################################################################################
#  Licensed to the Apache Software Foundation (ASF) under one
#  or more contributor license agreements.  See the NOTICE file
#  distributed with this work for additional information
#  regarding copyright ownership.  The ASF licenses this file
#  to you 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 pickle
from abc import ABC, abstractmethod
from typing import TypeVar, List, Tuple

from pemja import findClass

from pyflink.common import Row, RowKind, TypeInformation
from pyflink.common.typeinfo import (PickledBytesTypeInfo, PrimitiveArrayTypeInfo,
                                     BasicArrayTypeInfo, ObjectArrayTypeInfo, RowTypeInfo,
                                     TupleTypeInfo, MapTypeInfo, ListTypeInfo)
from pyflink.datastream import TimeWindow, CountWindow, GlobalWindow

IN = TypeVar('IN')
OUT = TypeVar('OUT')

# Java Window
JTimeWindow = findClass('org.apache.flink.table.runtime.operators.window.TimeWindow')
JCountWindow = findClass('org.apache.flink.table.runtime.operators.window.CountWindow')
JGlobalWindow = findClass('org.apache.flink.table.runtime.operators.window.GlobalWindow')


class DataConverter(ABC):

    @abstractmethod
    def to_internal(self, value) -> IN:
        pass

    @abstractmethod
    def to_external(self, value) -> OUT:
        pass

    def __eq__(self, other):
        return type(self) == type(other)


class IdentityDataConverter(DataConverter):
    def to_internal(self, value) -> IN:
        return value

    def to_external(self, value) -> OUT:
        return value


class PickleDataConverter(DataConverter):
    def to_internal(self, value) -> IN:
        if value is None:
            return None

        return pickle.loads(value)

    def to_external(self, value) -> OUT:
        if value is None:
            return None

        return pickle.dumps(value)


class FlattenRowDataConverter(DataConverter):
    def __init__(self, field_data_converters: List[DataConverter]):
        self._field_data_converters = field_data_converters

    def to_internal(self, value) -> IN:
        if value is None:
            return None

        return tuple([self._field_data_converters[i].to_internal(item)
                      for i, item in enumerate(value)])

    def to_external(self, value) -> OUT:
        if value is None:
            return None

        return tuple([self._field_data_converters[i].to_external(item)
                      for i, item in enumerate(value)])


class RowDataConverter(DataConverter):

    def __init__(self, field_data_converters: List[DataConverter], field_names: List[str]):
        self._field_data_converters = field_data_converters
        self._field_names = field_names

    def to_internal(self, value) -> IN:
        if value is None:
            return None

        row = Row()
        row._values = [self._field_data_converters[i].to_internal(item)
                       for i, item in enumerate(value[1])]
        row.set_field_names(self._field_names)
        row.set_row_kind(RowKind(value[0]))

        return row

    def to_external(self, value: Row) -> OUT:
        if value is None:
            return None

        values = value._values
        fields = tuple([self._field_data_converters[i].to_external(values[i])
                        for i in range(len(values))])
        return value.get_row_kind().value, fields


class TupleDataConverter(DataConverter):

    def __init__(self, field_data_converters: List[DataConverter]):
        self._field_data_converters = field_data_converters

    def to_internal(self, value) -> IN:
        if value is None:
            return None

        return tuple([self._field_data_converters[i].to_internal(item)
                      for i, item in enumerate(value)])

    def to_external(self, value: Tuple) -> OUT:
        if value is None:
            return None

        return tuple([self._field_data_converters[i].to_external(item)
                      for i, item in enumerate(value)])


class ListDataConverter(DataConverter):

    def __init__(self, field_converter: DataConverter):
        self._field_converter = field_converter

    def to_internal(self, value) -> IN:
        if value is None:
            return None

        return [self._field_converter.to_internal(item) for item in value]

    def to_external(self, value) -> OUT:
        if value is None:
            return None

        return [self._field_converter.to_external(item) for item in value]


class ArrayDataConverter(ListDataConverter):
    def __init__(self, field_converter: DataConverter):
        super(ArrayDataConverter, self).__init__(field_converter)

    def to_internal(self, value) -> IN:
        return tuple(super(ArrayDataConverter, self).to_internal(value))

    def to_external(self, value) -> OUT:
        return tuple(super(ArrayDataConverter, self).to_external(value))


