# -*- coding: utf-8 -*-
"option types and option description for the configuration management"
# 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
# ____________________________________________________________
import re
from copy import copy
from types import FunctionType
from IPy import IP

from tiramisu.error import ConflictConfigError
from tiramisu.setting import groups, multitypes
from tiramisu.i18n import _

name_regexp = re.compile(r'^\d+')


def valid_name(name):
    try:
        name = str(name)
    except:
        return False
    if re.match(name_regexp, name) is None:
        return True
    else:
        return False
#____________________________________________________________
#


class BaseInformation(object):
    __slots__ = ('_informations')

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

        :param key: information's key (ex: "help", "doc"
        :param value: information's value (ex: "the help string")
        """
        self._informations[key] = value

    def get_information(self, key, default=None):
        """retrieves one information's item

        :param key: the item string (ex: "help")
        """
        if key in self._informations:
            return self._informations[key]
        elif default is not None:
            return default
        else:
            raise ValueError(_("Information's item not found: {0}").format(key))


class Option(BaseInformation):
    """
    Abstract base class for configuration option's.

    Reminder: an Option object is **not** a container for the value
    """
    __slots__ = ('_name', '_requires', '_multi', '_validator', '_default_multi',
                 '_default', '_properties', '_callback', '_multitype',
                 '_master_slaves', '_consistencies')

    def __init__(self, name, doc, default=None, default_multi=None,
                 requires=None, multi=False, callback=None,
                 callback_params=None, validator=None, validator_args=None,
                 properties=None):
        #FIXME : validation de callback et callback_params !!!
        """
        :param name: the option's name
        :param doc: the option's description
        :param default: specifies the default value of the option,
                        for a multi : ['bla', 'bla', 'bla']
        :param default_multi: 'bla' (used in case of a reset to default only at
                        a given index)
        :param requires: is a list of names of options located anywhere
                         in the configuration.
        :param multi: if true, the option's value is a list
        :param callback: the name of a function. If set, the function's output
                         is responsible of the option's value
        :param callback_params: the callback's parameter
        :param validator: the name of a function wich stands for a custom
                          validation of the value
        :param validator_args: the validator's parameters
        """
        if not valid_name(name):
            raise ValueError(_("invalid name: {0} for option").format(name))
        self._name = name
        self._informations = {}
        self.set_information('doc', doc)
        validate_requires_arg(requires, self._name)
        self._requires = requires
        self._multi = multi
        self._consistencies = None
        if validator is not None:
            if type(validator) != FunctionType:
                raise TypeError(_("validator must be a function"))
            if validator_args is None:
                validator_args = {}
            self._validator = (validator, validator_args)
        else:
            self._validator = None
        if not self._multi and default_multi is not None:
            raise ValueError(_("a default_multi is set whereas multi is False"
                             " in option: {0}").format(name))
        if default_multi is not None and not self._validate(default_multi):
            raise ValueError(_("invalid default_multi value {0} "
                             "for option {1}").format(str(default_multi), name))
        if callback is not None and (default is not None or default_multi is not None):
            raise ValueError(_("defaut values not allowed if option: {0} "
                             "is calculated").format(name))
        if callback is None and callback_params is not None:
            raise ValueError(_("params defined for a callback function but "
                             "no callback defined yet for option {0}").format(name))
        if callback is not None:
            self._callback = (callback, callback_params)
        else:
            self._callback = None
        if self._multi:
            if default is None:
                default = []
            #if not isinstance(default, list):
            #    raise ValidateError("invalid default value {0} "
            #                        "for option {1} : not list type"
            #                        "".format(str(default), name))
            if not self.validate(default):
                raise ValueError(_("invalid default value {0} "
                                 "for option {1}"
                                 "").format(str(default), name))
            self._multitype = multitypes.default
            self._default_multi = default_multi
        else:
            if default is not None and not self.validate(default):
                raise ValueError(_("invalid default value {0} "
                                 "for option {1}").format(str(default), name))
        self._default = default
        if properties is None:
            properties = ()
        if not isinstance(properties, tuple):
            raise TypeError(_('invalid properties type {0} for {1},'
                            ' must be a tuple').format(type(properties), self._name))
        self._properties = properties  # 'hidden', 'disabled'...

