import pytest
import asyncio
import struct
from openttd.protocol import OpenTTDProtocol, PacketGameType
from openttd.client import OpenTTDClient

class MockTransport:
    def __init__(self): self._closing = False
    def is_closing(self): return self._closing
    def close(self): self._closing = True
    def write(self, data): return len(data)

class MockProtocol:
    async def send_packet(self, data):
        raise Exception("Send failed")

@pytest.mark.asyncio
async def test_client_connect_exception(monkeypatch):
    # Coverage for client.py:51-53
    client = OpenTTDClient(host="127.0.0.1")
    async def mock_fail(*args, **kwargs):
        raise Exception("Async Failure")
    monkeypatch.setattr(asyncio.get_running_loop(), "create_connection", mock_fail)
    with pytest.raises(Exception, match="Async Failure"):
        await client.connect()

@pytest.mark.asyncio
async def test_client_quit_exception():
    # Coverage for client.py:76
    client = OpenTTDClient(host="127.0.0.1")
    client._transport = MockTransport()
    client._protocol = MockProtocol() # send_packet raises
    await client.quit() # Should hit the except: pass

@pytest.mark.asyncio
async def test_client_no_company_password():
    # Coverage for client.py:126-127
    client = OpenTTDClient(host="127.0.0.1")
    # _company_password is empty by default
    await client.receive_ServerNeedCompanyPassword(None, 0, "srv")
    # Should log error and return

@pytest.mark.asyncio
async def test_client_chat_no_callback():
    # Coverage for client.py:162
    client = OpenTTDClient(host="127.0.0.1")
    # on_chat is None
    await client.receive_ServerChat(None, 1, "Hello")

@pytest.mark.asyncio
async def test_protocol_receive_exception():
    # Coverage for protocol.py:74-75
    # Trigger exception in receive_packet loop
    class BadHandler:
        encryption_enabled = False
    proto = OpenTTDProtocol(BadHandler())
    # data too short for read_uint16
    res = proto.receive_packet(None, memoryview(b"\x01"))
    assert res == (PacketGameType.ServerUnused, {})

def test_protocol_welcome_parser():
    # Coverage for protocol.py:110-112
    data = memoryview(struct.pack("<I", 42))
    res = OpenTTDProtocol.receive_ServerWelcome(None, data)
    assert res == {"client_id": 42}