# Copyright (C) 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/>.


from typing import Union, List, Optional
from argparse import ArgumentParser, Namespace, SUPPRESS, _HelpAction, HelpFormatter
try:
    from tiramisu import Config
    from tiramisu.error import PropertiesOptionError
except ImportError:
    Config = None
    from tiramisu_json_api.error import PropertiesOptionError
try:
    from tiramisu_json_api import Config as ConfigJson
    if Config is None:
        Config = ConfigJson
except ImportError:
    ConfigJson = Config


class TiramisuNamespace(Namespace):
    def _populate(self):
        #self._config.property.read_only()
        for tiramisu_key, tiramisu_value in self._config.value.dict().items():
            option = self._config.option(tiramisu_key)
            if not option.option.issymlinkoption():
                if tiramisu_value == [] and option.option.ismulti() and option.owner.isdefault():
                    tiramisu_value = None
                super().__setattr__(tiramisu_key, tiramisu_value)
        #self._config.property.read_write()

    def __init__(self, config):
        self._config = config
        super().__init__()

    def __setattr__(self, key, value):
        if key == '_config':
            super().__setattr__(key, value)
            return
        # self._config.property.read_write()
        option = self._config.option(key)
        if option.option.ismulti() and value is not None and not isinstance(value, list):
            value = [value]
        option.value.set(value)

    def __getattribute__(self, key):
        if key == '__dict__' and hasattr(self, '_config'):
            self._populate()
        return super().__getattribute__(key)


class TiramisuHelpFormatter(HelpFormatter):
    def _get_default_metavar_for_optional(self,
                                          action):
        ret = super()._get_default_metavar_for_optional(action)
        if '.' in ret:
            ret = ret.split('.', 1)[1]
        return ret


class _TiramisuHelpAction(_HelpAction):
    needs = False
    def __call__(self, *args, **kwargs):
        _TiramisuHelpAction.needs = True

    def display(self, parser):
        _HelpAction.__call__(self, parser, None, None)


class TiramisuCmdlineParser(ArgumentParser):
    def __init__(self,
                 config: Union[Config, ConfigJson],
                 *args,
                 fullpath: bool=True,
                 _forhelp: bool=False,
                 **kwargs):
        self.fullpath = fullpath
        self.config = config
        kwargs['formatter_class'] = TiramisuHelpFormatter
        super().__init__(*args, **kwargs)
        self.register('action', 'help', _TiramisuHelpAction)
        self._config_to_argparser(_forhelp,
                                  self.config.option)

    def _pop_action_class(self, kwargs, default=None):
        ret = super()._pop_action_class(kwargs, default)
        if kwargs.get('action') != 'help' and kwargs.get('dest') != 'help':
            return ret
        return _TiramisuHelpAction

    def _match_arguments_partial(self,
                                 actions,
                                 arg_string_pattern):
        # used only when check first proposal for first value
        # we have to remove all actions with propertieserror
        # so only first settable option will be returned
        actions_pop = []
        for idx, action in enumerate(actions):
            if self.config.option(action.dest).property.get(only_raises=True):
                actions_pop.append(idx)
            else:
                break
        for idx in actions_pop:
            actions.pop(0)
        return super()._match_arguments_partial(actions, arg_string_pattern)

    def _parse_known_args(self, args=None, namespace=None):

        namespace_, args_ = super()._parse_known_args(args, namespace)
        if args != args_ and args_ and args_[0].startswith(self.prefix_chars):
            # option that was disabled are no more disable
            # so create a new parser
            new_parser = TiramisuCmdlineParser(self.config,
                                               self.prog,
                                               fullpath=self.fullpath)
            namespace_, args_ = new_parser._parse_known_args(args_, namespace)
        else:
            if self._registries['action']['help'].needs:
                # display help only when all variables assignemnt are done
                self._registries['action']['help'].needs = False
                helper = self._registries['action']['help'](None)
                helper.display(self)
        return namespace_, args_

    def add_argument(self, *args, **kwargs):
        if args == ('-h', '--help'):
            super().add_argument(*args, **kwargs)
        else:
            raise NotImplementedError('do not use add_argument')

    def add_arguments(self, *args, **kwargs):
        raise NotImplementedError('do not use add_argument')

    def add_subparsers(self, *args, **kwargs):
        raise NotImplementedError('do not use add_subparsers')

    def _gen_argument(self, name, properties):
        if len(name) == 1 and 'longargument' not in properties:
            return self.prefix_chars + name
        return self.prefix_chars * 2 + name