    def validate(self, value, context=None, validate=True):
        """
        :param value: the option's value
        :param validate: if true enables ``self._validator`` validation
        """
        # generic calculation
        if context is not None:
            cons = context.cfgimpl_get_description()
        else:
            cons = None
        if not self._multi:
            # None allows the reset of the value
            if value is not None:
                # customizing the validator
                if validate and self._validator is not None and \
                        not self._validator[0](value, **self._validator[1]):
                    return False
                if not self._validate(value):
                    return False
                if cons is not None:
                    return cons.valid_consistency(self, value, context, None)
        else:
            if not isinstance(value, list):
                raise ValueError(_("invalid value {0} "
                                    "for option {1} which must be a list"
                                    "").format(value, self._name))
            for index in range(0, len(value)):
                val = value[index]
                # None allows the reset of the value
                if val is not None:
                    # customizing the validator
                    if validate and self._validator is not None and \
                            not self._validator[0](val, **self._validator[1]):
                        return False
                    if not self._validate(val):
                        return False
                    if cons is not None and not cons.valid_consistency(self, val, context, index):
                        return False
        return True

    def getdefault(self, default_multi=False):
        "accessing the default value"
        if not default_multi or not self.is_multi():
            return self._default
        else:
            return self.getdefault_multi()

    def getdefault_multi(self):
        "accessing the default value for a multi"
        return self._default_multi

    def get_multitype(self):
        return self._multitype

    def get_master_slaves(self):
        return self._master_slaves

    def is_empty_by_default(self):
        "no default value has been set yet"
        if ((not self.is_multi() and self._default is None) or
                (self.is_multi() and (self._default == [] or None in self._default))):
            return True
        return False

    def getdoc(self):
        "accesses the Option's doc"
        return self.get_information('doc')

    def has_callback(self):
        "to know if a callback has been defined or not"
        if self._callback is None:
            return False
        else:
            return True

    def reset(self, config):
        """resets the default value and owner
        """
        config._cfgimpl_context._cfgimpl_values.reset(self)

    def getkey(self, value):
        return value

    def is_multi(self):
        return self._multi

    def cons_not_equal(self, opt, value, context, index, opts):
        values = [value]
        descr = context.cfgimpl_get_description()
        for opt_ in opts:
            if opt_ is not opt:
                path = descr.get_path_by_opt(opt_)
                val = context._getattr(path, validate=False)
                if val is not None:
                    if val in values:
                        return False
                    values.append(val)
        return True

    def add_consistency(self, func, opts):
        pass
        if self._consistencies is None:
            self._consistencies = []
        if self not in opts:
            opts = list(opts)
            opts.append(self)
            opts = tuple(opts)
        self._consistencies.append(('cons_{}'.format(func), opts))


class ChoiceOption(Option):
    __slots__ = ('_values', '_open_values', 'opt_type')
    opt_type = 'string'

    def __init__(self, name, doc, values, default=None, default_multi=None,
                 requires=None, multi=False, callback=None,
                 callback_params=None, open_values=False, validator=None,
                 validator_args=None, properties=()):
        if not isinstance(values, tuple):
            raise TypeError(_('values must be a tuple for {0}').format(name))
        self._values = values
        if open_values not in (True, False):
            raise TypeError(_('open_values must be a boolean for '
                            '{0}').format(name))
        self._open_values = open_values
        super(ChoiceOption, self).__init__(name, doc, default=default,
                                           default_multi=default_multi,
                                           callback=callback,
                                           callback_params=callback_params,
                                           requires=requires,
                                           multi=multi,
                                           validator=validator,
                                           validator_args=validator_args,
                                           properties=properties)

    def _validate(self, value):
        if not self._open_values:
            return value is None or value in self._values
        else:
            return True


class BoolOption(Option):
    __slots__ = ('opt_type')
    opt_type = 'bool'

    def _validate(self, value):
        return isinstance(value, bool)


class IntOption(Option):
    __slots__ = ('opt_type')
    opt_type = 'int'

    def _validate(self, value):
        return isinstance(value, int)


class FloatOption(Option):
    __slots__ = ('opt_type')
    opt_type = 'float'

    def _validate(self, value):
        return isinstance(value, float)


class StrOption(Option):
    __slots__ = ('opt_type')
    opt_type = 'string'

    def _validate(self, value):
        return isinstance(value, str)


class UnicodeOption(Option):
    __slots__ = ('opt_type')
    opt_type = 'unicode'

    def _validate(self, value):
        return isinstance(value, unicode)


class SymLinkOption(object):
    __slots__ = ('_name', 'opt', '_consistencies')
    opt_type = 'symlink'
    _consistencies = None

    def __init__(self, name, path, opt):
        self._name = name
        self.opt = opt

    def setoption(self, context, value):
        path = context.cfgimpl_get_description().get_path_by_opt(self.opt)
        setattr(context, path, value)

    def __getattr__(self, name):
        if name in ('_name', 'opt', 'setoption'):
            return object.__gettattr__(self, name)
        else:
            return getattr(self.opt, name)


class IPOption(Option):
    __slots__ = ('opt_type', '_only_private')
    opt_type = 'ip'

