# -*- coding: utf-8 -*-
# !/usr/bin/env python

import datetime
import decimal
import json
import logging
import re
import time
from collections import Callable
from copy import deepcopy
from decimal import Decimal
from functools import reduce

import inspect

import bson
import six
from bson import DBRef, ObjectId
from bson.decimal128 import Decimal128
from bson.regex import Regex
from django.http.request import QueryDict
from mongoengine import Q, Document, DynamicDocument, QuerySet, DecimalField, DictField, SequenceField, BooleanField
from mongoengine.base import BaseField
from mongoengine.common import _import_class
from typing import Union, TYPE_CHECKING

from apilib.monetary import RMB, VirtualCoin, Ratio, Percent, Money, Permillage, AccuracyRMB
from apilib.quantity import Quantity
from apilib.utils_string import md5
from apps.web.constant import Const
from apps.web.core.exceptions import ParameterError, ImproperlyConfigured

if TYPE_CHECKING:
    from pymongo.collection import Collection

logger = logging.getLogger(__name__)


def copy_document_classes(clazz, new_name, db_alias):
    exclude = ['_fields', '_db_field_map', '_reverse_db_field_map', '_fields_ordered', '_is_document',
               'MultipleObjectsReturned', '_superclasses', '_subclasses', '_types', '_class_name',
               '_meta', '__doc__', '__module__', '_collection', '_is_base_cls', '_auto_id_field', 'id',
               'DoesNotExist', 'objects', '_cached_reference_fields']

    new_cls_key = '{}_{}'.format(db_alias, clazz.__name__)

    if new_cls_key not in clazz.new_cls_list.keys():
        dicts = {}

        for name, field in clazz.__dict__.iteritems():
            if name in exclude:
                continue
            else:
                if isinstance(field, BaseField):
                    if field.unique:
                        field.unique = False

                    dicts[name] = field

        assert hasattr(clazz, '_origin_meta'), u'必须提供_origin_meta'

        dicts['meta'] = deepcopy(clazz._origin_meta)
        dicts['meta'].pop('indexes', None)
        dicts['meta']['index_background'] = True
        dicts['meta']['auto_create_index'] = False
        dicts['meta']['shard_key'] = clazz._shard_key

        dicts['__module__'] = clazz.__module__
        dicts['meta']['db_alias'] = db_alias

        new_cls = type(new_name, clazz.__bases__, dicts)

        for name, field in clazz.__dict__.iteritems():
            if name in exclude:
                continue
            else:
                field = getattr(clazz, name)
                if isinstance(field, BaseField):
                    continue
                else:
                    if inspect.ismethod(field):
                        if not field.im_self:
                            setattr(new_cls, name, field.im_func)
                        else:
                            setattr(new_cls, name, classmethod(field.im_func))
                    elif inspect.isfunction(field):
                        setattr(new_cls, name, staticmethod(field))
                    else:
                        setattr(new_cls, name, field)

        clazz.new_cls_list[new_cls_key] = new_cls
    else:
        pass

    return clazz.new_cls_list[new_cls_key]


# Customized fields
class MonetaryField(DecimalField):
    def __init__(self, min_value = None, max_value = None, force_string = False,
                 precision = 4, rounding = decimal.ROUND_HALF_UP, **kwargs):

        #: 默认精度四位，展示2-3位

        super(MonetaryField, self).__init__(min_value = min_value, max_value = max_value,
                                            force_string = force_string, precision = precision, rounding = rounding,
                                            **kwargs)

    def to_mongo(self, value):
        value = self.to_python(value)  # type: Union[RMB, VirtualCoin]
        return Decimal128(value.amount)

    def to_python(self, value, precision=3):
        if value is None:
            return value

        try:
            value = decimal.Decimal('%s' % value)
        except (TypeError, ValueError, decimal.InvalidOperation):
            return RMB(value)
        return RMB(
            value.quantize(decimal.Decimal('.%s' % ('0' * (precision or self.precision))), rounding = self.rounding))

    def validate(self, value):
        value = self.to_python(value)

        if self.min_value is not None and value < self.min_value:
            self.error('Monetary value is too small')

        if self.max_value is not None and value > self.max_value:
            self.error('Monetary value is too large')


