# Copyright 1999-2021 Alibaba Group Holding Ltd.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import numpy as np

from ... import opcodes
from ...config import options
from ...core import OutputType
from .core import DataFrameReductionOperand, DataFrameReductionMixin


class DataFrameSum(DataFrameReductionOperand, DataFrameReductionMixin):
    _op_type_ = opcodes.SUM
    _func_name = "sum"

    @property
    def is_atomic(self):
        return self.min_count == 0

    @classmethod
    def get_reduction_callable(cls, op):
        from .aggregation import where_function

        skipna, min_count = op.skipna, op.min_count

        def sum_(value):
            if min_count == 0:
                return value.sum(skipna=skipna)
            else:
                return where_function(
                    value.count() >= min_count, value.sum(skipna=skipna), np.nan
                )

        return sum_


def sum_series(
    df, axis=None, skipna=True, level=None, min_count=0, combine_size=None, method=None
):
    use_inf_as_na = options.dataframe.mode.use_inf_as_na
    op = DataFrameSum(
        axis=axis,
        skipna=skipna,
        level=level,
        min_count=min_count,
        combine_size=combine_size,
        output_types=[OutputType.scalar],
        use_inf_as_na=use_inf_as_na,
        method=method,
    )
    return op(df)


def sum_dataframe(
    df,
    axis=None,
    skipna=True,
    level=None,
    min_count=0,
    numeric_only=None,
    combine_size=None,
    method=None,
):
    use_inf_as_na = options.dataframe.mode.use_inf_as_na
    op = DataFrameSum(
        axis=axis,
        skipna=skipna,
        level=level,
        min_count=min_count,
        numeric_only=numeric_only,
        combine_size=combine_size,
        output_types=[OutputType.series],
        use_inf_as_na=use_inf_as_na,
        method=method,
    )
    return op(df)
