"""Tests for gRPC transport.

TDD approach: Test first, then implement.
"""

from unittest.mock import AsyncMock, Mock

import pytest

# Skip if grpc not installed
pytest.importorskip("grpc")

from agent_ros_bridge.gateway_v2.transports.grpc_transport import (
    GRPCClient,
    GRPCServicer,
    GRPCTransport,
)


class TestGRPCServicer:
    """Test gRPC servicer."""

    @pytest.fixture
    def mock_authenticator(self):
        auth = Mock()
        auth.verify_token = Mock(return_value={"sub": "user123"})
        return auth

    @pytest.fixture
    def mock_handler(self):
        return AsyncMock(return_value={"success": True, "data": {}})

    @pytest.fixture
    def servicer(self, mock_handler, mock_authenticator):
        return GRPCServicer(mock_handler, mock_authenticator)

    @pytest.mark.asyncio
    async def test_execute_command_success(self, servicer, mock_handler):
        """Test successful command execution."""
        # Given
        request = Mock()
        request.action = "move"
        request.parameters = {"direction": "forward"}

        context = Mock()
        context.invocation_metadata = Mock(return_value=[("authorization", "Bearer valid_token")])

        # When
        # response = await servicer.ExecuteCommand(request, context)

        # Then
        # assert response.success is True
        mock_handler.assert_called_once()

    @pytest.mark.asyncio
    async def test_execute_command_missing_auth(self, servicer):
        """Test command with missing authentication."""
        # Given
        request = Mock()
        context = Mock()
        context.invocation_metadata = Mock(return_value=[])

        # When
        # await servicer.ExecuteCommand(request, context)

        # Then
        context.set_code.assert_called()
        context.set_details.assert_called_with("Missing authentication token")

    @pytest.mark.asyncio
    async def test_execute_command_invalid_token(self, servicer, mock_authenticator):
        """Test command with invalid token."""
        # Given
        mock_authenticator.verify_token.side_effect = Exception("Invalid token")

        request = Mock()
        context = Mock()
        context.invocation_metadata = Mock(return_value=[("authorization", "Bearer invalid_token")])

        # When
        # await servicer.ExecuteCommand(request, context)

        # Then
        context.set_code.assert_called()


class TestGRPCTransport:
    """Test gRPC transport."""

    @pytest.fixture
    def transport(self):
        return GRPCTransport(
            {
                "host": "127.0.0.1",
                "port": 50052,  # Use different port for testing
                "max_workers": 2,
                "jwt_secret": "test-secret",
            }
        )

    @pytest.mark.asyncio
    async def test_transport_initialization(self, transport):
        """Test transport initialization."""
        assert transport.host == "127.0.0.1"
        assert transport.port == 50052
        assert transport.max_workers == 2
        assert transport.server is None

    @pytest.mark.asyncio
    async def test_start_stop(self, transport):
        """Test starting and stopping server."""
        # Given - transport not started
        assert transport.server is None

        # When - start server
        await transport.start()

        # Then - server should be running
        assert transport.server is not None

        # When - stop server
        await transport.stop()

        # Then - server should be stopped
        # Note: server object still exists but stopped

    @pytest.mark.asyncio
    async def test_handle_command(self, transport):
        """Test command handling."""
        # Given
        command = {"action": "move", "parameters": {"direction": "forward"}}

        # When
        result = await transport.handle_command(command)

        # Then
        assert result["success"] is True
        assert "data" in result


class TestGRPCClient:
    """Test gRPC client."""

    @pytest.fixture
    def client(self):
        return GRPCClient(host="localhost", port=50052, token="test-token")

    @pytest.mark.asyncio
    async def test_client_initialization(self, client):
        """Test client initialization."""
        assert client.host == "localhost"
        assert client.port == 50052
        assert client.token == "test-token"
        assert client.channel is None

    @pytest.mark.asyncio
    async def test_connect_disconnect(self, client):
        """Test connect and disconnect."""
        # Given - not connected
        assert client.channel is None

        # When - connect
        # Note: This would fail without actual server, so we mock
        # await client.connect()

        # Then - should be connected
        # assert client.channel is not None

        # When - disconnect
        # await client.disconnect()

        # Then - should be disconnected
        # assert client.channel is None
        pass  # Placeholder until server mocking implemented

    @pytest.mark.asyncio
    async def test_execute_command_not_connected(self, client):
        """Test command execution when not connected."""
        # Given - not connected
        assert client.channel is None

        # When/Then - should raise error
        with pytest.raises(RuntimeError, match="Not connected"):
            await client.execute_command("move", {})


class TestGRPCIntegration:
    """Integration tests for gRPC transport."""

    @pytest.mark.asyncio
    @pytest.mark.integration
    async def test_full_command_flow(self):
        """Test full command flow: client → server → handler → response."""
        # This would be a full integration test with actual server
        # Skipping for now as it requires protobuf generation
        pytest.skip("Requires protobuf generation")

    @pytest.mark.asyncio
    @pytest.mark.integration
    async def test_concurrent_connections(self):
        """Test handling multiple concurrent connections."""
        pytest.skip("Requires protobuf generation")

    @pytest.mark.asyncio
    @pytest.mark.integration
    async def test_large_message_handling(self):
        """Test handling large messages (e.g., camera images)."""
        pytest.skip("Requires protobuf generation")


# Performance tests
class TestGRPCPerformance:
    """Performance tests for gRPC transport."""

    @pytest.mark.benchmark
    @pytest.mark.asyncio
    async def test_command_latency(self):
        """Test command execution latency."""
        pytest.skip("Requires protobuf generation")

    @pytest.mark.benchmark
    @pytest.mark.asyncio
    async def test_throughput(self):
        """Test maximum throughput."""
        pytest.skip("Requires protobuf generation")
