# Copyright 2024 Bytedance Ltd. and/or its affiliates
#
# 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
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# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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"""
Critic config
"""

from dataclasses import dataclass, field
from typing import Optional

from ..actor.config import FSDPConfig, ModelConfig, OffloadConfig, OptimConfig


@dataclass
class CriticConfig:
    strategy: str = "fsdp"
    global_batch_size: int = 256
    """number of samples per minibatch for updating critic"""
    micro_batch_size_per_device_for_update: int = 4
    """number of samples per forward pass for updating critic"""
    micro_batch_size_per_device_for_experience: int = 16
    """number of samples per forward pass for computing values"""
    max_grad_norm: float = 1.0
    """number to clip grad norm"""
    cliprange_value: float = 0.5
    """clip range for value loss"""
    loss_avg_mode: str = "token"
    """loss average mode: `token`, `seq`"""
    ppo_epochs: int = 1
    """number of ppo epochs for each rollout batch"""
    padding_free: bool = False
    """use padding-free training"""
    dynamic_batching: bool = True
    """enable dynamic batching"""
    max_token_len_per_gpu: Optional[int] = None
    """max token length per GPU for dynamic batching. If None, use micro_batch_size * max_seq_len"""
    ulysses_size: int = 1
    """ulysses sequence parallel size"""
    model: ModelConfig = field(default_factory=ModelConfig)
    optim: OptimConfig = field(default_factory=OptimConfig)
    fsdp: FSDPConfig = field(default_factory=FSDPConfig)
    offload: OffloadConfig = field(default_factory=OffloadConfig)
    # below are auto keys
    global_batch_size_per_device: int = field(default=-1, init=False)