"""A real bootstrap reader pins its generation before GC can select victims."""
import json
import os
import subprocess
import sys


def test_bootstrap_lease_survives_selection_change(tmp_path, monkeypatch):
    from pm.environments import install_state_dir, runtime_facts_path, site_packages
    from hermes_cli.runtime_state import collect_generations

    repo = tmp_path / "repo"
    repo.mkdir()
    monkeypatch.setenv("HERMES_HOME", str(tmp_path / "home"))
    state = install_state_dir(repo)
    for name in ("first", "second", "unused"):
        venv = state / "environments" / name / "venv"
        venv.mkdir(parents=True)
        # pyvenv.cfg first: the layout keys its site-packages path off the recorded version.
        (venv / "pyvenv.cfg").write_text("version = 3.11")
        site_packages(venv).mkdir(parents=True)
        (venv.parent / ".lease-managed").touch()
    legacy = state / "environments" / "old-unleased"
    legacy.mkdir()

    def select(name):
        environment = state / "environments" / name / "venv"
        runtime_facts_path(repo).write_text(json.dumps({"packages": {"venv": {"environment": str(environment)}}}))
        return environment

    first = select("first")
    code = '''
import sys
from pathlib import Path
from pm.environments import activate_dependencies
activate_dependencies(Path(sys.argv[1]))
print("ready", flush=True)
sys.stdin.readline()
'''
    child = subprocess.Popen([sys.executable, "-c", code, str(repo)], env=dict(os.environ),
                             stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True)
    try:
        assert child.stdout.readline().strip() == "ready"
        select("second")
        collect_generations(repo, min_age_seconds=0)
        assert first.is_dir()
        assert not (state / "environments" / "unused").exists()
        assert legacy.is_dir()
    finally:
        child.communicate("done\n", timeout=15)
    assert child.returncode == 0
    collect_generations(repo, min_age_seconds=0)
    assert not first.exists()
    assert (state / "environments" / "second").is_dir()
    assert legacy.is_dir()