"""Regression tests for EXP-002: Shrinking electorate: serial expulsions manufacture a supermajority.

Simple-majority expulsions remove opposing voters one by one until a kernel amendment passes with only 55% support of the original roll.

Severity: critical | Capture objective: entrench_power | Found by detector: entrenchment

GENERATED by fable_selfplay.exploit_to_test. Do not edit by hand.
Regenerate with: fable-selfplay exploit-to-test --exploits exploits --out tests/regression
"""

from pathlib import Path

import pytest

from fable_selfplay import replay
from fable_selfplay.exploit_to_test import ExploitRecord

_ROOT = Path(__file__).resolve().parents[2]
RECORD_PATH = _ROOT / "exploits" / "EXP-002.json"
KERNEL_V02_PATH = _ROOT / "kernel" / "kernel-v0.2.yaml"


@pytest.fixture(scope="module")
def record() -> ExploitRecord:
    return ExploitRecord.from_path(RECORD_PATH)


def _run(record: ExploitRecord, params: dict) -> "replay.ReplayResult":
    return replay.run_trace(
        params,
        record.citizens,
        record.initial_treasury,
        record.action_trace,
    )


def test_exp_002_reproduces_under_discovery_kernel(record: ExploitRecord) -> None:
    """The exploit must still succeed under the kernel it was discovered against.

    If this fails, the archived record no longer reproduces and the exploit
    archive itself is corrupt; investigate before touching the kernel.
    """
    result = _run(record, record.kernel_params_at_discovery)
    assert replay.evaluate_predicate(record.success_predicate, result), (
        "EXP-002 no longer reproduces against its discovery kernel"
    )


def test_exp_002_blocked_under_kernel_v0_2(record: ExploitRecord) -> None:
    """The patched kernel must defeat the recorded exploit trace."""
    params = replay.load_kernel_params(KERNEL_V02_PATH)
    result = _run(record, params)
    assert not replay.evaluate_predicate(record.success_predicate, result), (
        "EXP-002 succeeds under kernel v0.2: regression"
    )


def test_exp_002_patched_invariants_hold(record: ExploitRecord) -> None:
    """Exploit-specific guarantees the patch is expected to provide."""
    params = replay.load_kernel_params(KERNEL_V02_PATH)
    result = _run(record, params)
    for assertion in record.patched_assertions:
        assert replay.evaluate_predicate(assertion, result), (
            f"patched invariant violated: {assertion}"
        )