#!/usr/bin/env python3
"""Disposable regression for the ISO rootfs archive's traversable root."""

from pathlib import Path
import os
import subprocess
import tempfile
import unittest


BUILDER = Path(__file__).resolve().parents[2] / "image-recipe/_archived/build-auto-installer-iso.sh"


def archive_root(root: Path, archive: Path) -> None:
    subprocess.run(
        ["tar", "--numeric-owner", "-cf", str(archive), "-C", str(root), "."],
        check=True,
    )


def root_mode(archive: Path) -> str:
    listing = subprocess.run(
        ["tar", "-tvf", str(archive), "."],
        check=True, capture_output=True, text=True,
    ).stdout
    return listing.splitlines()[0].split()[0]


def production_guard(source: str) -> str:
    start = source.index('if [ "$(tar --occurrence=1 -tvf "$ROOTFS_TAR" . | awk')
    end = source.index("\nfi", start) + len("\nfi")
    return source[start:end]


class IsoRootModeTest(unittest.TestCase):
    def test_old_archive_is_rejected_and_corrected_archive_passes(self) -> None:
        source = BUILDER.read_text()
        guard = production_guard(source)
        with tempfile.TemporaryDirectory() as scratch:
            root = Path(scratch) / "root"
            root.mkdir(mode=0o700)
            archive = Path(scratch) / "rootfs.tar"
            archive_root(root, archive)
            self.assertEqual(root_mode(archive), "drwx------")
            invalid = subprocess.run(
                ["bash", "-eu", "-c", guard],
                env={**os.environ, "ROOTFS_TAR": str(archive)},
                capture_output=True, text=True,
            )
            self.assertNotEqual(invalid.returncode, 0)
            self.assertIn("must be mode 0755", invalid.stderr)

            root.chmod(0o755)
            archive_root(root, archive)
            self.assertEqual(root_mode(archive), "drwxr-xr-x")
            valid = subprocess.run(
                ["bash", "-eu", "-c", guard],
                env={**os.environ, "ROOTFS_TAR": str(archive)},
                capture_output=True, text=True,
            )
            self.assertEqual(valid.returncode, 0, valid.stderr)

    def test_guard_covers_cached_archive_and_installed_root(self) -> None:
        source = BUILDER.read_text()
        guard = production_guard(source)
        self.assertLess(source.index("Using cached root filesystem"), source.index(guard))
        self.assertLess(source.index(guard), source.index('if [ -n "$UAT_KERNEL" ]', source.index(guard)))
        self.assertLess(source.index('run tar -xf "$ROOTFS_TAR" -C /mnt/target'),
                        source.index('run chmod 755 /mnt/target'))
        self.assertLess(source.index('run chmod 755 /mnt/target'),
                        source.index('step "Encrypting data partition"'))

    def test_builder_shell_syntax(self) -> None:
        subprocess.run(["bash", "-n", str(BUILDER)], check=True)


if __name__ == "__main__":
    unittest.main()