import pytest
from youtube import extract_youtube_id, InvalidYoutubeUrl


@pytest.mark.parametrize("url,expected", [
    ("https://www.youtube.com/watch?v=dQw4w9WgXcQ", "dQw4w9WgXcQ"),
    ("https://youtu.be/dQw4w9WgXcQ", "dQw4w9WgXcQ"),
    ("https://www.youtube.com/watch?v=dQw4w9WgXcQ&list=PL", "dQw4w9WgXcQ"),
    ("https://m.youtube.com/watch?v=dQw4w9WgXcQ", "dQw4w9WgXcQ"),
    ("https://www.youtube.com/shorts/dQw4w9WgXcQ", "dQw4w9WgXcQ"),
])
def test_extract_youtube_id_valid(url, expected):
    assert extract_youtube_id(url) == expected


@pytest.mark.parametrize("url", [
    "https://example.com/watch?v=dQw4w9WgXcQ",
    "not a url",
    "https://www.youtube.com/",
    "https://youtu.be/",
    "",
])
def test_extract_youtube_id_invalid(url):
    with pytest.raises(InvalidYoutubeUrl):
        extract_youtube_id(url)


from unittest.mock import MagicMock, patch
from pathlib import Path
from youtube import fetch_metadata, download_audio, YoutubeFetchError, VideoTooLong


@patch("youtube.yt_dlp.YoutubeDL")
def test_fetch_metadata_returns_normalized_dict(mock_ydl_cls):
    mock_ydl = MagicMock()
    mock_ydl_cls.return_value.__enter__.return_value = mock_ydl
    mock_ydl.extract_info.return_value = {
        "id": "dQw4w9WgXcQ",
        "title": "Rick Astley - Never Gonna Give You Up (Official Video)",
        "uploader": "Rick Astley",
        "artist": None,
        "duration": 213,
        "thumbnail": "https://i.ytimg.com/vi/dQw4w9WgXcQ/hqdefault.jpg",
    }
    meta = fetch_metadata("https://youtu.be/dQw4w9WgXcQ")
    assert meta["youtube_id"] == "dQw4w9WgXcQ"
    assert meta["artist"] == "Rick Astley"
    assert meta["title"] == "Never Gonna Give You Up (Official Video)"
    assert meta["duration_sec"] == 213
    assert meta["thumbnail_url"].startswith("https://i.ytimg.com/")


@patch("youtube.yt_dlp.YoutubeDL")
def test_fetch_metadata_raises_on_too_long(mock_ydl_cls):
    mock_ydl = MagicMock()
    mock_ydl_cls.return_value.__enter__.return_value = mock_ydl
    mock_ydl.extract_info.return_value = {
        "id": "abc12345678", "title": "x", "uploader": "x",
        "duration": 99999, "thumbnail": "",
    }
    with pytest.raises(VideoTooLong):
        fetch_metadata("https://youtu.be/abc12345678", max_duration_sec=600)


@patch("youtube.yt_dlp.YoutubeDL")
def test_fetch_metadata_raises_fetch_error(mock_ydl_cls):
    from yt_dlp.utils import DownloadError
    mock_ydl = MagicMock()
    mock_ydl_cls.return_value.__enter__.return_value = mock_ydl
    mock_ydl.extract_info.side_effect = DownloadError("Sign in to confirm you're not a bot")
    with pytest.raises(YoutubeFetchError):
        fetch_metadata("https://youtu.be/abc12345678")


@patch("youtube.yt_dlp.YoutubeDL")
def test_download_audio_writes_file(mock_ydl_cls, tmp_path):
    mock_ydl = MagicMock()
    mock_ydl_cls.return_value.__enter__.return_value = mock_ydl
    # Simulate yt-dlp writing the output file:
    def fake_download(urls):
        (tmp_path / "dQw4w9WgXcQ.m4a").write_bytes(b"fake audio")
    mock_ydl.download.side_effect = fake_download
    out = download_audio("https://youtu.be/dQw4w9WgXcQ", "dQw4w9WgXcQ", tmp_path)
    assert out.exists()
    assert out.suffix == ".m4a"