class AccuracyMoneyField(MonetaryField):

    def to_mongo(self, value):
        value = self.to_python(value)  # type: Union[AccuracyRMB]
        return Decimal128(value.amount)

    def to_python(self, value, precision=5):
        if value is None:
            return value

        try:
            value = decimal.Decimal('%s' % value)
        except (TypeError, ValueError, decimal.InvalidOperation):
            return AccuracyRMB(value)
        return AccuracyRMB(value.quantize(decimal.Decimal('.%s' % ('0' * (precision or self.precision))), rounding=self.rounding))


class VirtualCoinField(MonetaryField):
    def to_python(self, value, precision = 2):
        if value is None:
            return value

        # Convert to string for python 2.6 before casting to Decimal
        try:
            value = decimal.Decimal('%s' % value)
        except (TypeError, ValueError, decimal.InvalidOperation):
            return VirtualCoin(value)
        return VirtualCoin(value.quantize(
            decimal.Decimal('.%s' % ('0' * (precision or self.precision))), rounding = self.rounding))


class RatioField(MonetaryField):
    def to_python(self, value, precision = 3):
        if value is None:
            return value

        # Convert to string for python 2.6 before casting to Decimal
        try:
            value = decimal.Decimal('%s' % value)
        except (TypeError, ValueError, decimal.InvalidOperation):
            return Ratio(value)
        return Ratio(
            value.quantize(decimal.Decimal('.%s' % ('0' * (precision or self.precision))), rounding = self.rounding))


class PercentField(MonetaryField):
    """
    百分之
    """
    def to_python(self, value, precision = 2):

        if value is None:
            return value

        # Convert to string for python 2.6 before casting to Decimal
        try:
            value = decimal.Decimal('%s' % value)
        except (TypeError, ValueError, decimal.InvalidOperation):
            return Percent(value)
        return Percent(
            value.quantize(decimal.Decimal('.%s' % ('0' * (precision or self.precision))), rounding = self.rounding))


class PermillageField(MonetaryField):
    """

    """
    def to_python(self, value, precision = 2):

        if value is None:
            return value

        # Convert to string for python 2.6 before casting to Decimal
        try:
            value = decimal.Decimal('%s' % value)
        except (TypeError, ValueError, decimal.InvalidOperation):
            return Permillage(value)
        return Permillage(
            value.quantize(decimal.Decimal('.%s' % ('0' * (precision or self.precision))), rounding = self.rounding))


class StrictDictField(DictField):
    def to_mongo(self, value, use_db_field = True, fields = None):
        # type:(dict, bool, list)->dict
        """
        重载ComplexField的to_mongo方法，主要支持转换Mongo不支持的类型
        :param value:
        :param use_db_field:
        :param fields:
        :return:
        """

        #: 常用系统内部Python类型和Mongo类型的映射表
        converter_map = {
            Decimal: lambda _: Decimal128(_),
            Percent: lambda _: _.mongo_amount,
            Money: lambda _: _.mongo_amount,
            Ratio: lambda _: _.mongo_amount,
            Quantity: lambda _: _.mongo_amount,
        }

        Document = _import_class('Document')
        EmbeddedDocument = _import_class('EmbeddedDocument')
        GenericReferenceField = _import_class('GenericReferenceField')

        if isinstance(value, six.string_types):
            return value

        if hasattr(value, 'to_mongo'):
            if isinstance(value, Document):
                return GenericReferenceField().to_mongo(value)
            cls = value.__class__
            val = value.to_mongo(use_db_field, fields)
            # If it's a document that is not inherited add _cls
            if isinstance(value, EmbeddedDocument):
                val['_cls'] = cls.__name__
            return val

        if not hasattr(value, 'items'):
            try:
                value = {k: v for k, v in enumerate(value)}
            except TypeError:  # Not iterable return the value
                return value

        if self.field:
            value_dict = {
                key: self.field._to_mongo_safe_call(item, use_db_field, fields)
                for key, item in value.iteritems()
            }
        else:
            value_dict = {}
            for k, v in value.iteritems():
                if isinstance(v, Document):
                    # We need the id from the saved object to create the DBRef
                    if v.pk is None:
                        self.error('You can only reference documents once they'
                                   ' have been saved to the database')

