mbta-mpc-server

// ABOUTME: This file implements the vehicle status update functionality for the MCP server. // ABOUTME: It provides real-time status updates for transit vehicles. package server import ( "context" "encoding/json" "fmt" "log" "strconv" "github.com/crdant/mbta-mcp-server/pkg/mbta" "github.com/crdant/mbta-mcp-server/pkg/mbta/models" "github.com/mark3labs/mcp-go/mcp" ) // getVehicleStatusHandler handles requests for real-time status updates for transit vehicles func (s *Server) getVehicleStatusHandler(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) { log.Printf("Received request for vehicle status updates: %s", request.Params.Name) // Create MBTA client client := mbta.NewClient(s.config) // Extract parameters for filtering args := request.Params.Arguments params := make(map[string]string) // Process route_id filter if routeID, ok := args["route_id"]; ok { routeIDStr, ok := routeID.(string) if !ok { return createErrorResponse(fmt.Sprintf("Invalid route_id parameter: %v", routeID)), nil } log.Printf("Filtering status updates by route ID: %s", routeIDStr) params["filter[route]"] = routeIDStr } // Process status_type filter var statusFilter string if statusType, ok := args["status_type"]; ok { statusTypeStr, ok := statusType.(string) if !ok { return createErrorResponse(fmt.Sprintf("Invalid status_type parameter: %v", statusType)), nil } // Convert from user-friendly name to API status value switch statusTypeStr { case "arriving": statusFilter = models.VehicleStatusIncomingAt case "stopped": statusFilter = models.VehicleStatusStoppedAt case "in_transit": statusFilter = models.VehicleStatusInTransitTo case "all": statusFilter = "" default: return createErrorResponse(fmt.Sprintf("Invalid status_type value: %s. Must be 'arriving', 'stopped', 'in_transit', or 'all'", statusTypeStr)), nil } if statusFilter != "" { log.Printf("Filtering status updates by status type: %s", statusFilter) params["filter[current_status]"] = statusFilter } } // Process limit parameter limit := 10 // default limit if limitParam, ok := args["limit"]; ok { limitInt, ok := limitParam.(float64) if !ok { // Try to convert from string limitStr, ok := limitParam.(string) if ok { parsedLimit, err := strconv.Atoi(limitStr) if err != nil { return createErrorResponse(fmt.Sprintf("Invalid limit parameter: %v", limitParam)), nil } limit = parsedLimit } else { return createErrorResponse(fmt.Sprintf("Invalid limit parameter: %v", limitParam)), nil } } else { limit = int(limitInt) } if limit < 1 { limit = 1 } else if limit > 50 { limit = 50 } } // Get vehicles with the specified filters vehicles, err := client.GetVehicles(ctx, params) if err != nil { return createErrorResponse(fmt.Sprintf("Failed to retrieve vehicle status updates: %v", err)), nil } // If no vehicles are found, inform the user if len(vehicles) == 0 { return &mcp.CallToolResult{ Content: []mcp.Content{ mcp.TextContent{ Type: "text", Text: "No vehicle status updates found matching the specified criteria.", }, }, }, nil } // Limit the number of vehicles if needed if len(vehicles) > limit { vehicles = vehicles[:limit] } log.Printf("Retrieved %d vehicle status updates", len(vehicles)) // Format the status updates for response return formatVehicleStatusResponse(vehicles) } // formatVehicleStatusResponse formats vehicle status data for the MCP response func formatVehicleStatusResponse(vehicles []models.Vehicle) (*mcp.CallToolResult, error) { // Convert the vehicles to a status update format for the response statusUpdates := make([]map[string]interface{}, 0, len(vehicles)) for _, vehicle := range vehicles { // Base status data statusUpdate := map[string]interface{}{ "vehicle_id": vehicle.ID, "label": vehicle.Attributes.Label, "status": vehicle.GetStatusDescription(), "status_code": vehicle.Attributes.CurrentStatus, "latitude": vehicle.Attributes.Latitude, "longitude": vehicle.Attributes.Longitude, "route_id": vehicle.GetRouteID(), "stop_id": vehicle.GetStopID(), "trip_id": vehicle.GetTripID(), "direction_id": vehicle.Attributes.DirectionID, "updated_at": vehicle.Attributes.UpdatedAt, "is_moving": vehicle.Attributes.CurrentStatus == models.VehicleStatusInTransitTo, } // Add bearing and speed if moving if vehicle.Attributes.CurrentStatus == models.VehicleStatusInTransitTo { statusUpdate["bearing"] = vehicle.Attributes.Bearing if vehicle.Attributes.Speed != nil { statusUpdate["speed"] = *vehicle.Attributes.Speed } } // Add occupancy information if available if vehicle.HasOccupancyData() { totalOccupancy := 0 for _, carriage := range vehicle.Attributes.Carriages { totalOccupancy += carriage.OccupancyPercentage } // Calculate average occupancy averageOccupancy := totalOccupancy / len(vehicle.Attributes.Carriages) statusUpdate["occupancy_percentage"] = averageOccupancy // Determine overall occupancy status var overallStatus string if averageOccupancy < 25 { overallStatus = "MANY_SEATS_AVAILABLE" } else if averageOccupancy < 50 { overallStatus = "SEATS_AVAILABLE" } else if averageOccupancy < 75 { overallStatus = "FEW_SEATS_AVAILABLE" } else { overallStatus = "FULL" } statusUpdate["occupancy_status"] = overallStatus } statusUpdates = append(statusUpdates, statusUpdate) } // Create JSON string response jsonBytes, err := json.MarshalIndent(statusUpdates, "", " ") if err != nil { return createErrorResponse(fmt.Sprintf("Failed to serialize status data: %v", err)), nil } // Return data as a text content item return &mcp.CallToolResult{ Content: []mcp.Content{ mcp.TextContent{ Type: "text", Text: string(jsonBytes), }, }, }, nil }