import math
import struct

import pytest

from hass.vad import VadConfig, VadSegmenter


def _sine_frame(sample_rate: int, freq_hz: float, frame_ms: int = 20) -> bytes:
    samples = int(sample_rate * frame_ms / 1000)
    values = [
        int(10000 * math.sin(2 * math.pi * freq_hz * i / sample_rate))
        for i in range(samples)
    ]
    return struct.pack("<" + "h" * samples, *values)


def _silence_frame(sample_rate: int, frame_ms: int = 20) -> bytes:
    samples = int(sample_rate * frame_ms / 1000)
    return b"\x00\x00" * samples


@pytest.mark.parametrize("min_silence_ms", [40, 60])
def test_vad_emits_utterance(min_silence_ms: int):
    config = VadConfig(
        aggressiveness=1,
        min_silence_ms=min_silence_ms,
        max_utterance_ms=2000,
        sample_rate=16000,
    )
    seg = VadSegmenter(config)

    utterances = []
    for _ in range(6):
        utterances.extend(seg.feed(_sine_frame(16000, 440.0)))
    for _ in range(6):
        utterances.extend(seg.feed(_silence_frame(16000)))

    assert len(utterances) >= 1
    assert len(utterances[0]) > 0