"""Minimal haptic signal feature extractor."""


class MotokoHapticFeatureExtractor:
    def __init__(self, mean=None, std=None):
        self.mean = mean or [0.0] * 6
        self.std = std or [1.0] * 6

    def __call__(self, samples):
        return self.normalize(samples)

    def normalize(self, samples):
        return [
            [
                (value - self.mean[channel]) / self.std[channel]
                for channel, value in enumerate(frame)
            ]
            for frame in samples
        ]