# Copyright (c) ONNX Project Contributors
#
# SPDX-License-Identifier: Apache-2.0

import numpy as np

import onnx
from onnx.backend.test.case.base import Base
from onnx.backend.test.case.node import expect


class MelWeightMatrix(Base):
    @staticmethod
    def export() -> None:
        node = onnx.helper.make_node(
            "MelWeightMatrix",
            inputs=[
                "num_mel_bins",
                "dft_length",
                "sample_rate",
                "lower_edge_hertz",
                "upper_edge_hertz",
            ],
            outputs=["output"],
        )

        num_mel_bins = np.int32(8)
        dft_length = np.int32(16)
        sample_rate = np.int32(8192)
        lower_edge_hertz = np.float32(0)
        upper_edge_hertz = np.float32(8192 / 2)

        num_spectrogram_bins = dft_length // 2 + 1
        frequency_bins = np.arange(0, num_mel_bins + 2)

        low_frequency_mel = 2595 * np.log10(1 + lower_edge_hertz / 700)
        high_frequency_mel = 2595 * np.log10(1 + upper_edge_hertz / 700)
        mel_step = (high_frequency_mel - low_frequency_mel) / frequency_bins.shape[0]

        frequency_bins = frequency_bins * mel_step + low_frequency_mel
        frequency_bins = 700 * (np.power(10, (frequency_bins / 2595)) - 1)
        frequency_bins = ((dft_length + 1) * frequency_bins) // sample_rate
        frequency_bins = frequency_bins.astype(int)

        output = np.zeros((num_spectrogram_bins, num_mel_bins))
        output.flags.writeable = True

        for i in range(num_mel_bins):
            lower_frequency_value = frequency_bins[i]  # left
            center_frequency_point = frequency_bins[i + 1]  # center
            higher_frequency_point = frequency_bins[i + 2]  # right
            low_to_center = center_frequency_point - lower_frequency_value
            if low_to_center == 0:
                output[center_frequency_point, i] = 1
            else:
                for j in range(lower_frequency_value, center_frequency_point + 1):
                    output[j, i] = float(j - lower_frequency_value) / float(
                        low_to_center
                    )
            center_to_high = higher_frequency_point - center_frequency_point
            if center_to_high > 0:
                for j in range(center_frequency_point, higher_frequency_point):
                    output[j, i] = float(higher_frequency_point - j) / float(
                        center_to_high
                    )

        # Expected output
        # 1.000000, 1.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000,
        # 0.000000, 0.000000, 1.000000, 1.000000, 0.000000, 0.000000, 0.000000, 0.000000,
        # 0.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000,
        # 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000,
        # 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000,
        # 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 1.000000,
        # 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000,
        # 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000,
        # 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000, 0.000000,
        output = output.astype(np.float32)
        expect(
            node,
            inputs=[
                num_mel_bins,
                dft_length,
                sample_rate,
                lower_edge_hertz,
                upper_edge_hertz,
            ],
            outputs=[output],
            name="test_melweightmatrix",
        )