# -*- coding: utf-8 -*-
#
from functools import partial

from django.utils.translation import ugettext_lazy as _
from rest_framework import serializers

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

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

logger = get_logger(__file__)


def default_system_roles():
    return [BuiltinRole.system_user.get_role()]


def default_org_roles():
    return [BuiltinRole.org_user.get_role()]


class RolesSerializerMixin(serializers.Serializer):
    system_roles = ObjectRelatedField(
        queryset=Role.system_roles, attrs=('id', 'display_name'),
        label=_("System roles"), many=True, default=default_system_roles
    )
    org_roles = ObjectRelatedField(
        queryset=Role.org_roles, attrs=('id', 'display_name'),
        label=_("Org roles"), many=True, required=False,
        default=default_org_roles
    )

    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"],
            OrgRoleBinding: ["org_roles"],
        }

        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 = LabeledChoiceField(
        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")
    )
    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.BooleanField(
        source="can_use_ssh_key_login", label=_("Can public key authentication"),
        read_only=True
    )
    password = EncryptedField(
        label=_("Password"),
        required=False,
        allow_blank=True,
        allow_null=True,
        max_length=1024,
    )
    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",
            "need_update_password", "mfa_enabled",
            "is_service_account", "is_valid",
            "is_expired", "is_active",  # 布尔字段
            "is_otp_secret_key_bound", "can_public_key_auth",
            "date_expired", "date_joined",
            "last_login",  # 日期字段
            "created_by", "comment",  # 通用字段
            "wecom_id", "dingtalk_id", "feishu_id",
        ]
        # 包含不太常用的字段，可以没有
        fields_verbose = fields_small + [
            "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", "system_roles", "org_roles", ]
        # 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},
            "role": {"default": "User"},
            "is_otp_secret_key_bound": {"label": _("Is OTP bound")},
            "phone": {"validators": [PhoneValidator()]},
        }

    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


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