import socket
import json
import logging
from dataclasses import dataclass
from typing import Dict, Any
from config import config
# Configure logging using settings from config
logging.basicConfig(
level=getattr(logging, config.log_level),
format=config.log_format
)
logger = logging.getLogger("UnityMCP")
@dataclass
class UnityConnection:
"""Manages the socket connection to the Unity Editor."""
host: str = config.unity_host
port: int = config.unity_port
sock: socket.socket = None # Socket for Unity communication
def connect(self) -> bool:
"""Establish a connection to the Unity Editor."""
if self.sock:
return True
try:
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.sock.connect((self.host, self.port))
logger.info(f"Connected to Unity at {self.host}:{self.port}")
return True
except Exception as e:
logger.error(f"Failed to connect to Unity: {str(e)}")
self.sock = None
return False
def disconnect(self):
"""Close the connection to the Unity Editor."""
if self.sock:
try:
self.sock.close()
except Exception as e:
logger.error(f"Error disconnecting from Unity: {str(e)}")
finally:
self.sock = None
def receive_full_response(self, sock, buffer_size=config.buffer_size) -> bytes:
"""Receive a complete response from Unity, handling chunked data."""
chunks = []
sock.settimeout(config.connection_timeout) # Use timeout from config
try:
while True:
chunk = sock.recv(buffer_size)
if not chunk:
if not chunks:
raise Exception("Connection closed before receiving data")
break
chunks.append(chunk)
# Process the data received so far
data = b''.join(chunks)
decoded_data = data.decode('utf-8')
# Check if we've received a complete response
try:
# Special case for ping-pong
if decoded_data.strip().startswith('{"status":"success","result":{"message":"pong"'):
logger.debug("Received ping response")
return data
# Handle escaped quotes in the content
if '"content":' in decoded_data:
# Find the content field and its value
content_start = decoded_data.find('"content":') + 9
content_end = decoded_data.rfind('"', content_start)
if content_end > content_start:
# Replace escaped quotes in content with regular quotes
content = decoded_data[content_start:content_end]
content = content.replace('\\"', '"')
decoded_data = decoded_data[:content_start] + content + decoded_data[content_end:]
# Validate JSON format
json.loads(decoded_data)
# If we get here, we have valid JSON
logger.info(f"Received complete response ({len(data)} bytes)")
return data
except json.JSONDecodeError:
# We haven't received a complete valid JSON response yet
continue
except Exception as e:
logger.warning(f"Error processing response chunk: {str(e)}")
# Continue reading more chunks as this might not be the complete response
continue
except socket.timeout:
logger.warning("Socket timeout during receive")
raise Exception("Timeout receiving Unity response")
except Exception as e:
logger.error(f"Error during receive: {str(e)}")
raise
def send_command(self, command_type: str, params: Dict[str, Any] = None) -> Dict[str, Any]:
"""Send a command to Unity and return its response."""
if not self.sock and not self.connect():
raise ConnectionError("Not connected to Unity")
# Special handling for ping command
if command_type == "ping":
try:
logger.debug("Sending ping to verify connection")
self.sock.sendall(b"ping")
response_data = self.receive_full_response(self.sock)
response = json.loads(response_data.decode('utf-8'))
if response.get("status") != "success":
logger.warning("Ping response was not successful")
self.sock = None
raise ConnectionError("Connection verification failed")
return {"message": "pong"}
except Exception as e:
logger.error(f"Ping error: {str(e)}")
self.sock = None
raise ConnectionError(f"Connection verification failed: {str(e)}")
# Normal command handling
command = {"type": command_type, "params": params or {}}
try:
logger.info(f"Sending command: {command_type} with params: {params}")
self.sock.sendall(json.dumps(command).encode('utf-8'))
response_data = self.receive_full_response(self.sock)
response = json.loads(response_data.decode('utf-8'))
if response.get("status") == "error":
error_message = response.get("error") or response.get("message", "Unknown Unity error")
logger.error(f"Unity error: {error_message}")
raise Exception(error_message)
return response.get("result", {})
except Exception as e:
logger.error(f"Communication error with Unity: {str(e)}")
self.sock = None
raise Exception(f"Failed to communicate with Unity: {str(e)}")
# Global Unity connection
_unity_connection = None
def get_unity_connection() -> UnityConnection:
"""Retrieve or establish a persistent Unity connection."""
global _unity_connection
if _unity_connection is not None:
try:
# Try to ping with a short timeout to verify connection
result = _unity_connection.send_command("ping")
# If we get here, the connection is still valid
logger.debug("Reusing existing Unity connection")
return _unity_connection
except Exception as e:
logger.warning(f"Existing connection failed: {str(e)}")
try:
_unity_connection.disconnect()
except:
pass
_unity_connection = None
# Create a new connection
logger.info("Creating new Unity connection")
_unity_connection = UnityConnection()
if not _unity_connection.connect():
_unity_connection = None
raise ConnectionError("Could not connect to Unity. Ensure the Unity Editor and MCP Bridge are running.")
try:
# Verify the new connection works
_unity_connection.send_command("ping")
logger.info("Successfully established new Unity connection")
return _unity_connection
except Exception as e:
logger.error(f"Could not verify new connection: {str(e)}")
try:
_unity_connection.disconnect()
except:
pass
_unity_connection = None
raise ConnectionError(f"Could not establish valid Unity connection: {str(e)}")
