# coding=utf-8
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# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
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#     http://www.apache.org/licenses/LICENSE-2.0
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from dataclasses import dataclass, field
from pathlib import Path
from typing import Optional, Union

from optimum.utils import logging

from .generation import GaudiGenerationConfig
from .training_args import GaudiTrainingArguments


logger = logging.get_logger(__name__)


@dataclass
class GaudiSeq2SeqTrainingArguments(GaudiTrainingArguments):
    """
    GaudiSeq2SeqTrainingArguments is built on top of the Tranformers' [Seq2SeqTrainingArguments](https://huggingface.co/docs/transformers/main_classes/trainer#transformers.Seq2SeqTrainingArguments)
    to enable deployment on Habana's Gaudi.

    Args:
        sortish_sampler (`bool`, *optional*, defaults to `False`):
            Whether to use a *sortish sampler* or not. Only possible if the underlying datasets are *Seq2SeqDataset*
            for now but will become generally available in the near future.
            It sorts the inputs according to lengths in order to minimize the padding size, with a bit of randomness
            for the training set.
        predict_with_generate (`bool`, *optional*, defaults to `False`):
            Whether to use generate to calculate generative metrics (ROUGE, BLEU).
        generation_max_length (`int`, *optional*):
            The `max_length` to use on each evaluation loop when `predict_with_generate=True`. Will default to the
            `max_length` value of the model configuration.
        generation_num_beams (`int`, *optional*):
            The `num_beams` to use on each evaluation loop when `predict_with_generate=True`. Will default to the
            `num_beams` value of the model configuration.
        generation_config (`str` or `Path` or [`transformers.generation.GenerationConfig`], *optional*):
            Allows to load a [`transformers.generation.GenerationConfig`] from the `from_pretrained` method. This can be either:

            - a string, the *model id* of a pretrained model configuration hosted inside a model repo on
              huggingface.co. Valid model ids can be located at the root-level, like `bert-base-uncased`, or namespaced
              under a user or organization name, like `dbmdz/bert-base-german-cased`.
            - a path to a *directory* containing a configuration file saved using the
              [`transformers.GenerationConfig.save_pretrained`] method, e.g., `./my_model_directory/`.
            - a [`transformers.generation.GenerationConfig`] object.
    """

    sortish_sampler: bool = field(default=False, metadata={"help": "Whether to use SortishSampler or not."})
    predict_with_generate: bool = field(
        default=False, metadata={"help": "Whether to use generate to calculate generative metrics (ROUGE, BLEU)."}
    )
    generation_max_length: Optional[int] = field(
        default=None,
        metadata={
            "help": (
                "The `max_length` to use on each evaluation loop when `predict_with_generate=True`. Will default "
                "to the `max_length` value of the model configuration."
            )
        },
    )
    generation_num_beams: Optional[int] = field(
        default=None,
        metadata={
            "help": (
                "The `num_beams` to use on each evaluation loop when `predict_with_generate=True`. Will default "
                "to the `num_beams` value of the model configuration."
            )
        },
    )
    generation_config: Optional[Union[str, Path, GaudiGenerationConfig]] = field(
        default=None,
        metadata={
            "help": "Model id, file path or url pointing to a GenerationConfig json file, to use during prediction."
        },
    )

    def to_dict(self):
        """
        Serializes this instance while replace `Enum` by their values and `GaudiGenerationConfig` by dictionaries (for JSON
        serialization support). It obfuscates the token values by removing their value.
        """
        # filter out fields that are defined as field(init=False)
        d = super().to_dict()
        for k, v in d.items():
            if isinstance(v, GaudiGenerationConfig):
                d[k] = v.to_dict()
        return d
