"""Test the generated storage readiness script in a private mount namespace.

Usage: sudo python3 scripts/media-storage-check.py <media-storage-ready-unit>
Uses temporary tmpfs mounts and NSS fixtures; host media and mount state are untouched.
"""

import os, re, subprocess as sp, sys, tempfile
from pathlib import Path

original = os.environ.get("FRED_TEST_ORIGINAL_MNTNS")
if not original:
    os.execvpe(
        "unshare",
        ["unshare", "-m", sys.executable, *sys.argv],
        {**os.environ, "FRED_TEST_ORIGINAL_MNTNS": os.readlink("/proc/self/ns/mnt")},
    )
assert original != os.readlink("/proc/self/ns/mnt")
sp.run(["mount", "--make-rprivate", "/"], check=True)
sp.run(["mount", "-t", "tmpfs", "tmpfs", "/mnt"], check=True)
for name in ["storage", "disk1", "disk2", "disk3"]:
    Path("/mnt", name).mkdir()
unit = (Path(sys.argv[1]) / "media-storage-ready.service").read_text()
script = re.search(r"^ExecStart=(\S+)", unit, re.M)[1]


def ready(expected):
    r = sp.run([script], capture_output=True, text=True)
    assert (r.returncode == 0) == expected, r.stderr
    print(r.stderr.strip() or "Readiness succeeded", flush=True)


ready(False)
assert list(Path("/mnt/storage").iterdir()) == []
for name in ["storage", "disk1", "disk2"]:
    sp.run(["mount", "-t", "tmpfs", "tmpfs", "/mnt/" + name], check=True)
ready(False)
assert list(Path("/mnt/storage").iterdir()) == []
# Isolated NSS fixtures let tmpfiles resolve the real configured names.
root = Path(tempfile.mkdtemp(prefix="fred-storage-users."))
(root / "passwd").write_text(
    "root:x:0:0:root:/root:/bin/sh\n"
    + "".join(
        f"{name}:x:0:0::{root}:/bin/sh\n"
        for name in ["fred", "qbittorrent", "sonarr", "radarr", "sabnzbd"]
    )
)
(root / "group").write_text("root:x:0:\nmedia:x:0:\n")
for name in ["passwd", "group"]:
    sp.run(["mount", "--bind", str(root / name), "/etc/" + name], check=True)
sp.run(["mount", "-t", "tmpfs", "tmpfs", "/mnt/disk3"], check=True)
ready(True)
assert Path("/mnt/storage/torrents/shows").is_dir()
sp.run(["umount", "/mnt/disk2"], check=True)
ready(False)
sp.run(["umount", "/mnt/storage"], check=True)
assert list(Path("/mnt/storage").iterdir()) == [], (
    "wrote into underlying root directory"
)
print(
    "Storage guard: missing pool/branch and lost branch refused; mounted pool prepared; underlying directory untouched"
)