import unittest
from feedtrust.policy import PolicyEngine


class TestPolicyEngine(unittest.TestCase):
    def test_basic_policy_compile_and_check(self):
        engine = PolicyEngine()
        dsl = (
            'allow subject="traderA" venue="venue1" signal="price" action="read" '
            'latency_ms=5 volume_cap=1000 regulatory="none"'
        )
        engine.load_policies(dsl)
        ok = engine.check_access(
            subject="traderA",
            venue="venue1",
            signal="price",
            action="read",
        )
        self.assertTrue(ok)

    def test_policy_denies_wrong_subject(self):
        engine = PolicyEngine()
        dsl = 'allow subject="traderA" venue="venue1" signal="price" action="read" latency_ms=5'
        engine.load_policies(dsl)
        ok = engine.check_access(subject="traderB", venue="venue1", signal="price", action="read")
        self.assertFalse(ok)


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