"""
# Copyright (c) 2024 PaddlePaddle Authors. All Rights Reserved.
#
# 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.
"""
from abc import ABC, abstractmethod
from typing import Dict, Union

import numpy as np
import paddle
from paddle import nn


class ModelRegistry:
    """
    Used to register and retrieve model classes.
    """
    _registry = {}

    @classmethod
    def register(cls, model_class):
        """register model class"""
        if issubclass(
                model_class,
                ModelForCasualLM) and model_class is not ModelForCasualLM:
            cls._registry[model_class.name()] = model_class
        return model_class

    @classmethod
    def get_class(cls, name):
        """get model class"""
        if name not in cls._registry:
            raise ValueError(f"Model '{name}' is not registered!")
        return cls._registry[name]


class ModelForCasualLM(nn.Layer, ABC):
    """
    Base class for LM
    """

    def __init__(self, configs):
        """
        Args:
            configs (dict): Configurations including parameters such as max_dec_len, min_dec_len, decode_strategy,
                vocab_size, use_topp_sampling, etc.
        """
        super(ModelForCasualLM, self).__init__()
        self.fd_config = configs

    @abstractmethod
    def set_state_dict(self, state_dict: Dict[str, Union[np.ndarray,
                                                         paddle.Tensor]]):
        """
        Load model parameters from a given state dictionary.

        Args:
            state_dict (dict[str, np.ndarray | paddle.Tensor]):
                A dictionary containing model parameters, where keys are parameter names
                and values are NumPy arrays or PaddlePaddle tensors.
        """
        raise NotImplementedError

    @abstractmethod
    def forward(
        self,
        input_ids=None,
        pos_emb=None,
        **model_kwargs,
    ):
        """
        Defines the forward pass of the model for generating text.

        Args:
            input_ids (Tensor, optional): The input token ids to the model.
            pos_emb (Tensor, optional): position Embeddings for model.
            **model_kwargs: Additional keyword arguments for the model.

        Returns:
            Tensor or list of Tensors: Generated tokens or decoded outputs.
        """
        raise NotImplementedError

    @abstractmethod
    def compute_logits(self, hidden_state, **logits_prosessor_kwargs):
        raise NotImplementedError

    @classmethod
    @abstractmethod
    def name(self):
        raise NotImplementedError
