"""
"""

# Created on 2014.08.23
#
# Author: Giovanni Cannata
#
# Copyright 2014 - 2018 Giovanni Cannata
#
# This file is part of ldap3.
#
# ldap3 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.
#
# ldap3 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 ldap3 in the COPYING and COPYING.LESSER files.
# If not, see <http://www.gnu.org/licenses/>.

try:
    from collections.abc import MutableMapping, Mapping
except ImportError:
    from collections import MutableMapping, Mapping

from .. import SEQUENCE_TYPES


class CaseInsensitiveDict(MutableMapping):
    def __init__(self, other=None, **kwargs):
        self._store = dict()  # store use the original key
        self._case_insensitive_keymap = dict()  # is a mapping ci_key -> key
        if other or kwargs:
            if other is None:
                other = dict()
            self.update(other, **kwargs)

    def __contains__(self, item):
        try:
            self.__getitem__(item)
            return True
        except KeyError:
            return False

    @staticmethod
    def _ci_key(key):
        return key.strip().lower() if hasattr(key, 'lower') else key

    def __delitem__(self, key):
        ci_key = self._ci_key(key)
        del self._store[self._case_insensitive_keymap[ci_key]]
        del self._case_insensitive_keymap[ci_key]

    def __setitem__(self, key, item):
        ci_key = self._ci_key(key)
        if ci_key in self._case_insensitive_keymap:  # updates existing value
            self._store[self._case_insensitive_keymap[ci_key]] = item
        else:  # new key
            self._store[key] = item
            self._case_insensitive_keymap[ci_key] = key

    def __getitem__(self, key):
        return self._store[self._case_insensitive_keymap[self._ci_key(key)]]

    def __iter__(self):
        return self._store.__iter__()

    def __len__(self):  # if len is 0 then the cidict appears as False in IF statement
        return len(self._store)

    def __repr__(self):
        return repr(self._store)

    def __str__(self):
        return str(self._store)

    def keys(self):
        return self._store.keys()

    def values(self):
        return self._store.values()

    def items(self):
        return self._store.items()

    def __eq__(self, other):
        if not isinstance(other, (Mapping, dict)):
            return NotImplemented

        if isinstance(other, CaseInsensitiveDict):
            if len(self.items()) != len(other.items()):
                return False
            else:
                for key, value in self.items():
                    if not (key in other and other[key] == value):
                        return False
                return True

        return self == CaseInsensitiveDict(other)

    def copy(self):
        return CaseInsensitiveDict(self._store)


class CaseInsensitiveWithAliasDict(CaseInsensitiveDict):
    def __init__(self, other=None, **kwargs):
        self._aliases = dict()
        self._alias_keymap = dict()  # is a mapping key -> [alias1, alias2, ...]
        CaseInsensitiveDict.__init__(self, other, **kwargs)

    def aliases(self):
        return self._aliases.keys()

    def __setitem__(self, key, value):
        if isinstance(key, SEQUENCE_TYPES):
            ci_key = self._ci_key(key[0])
            if ci_key not in self._aliases:
                CaseInsensitiveDict.__setitem__(self, key[0], value)
                self.set_alias(ci_key, key[1:])
            else:
                raise KeyError('\'' + str(key[0] + ' already used as alias'))
        else:
            ci_key = self._ci_key(key)
            if ci_key not in self._aliases:
                CaseInsensitiveDict.__setitem__(self, key, value)
            else:
                self[self._aliases[ci_key]] = value

    def __delitem__(self, key):
        ci_key = self._ci_key(key)
        try:
            CaseInsensitiveDict.__delitem__(self, ci_key)
            if ci_key in self._alias_keymap:
                for alias in self._alias_keymap[ci_key][:]:  # removes aliases, uses a copy of _alias_keymap because iterator gets confused when aliases are removed from _alias_keymap
                    self.remove_alias(alias)
            return
        except KeyError:  # try to remove alias
            if ci_key in self._aliases:
                self.remove_alias(ci_key)

    def set_alias(self, key, alias):
        if not isinstance(alias, SEQUENCE_TYPES):
            alias = [alias]
        for alias_to_add in alias:
            ci_key = self._ci_key(key)
            if ci_key in self._case_insensitive_keymap:
                ci_alias = self._ci_key(alias_to_add)
                if ci_alias not in self._case_insensitive_keymap:  # checks if alias is used a key
                    if ci_alias not in self._aliases:  # checks if alias is used as another alias
                        self._aliases[ci_alias] = ci_key
                        if ci_key in self._alias_keymap:  # extend alias keymap
                            self._alias_keymap[ci_key].append(self._ci_key(ci_alias))
                        else:
                            self._alias_keymap[ci_key] = list()
                            self._alias_keymap[ci_key].append(self._ci_key(ci_alias))
                    else:
                        if ci_key == self._ci_key(self._alias_keymap[ci_alias]):  # passes if alias is already defined to the same key
                            pass
                        else:
                            raise KeyError('\'' + str(alias_to_add) + '\' already used as alias')
                else:
                    if ci_key == self._ci_key(self._case_insensitive_keymap[ci_alias]):  # passes if alias is already defined to the same key
                        pass
                    else:
                        raise KeyError('\'' + str(alias_to_add) + '\' already used as key')
            else:
                raise KeyError('\'' + str(ci_key) + '\' is not an existing key')

    def remove_alias(self, alias):
        if not isinstance(alias, SEQUENCE_TYPES):
            alias = [alias]
        for alias_to_remove in alias:
            ci_alias = self._ci_key(alias_to_remove)
            self._alias_keymap[self._aliases[ci_alias]].remove(ci_alias)
            if not self._alias_keymap[self._aliases[ci_alias]]:  # remove keymap if empty
                del self._alias_keymap[self._aliases[ci_alias]]
            del self._aliases[ci_alias]

    def __getitem__(self, key):
        try:
            return CaseInsensitiveDict.__getitem__(self, key)
        except KeyError:
            return CaseInsensitiveDict.__getitem__(self, self._aliases[self._ci_key(key)])

    def copy(self):
        new = CaseInsensitiveWithAliasDict(self._store)
        new._aliases = self._aliases.copy()
        new._alias_keymap = self._alias_keymap
        return new
