implement guided auth flow for both chat based and server callback flows

core/server.py

@@ -1,10 +1,70 @@
-from mcp import FastMCP
+import logging
+import os
+from fastmcp import FastMCP
+from google.auth.exceptions import RefreshError
+from auth.google_auth import handle_auth_callback
+
+# Configure logging
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+# Required OAuth scopes
+SCOPES = [
+    'https://www.googleapis.com/auth/userinfo.email',
+    'https://www.googleapis.com/auth/calendar.readonly'
+]
 
 # Basic MCP server instance
 server = FastMCP(name="google_workspace")
-# Import tool modules to register them
-import calendar.calendar_tools
 
-# Placeholder for adding tools and resources later
-# server.add_tool(...)
-# server.add_resource(...)
+# Import tool modules to register them
+from gcalendar.calendar_tools import *
+
+# Define OAuth callback as a tool
+@server.tool("oauth2callback")
+async def oauth2callback(code: str = None, state: str = None, redirect_uri: str = "http://localhost:8080/callback"):
+    """
+    Handle OAuth2 callback from Google - for integration with external servers.
+    
+    Most users should use the complete_auth tool instead.
+    """
+    if not code:
+        logger.error("Authorization code not found in callback request.")
+        return {
+            "success": False,
+            "error": "Authorization code not found"
+        }
+
+    try:
+        client_secrets_path = os.path.join(os.path.dirname(__file__), '..', 'client_secret.json')
+        
+        # Construct full authorization response URL
+        full_callback_url = f"{redirect_uri}?code={code}"
+        if state:
+            full_callback_url += f"&state={state}"
+            
+        # Exchange code for credentials
+        user_id, credentials = handle_auth_callback(
+            client_secrets_path=client_secrets_path,
+            scopes=SCOPES,
+            authorization_response=full_callback_url,
+            redirect_uri=redirect_uri
+        )
+        
+        logger.info(f"Successfully exchanged code for credentials for user: {user_id}")
+        return {
+            "success": True,
+            "message": f"Authentication successful for user: {user_id}"
+        }
+    except RefreshError as e:
+        logger.error(f"Failed to exchange authorization code for tokens: {e}", exc_info=True)
+        return {
+            "success": False,
+            "error": f"Could not exchange authorization code for tokens: {str(e)}"
+        }
+    except Exception as e:
+        logger.error(f"An unexpected error occurred during OAuth callback: {e}", exc_info=True)
+        return {
+            "success": False,
+            "error": f"An unexpected error occurred: {str(e)}"
+        }