    def set_private(self):
        self._only_private = True

    def _validate(self, value):
        try:
            only_private = self._only_private
        except AttributeError:
            only_private = False
        try:
            ip = IP('{0}/32'.format(value))
            if only_private:
                return ip.iptype() == 'PRIVATE'
            return True
        except ValueError:
            return False


class NetworkOption(Option):
    __slots__ = ('opt_type')
    opt_type = 'network'

    def _validate(self, value):
        try:
            IP(value)
            return True
        except ValueError:
            return False


class NetmaskOption(Option):
    __slots__ = ('opt_type')
    opt_type = 'netmask'

    def __init__(self, name, doc, default=None, default_multi=None,
                 requires=None, multi=False, callback=None,
                 callback_params=None, validator=None, validator_args=None,
                 properties=None, opt_ip=None):
        if opt_ip is not None and not isinstance(opt_ip, IPOption) and \
                not isinstance(opt_ip, NetworkOption):
            raise TypeError(_('opt_ip must be a IPOption not {}').format(type(opt_ip)))
        super(NetmaskOption, self).__init__(name, doc, default=default,
                                            default_multi=default_multi,
                                            callback=callback,
                                            callback_params=callback_params,
                                            requires=requires,
                                            multi=multi,
                                            validator=validator,
                                            validator_args=validator_args,
                                            properties=properties)
        if opt_ip is None:
            pass
        elif isinstance(opt_ip, IPOption):
            self._consistencies = [('cons_ip_netmask', (self, opt_ip))]
        elif isinstance(opt_ip, NetworkOption):
            self._consistencies = [('cons_network_netmask', (self, opt_ip))]
        else:
            raise TypeError(_('unknown type for opt_ip'))

    def _validate(self, value):
        try:
            IP('0.0.0.0/{}'.format(value))
            return True
        except ValueError:
            return False

    def cons_network_netmask(self, opt, value, context, index, opts):
        #opts must be (netmask, network) options
        return self._cons_netmask(opt, value, context, index, opts, False)

    def cons_ip_netmask(self, opt, value, context, index, opts):
        #opts must be (netmask, ip) options
        return self._cons_netmask(opt, value, context, index, opts, True)

    def _cons_netmask(self, opt, value, context, index, opts, make_net):
        opt_netmask, opt_ipnetwork = opts
        descr = context.cfgimpl_get_description()
        if opt is opt_ipnetwork:
            val_ipnetwork = value
            path = descr.get_path_by_opt(opt_netmask)
            val_netmask = context._getattr(path, validate=False)
            if opt_netmask.is_multi():
                val_netmask = val_netmask[index]
            if val_netmask is None:
                return True
        else:
            val_netmask = value
            path = descr.get_path_by_opt(opt_ipnetwork)
            val_ipnetwork = getattr(context, path)
            if opt_ipnetwork.is_multi():
                val_ipnetwork = val_ipnetwork[index]
            if val_ipnetwork is None:
                return True
        try:
            IP('{}/{}'.format(val_ipnetwork, val_netmask, make_net=make_net))
            return True
        except ValueError:
            return False


class OptionDescription(BaseInformation):
    """Config's schema (organisation, group) and container of Options"""
    __slots__ = ('_name', '_requires', '_cache_paths', '_group_type',
                 '_properties', '_children', '_consistencies')

    def __init__(self, name, doc, children, requires=None, properties=()):
        """
        :param children: is a list of option descriptions (including
        ``OptionDescription`` instances for nested namespaces).
        """
        if not valid_name(name):
            raise ValueError(_("invalid name: {0} for option descr").format(name))
        self._name = name
        self._informations = {}
        self.set_information('doc', doc)
        child_names = [child._name for child in children]
        #better performance like this
        valid_child = copy(child_names)
        valid_child.sort()
        old = None
        for child in valid_child:
            if child == old:
                raise ConflictConfigError(_('duplicate option name: '
                                          '{0}').format(child))
            old = child
        self._children = (tuple(child_names), tuple(children))
        validate_requires_arg(requires, self._name)
        self._requires = requires
        self._cache_paths = None
        self._consistencies = None
        if not isinstance(properties, tuple):
            raise TypeError(_('invalid properties type {0} for {1},'
                              ' must be a tuple').format(type(properties), self._name))
        self._properties = properties  # 'hidden', 'disabled'...
        # the group_type is useful for filtering OptionDescriptions in a config
        self._group_type = groups.default

    def getdoc(self):
        return self.get_information('doc')

    def __getattr__(self, name):
        try:
            return self._children[1][self._children[0].index(name)]
        except ValueError:
            raise AttributeError(_('unknown Option {} in OptionDescription {}'
                                 '').format(name, self._name))

    def getkey(self, config):
        return tuple([child.getkey(getattr(config, child._name))
                      for child in self._children[1]])

