"""Tests for waveform peak extraction (no Essentia required)."""

import json

import numpy as np
import pytest

from worker.pipeline.waveform import extract_peaks, generate_waveform_file, peaks_to_json


def test_extract_peaks_returns_correct_length(sine_440hz):
    audio, sr = sine_440hz
    peaks = extract_peaks(audio, num_points=500)
    assert len(peaks) == 500


def test_extract_peaks_normalized_between_0_and_1(sine_440hz):
    audio, sr = sine_440hz
    peaks = extract_peaks(audio, num_points=200)
    assert all(0.0 <= p <= 1.0 for p in peaks)
    assert max(peaks) == pytest.approx(1.0, abs=0.01)


def test_extract_peaks_empty_audio():
    audio = np.array([], dtype=np.float32)
    peaks = extract_peaks(audio, num_points=100)
    assert len(peaks) == 100
    assert all(p == 0.0 for p in peaks)


def test_peaks_to_json_valid_structure(sine_440hz):
    audio, _ = sine_440hz
    peaks = extract_peaks(audio)
    json_str = peaks_to_json(peaks)
    data = json.loads(json_str)
    assert data["version"] == 2
    assert data["channels"] == 1
    assert len(data["data"]) == len(peaks)


@pytest.mark.asyncio
async def test_generate_waveform_file_writes_json(tmp_path, sine_440hz):
    audio, _ = sine_440hz
    output = str(tmp_path / "waveform.json")
    await generate_waveform_file(audio, output)
    with open(output) as f:
        data = json.load(f)
    assert data["version"] == 2
    assert len(data["data"]) == 1000