"""Tests for core-api T-3: alembic refuses to run without a named target.

`alembic/env.py` resolves `-x target=test` or `-x target=production`; no
target, or anything else, must exit non-zero before any engine is built —
not skip, not fall back to the production settings a bare `alembic current`
used to reach by accident. Both tests point the *production* settings
(`POSTGRES_*`) at an unreachable host: if the refusal ever started
connecting before checking the target, these would hang (and the
subprocess timeout below would fire) instead of returning quickly.
"""
import os
import subprocess

from tests.conftest import ALEMBIC_BIN, REPO_ROOT

UNREACHABLE_HOST = "10.255.255.1"  # non-routed; a real connection attempt would hang


def _run_with_unreachable_production(*args: str) -> subprocess.CompletedProcess:
    env = os.environ.copy()
    env["POSTGRES_HOST"] = UNREACHABLE_HOST
    env["POSTGRES_USER"] = "probe"
    env["POSTGRES_PASSWORD"] = "probe"
    env["POSTGRES_DATABASE"] = "probe"
    env.pop("TEST_DATABASE_URL", None)
    return subprocess.run(
        [str(ALEMBIC_BIN), *args],
        cwd=str(REPO_ROOT),
        env=env,
        capture_output=True,
        text=True,
        timeout=10,  # a real connection attempt to an unreachable host hangs well past this
    )


def test_no_target_refuses_before_connecting():
    result = _run_with_unreachable_production("current")
    assert result.returncode != 0
    combined = result.stdout + result.stderr
    assert "target=test" in combined
    assert "target=production" in combined


def test_nonsense_target_refuses_before_connecting():
    result = _run_with_unreachable_production("-x", "target=nonsense", "current")
    assert result.returncode != 0
    combined = result.stdout + result.stderr
    assert "target=test" in combined
    assert "target=production" in combined