import random

import numpy as np

from audiomentations.core.transforms_interface import BaseWaveformTransform


class AddGaussianNoise(BaseWaveformTransform):
    """Add gaussian noise to the samples"""

    supports_multichannel = True

    def __init__(self, min_amplitude=0.001, max_amplitude=0.015, p=0.5):
        """

        :param min_amplitude: Minimum noise amplification factor
        :param max_amplitude: Maximum noise amplification factor
        :param p:
        """
        super().__init__(p)
        assert min_amplitude > 0.0
        assert max_amplitude > 0.0
        assert max_amplitude >= min_amplitude
        self.min_amplitude = min_amplitude
        self.max_amplitude = max_amplitude

    def randomize_parameters(self, samples: np.ndarray, sample_rate: int):
        super().randomize_parameters(samples, sample_rate)
        if self.parameters["should_apply"]:
            self.parameters["amplitude"] = random.uniform(
                self.min_amplitude, self.max_amplitude
            )

    def apply(self, samples: np.ndarray, sample_rate: int):
        noise = np.random.randn(*samples.shape).astype(np.float32)
        samples = samples + self.parameters["amplitude"] * noise
        return samples
