import logging
import config
import json
import math

from config import ldap_manager
from helper import resolve_product

etcd_client = config.etcd_client


class ValidationException(Exception):
    """Validation Error"""


class Field:
    def __init__(self, _name, _type, _value=None, validators=None, disable_validation=False):
        self.validation_disabled = disable_validation
        self.name = _name
        self.value = _value
        self.type = _type
        self.validators = validators or []

    def is_valid(self):
        if not self.validation_disabled:
            if not isinstance(self.value, self.type):
                try:
                    self.value = self.type(self.value)
                except Exception:
                    raise ValidationException("Incorrect Type for '{}' field".format(self.name))

            for validator in self.validators:
                validator()

    def __repr__(self):
        return self.name


class BaseSchema:
    def __init__(self):
        self.objects = {}

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

    def get_fields(self):
        return [getattr(self, field) for field in dir(self) if isinstance(getattr(self, field), Field)]

    def is_valid(self):
        for field in self.get_fields():
            field.is_valid()
        self.validation()

    def get_cleaned_values(self):
        field_kv_dict = {
            field.name: field.value
            for field in self.get_fields()
        }
        cleaned_values = field_kv_dict
        cleaned_values.update(self.objects)

        return cleaned_values

    def add_schema(self, schema, data, under_field_name=None):
        s = schema(data)
        s.is_valid()

        base = self
        if under_field_name:
            # Create a field in self
            setattr(self, under_field_name, Field(under_field_name, dict, _value={}, disable_validation=True))
            base = getattr(self, under_field_name)

        for field in s.get_fields():
            if under_field_name:
                getattr(base, 'value')[field.name] = field.value
            else:
                setattr(base, field.name, field)

        self.objects.update(s.objects)

    @staticmethod
    def get(dictionary: dict, key: str, return_default=False, default=None):
        if dictionary is None:
            raise ValidationException('No data provided at all.')
        try:
            value = dictionary[key]
        except KeyError:
            if return_default:
                return {'_value': default, 'disable_validation': True}
            raise ValidationException("Missing data for '{}' field.".format(key))
        else:
            return {'_value': value, 'disable_validation': False}


class AddProductSchema(BaseSchema):
    def __init__(self, data):
        super().__init__()
        self.add_schema(UserCredentialSchema, data)
        self.specs = Field('specs', dict, **self.get(data, 'specs'))
        self.update = Field('update', bool, **self.get(data, 'update', return_default=True, default=False))

    def validation(self):
        user = self.objects['user']
        user = json.loads(user.entry_to_json())
        uid, ou, *dc = user['dn'].replace('ou=', '').replace('dc=', '').replace('uid=', '').split(',')
        if ou != config.config['ldap']['internal_user_ou']:
            raise ValidationException('You do not have access to create product.')

        product = resolve_product(self.specs.value['usable-id'], etcd_client)
        if product:
            self.objects['product'] = product


class AddressSchema(BaseSchema):
    def __init__(self, data):
        super().__init__()
        self.line1 = Field('line1', str, **self.get(data, 'line1'))
        self.line2 = Field('line2', str, **self.get(data, 'line2', return_default=True))
        self.city = Field('city', str, **self.get(data, 'city'))
        self.country = Field('country', str, **self.get(data, 'country'))
        self.state = Field('state', str, **self.get(data, 'state', return_default=True))
        self.postal_code = Field('postal_code', str, **self.get(data, 'postal_code', return_default=True))


class UserRegisterPaymentSchema(BaseSchema):
    def __init__(self, data):
        super().__init__()

        self.add_schema(UserCredentialSchema, data)
        self.add_schema(AddressSchema, data, under_field_name='address')

        self.card_number = Field('card_number', str, **self.get(data, 'card_number'))
        self.cvc = Field('cvc', str, **self.get(data, 'cvc'))
        self.expiry_year = Field('expiry_year', int, **self.get(data, 'expiry_year'))
        self.expiry_month = Field('expiry_month', int, **self.get(data, 'expiry_month'))
        self.card_holder_name = Field('card_holder_name', str, **self.get(data, 'card_holder_name'))


class UserCredentialSchema(BaseSchema):
    def __init__(self, data):
        super().__init__()
        self.username = Field('username', str, **self.get(data, 'username'))
        self.password = Field('password', str, **self.get(data, 'password'))

    def validation(self):
        try:
            entry = ldap_manager.is_password_valid(self.username.value, self.password.value, query_key='uid')
        except ValueError:
            raise ValidationException('No user with \'{}\' username found. You can create account at '
                                      'https://account.ungleich.ch'.format(self.username.value))
        except Exception:
            raise ValidationException('Invalid username/password.')
        else:
            self.objects['user'] = entry


class ProductOrderSchema(BaseSchema):
    def __init__(self, data):
        super().__init__()
        self.product_id = Field(
            'product_id', str, **self.get(data, 'product_id'), validators=[self.product_id_validation]
        )
        self.pay_consent = Field('pay', bool, **self.get(data, 'pay', return_default=True, default=False))
        self.add_schema(UserCredentialSchema, data)

    def product_id_validation(self):
        product = resolve_product(self.product_id.value, etcd_client)
        if product:
            self.product_id.value = product['uuid']
            self.objects['product'] = product
            logging.debug('Got product {}'.format(product))

            if not product['active']:
                raise ValidationException('Product is not active at the moment.')

            if product['quantity'] <= 0:
                raise ValidationException('Out of stock.')
        else:
            raise ValidationException('No such product exists.')

    def validation(self):
        customer_previous_orders = etcd_client.get_prefix('/v1/user/{}'.format(self.username.value), value_in_json=True)
        customer_previous_orders = [o.value for o in customer_previous_orders]
        membership = next(filter(lambda o: o['product'] == 'membership', customer_previous_orders), None)
        if membership is None and self.objects['product']['usable-id'] != 'membership':
            raise ValidationException('Please buy membership first to use this facility')
        max_quantity_user_can_order = float(self.objects['product'].get('max_per_user', math.inf))
        previous_order_of_same_product = [
            o for o in customer_previous_orders if o['product'] == self.objects['product']['usable-id']
        ]
        if len(previous_order_of_same_product) >= max_quantity_user_can_order:
            raise ValidationException(
                'You cannot buy {} more than {} times'.format(
                    self.objects['product']['name'], int(max_quantity_user_can_order)
                )
            )


class OrderListSchema(BaseSchema):
    def __init__(self, data):
        super().__init__()
        self.add_schema(UserCredentialSchema, data)


def make_return_message(err, status_code=200):
    logging.debug('message: {}'.format(str(err)))
    return {'message': str(err)}, status_code


def create_schema(specification, data):
    fields = {}
    for feature_name, feature_detail in specification['features'].items():
        if not feature_detail['constant']:
            fields[feature_name] = Field(
                feature_name, eval(feature_detail['unit']['type']), **BaseSchema.get(data, feature_name)
            )

    return type('{}Schema'.format(specification['name']), (BaseSchema,), fields)