    def getpaths(self, include_groups=False, _currpath=None):
        """returns a list of all paths in self, recursively
           _currpath should not be provided (helps with recursion)
        """
        #FIXME : cache
        if _currpath is None:
            _currpath = []
        paths = []
        for option in self._children[1]:
            attr = option._name
            if isinstance(option, OptionDescription):
                if include_groups:
                    paths.append('.'.join(_currpath + [attr]))
                paths += option.getpaths(include_groups=include_groups,
                                         _currpath=_currpath + [attr])
            else:
                paths.append('.'.join(_currpath + [attr]))
        return paths

    def getchildren(self):
        return self._children[1]

    def build_cache(self, cache_path=None, cache_option=None, _currpath=None, _consistencies=None):
        if _currpath is None and self._cache_paths is not None:
            return
        if _currpath is None:
            save = True
            _currpath = []
            _consistencies = {}
        else:
            save = False
        if cache_path is None:
            cache_path = [self._name]
            cache_option = [self]
        for option in self._children[1]:
            attr = option._name
            if attr.startswith('_cfgimpl'):
                continue
            cache_option.append(option)
            cache_path.append(str('.'.join(_currpath + [attr])))
            if not isinstance(option, OptionDescription):
                if option._consistencies is not None:
                    for consistency in option._consistencies:
                        func, opts = consistency
                        for opt in opts:
                            _consistencies.setdefault(opt, []).append((func, opts))
            else:
                _currpath.append(attr)
                option.build_cache(cache_path, cache_option, _currpath, _consistencies)
                _currpath.pop()
        if save:
            #valid no duplicated option
            valid_child = copy(cache_option)
            valid_child.sort()
            old = None
            for child in valid_child:
                if child == old:
                    raise ConflictConfigError(_('duplicate option: '
                                              '{0}').format(child))
                old = child
            self._cache_paths = (tuple(cache_option), tuple(cache_path))
            self._consistencies = _consistencies

    def get_opt_by_path(self, path):
        try:
            return self._cache_paths[0][self._cache_paths[1].index(path)]
        except ValueError:
            raise AttributeError(_('no option for path {}').format(path))

    def get_path_by_opt(self, opt):
        try:
            return self._cache_paths[1][self._cache_paths[0].index(opt)]
        except ValueError:
            raise AttributeError(_('no option {} found').format(opt))

    # ____________________________________________________________
    def set_group_type(self, group_type):
        """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 TypeError(_('cannot change group_type if already set '
                            '(old {}, new {})').format(self._group_type, group_type))
        if isinstance(group_type, groups.GroupType):
            self._group_type = group_type
            if isinstance(group_type, groups.MasterGroupType):
                #if master (same name has group) is set
                identical_master_child_name = False
                #for collect all slaves
                slaves = []
                master = None
                for child in self._children[1]:
                    if isinstance(child, OptionDescription):
                        raise ValueError(_("master group {} shall not have "
                                         "a subgroup").format(self._name))
                    if not child.is_multi():
                        raise ValueError(_("not allowed option {0} in group {1}"
                                         ": this option is not a multi"
                                         "").format(child._name, self._name))
                    if child._name == self._name:
                        identical_master_child_name = True
                        child._multitype = multitypes.master
                        master = child
                    else:
                        slaves.append(child)
                if master is None:
                    raise ValueError(_('master group with wrong master name for {}'
                                     '').format(self._name))
                master._master_slaves = tuple(slaves)
                for child in self._children[1]:
                    if child != master:
                        child._master_slaves = master
                        child._multitype = multitypes.slave
                if not identical_master_child_name:
                    raise ValueError(_("the master group: {} has not any "
                                     "master child").format(self._name))
        else:
            raise ValueError(_('not allowed group_type : {0}').format(group_type))

    def get_group_type(self):
        return self._group_type

    def valid_consistency(self, opt, value, context, index):
        consistencies = self._consistencies.get(opt)
        if consistencies is not None:
            for consistency in consistencies:
                func, opts = consistency
                ret = getattr(opts[0], func)(opt, value, context, index, opts)
                if ret is False:
                    return False
        return True


def validate_requires_arg(requires, name):
    "check malformed requirements"
    if requires is not None:
        config_action = {}
        for req in requires:
            if not type(req) == tuple:
                raise ValueError(_("malformed requirements type for option:"
                                 " {0}, must be a tuple").format(name))
            if len(req) == 3:
                action = req[2]
                inverse = False
            elif len(req) == 4:
                action = req[2]
                inverse = req[3]
            else:
                raise ValueError(_("malformed requirements for option: {0}"
                                 " invalid len").format(name))
            if action in config_action:
                if inverse != config_action[action]:
                    raise ValueError(_("inconsistency in action types for option: {0}"
                                     " action: {1}").format(name, action))
            else:
                config_action[action] = inverse