"""Bounds/replay checks for untrusted cursor metadata before SDL allocation."""
import base64
import importlib.util
import hashlib
from pathlib import Path
import unittest
import tempfile

spec = importlib.util.spec_from_file_location(
    'native_cursor_client', Path(__file__).resolve().parents[2] /
    'terminal/native-cursor/client.py')
client = importlib.util.module_from_spec(spec)
spec.loader.exec_module(client)


class CursorProtocolTests(unittest.TestCase):
    def state(self):
        return dict(type='cursor', version=1, lease='c'*32, seq=2, ack=0, w=2, h=2,
                    hx=1, hy=1, x=100, y=100, sw=2560, sh=1440,
                    rgba=base64.b64encode(bytes([255]*16)).decode())

    def test_valid_and_hidden(self):
        for pixels in (bytes([255]*16), bytes(16)):
            s = self.state()
            s['rgba'] = base64.b64encode(pixels).decode()
            packet = client.validate(s, 'c'*32, [2560, 1440], 1)
            self.assertEqual(len(packet), 88)
            self.assertEqual(packet[64:80], pixels)

    def test_bad_metadata(self):
        for key, value in [('version', 2), ('version', True), ('ack', -1),
                           ('ack', 2**63), ('lease', 'd'*32), ('type', 'ready'),
                           ('seq', 1), ('seq', 2**63), ('w', 0), ('w', 129),
                           ('h', -1), ('hx', 2), ('hy', -1), ('x', -1),
                           ('y', 1440), ('sw', 1920), ('w', True),
                           ('seq', 2.0), ('rgba', '***'), ('rgba', 'AAAA')]:
            with self.subTest(key=key, value=value):
                state = self.state()
                state[key] = value
                with self.assertRaises(ValueError):
                    client.validate(state, 'c'*32, [2560, 1440], 1)

    def test_missing_field(self):
        state = self.state()
        del state['h']
        with self.assertRaises(ValueError):
            client.validate(state, 'c'*32, [2560, 1440], 1)

    def test_old_client_rejected_before_lease(self):
        with tempfile.TemporaryDirectory() as directory:
            binary = Path(directory) / 'client'
            binary.write_bytes(b'validated client')
            expected = hashlib.sha256(binary.read_bytes()).hexdigest()
            client.verify_client(binary, expected)
            binary.write_bytes(b'old client without cursor receiver')
            with self.assertRaises(ValueError):
                client.verify_client(binary, expected)
            with self.assertRaises(ValueError):
                client.verify_client(binary, None)


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