                    # If its a document that is not inheritable it won't have
                    # any _cls data so make it a generic reference allows
                    # us to dereference
                    meta = getattr(v, '_meta', {})
                    allow_inheritance = meta.get('allow_inheritance')
                    if not allow_inheritance and not self.field:
                        value_dict[k] = GenericReferenceField().to_mongo(v)
                    else:
                        collection = v._get_collection_name()
                        value_dict[k] = DBRef(collection, v.pk)
                elif hasattr(v, 'to_mongo'):
                    cls = v.__class__
                    val = v.to_mongo(use_db_field, fields)
                    # If it's a document that is not inherited add _cls
                    if isinstance(v, (Document, EmbeddedDocument)):
                        val['_cls'] = cls.__name__
                    value_dict[k] = val

                else:

                    for type_, func in converter_map.items():
                        if isinstance(v, type_):
                            value_dict[k] = converter_map[type_](v)
                            break
                        else:
                            value_dict[k] = self.to_mongo(v, use_db_field, fields)

        return value_dict


class CustomizedSequenceField(SequenceField):

    def prepare_query_value(self, op, value):
        """
        父类的返回的是 decorator_fn(value) (* fn : x = x + 10000 *), 但是实质我们存储的是已经decorated的value。这里直接返回存储的值
        :param op:
        :param value:
        :return:
        """
        return value

    def inverse_value_decorator(self, fn, value):
        # type: (Callable[int, int], int)->int
        offset = fn(value) - value
        return value - offset


class BooleanIntField(BooleanField):
    """
    使用Int存储boolean 方便前台传参
    """
    __interval = (0, 1)

    def to_python(self, value):
        try:
            value = int(bool(value))
        except ValueError:
            pass
        return value

    def to_mongo(self, value):
        if value in self.__interval:
            return value
        return int(value)

    def validate(self, value):
        if value not in [0, 1] and not isinstance(value, bool):
            self.error('BooleanIntField only accepts 0/1 or bool value')


def prepare_condition(condition):
    field = [condition['field'], condition['operator']]
    field = (s for s in field if s)
    field = '__'.join(field)
    return {field: condition['value']}


def prepare_conditions(row):
    return (Q(**prepare_condition(condition)) for condition in row)


def join_conditions(row):
    return reduce(lambda a, b: a | b, prepare_conditions(row))


def join_rows(rows):
    return reduce(lambda a, b: a & b, rows)


def dynamic_query(query_input): return join_rows(join_conditions(row) for row in query_input)


def search_query(fields, search_text):
    """
    组装搜索查询
    :param fields: 供搜索的字段
    :param search_text: 供搜索的键值
    :return:
    """
    pattern = Regex.from_native(re.compile('.*' + search_text + '.*', re.IGNORECASE))

    filter_dict = {"$or": [{field: {"$regex": pattern}} for field in fields if field != 'id']}

    if 'id' in fields:
        try:
            filter_dict['$or'].insert(0, {'_id': ObjectId(str(search_text))})
        except Exception as e:
            logger.error("[search_query] get an error = {}, fields = {}, search_text = {}".format(e, fields, search_text))
            pass

    return Q(__raw__ = filter_dict)


class CustomQuerySet(QuerySet):
    def paginate(self, pageIndex, pageSize):
        # type: (int, int)->CustomQuerySet
        front = (pageIndex - 1) if pageIndex >= 1 else 0
        return self.skip(front * pageSize).limit(pageSize)

    def search(self, search_key, fields = None):
        # type:(str, list)->CustomQuerySet
        """
        提供搜索接口，有优化空间，如数据量加大，考虑使用成熟的搜索引擎后端如`ElasticSearch`建立索引
        代码层面
        :param search_key:
        :param fields: 可选特定字段搜索
        :return:
        """
        if not search_key:
            return self

        if fields is None:
            fields = self._document.search_fields
            try:
                assert len(fields) >= 1
            except (AssertionError, TypeError):
                raise ImproperlyConfigured(
                    'in order to search, search_fields has to be defined(length > 1) or supplied, model = %r' % self._document
                )
        else:
            if not isinstance(fields, (tuple, list)):
                raise TypeError('parameter fields has to be a list')

        return self(search_query(fields = fields, search_text = search_key))

    def rev_by_time(self):
        """

