# -*- coding: utf-8 -*-
# Copyright 2023 Ant Group CO., 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.

from abc import ABC
from enum import Enum
from typing import List, Dict, Any, Type, Sequence, Union

from knext import rest

from knext.common.restable import RESTable
from knext.common.runnable import Runnable, Other, Input, Output
from knext.common.schema_helper import SPGTypeHelper
from knext.operator.eval_result import EvalResult
from knext.operator.spg_record import SPGRecord


class OperatorTypeEnum(str, Enum):
    EntityLinkOp = "ENTITY_LINK"
    EntityFuseOp = "ENTITY_FUSE"
    PropertyNormalizeOp = "PROPERTY_NORMALIZE"
    KnowledgeExtractOp = "KNOWLEDGE_EXTRACT"


class BaseOp(ABC):
    """Base class for all user-defined operator functions.

    The execution logic of the operator needs to be implemented in the `eval` method.
    """

    """Operator name."""
    name: str
    """Operator description."""
    desc: str = ""
    """SPG type the operator bind to."""
    bind_to: Union[str, SPGTypeHelper] = None

    params: Dict[str, str] = None

    _registry = {}
    _local_path: str
    _type: str
    _version: int

    def __init__(self, params: Dict[str, str] = None):
        self.params = params

    def eval(self, *args):
        """Used to implement operator execution logic."""
        raise NotImplementedError(
            f"{self.__class__.__name__} need to implement `eval` method."
        )

    def _handle(self, *inputs) -> Dict[str, Any]:
        """Only available for Builder in OpenSPG to call through the pemja tool."""
        pre_input = self._pre_process(*inputs)
        output = self.eval(*pre_input)
        post_output = self._post_process(output)
        return post_output

    @staticmethod
    def _pre_process(*inputs):
        """Convert data structures in building job into structures in operator before `eval` method."""
        pass

    @staticmethod
    def _post_process(output: EvalResult) -> Dict[str, Any]:
        """Convert result structures in operator into structures in building job after `eval` method."""
        pass

    @classmethod
    def register(cls, name: str, local_path: str):
        """
        Register a class as subclass of BaseOp with name and local_path.
        After registration, the subclass object can be inspected by `BaseOp.by_name(op_name)`.
        """

        def add_subclass_to_registry(subclass: Type["BaseOp"]):
            subclass.name = name
            subclass._local_path = local_path
            subclass._type = OperatorTypeEnum[subclass.__base__.__name__]
            if name in cls._registry:
                raise ValueError(
                    f"Operator [{name}] conflict in {subclass._local_path} and {cls.by_name(name)._local_path}."
                )
            cls._registry[name] = subclass
            return subclass

        return add_subclass_to_registry

    @classmethod
    def by_name(cls, name: str):
        """Reflection from op name to subclass object of BaseOp."""
        if name in cls._registry:
            subclass = cls._registry[name]
            return subclass
        else:
            raise ValueError(f"{name} is not a registered name for {cls.__name__}. ")

    def to_rest(self):
        return rest.OperatorConfig(file_path=self._local_path,
                                   module_path="",
                                   class_name=self.name,
                                   method="_handle",
                                   params=self.params,
                                   )

    def from_rest(cls, node):
        pass