from __future__ import annotations

from pathlib import Path

import pytest

from yt_shorts_downloader import api
from yt_shorts_downloader.exceptions import InvalidSessionError, InvalidUrlError
from yt_shorts_downloader.models import DownloadedVideo, SessionValidation


def _build_valid_session_validation(path: Path) -> SessionValidation:
    return SessionValidation(True, True, True, True, str(path))


def test_download_returns_binary_mp4(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
    expected_content = b'mp4-binary-content'

    def fake_validate_session_file(path: Path) -> SessionValidation:
        return _build_valid_session_validation(path)

    def fake_download_video(*, url: str, output_dir: Path, session_path: Path) -> Path:
        del url, session_path
        downloaded_file = output_dir / 'video.mp4'
        downloaded_file.write_bytes(expected_content)
        return downloaded_file

    monkeypatch.setattr(api, 'validate_session_file', fake_validate_session_file)
    monkeypatch.setattr(api, 'download_video', fake_download_video)

    downloaded_video = api.download(
        'https://youtube.com/shorts/example',
        session_path='cookies.txt',
    )

    assert downloaded_video == DownloadedVideo(
        filename='video.mp4',
        content=expected_content,
    )


def test_download_to_path_returns_path_from_downloader(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
    expected_path = tmp_path / 'video.mp4'

    def fake_validate_session_file(path: Path) -> SessionValidation:
        return _build_valid_session_validation(path)

    def fake_download_video(*, url: str, output_dir: Path, session_path: Path) -> Path:
        del url, session_path
        expected_path.write_bytes(b'mp4')
        return output_dir / expected_path.name

    monkeypatch.setattr(api, 'validate_session_file', fake_validate_session_file)
    monkeypatch.setattr(api, 'download_video', fake_download_video)

    downloaded_path = api.download_to_path(
        'https://youtube.com/shorts/example',
        session_path='cookies.txt',
        output_dir=tmp_path,
    )

    assert downloaded_path == expected_path


def test_download_rejects_invalid_url() -> None:
    with pytest.raises(InvalidUrlError):
        api.download('https://example.com/watch?v=1', session_path='cookies.txt')


def test_download_rejects_invalid_session(monkeypatch: pytest.MonkeyPatch) -> None:
    def fake_validate_session_file(path: Path) -> SessionValidation:
        del path
        return SessionValidation(False, False, False, False, 'bad session')

    monkeypatch.setattr(api, 'validate_session_file', fake_validate_session_file)

    with pytest.raises(InvalidSessionError, match='bad session'):
        api.download('https://youtube.com/shorts/example', session_path='cookies.txt')