# -*- coding: utf-8 -*-
#
from functools import partial
from django.utils.translation import ugettext_lazy as _
from rest_framework import serializers

from common.drf.serializers import CommonBulkSerializerMixin
from common.validators import PhoneValidator
from common.utils import pretty_string, get_logger
from common.drf.fields import EncryptedField
from rbac.builtin import BuiltinRole
from rbac.permissions import RBACPermission
from rbac.models import OrgRoleBinding, SystemRoleBinding, Role
from ..models import User
from ..const import PasswordStrategy

__all__ = [
    'UserSerializer', 'MiniUserSerializer',
    'InviteSerializer', 'ServiceAccountSerializer',
]

logger = get_logger(__file__)


class RolesSerializerMixin(serializers.Serializer):
    system_roles = serializers.ManyRelatedField(
        child_relation=serializers.PrimaryKeyRelatedField(queryset=Role.system_roles),
        label=_('System roles'),
    )
    org_roles = serializers.ManyRelatedField(
        required=False,
        child_relation=serializers.PrimaryKeyRelatedField(queryset=Role.org_roles),
        label=_('Org roles'),
    )
    system_roles_display = serializers.SerializerMethodField(label=_('System roles display'))
    org_roles_display = serializers.SerializerMethodField(label=_('Org roles display'))

    @staticmethod
    def get_system_roles_display(user):
        return user.system_roles.display

    @staticmethod
    def get_org_roles_display(user):
        return user.org_roles.display

    def pop_roles_if_need(self, fields):
        request = self.context.get('request')
        view = self.context.get('view')

        if not all([request, view, hasattr(view, 'action')]):
            return fields
        if request.user.is_anonymous:
            return fields

        action = view.action or 'list'
        if action in ('partial_bulk_update', 'bulk_update', 'partial_update', 'update'):
            action = 'create'
        model_cls_field_mapper = {
            SystemRoleBinding: ['system_roles', 'system_roles_display'],
            OrgRoleBinding: ['org_roles', 'system_roles_display']
        }

        for model_cls, fields_names in model_cls_field_mapper.items():
            perms = RBACPermission.parse_action_model_perms(action, model_cls)
            if request.user.has_perms(perms):
                continue
            # 没有权限就去掉
            for field_name in fields_names:
                fields.pop(field_name, None)
        return fields

    def get_fields(self):
        fields = super().get_fields()
        self.pop_roles_if_need(fields)
        return fields


class UserSerializer(RolesSerializerMixin, CommonBulkSerializerMixin, serializers.ModelSerializer):
    password_strategy = serializers.ChoiceField(
        choices=PasswordStrategy.choices, default=PasswordStrategy.email, required=False,
        write_only=True, label=_('Password strategy')
    )
    mfa_enabled = serializers.BooleanField(read_only=True, label=_('MFA enabled'))
    mfa_force_enabled = serializers.BooleanField(read_only=True, label=_('MFA force enabled'))
    mfa_level_display = serializers.ReadOnlyField(
        source='get_mfa_level_display', label=_('MFA level display')
    )
    login_blocked = serializers.BooleanField(read_only=True, label=_('Login blocked'))
    is_expired = serializers.BooleanField(read_only=True, label=_('Is expired'))
    can_public_key_auth = serializers.ReadOnlyField(
        source='can_use_ssh_key_login', label=_('Can public key authentication')
    )
    password = EncryptedField(
        label=_('Password'), required=False, allow_blank=True, allow_null=True, max_length=1024
    )
    # Todo: 这里看看该怎么搞
    # can_update = serializers.SerializerMethodField(label=_('Can update'))
    # can_delete = serializers.SerializerMethodField(label=_('Can delete'))
    custom_m2m_fields = {
        'system_roles': [BuiltinRole.system_user],
        'org_roles': [BuiltinRole.org_user]
    }

    class Meta:
        model = User
        # mini 是指能识别对象的最小单元
        fields_mini = ['id', 'name', 'username']
        # 只能写的字段, 这个虽然无法在框架上生效，但是更多对我们是提醒
        fields_write_only = [
            'password', 'public_key',
        ]
        # small 指的是 不需要计算的直接能从一张表中获取到的数据
        fields_small = fields_mini + fields_write_only + [
            'email', 'wechat', 'phone', 'mfa_level', 'source', 'source_display',
            'can_public_key_auth', 'need_update_password',
            'mfa_enabled', 'is_service_account', 'is_valid', 'is_expired', 'is_active',  # 布尔字段
            'date_expired', 'date_joined', 'last_login',  # 日期字段
            'created_by', 'comment',  # 通用字段
            'is_wecom_bound', 'is_dingtalk_bound', 'is_feishu_bound', 'is_otp_secret_key_bound',
            'wecom_id', 'dingtalk_id', 'feishu_id'
        ]
        # 包含不太常用的字段，可以没有
        fields_verbose = fields_small + [
            'mfa_level_display', 'mfa_force_enabled', 'is_first_login',
            'date_password_last_updated', 'avatar_url',
        ]
        # 外键的字段
        fields_fk = []
        # 多对多字段
        fields_m2m = [
            'groups', 'groups_display', 'system_roles', 'org_roles',
            'system_roles_display', 'org_roles_display'
        ]
        # 在serializer 上定义的字段
        fields_custom = ['login_blocked', 'password_strategy']
        fields = fields_verbose + fields_fk + fields_m2m + fields_custom

