import json
import decouple
import pyotp

from os.path import join

from helper import is_valid_otp
from config import etcd_client
from typing import Union


class Field:
    def __init__(self, _name, _type, _value=None):
        self.name = _name
        self.value = _value
        self.type = _type
        self.__errors = []

    def validation(self):
        return True

    def is_valid(self):
        if self.value == KeyError:
            self.add_error("'{}' field is a required field".format(self.name))
        else:
            try:
                _type = self.type.__args__
            except Exception:
                _type = self.type

            if not isinstance(self.value, _type):
                self.add_error("Incorrect Type for '{}' field".format(self.name))
            else:
                self.validation()

        if self.__errors:
            return False
        return True

    def get_errors(self):
        return self.__errors

    def add_error(self, error):
        self.__errors.append(error)


class BaseSchema:
    def __init__(self, data, fields=None):
        self.__errors = []
        if fields is None:
            self.fields = []
        else:
            self.fields = fields

    def validation(self):
        # custom validation is optional
        return True

    def is_valid(self):
        for field in self.fields:
            field.is_valid()
            self.add_field_errors(field)

        for parent in self.__class__.__bases__:
            try:
                parent.validation(self)
            except AttributeError:
                pass
        if not self.__errors:
            self.validation()

        if self.__errors:
            return False
        return True

    def get_errors(self):
        return {"message": self.__errors}

    def add_field_errors(self, field: Field):
        self.__errors += field.get_errors()

    def add_error(self, error):
        self.__errors.append(error)


class DataRequiredSchema(BaseSchema):
    def __init__(self, data, fields=None):
        if data is None:
            self.add_error("No Data is provided.")
            data = {}
        super().__init__(data, fields=fields)


class OTPSchema(DataRequiredSchema):
    def __init__(self, data: dict, fields=None):
        self.name = Field("name", str, data.get("name", KeyError))
        self.realm = Field("realm", str, data.get("realm", KeyError))
        self.token = Field("token", str, data.get("token", KeyError))

        self.auth_name = Field("auth_name", str, data.get("auth_name", KeyError))
        self.auth_realm = Field("auth_realm", str, data.get("auth_realm", KeyError))
        self.auth_token = Field("auth_token", str, data.get("auth_token", KeyError))
        self.auth_realm.validation = self.auth_realm_validation
        _fields = [
            self.name,
            self.realm,
            self.token,
            self.auth_name,
            self.auth_realm,
            self.auth_token,
        ]
        if fields:
            _fields += fields

        super().__init__(data=data, fields=_fields)

    def auth_realm_validation(self):
        if self.auth_realm.value != decouple.config("AUTH_REALM"):
            self.add_error(
                "Authentication realm must be {}".format(decouple.config("AUTH_REALM"))
            )

    def validation(self):
        if is_valid_otp(
            etcd_client,
            self.auth_name.value,
            self.auth_realm.value,
            self.auth_token.value,
        ):

            if is_valid_otp(
                etcd_client, self.name.value, self.realm.value, self.token.value
            ):
                _key = join(decouple.config("BASE_PREFIX"), self.name.value)
                entry = etcd_client.get(_key, value_in_json=True)
                if not entry:
                    self.add_error("No such Account Found")
            else:
                self.add_error("Invalid OTP Credentials")
        else:
            self.add_error("Invalid Auth Credentials")


class CreateOTPSchema(DataRequiredSchema):
    def __init__(self, data: dict, fields=None):
        self.name = Field("name", str, data.get("name", KeyError))
        self.realm = Field("realm", Union[str, list], data.get("realm", KeyError))

        self.admin_name = Field("admin_name", str, data.get("admin_name", KeyError))
        self.admin_realm = Field("admin_realm", str, data.get("admin_realm", KeyError))
        self.admin_token = Field("admin_token", str, data.get("admin_token", KeyError))

        self.admin_realm.validation = self.admin_realm_validation
        _fields = [
            self.name,
            self.realm,
            self.admin_name,
            self.admin_realm,
            self.admin_token,
        ]
        if fields:
            _fields += fields
        super().__init__(data=data, fields=_fields)

    def admin_realm_validation(self):
        if self.admin_realm.value != decouple.config("ADMIN_REALM"):
            self.add_error(
                "Admin must be from {} realm".format(decouple.config("ADMIN_REALM"))
            )

    def validation(self):
        if is_valid_otp(
            etcd_client,
            self.admin_name.value,
            self.admin_realm.value,
            self.admin_token.value,
        ):

            _key = join(decouple.config("BASE_PREFIX"), self.name.value)
            if etcd_client.get(_key):
                self.add_error("Account already exists")
        else:
            self.add_error("Invalid Admin OTP Credentials")


class DeleteOTPSchema(DataRequiredSchema):
    def __init__(self, data: dict, fields=None):
        self.name = Field("name", str, data.get("name", KeyError))

        self.admin_name = Field("admin_name", str, data.get("admin_name", KeyError))
        self.admin_realm = Field("admin_realm", str, data.get("admin_realm", KeyError))
        self.admin_token = Field("admin_token", str, data.get("admin_token", KeyError))

        self.admin_realm.validation = self.admin_realm_validation
        _fields = [self.name, self.admin_name, self.admin_realm, self.admin_token]
        if fields:
            _fields += fields
        super().__init__(data=data, fields=_fields)

    def admin_realm_validation(self):
        if self.admin_realm.value != decouple.config("ADMIN_REALM"):
            self.add_field_errors(
                "Admin must be from {} realm".format(decouple.config("ADMIN_REALM"))
            )

    def validation(self):
        if is_valid_otp(
            etcd_client,
            self.admin_name.value,
            self.admin_realm.value,
            self.admin_token.value,
        ):

            _key = join(decouple.config("BASE_PREFIX"), self.name.value)
            if not etcd_client.get(_key):
                self.add_error("Account does not exists")
        else:
            self.add_error("Invalid Admin OTP Credentials")


class ListAccountSchema(DataRequiredSchema):
    def __init__(self, data: dict, fields=None):
        data = data or {"": None}
        self.admin_name = Field("admin_name", str, data.get("admin_name", KeyError))
        self.admin_realm = Field("admin_realm", str, data.get("admin_realm", KeyError))
        self.admin_token = Field("admin_token", str, data.get("admin_token", KeyError))

        self.admin_realm.validation = self.admin_realm_validation
        _fields = [self.admin_name, self.admin_realm, self.admin_token]
        if fields:
            _fields += fields
        super().__init__(data=data, fields=_fields)

    def admin_realm_validation(self):
        if self.admin_realm.value != decouple.config("ADMIN_REALM"):
            self.add_field_errors(
                "Admin must be from {} realm".format(decouple.config("ADMIN_REALM"))
            )

    def validation(self):
        if not is_valid_otp(
            etcd_client,
            self.admin_name.value,
            self.admin_realm.value,
            self.admin_token.value,
        ):
            self.add_error("Invalid Admin OTP Credentials")