"""Test the resume-idempotency cluster: three extracted installer helpers.

Each fix targets a step that misbehaves on a resume re-run or with unexpected
system state:

- crontab_append_once: the log-cleanup cron line was appended unconditionally,
  so a resume re-run of essential_services stacked a duplicate line each time.
  The helper appends only when no existing line matches.
- zfs_scrub_timer_units: the scrub timer used `zpool list | head -1`, which
  picks an arbitrary pool when several exist and yields the malformed unit
  `zfs-scrub-weekly@.timer` when none do. The helper emits one unit per pool
  and nothing for no pools.
- enable_user_service: gamemode was enabled via `systemctl --user enable`,
  which the script itself documents fails at install time (no user bus). The
  helper creates the wants symlink directly, the pattern syncthing already uses.

Method: sed-extract each helper from the real `archsetup` and drive it with
plain stdin/args (the first two are pure) or a temp HOME (the third).

Run from repo root:
    python3 -m unittest tests.installer-steps.test_idempotency_cluster
"""

import os
import subprocess
import tempfile
import unittest

REPO_ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", ".."))
ARCHSETUP = os.path.join(REPO_ROOT, "archsetup")
ME = os.environ.get("USER") or __import__("getpass").getuser()


def extract(func):
    return (
        "source <(sed -n '/^{f}() {{/,/^}}/p' \"{a}\")".format(f=func, a=ARCHSETUP)
    )


def run(func, body, stdin=None):
    script = f"{extract(func)}\n{body}\n"
    return subprocess.run(
        ["bash", "-c", script], capture_output=True, text=True, timeout=10,
        input=stdin,
    )


class CrontabAppendOnce(unittest.TestCase):
    def call(self, existing, match, line):
        body = f'crontab_append_once {match!r} {line!r}'
        return run("crontab_append_once", body, stdin=existing).stdout

    def test_appends_when_absent(self):
        out = self.call("", "log-cleanup", "0 12 * * * run-cleanup")
        self.assertIn("0 12 * * * run-cleanup", out)

    def test_preserves_existing_and_appends(self):
        out = self.call("0 0 * * * other-job\n", "log-cleanup", "0 12 * * * cleanup")
        self.assertIn("other-job", out)
        self.assertIn("0 12 * * * cleanup", out)

    def test_does_not_duplicate_when_present(self):
        existing = "0 12 * * * $HOME/.local/bin/cron/log-cleanup\n"
        out = self.call(existing, "cron/log-cleanup", "0 12 * * * dup")
        self.assertNotIn("0 12 * * * dup", out)
        self.assertEqual(out.count("log-cleanup"), 1)


class ZfsScrubTimerUnits(unittest.TestCase):
    def units(self, pools_text):
        out = run("zfs_scrub_timer_units", "zfs_scrub_timer_units", stdin=pools_text).stdout
        return [ln for ln in out.splitlines() if ln]

    def test_single_pool(self):
        self.assertEqual(self.units("zroot\n"),
                         ["zfs-scrub-weekly@zroot.timer"])

    def test_no_pool_yields_no_unit(self):
        self.assertEqual(self.units(""), [])

    def test_multiple_pools_each_get_a_unit(self):
        self.assertEqual(
            self.units("zroot\ntank\n"),
            ["zfs-scrub-weekly@zroot.timer", "zfs-scrub-weekly@tank.timer"],
        )

    def test_blank_lines_are_skipped(self):
        self.assertEqual(self.units("zroot\n\n"),
                         ["zfs-scrub-weekly@zroot.timer"])


class EnableUserService(unittest.TestCase):
    def test_creates_wants_symlink_in_user_config(self):
        with tempfile.TemporaryDirectory() as home:
            body = (
                f'enable_user_service {ME!r} gamemoded.service '
                f'/usr/lib/systemd/user/gamemoded.service {home!r}\n'
                f'link="{home}/.config/systemd/user/default.target.wants/gamemoded.service"\n'
                f'[ -L "$link" ] && echo "LINK=yes" || echo "LINK=no"\n'
                f'echo "TARGET=$(readlink "$link")"'
            )
            out = run("enable_user_service", body).stdout
            self.assertIn("LINK=yes", out)
            self.assertIn("TARGET=/usr/lib/systemd/user/gamemoded.service", out)

    def test_idempotent_on_rerun(self):
        with tempfile.TemporaryDirectory() as home:
            svc = "/usr/lib/systemd/user/gamemoded.service"
            one = (
                f'enable_user_service {ME!r} gamemoded.service {svc!r} {home!r}\n'
                f'enable_user_service {ME!r} gamemoded.service {svc!r} {home!r}\n'
                f'echo "RC=$?"'
            )
            out = run("enable_user_service", one).stdout
            self.assertIn("RC=0", out)


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