import copy
from typing import Optional, Iterator, Union, List


from ..i18n import _
from ..setting import ConfigBag, OptionBag, groups, undefined, owners, Undefined
from .baseoption import BaseOption
from .option import ALLOWED_CONST_LIST
from .syndynoptiondescription import SynDynOptionDescription
from ..error import ConfigError, ConflictError


class CacheOptionDescription(BaseOption):
    __slots__ = ('_cache_consistencies',
                 '_cache_force_store_values')

    def impl_already_build_caches(self) -> bool:
        return self.impl_is_readonly()

    def _build_cache(self,
                     path='',
                     _consistencies=None,
                     _consistencies_id=0,
                     currpath: List[str]=None,
                     cache_option=None,
                     force_store_values=None) -> None:
        """validate options and set option has readonly option
        """
        # _consistencies is None only when we start to build cache
        if _consistencies is None:
            init = True
            _consistencies = {}
            if __debug__:
                cache_option = []
            force_store_values = []
            currpath = []
        else:
            init = False

        if self.impl_is_readonly():
            # cache already set
            raise ConfigError(_('option description seems to be part of an other '
                                'config'))
        for option in self.get_children(config_bag=undefined,
                                        dyn=False):
            if __debug__:
                cache_option.append(option)
            sub_currpath = currpath + [option.impl_getname()]
            subpath = '.'.join(sub_currpath)
            if isinstance(option, OptionDescription):
                option._build_cache(subpath,
                                    _consistencies,
                                    _consistencies_id,
                                    sub_currpath,
                                    cache_option,
                                    force_store_values)
            else:
                is_multi = option.impl_is_multi()
                if not option.impl_is_symlinkoption():
                    properties = option.impl_getproperties()
                    if 'force_store_value' in properties:
                        if __debug__:
                            if option.impl_is_master_slaves('slave'):
                                # problem with index
                                raise ConfigError(_('the slave "{0}" cannot have '
                                                    '"force_store_value" property').format(
                                                        option.impl_get_display_name()))
                            if option.issubdyn():
                                raise ConfigError(_('the dynoption "{0}" cannot have '
                                                    '"force_store_value" property').format(
                                                        option.impl_get_display_name()))
                        force_store_values.append((subpath, option))
                    if __debug__ and 'force_default_on_freeze' in properties and \
                            'frozen' not in properties and \
                            option.impl_is_master_slaves('master'):
                        raise ConfigError(_('a master ({0}) cannot have '
                                            '"force_default_on_freeze" property without "frozen"'
                                            '').format(subpath))
                for cons_id, func, all_cons_opts, params in option.get_consistencies():
                    option._valid_consistencies(all_cons_opts[1:], init=False)
                    if func not in ALLOWED_CONST_LIST and is_multi:
                        if __debug__ and not option.impl_is_master_slaves():
                            raise ConfigError(_('malformed consistency option "{0}" '
                                               'must be a masterslaves').format(
                                                   option.impl_getname()))
                        masterslaves = option.impl_get_master_slaves()
                    for weak_opt in all_cons_opts:
                        opt = weak_opt()
                        if __debug__ and func not in ALLOWED_CONST_LIST and is_multi:
                            if not opt.impl_is_master_slaves():
                                raise ConfigError(_('malformed consistency option "{0}" '
                                                   'must not be a multi for "{1}"').format(
                                                       option.impl_getname(), opt.impl_getname()))
                            elif masterslaves != opt.impl_get_master_slaves():
                                raise ConfigError(_('malformed consistency option "{0}" '
                                                   'must be in same masterslaves as "{1}"').format(
                                                       option.impl_getname(), opt.impl_getname()))
                        _consistencies.setdefault(weak_opt,
                                                  []).append((_consistencies_id,
                                                             func,
                                                             all_cons_opts,
                                                             params))
                    _consistencies_id += 1
                # if context is set to callback, must be reset each time a value change
                if hasattr(option, '_has_calc_context'):
                    self._add_dependency(option)

                if __debug__:
                    is_slave = None
                    if is_multi:
                        all_requires = option.impl_getrequires()
                        for requires in all_requires:
                            for require in requires:
                                #if option in require is a multi:
                                # * option in require must be a master or a slave
                                # * current option must be a slave (and only a slave)
                                # * option in require and current option must be in same masterslaves
                                for require_opt, values in require[0]:
                                    if require_opt.impl_is_multi():
                                        if is_slave is None:
                                            is_slave = option.impl_is_master_slaves('slave')
                                            if is_slave:
                                                masterslaves = option.impl_get_master_slaves()
                                        if is_slave and require_opt.impl_is_master_slaves():
                                            if masterslaves != require_opt.impl_get_master_slaves():
                                                raise ValueError(_('malformed requirements option "{0}" '
                                                                   'must be in same masterslaves for "{1}"').format(
                                                                       require_opt.impl_getname(), option.impl_getname()))
                                        else:
                                            raise ValueError(_('malformed requirements option "{0}" '
                                                               'must not be a multi for "{1}"').format(
                                                                   require_opt.impl_getname(), option.impl_getname()))
            if not hasattr(option, '_path'):
                option._path = subpath
                option._set_readonly()
        if init:
            if __debug__ and len(cache_option) != len(set(cache_option)):
                for idx in range(1, len(cache_option) + 1):
                    opt = cache_option.pop(0)
                    if opt in cache_option:
                        raise ConflictError(_('duplicate option: {0}').format(opt))
            if _consistencies != {}:
                self._cache_consistencies = {}
                for weak_opt, cons in _consistencies.items():
                    opt = weak_opt()
                    if __debug__ and opt not in cache_option:
                        raise ConfigError(_('consistency with option {0} '
                                            'which is not in Config').format(
                                                opt.impl_getname()))
                    self._cache_consistencies[opt] = tuple(cons)
            self._cache_force_store_values = force_store_values
            self._set_readonly()