        :return:
        """
        if self._document.time_field is not None:
            key = self._document.time_field
        elif Const.DEFAULT_TIME_FIELD_NAME in dir(self._document):
            key = Const.DEFAULT_TIME_FIELD_NAME
        else:
            raise ValueError('cannot call rev_by_time without time_field set on document class')
        return self().order_by('-{key}'.format(key = key))

    def head(self, default = None):
        """
        :return:
        """
        queryset = self.clone()
        try:
            result = queryset[0]
        except IndexError:
            if callable(default):
                result = default()
            else:
                result = default
        return result

    def sum_and_count(self, field):
        """Sum over the values of the specified field.
        # TODO zjl 使用 count_document 重写
        :param field: the field to sum over; use dot notation to refer to
            embedded document fields
        """

        db_field = self._fields_to_dbfields([field]).pop()
        pipeline = [
            {'$match': self._query},
            {'$group': {'_id': 'sum', 'count': {'$sum': 1}, 'total': {'$sum': '$' + db_field}}}
        ]

        # if we're performing a sum over a list field, we sum up all the
        # elements in the list, hence we need to $unwind the arrays first
        ListField = _import_class('ListField')
        field_parts = field.split('.')
        field_instances = self._document._lookup_field(field_parts)
        if isinstance(field_instances[-1], ListField):
            pipeline.insert(1, {'$unwind': '$' + field})

        result = self._document._get_collection().aggregate(pipeline)

        from mongoengine.python_support import IS_PYMONGO_3
        if IS_PYMONGO_3:
            result = tuple(result)
        else:
            result = result.get('result')

        if result:
            return int(result[0]['count']), result[0]['total']
        return 0, 0

    def _count_documents(self, with_limit_and_skip = False):
        if self._limit == 0 and with_limit_and_skip is False or self._none:
            return 0

        if with_limit_and_skip:
            kwargs = {}

            if self._limit:
                kwargs["limit"] = self._limit

            if self._skip:
                kwargs["skip"] = self._skip

            return self._collection.count_documents(filter = self._query, **kwargs)
        else:
            return self._collection.count_documents(filter = self._query)

    def count(self, with_limit_and_skip = False):
        if with_limit_and_skip is False:
            return self._count_documents(with_limit_and_skip)
        else:
            if self._len is None:
                self._len = self._count_documents(with_limit_and_skip)

            return self._len


class UtilMixin(object):

    def to_js_timestamp(self, datetime_):
        #: js 时间戳以毫秒计
        return time.mktime(datetime_.timetuple()) * 1000

    def to_datetime_str(self, datetime_):
        if not datetime_:
            return ''

        if isinstance(datetime_, datetime.datetime):
            return datetime_.strftime(Const.DATETIME_FMT)
        else:
            return str(datetime_)

    def to_date_str(self, datetime_):
        return datetime_.strftime(Const.DATE_FMT)


class BaseDocument(DynamicDocument, UtilMixin):
    meta = {
        'abstract': True,
        'queryset_class': CustomQuerySet,
        'index_background': True,
        'auto_create_index': False
    }

    time_field = None

    new_cls_list = {}

    def __repr__(self):
        return self.__str__()

    def __str__(self):
        return '{}<id={}>'.format(self.__class__.__name__, str(self.id))

    @classmethod
    def get_collection(cls):
        # type: ()->Collection
        return cls._get_collection()

    clt = get_collection

    @classmethod
    def agg(cls, pipeline, **kwargs):
        return cls.get_collection().aggregate(pipeline, **kwargs)

    @classmethod
    def last1(cls):
        return cls.objects().rev_by_time().first()

    @classmethod
    def first1(cls):
        return cls.objects().first()

    def to_dict(self):
        result = {}

        for field in self.__class__._fields_ordered:
            if field == 'id':
                value = str(getattr(self, field))
            else:
                value = getattr(self, field)

            if isinstance(value, datetime.datetime):
                value = value.strftime('%Y-%m-%d %H:%M:%S')

            result[field] = value

        return result


class Searchable(BaseDocument):
    search_fields = ()

    meta = {
        'abstract': True,
    }

    @classmethod
    def search(cls, search_key, fields = None):
        """
        搜索功能
        :param search_key:
        :param fields: 可选特定字段搜索
        :return:
        """
        return cls.objects.search(search_key, fields = fields)


class RoleBaseDocument(Searchable):
    meta = {
        'abstract': True,
    }

    @property
    def __role__(self):
        return self.__class__.__name__.lower()