class DictDataConverter(DataConverter):
    def __init__(self, key_converter: DataConverter, value_converter: DataConverter):
        self._key_converter = key_converter
        self._value_converter = value_converter

    def to_internal(self, value) -> IN:
        if value is None:
            return None

        return {self._key_converter.to_internal(k): self._value_converter.to_internal(v)
                for k, v in value.items()}

    def to_external(self, value) -> OUT:
        if value is None:
            return None

        return {self._key_converter.to_external(k): self._value_converter.to_external(v)
                for k, v in value.items()}


class TimeWindowConverter(DataConverter):
    def to_internal(self, value) -> TimeWindow:
        return TimeWindow(value.getStart(), value.getEnd())

    def to_external(self, value: TimeWindow) -> OUT:
        return JTimeWindow(value.start, value.end)


class CountWindowConverter(DataConverter):

    def to_internal(self, value) -> CountWindow:
        return CountWindow(value.getId())

    def to_external(self, value: CountWindow) -> OUT:
        return JCountWindow(value.id)


class GlobalWindowConverter(DataConverter):

    def to_internal(self, value) -> IN:
        return GlobalWindow()

    def to_external(self, value) -> OUT:
        return JGlobalWindow.get()


def from_type_info_proto(type_info):
    # for data stream type information.
    from pyflink.fn_execution import flink_fn_execution_pb2

    type_info_name = flink_fn_execution_pb2.TypeInfo

    type_name = type_info.type_name
    if type_name == type_info_name.PICKLED_BYTES:
        return PickleDataConverter()
    elif type_name == type_info_name.ROW:
        return RowDataConverter(
            [from_type_info_proto(f.field_type) for f in type_info.row_type_info.fields],
            [f.field_name for f in type_info.row_type_info.fields])
    elif type_name == type_info_name.TUPLE:
        return TupleDataConverter(
            [from_type_info_proto(field_type)
             for field_type in type_info.tuple_type_info.field_types])
    elif type_name in (type_info_name.BASIC_ARRAY,
                       type_info_name.OBJECT_ARRAY):
        return ArrayDataConverter(from_type_info_proto(type_info.collection_element_type))
    elif type_info == type_info_name.LIST:
        return ListDataConverter(from_type_info_proto(type_info.collection_element_type))
    elif type_name == type_info_name.MAP:
        return DictDataConverter(from_type_info_proto(type_info.map_type_info.key_type),
                                 from_type_info_proto(type_info.map_type_info.value_type))

    return IdentityDataConverter()


def from_schema_proto(schema, one_arg_optimized=False):
    field_converters = [from_field_type_proto(f.type) for f in schema.fields]
    if one_arg_optimized and len(field_converters) == 1:
        return field_converters[0]
    else:
        return FlattenRowDataConverter(field_converters)


def from_field_type_proto(field_type):
    from pyflink.fn_execution import flink_fn_execution_pb2

    schema_type_name = flink_fn_execution_pb2.Schema

    type_name = field_type.type_name
    if type_name == schema_type_name.ROW:
        return RowDataConverter(
            [from_field_type_proto(f.type) for f in field_type.row_schema.fields],
            [f.name for f in field_type.row_schema.fields])
    elif type_name == schema_type_name.BASIC_ARRAY:
        return ArrayDataConverter(from_field_type_proto(field_type.collection_element_type))
    elif type_name == schema_type_name.MAP:
        return DictDataConverter(from_field_type_proto(field_type.map_info.key_type),
                                 from_field_type_proto(field_type.map_info.value_type))

    return IdentityDataConverter()


def from_type_info(type_info: TypeInformation):
    if isinstance(type_info, (PickledBytesTypeInfo, RowTypeInfo, TupleTypeInfo)):
        return PickleDataConverter()
    elif isinstance(type_info, (PrimitiveArrayTypeInfo, BasicArrayTypeInfo, ObjectArrayTypeInfo)):
        return ArrayDataConverter(from_type_info(type_info._element_type))
    elif isinstance(type_info, ListTypeInfo):
        return ListDataConverter(from_type_info(type_info.elem_type))
    elif isinstance(type_info, MapTypeInfo):
        return DictDataConverter(from_type_info(type_info._key_type_info),
                                 from_type_info(type_info._value_type_info))

    return IdentityDataConverter()