    def impl_build_force_store_values(self,
                                      config_bag: ConfigBag) -> None:
        commit = False
        if not hasattr(self, '_cache_force_store_values'):
            raise ConfigError(_('option description seems to be part of an other '
                                'config'))
        values = config_bag.context.cfgimpl_get_values()
        for subpath, option in self._cache_force_store_values:
            if not values._p_.hasvalue(subpath):
                option_bag = OptionBag()
                option_bag.set_option(option,
                                      subpath,
                                      None,
                                      config_bag)
                option_bag.properties = frozenset()
                values._p_.setvalue(subpath,
                                    values.getvalue(option_bag),
                                    owners.forced,
                                    None,
                                    False)
                commit = True

        if commit:
            values._p_.commit()


class OptionDescriptionWalk(CacheOptionDescription):
    __slots__ = ('_children',)

    def get_child(self,
                  name: str,
                  config_bag: ConfigBag,
                  subpath: str) -> Union[BaseOption, SynDynOptionDescription]:
        # if not dyn
        if name in self._children[0]:
            return self._children[1][self._children[0].index(name)]
        # if dyn
        for child in self._children[1]:
            if child.impl_is_dynoptiondescription():
                cname = child.impl_getname()
                if name.startswith(cname):
                    for value in child.impl_get_suffixes(config_bag):
                        if name == cname + value:
                            return SynDynOptionDescription(child,
                                                           subpath,
                                                           value)
        raise AttributeError(_('unknown option "{0}" '
                               'in optiondescription "{1}"'
                               '').format(name, self.impl_getname()))

    def get_children(self,
                     config_bag: Union[ConfigBag, Undefined],
                     dyn: bool=True) -> Iterator[Union[BaseOption, SynDynOptionDescription]]:
        if not dyn or config_bag is undefined or \
                config_bag.context.cfgimpl_get_description() == self:
            subpath = ''
        else:
            subpath = self.impl_getpath()
        for child in self._children[1]:
            if dyn and child.impl_is_dynoptiondescription():
                for suffix in child.impl_get_suffixes(config_bag):
                    yield SynDynOptionDescription(child,
                                                  subpath,
                                                  suffix)
            else:
                yield child

    def get_children_recursively(self,
                                 bytype: Optional[BaseOption],
                                 byname: Optional[str],
                                 config_bag: ConfigBag,
                                 self_opt: BaseOption=None) -> Iterator[Union[BaseOption, SynDynOptionDescription]]:
        if self_opt is None:
            self_opt = self
        for option in self_opt.get_children(config_bag):
            if option.impl_is_optiondescription():
                for subopt in option.get_children_recursively(bytype,
                                                              byname,
                                                              config_bag):
                    yield subopt
            elif (byname is None or option.impl_getname() == byname) and \
                    (bytype is None or isinstance(option, bytype)):
                yield option


class OptionDescription(OptionDescriptionWalk):
    """Config's schema (organisation, group) and container of Options
    The `OptionsDescription` objects lives in the `tiramisu.config.Config`.
    """
    __slots__ = ('_group_type',)

    def __init__(self,
                 name: str,
                 doc: str,
                 children: List[BaseOption],
                 requires=None,
                 properties=None) -> None:
        """
        :param children: a list of options (including optiondescriptions)

        """
        assert isinstance(children, list), _('children in optiondescription "{}" '
                                             'must be a list').format(name)
        super().__init__(name,
                         doc=doc,
                         requires=requires,
                         properties=properties)
        child_names = []
        if __debug__:
            dynopt_names = []
        for child in children:
            name = child.impl_getname()
            child_names.append(name)
            if __debug__ and child.impl_is_dynoptiondescription():
                dynopt_names.append(name)

        # before sorting
        children_ = (tuple(child_names), tuple(children))

        if __debug__:
            # better performance like this
            child_names.sort()
            old = None
            for child in child_names:
                if child == old:
                    raise ConflictError(_('duplicate option name: '
                                          '"{0}"').format(child))
                if dynopt_names:
                    for dynopt in dynopt_names:
                        if child != dynopt and child.startswith(dynopt):
                            raise ConflictError(_('the option\'s name "{}" start as '
                                                  'the dynoptiondescription\'s name "{}"').format(child, dynopt))
                old = child
        self._children = children_
        # the group_type is useful for filtering OptionDescriptions in a config
        self._group_type = groups.default

    def impl_is_optiondescription(self) -> bool:
        return True

    def impl_is_dynoptiondescription(self) -> bool:
        return False

    def impl_is_master_slaves(self,
                              *args,
                              **kwargs) -> bool:
        return False

    # ____________________________________________________________
    def impl_set_group_type(self,
                            group_type: groups.GroupType) -> None:
        """sets a given group object to an OptionDescription

        :param group_type: an instance of `GroupType` or `MasterGroupType`
                              that lives in `setting.groups`
        """
        if self._group_type != groups.default:
            raise ValueError(_('cannot change group_type if already set '
                               '(old {0}, new {1})').format(self._group_type,
                                                           group_type))
        if not isinstance(group_type, groups.GroupType):
            raise ValueError(_('group_type: {0}'
                               ' not allowed').format(group_type))
        if isinstance(group_type, groups.MasterGroupType):
            raise ConfigError('please use MasterSlaves object instead of OptionDescription')
        self._group_type = group_type

    def impl_get_group_type(self) -> groups.GroupType:
        return self._group_type