import os
import shutil
import subprocess

import pytest

# Let widget-level tests run headless; harmless for the non-GUI tests.
os.environ.setdefault("QT_QPA_PLATFORM", "offscreen")


@pytest.fixture(scope="session")
def qapp():
    """A Qt application so QObject/QTimer and real widgets work in tests.

    Prefers a GUI QApplication (offscreen) so widget tests are possible;
    QApplication is a QCoreApplication, so existing non-GUI tests are unaffected.
    Falls back to QCoreApplication if no GUI platform is available.
    """
    from PyQt6.QtCore import QCoreApplication
    inst = QCoreApplication.instance()
    if inst is not None:
        return inst
    try:
        from PyQt6.QtWidgets import QApplication
        return QApplication([])
    except Exception:
        return QCoreApplication([])


def _generate_audio(path, codec_args):
    """Generate a 1-second sine-wave audio file with ffmpeg."""
    if shutil.which("ffmpeg") is None:
        pytest.skip("ffmpeg not available to generate audio fixtures")
    result = subprocess.run(
        ["ffmpeg", "-y", "-f", "lavfi", "-i", "sine=frequency=440:duration=1",
         *codec_args, str(path)],
        capture_output=True,
    )
    if result.returncode != 0:
        pytest.skip(f"ffmpeg could not generate {path.suffix} fixture")
    return path


@pytest.fixture
def mp3_file(tmp_path):
    return _generate_audio(tmp_path / "test.mp3", ["-codec:a", "libmp3lame", "-b:a", "64k"])


@pytest.fixture
def m4a_file(tmp_path):
    return _generate_audio(tmp_path / "test.m4a", ["-codec:a", "aac", "-b:a", "64k"])


@pytest.fixture
def flac_file(tmp_path):
    return _generate_audio(tmp_path / "test.flac", ["-codec:a", "flac"])


@pytest.fixture
def jpeg_bytes(tmp_path):
    """A tiny valid JPEG for artwork tests."""
    if shutil.which("ffmpeg") is None:
        pytest.skip("ffmpeg not available to generate image fixture")
    path = tmp_path / "art.jpg"
    result = subprocess.run(
        ["ffmpeg", "-y", "-f", "lavfi", "-i", "color=red:size=8x8",
         "-frames:v", "1", str(path)],
        capture_output=True,
    )
    if result.returncode != 0:
        pytest.skip("ffmpeg could not generate jpeg fixture")
    return path.read_bytes()