import numpy as np
import io
import pytest
import soundfile as sf
from app.services.audio_loader import load_audio_bytes, chunk_audio


def make_wav(duration=30.0, sr=22050) -> bytes:
    t = np.linspace(0, duration, int(sr * duration))
    y = (np.sin(2 * np.pi * 440 * t) * 0.5).astype(np.float32)
    buf = io.BytesIO()
    sf.write(buf, y, sr, format="WAV")
    return buf.getvalue()


def test_load_shape():
    y, sr, duration = load_audio_bytes(make_wav(10.0))
    assert sr == 22050
    assert abs(duration - 10.0) < 0.1
    assert y.ndim == 1


def test_chunk_count_60s():
    sr = 22050
    chunks = chunk_audio(np.zeros(sr * 60), sr, chunk_duration=10.0, overlap=0.5)
    assert len(chunks) == 11  # (60-10)/5 + 1


def test_chunk_keys():
    sr = 22050
    for c in chunk_audio(np.zeros(sr * 30), sr, chunk_duration=10.0, overlap=0.5):
        assert {"y", "start", "end"} == set(c.keys())
        assert c["end"] > c["start"]


def test_chunk_timing():
    sr = 22050
    chunks = chunk_audio(np.zeros(sr * 30), sr, chunk_duration=10.0, overlap=0.5)
    assert chunks[0]["start"] == 0.0
    assert abs(chunks[0]["end"] - 10.0) < 0.01
    assert abs(chunks[1]["start"] - 5.0) < 0.01


def test_chunk_shorter_than_window():
    sr = 22050
    chunks = chunk_audio(np.zeros(sr * 5), sr, chunk_duration=10.0, overlap=0.5)
    assert len(chunks) == 1
    assert chunks[0]["start"] == 0.0
    assert abs(chunks[0]["end"] - 5.0) < 0.01