# *******************************************************************************
# Copyright (c) 2026 Ahmad Ali Parr and others.
#
# This program and the accompanying materials are made available under the
# terms of the CPSC Eclipse Strict Copyleft License, Version 1.0, which is
# available in LICENSES/CPSC-ESCL-1.0.txt, or, at your option, under the
# GNU Affero General Public License, Version 3 only, which is available in
# LICENSES/AGPL-3.0.txt. Both options are strict copyleft. There is no
# classpath exception and no permissive relicensing.
#
# SPDX-License-Identifier: LicenseRef-CPSC-ESCL-1.0 OR AGPL-3.0-only
# *******************************************************************************

import pytest

from cpsc.analyzer import CompilationRejected, SymmetryAnalyzer, rx_pair, x, zz


def test_forbidden_bit_flip_rejected_at_compile_time():
    analyzer = SymmetryAnalyzer(4)
    rejected = analyzer.check([zz(0, 1), x(2), zz(2, 3)])
    assert len(rejected) == 1
    assert rejected[0].gate.name == "X[2]"
    assert "parity" in rejected[0].reason


def test_legal_circuit_admitted():
    analyzer = SymmetryAnalyzer(4, conserve_magnetization=True)
    gates = analyzer.admit([zz(0, 1), zz(2, 3), rx_pair(1, 2)])
    assert len(gates) == 3


def test_admit_raises_on_adversarial_edit():
    analyzer = SymmetryAnalyzer(6)
    with pytest.raises(CompilationRejected):
        analyzer.admit([zz(0, 1), x(5)])