# --------------------------------------------------------
# Based on timm and MAE-priv code bases
# https://github.com/rwightman/pytorch-image-models/tree/master/timm
# https://github.com/BUPT-PRIV/MAE-priv
# --------------------------------------------------------
""" Eval metrics and related

Hacked together by / Copyright 2020 Ross Wightman
"""


class AverageMeter:
    """Computes and stores the average and current value"""

    def __init__(self):
        self.reset()

    def reset(self):
        self.val = 0
        self.avg = 0
        self.sum = 0
        self.count = 0

    def update(self, val, n=1):
        self.val = val
        self.sum += val * n
        self.count += n
        self.avg = self.sum / self.count


def accuracy(output, target, topk=(1,)):
    """Computes the accuracy over the k top predictions for the specified values of k"""
    maxk = min(max(topk), output.size()[1])
    batch_size = target.size(0)
    _, pred = output.topk(maxk, 1, True, True)
    pred = pred.t()
    correct = pred.eq(target.reshape(1, -1).expand_as(pred))
    return [correct[:min(k, maxk)].reshape(-1).float().sum(0) * 100. / batch_size for k in topk]


def cls_map(output, target):
    # batch_size = target.size(0)
    # idx_axes = torch.arange(batch_size)
    scores, preds = output.softmax(dim=-1).topk(1, 1, True, True)
    return scores, preds