    def _config_to_argparser(self,
                             _forhelp: bool,
                             config,
                             prefix: Optional[str]=None,
                             group=None) -> None:
        if group is None:
            group = super()
        actions = {}
        for obj in config.list(type='all'):
            option = obj.option
            if option.isoptiondescription():
                if _forhelp:
                    group = self.add_argument_group(option.doc())
                if prefix:
                    prefix_ = prefix + '.' + option.name()
                else:
                    prefix_ = option.path()
                self._config_to_argparser(_forhelp, obj, prefix_, group)
                continue
            if 'frozen' in option.properties():
                continue
            name = option.name()
            if name.startswith(self.prefix_chars):
                raise ValueError('name cannot startswith "{}"'.format(self.prefix_chars))
            if self.fullpath and prefix:
                name = prefix + '.' + name
            properties = obj.property.get()
            kwargs = {'help': option.doc().replace('%', '%%')}
            if option.issymlinkoption():
                actions[option.name(follow_symlink=True)][0].insert(0, self._gen_argument(option.name(), properties))
                continue
            if 'positional' in properties:
                if not 'mandatory' in properties:
                    raise ValueError('"positional" argument must be "mandatory" too')
                args = [option.path()]
                if _forhelp:
                    kwargs['default'] = obj.value.default()
                else:
                    kwargs['default'] = obj.value.get()
                    kwargs['nargs'] = '?'
            else:
                kwargs['dest'] = option.path()
                kwargs['default'] = SUPPRESS
                args = [self._gen_argument(name, properties)]
                if _forhelp and 'mandatory' in properties:
                    kwargs['required'] = True
            if option.type() == 'boolean':
                if 'mandatory' in properties:
                    raise ValueError('"mandatory" property is not allowed for BoolOption')
                #if not isinstance(option.default(), bool):
                #    raise ValueError('default value is mandatory for BoolOption')
                if obj.value.get() is False:
                    action = 'store_true'
                else:
                    action = 'store_false'
                kwargs['action'] = action
            else:
                if _forhelp:
                    value = obj.value.default()
                else:
                    value = obj.value.get()
                if value not in [None, []]:
                    #kwargs['default'] = kwargs['const'] = option.default()
                    #kwargs['action'] = 'store_const'
                    kwargs['nargs'] = '?'
                if option.ismulti():
                    if _forhelp and 'mandatory' in properties:
                        kwargs['nargs'] = '+'
                    else:
                        kwargs['nargs'] = '*'
                if option.type() == 'string':
                    pass
                elif option.type() == 'integer':
                    kwargs['type'] = int
                elif option.type() == 'choice':
                    kwargs['choices'] = obj.value.list()
                else:
                    pass
                    #raise NotImplementedError('not supported yet')
            actions[option.name()] = (args, kwargs)
        for args, kwargs in actions.values():
            group.add_argument(*args, **kwargs)

    def parse_args(self,
                   *args,
                   valid_mandatory=True,
                   **kwargs):
        kwargs['namespace'] = TiramisuNamespace(self.config)
        try:
            namespaces = super().parse_args(*args, **kwargs)
            del namespaces.__dict__['_config']
        except PropertiesOptionError as err:
            name = err._option_bag.option.impl_getname()
            properties = self.config.option(name).property.get()
            if self.fullpath and 'positional' not in properties:
                if len(name) == 1 and 'longargument' not in properties:
                    name = self.prefix_chars + name
                else:
                    name = self.prefix_chars * 2 + name
            if err.proptype == ['mandatory']:
                self.error('the following arguments are required: {}'.format(name))
            else:
                self.error('unrecognized arguments: {}'.format(name))
        if valid_mandatory:
            for key in self.config.value.mandatory():
                properties = self.config.option(key).property.get()
                if 'positional' not in properties:
                    if self.fullpath or '.' not in key:
                        name = key
                    else:
                        name = key.rsplit('.', 1)[1]
                    args = self._gen_argument(name, self.config.option(key).property.get())
                else:
                    args = key
                if not self.fullpath and '.' in args:
                    args = args.rsplit('.', 1)[1]
                self.error('the following arguments are required: {}'.format(args))
        return namespaces

    def format_usage(self,
                     *args,
                     **kwargs):
        help_formatter = TiramisuCmdlineParser(self.config,
                                               self.prog,
                                               fullpath=self.fullpath,
                                               _forhelp=True)
        return super(TiramisuCmdlineParser, help_formatter).format_usage(*args, **kwargs)

    def format_help(self,
                    *args,
                    **kwargs):
        help_formatter = TiramisuCmdlineParser(self.config,
                                               self.prog,
                                               fullpath=self.fullpath,
                                               _forhelp=True)
        return super(TiramisuCmdlineParser, help_formatter).format_help(*args, **kwargs)

    def get_config(self):
        return self.config