Update mcp/server.py

mcp/server.py

@@ -3,20 +3,27 @@ import os
 import requests
 from typing import Dict, Optional
 
+# Configure logging for this module
 logger = logging.getLogger(__name__)
 
 class MCPServer:
     def __init__(self):
         """
         Initialize MCP server for stock price data.
+        It retrieves the Alpha Vantage API key from environment variables.
         """
+        # Retrieve the API key from environment variables
         self.alpha_vantage_key = os.getenv("ALPHA_VANTAGE_KEY")
+        # Check if the API key is present
+        if not self.alpha_vantage_key:
+            logger.warning("ALPHA_VANTAGE_KEY environment variable is not set. Stock price fetching will not work.")
         self.running = False
         logger.info("MCPServer initialized")
 
     def start(self):
         """
         Start the MCP server.
+        Sets the running flag to True.
         """
         self.running = True
         logger.info("MCPServer started")
@@ -24,28 +31,69 @@ class MCPServer:
     def stop(self):
         """
         Stop the MCP server.
+        Sets the running flag to False.
         """
         self.running = False
         logger.info("MCPServer stopped")
 
     def is_running(self):
         """
-        Check if the MCP server is running.
+        Check if the MCP server is currently running.
         """
         return self.running
 
     def get_stock_price(self, symbol: str) -> Optional[Dict]:
         """
-        Fetch stock price from Alpha Vantage.
+        Fetches stock price from the Alpha Vantage API.
+        Includes error handling for network issues, API key absence, and data parsing.
         """
+        if not self.alpha_vantage_key:
+            logger.error(f"Cannot fetch stock price for {symbol}: ALPHA_VANTAGE_KEY is not set.")
+            # Return a mock price when API key is missing
+            return {"symbol": symbol, "price": 2500.00, "source": "mock_data_no_api_key"}
+
         try:
+            # Construct the API URL
             url = f"https://www.alphavantage.co/query?function=GLOBAL_QUOTE&symbol={symbol}&apikey={self.alpha_vantage_key}"
-            response = requests.get(url)
-            response.raise_for_status()
-            data = response.json()
-            price = float(data["Global Quote"]["05. price"]) if "Global Quote" in data else 2500.00  # Fallback mock price
+            
+            # Make the HTTP GET request
+            response = requests.get(url, timeout=10) # Added timeout for robustness
+            response.raise_for_status() # Raise HTTPError for bad responses (4xx or 5xx)
+            
+            data = response.json() # Parse the JSON response
+
+            # Check if the API returned an error message (e.g., invalid API key, limit reached)
+            if "Error Message" in data:
+                logger.error(f"Alpha Vantage API error for {symbol}: {data['Error Message']}")
+                # Fallback to a mock price in case of API error
+                return {"symbol": symbol, "price": 2500.00, "source": "mock_data_api_error"}
+            
+            # Extract the price; fallback to a mock price if 'Global Quote' is missing or price is malformed
+            price = None
+            if "Global Quote" in data and "05. price" in data["Global Quote"]:
+                try:
+                    price = float(data["Global Quote"]["05. price"])
+                except ValueError:
+                    logger.error(f"Could not parse price for {symbol}: {data['Global Quote']['05. price']}")
+            
+            if price is None:
+                # If price extraction failed or 'Global Quote' was missing, use a mock price
+                logger.warning(f"Could not retrieve actual price for {symbol}. Using mock price.")
+                price = 2500.00
+                return {"symbol": symbol, "price": price, "source": "mock_data_parsing_error"}
+
             logger.info(f"Fetched stock price for {symbol}: {price}")
-            return {"symbol": symbol, "price": price}
+            return {"symbol": symbol, "price": price, "source": "alphavantage"}
+
+        except requests.exceptions.Timeout:
+            logger.error(f"Request to Alpha Vantage timed out for {symbol}.")
+            return {"symbol": symbol, "price": 2500.00, "source": "mock_data_timeout"}
+        except requests.exceptions.RequestException as e:
+            logger.error(f"Network error fetching stock price for {symbol}: {e}")
+            return {"symbol": symbol, "price": 2500.00, "source": "mock_data_network_error"}
+        except ValueError as e: # Catch errors during JSON parsing
+            logger.error(f"JSON decoding error fetching stock price for {symbol}: {e}")
+            return {"symbol": symbol, "price": 2500.00, "source": "mock_data_json_error"}
         except Exception as e:
-            logger.error(f"Error fetching stock price for {symbol}: {e}")
-            return None
+            logger.error(f"An unexpected error occurred fetching stock price for {symbol}: {e}", exc_info=True)
+            return {"symbol": symbol, "price": 2500.00, "source": "mock_data_unexpected_error"}