"""CLI entrypoint tests: `python app.py --cli <file> --output <dir>`.

Run as a real subprocess (not in-process) so argparse, exit codes and
stdout behavior are tested exactly as a user would invoke them.
"""
import os
import sys
import zipfile
import subprocess
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]
FIXTURE_EBOOK = ROOT / "test_book.epub"


def _run_cli(*args):
    env = dict(os.environ)
    return subprocess.run(
        [sys.executable, str(ROOT / "app.py"), *args],
        capture_output=True,
        text=True,
        timeout=120,
        env=env,
        cwd=str(ROOT),
    )


def test_cli_convert_success(tmp_path):
    out_dir = tmp_path / "out"
    proc = _run_cli("--cli", str(FIXTURE_EBOOK), "--output", str(out_dir))
    assert proc.returncode == 0, proc.stderr
    assert "Saved:" in proc.stdout
    pdfs = list(out_dir.glob("*.pdf"))
    assert len(pdfs) == 1
    assert pdfs[0].stat().st_size > 1024
    assert pdfs[0].read_bytes()[:4] == b"%PDF"


def test_cli_missing_file_exits_2(tmp_path):
    proc = _run_cli("--cli", str(tmp_path / "nope.epub"), "--output", str(tmp_path))
    assert proc.returncode == 2
    assert "not found" in proc.stdout


def test_cli_corrupt_epub_exits_1(tmp_path):
    bad = tmp_path / "bad.epub"
    bad.write_bytes(b"not a zip")
    proc = _run_cli("--cli", str(bad), "--output", str(tmp_path))
    assert proc.returncode == 1
    assert "error:" in proc.stdout