"""Tests for the crypto-signed audit log."""

import unittest

from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey

from deltatrace.audit_log import AuditLog


class TestAuditLog(unittest.TestCase):
    def setUp(self):
        self.key = Ed25519PrivateKey.generate()
        self.log = AuditLog(self.key)

    def test_append_entry(self):
        entry = self.log.append("evt-1", "processed:md_tick", {"symbol": "AAPL"})
        self.assertEqual(entry.sequence, 0)
        self.assertEqual(entry.event_id, "evt-1")
        self.assertEqual(entry.action, "processed:md_tick")

    def test_chain_linkage(self):
        e1 = self.log.append("evt-1", "action1")
        e2 = self.log.append("evt-2", "action2")
        self.assertEqual(e2.prev_hash, e1.entry_hash)

    def test_verify_valid_chain(self):
        for i in range(5):
            self.log.append(f"evt-{i}", f"action-{i}")
        self.assertTrue(self.log.verify())

    def test_verify_with_public_key(self):
        self.log.append("evt-1", "action1")
        public_key = self.key.public_key()
        self.assertTrue(self.log.verify(public_key))

    def test_tampered_entry_fails_verify(self):
        self.log.append("evt-1", "action1")
        self.log.append("evt-2", "action2")
        # Tamper with an entry
        self.log._entries[0] = self.log._entries[0].__class__(
            sequence=0,
            timestamp_ns=self.log._entries[0].timestamp_ns,
            event_id="TAMPERED",
            action=self.log._entries[0].action,
            details=self.log._entries[0].details,
            prev_hash=self.log._entries[0].prev_hash,
            entry_hash=self.log._entries[0].entry_hash,
            signature=self.log._entries[0].signature,
        )
        self.assertFalse(self.log.verify())

    def test_to_dict(self):
        self.log.append("evt-1", "test")
        data = self.log.to_dict()
        self.assertEqual(len(data["entries"]), 1)
        self.assertIn("signature", data["entries"][0])


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