import torch

from timm.utils.agc import adaptive_clip_grad


def dispatch_clip_grad(
        parameters,
        value: float,
        mode: str = 'norm',
        norm_type: float = 2.0):
    """ Dispatch to gradient clipping method

    Args:
        parameters (Iterable): model parameters to clip
        value (float): clipping value/factor/norm, mode dependant
        mode (str): clipping mode, one of 'norm', 'value', 'agc'
        norm_type (float): p-norm, default 2.0
    """
    if mode == 'norm':
        torch.nn.utils.clip_grad_norm_(parameters, value, norm_type=norm_type)
    elif mode == 'value':
        torch.nn.utils.clip_grad_value_(parameters, value)
    elif mode == 'agc':
        adaptive_clip_grad(parameters, value, norm_type=norm_type)
    else:
        assert False, f"Unknown clip mode ({mode})."