        read_only_fields = [
            'date_joined', 'last_login', 'created_by', 'is_first_login',
            'wecom_id', 'dingtalk_id', 'feishu_id'
        ]
        disallow_self_update_fields = ['is_active']
        extra_kwargs = {
            'password': {'write_only': True, 'required': False, 'allow_null': True, 'allow_blank': True},
            'public_key': {'write_only': True},
            'is_first_login': {'label': _('Is first login'), 'read_only': True},
            'is_active': {'label': _('Is active')},
            'is_valid': {'label': _('Is valid')},
            'is_service_account': {'label': _('Is service account')},
            'is_expired': {'label': _('Is expired')},
            'avatar_url': {'label': _('Avatar url')},
            'created_by': {'read_only': True, 'allow_blank': True},
            'groups_display': {'label': _('Groups name')},
            'source_display': {'label': _('Source name')},
            'org_role_display': {'label': _('Organization role name')},
            'role_display': {'label': _('Super role name')},
            'total_role_display': {'label': _('Total role name')},
            'role': {'default': "User"},
            'is_wecom_bound': {'label': _('Is wecom bound')},
            'is_dingtalk_bound': {'label': _('Is dingtalk bound')},
            'is_feishu_bound': {'label': _('Is feishu bound')},
            'is_otp_secret_key_bound': {'label': _('Is OTP bound')},
            'phone': {'validators': [PhoneValidator()]},
            'system_role_display': {'label': _('System role name')},
        }

    def validate_password(self, password):
        password_strategy = self.initial_data.get('password_strategy')
        if self.instance is None and password_strategy != PasswordStrategy.custom:
            # 创建用户，使用邮件设置密码
            return
        if self.instance and not password:
            # 更新用户, 未设置密码
            return
        return password

    @staticmethod
    def change_password_to_raw(attrs):
        password = attrs.pop('password', None)
        if password:
            attrs['password_raw'] = password
        return attrs

    @staticmethod
    def clean_auth_fields(attrs):
        for field in ('password', 'public_key'):
            value = attrs.get(field)
            if not value:
                attrs.pop(field, None)
        return attrs

    def check_disallow_self_update_fields(self, attrs):
        request = self.context.get('request')
        if not request or not request.user.is_authenticated:
            return attrs
        if not self.instance:
            return attrs
        if request.user.id != self.instance.id:
            return attrs
        disallow_fields = set(list(attrs.keys())) & set(self.Meta.disallow_self_update_fields)
        if not disallow_fields:
            return attrs
        # 用户自己不能更新自己的一些字段
        logger.debug('Disallow update self fields: %s', disallow_fields)
        for field in disallow_fields:
            attrs.pop(field, None)
        return attrs

    def validate(self, attrs):
        attrs = self.check_disallow_self_update_fields(attrs)
        attrs = self.change_password_to_raw(attrs)
        attrs = self.clean_auth_fields(attrs)
        attrs.pop('password_strategy', None)
        return attrs

    def save_and_set_custom_m2m_fields(self, validated_data, save_handler, created):
        m2m_values = {}
        for f, default_roles in self.custom_m2m_fields.items():
            roles = validated_data.pop(f, None)
            if created and not roles:
                roles = [
                    Role.objects.filter(id=role.id).first()
                    for role in default_roles
                ]
            m2m_values[f] = roles

        instance = save_handler(validated_data)
        for field_name, value in m2m_values.items():
            if value is None:
                continue
            field = getattr(instance, field_name)
            field.set(value)
        return instance

    def update(self, instance, validated_data):
        save_handler = partial(super().update, instance)
        instance = self.save_and_set_custom_m2m_fields(validated_data, save_handler, created=False)
        return instance

    def create(self, validated_data):
        save_handler = super().create
        instance = self.save_and_set_custom_m2m_fields(validated_data, save_handler, created=True)
        return instance


class UserRetrieveSerializer(UserSerializer):
    login_confirm_settings = serializers.PrimaryKeyRelatedField(
        read_only=True, source='login_confirm_setting.reviewers', many=True
    )

    class Meta(UserSerializer.Meta):
        fields = UserSerializer.Meta.fields + ['login_confirm_settings']


class MiniUserSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = UserSerializer.Meta.fields_mini


class InviteSerializer(RolesSerializerMixin, serializers.Serializer):
    users = serializers.PrimaryKeyRelatedField(
        queryset=User.get_nature_users(), many=True, label=_('Select users'),
        help_text=_('For security, only list several users')
    )
    system_roles = None
    system_roles_display = None
    org_roles_display = None


class ServiceAccountSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = ['id', 'name', 'access_key', 'comment']
        read_only_fields = ['access_key']

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        from authentication.serializers import AccessKeySerializer
        self.fields['access_key'] = AccessKeySerializer(read_only=True)

    def get_username(self):
        return self.initial_data.get('name')

    def get_email(self):
        name = self.initial_data.get('name')
        name_max_length = 128 - len(User.service_account_email_suffix)
        name = pretty_string(name, max_length=name_max_length, ellipsis_str='-')
        return '{}{}'.format(name, User.service_account_email_suffix)

    def validate_name(self, name):
        email = self.get_email()
        username = self.get_username()
        if self.instance:
            users = User.objects.exclude(id=self.instance.id)
        else:
            users = User.objects.all()
        if users.filter(email=email) or users.filter(username=username):
            raise serializers.ValidationError(_('name not unique'), code='unique')
        return name

    def create(self, validated_data):
        name = validated_data['name']
        email = self.get_email()
        comment = validated_data.get('comment', '')
        user, ak = User.create_service_account(name, email, comment)
        return user