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# Licensed under the Apache License, Version 2.0 (the "License");
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#     http://www.apache.org/licenses/LICENSE-2.0
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from dataclasses import dataclass
from typing import Any, Dict, Optional

from .sft_config import SFTConfig


@dataclass
class GKDConfig(SFTConfig):
    """
    Configuration class for GKDTrainer.

    Args:
        temperature (`float`, *optional*, defaults to `0.9`):
            Temperature for sampling. The higher the temperature, the more random the completions.
        lmbda (`float`, *optional*, defaults to `0.5`):
            Lambda parameter that controls the student data fraction (i.e., the proportion of on-policy
            student-generated outputs).
        beta (`float`, *optional*, defaults to `0.5`):
            Interpolation coefficient between `0.0` and `1.0` of the Generalized Jensen-Shannon Divergence loss. When
            beta is `0.0`, the loss is the KL divergence. When beta is `1.0`, the loss is the Inverse KL Divergence.
        max_new_tokens (`int`, *optional*, defaults to `128`):
            Maximum number of tokens to generate per completion.
        teacher_model_name_or_path (`Optional[str]`, *optional*, defaults to `None`):
            Model name or path of the teacher model. If `None`, the teacher model will be the same as the model
            being trained.
        teacher_model_init_kwargs (`Optional[Dict[str, Any]]`, *optional*, defaults to `None`):
            Keyword arguments to pass to `AutoModelForCausalLM.from_pretrained` when instantiating the teacher model
            from a string.
        disable_dropout (`bool`, *optional*, defaults to `True`):
            Whether or not to disable dropouts in `model`.
        seq_kd (`bool`, *optional*, defaults to `False`):
            Seq_kd parameter that controls whether to perform Sequence-Level KD (can be viewed as supervised FT
            on teacher-generated output).
    """

    temperature: float = 0.9
    lmbda: float = 0.5
    beta: float = 0.5
    max_new_tokens: int = 128
    teacher_model_name_or_path: Optional[str] = None
    teacher_model_init_kwargs: Optional[Dict[str, Any]] = None
    disable_dropout: bool = True
    seq_kd: bool = False

    def __post_init__(self):
        super().__post_init__()
        # check lmbda and beta are in the range [0, 1]
        if self.lmbda < 0.0 or self.lmbda > 1.0:
            raise ValueError("lmbda must be in the range [0.0, 1.0].")
        if self.beta < 0.0 or self.beta > 1.0:
            raise ValueError("beta must be in the range [0.0, 1.0].")