    @property
    def role(self):
        role = getattr(self, '__role__', None)
        if role is None:
            raise ImproperlyConfigured('no __role__ attr provided')

        return role

    @property
    def logName(self):
        return '{}<id={}>'.format(self.__class__.__name__, str(self.id))

    @property
    def request_limit_key(self):
        return '{}_{}'.format(str(self.role), str(self.id))


def paginate(queryset, pageIndex, pageSize):
    """TODO 添加此方法至自定义的QuerySet"""
    if isinstance(queryset, list):
        return queryset[(pageIndex - 1) * pageSize: pageIndex * pageSize]
    return queryset.skip((pageIndex - 1) * pageSize).limit(pageSize)


class Query(object):

    def __init__(self, raw, attrs, pageIndex = 1, pageSize = 10, channel = 'unknown'):
        self.raw = raw
        self.attrs = attrs
        self.pageIndex = pageIndex
        self.pageSize = pageSize
        self.channel = channel

    def to_string(self):
        return '&'.join('%s=%s' % (k, v) for k, v in sorted(self.raw.iteritems()))

    @property
    def cache_key(self):
        return '%s:query:%s' % (self.channel, self.to_string(),)

    @property
    def hashed(self):
        return md5(self.to_string())

    @classmethod
    def from_query_dict(cls, queryDict, ignoreKeys = None):
        ignoreKeys = [] if ignoreKeys is None else ignoreKeys

        if isinstance(queryDict, QueryDict):
            unprocessedPayload = {k: v[0] for k, v in dict(queryDict).items() if v[0] and k not in ignoreKeys}

            processedPayload = unprocessedPayload.copy()

            pageIndex = int(processedPayload.pop('pageIndex', 1))
            pageSize = int(processedPayload.pop('pageSize', 10))

            todayDate = datetime.datetime.now().strftime(Const.DATE_FMT)

            startTime = datetime.datetime.strptime(str(processedPayload.pop('startTime', todayDate)) + ' 00:00:00',
                                                   Const.DATETIME_FMT)
            endTime = datetime.datetime.strptime(str(processedPayload.pop('endTime', todayDate)) + ' 23:59:59',
                                                 Const.DATETIME_FMT)

            processedPayload['dateTimeAdded__lte'] = endTime
            processedPayload['dateTimeAdded__gte'] = startTime

            return cls(raw = unprocessedPayload, attrs = processedPayload, pageIndex = pageIndex, pageSize = pageSize)


def prepare_query(queryDict, ignoreKeys = None): return Query.from_query_dict(queryDict, ignoreKeys)


def calc_doc_size(doc, unit = 'bytes'):
    # type: (Union[dict, Document], str)->int

    _unit_convert = {
        'bytes': lambda _: _,
        'kilobytes': lambda _: _ / 1024.,
        'megabytes': lambda _: _ / 1024. / 1024.
    }

    _calc = lambda _: _unit_convert[unit](len(bson.BSON.encode(_)))

    if isinstance(doc, dict):
        return _calc(doc)
    elif isinstance(doc, Document):
        return _calc(doc.to_mongo())

    else:
        raise ParameterError('only mongoengine Document or raw dicts are supported')


if __name__ == '__main__':
    #: test
    #: the snippet adapted from https://blog.sneawo.com/blog/2017/03/26/how-to-build-a-dynamic-query-with-mongoengine/
    query_input = [
        [
            {
                "field": "some_field",
                "operator": "gt",
                "value": 30
            },
            {
                "field": "some_field",
                "operator": "lt",
                "value": 40
            },
            {
                "field": "some_field",
                "operator": "",
                "value": 35
            }
        ],
        [
            {
                "field": "another_field",
                "operator": "istartswith",
                "value": "test"
            }
        ]
    ]

    print json.dumps(dynamic_query(query_input).to_query(None))