Ballerina gRPC attempt

drone_mgmt_svc.bal

import ballerina/grpc;

endpoint grpc:Listener listener {
    host: "localhost",
    port: 9090
};

map <droneInfo> dronesMap;

type droneInfo record {
    string id;
    string name;
    int battery_remaining;
};

@grpc:ServiceConfig
service droneMgmt bind listener {

    getDrone(endpoint caller, string droneId) {
        if (dronesMap.hasKey(droneId)) {
            //json droneDetails = check <json>dronesMap[droneId];
            //payload = droneDetails.toString();
	          var payload = dronesMap[droneId];
             _ = caller->send(payload);
        } else {
           // payload = "No such drone";
        }
        _ = caller->complete();
    }

    addDrone(endpoint caller, droneInfo addDroneRequest) {
        string droneId =
        addDroneRequest.id;
        dronesMap[droneId] =
                             addDroneRequest;

        string payload = "Status: Drone created; DroneID = " + droneId;

        _ = caller ->send(payload);
        _ = caller ->complete();
    }

    updateDrone(endpoint caller, droneInfo updateDroneRequest) {
        string payload;

        string droneId =
        updateDroneRequest.id;
        if (dronesMap .hasKey(droneId)) {
            dronesMap[droneId] =
                                 updateDroneRequest;
            payload = "Drone '" + droneId + "' updated.";
        } else {
            payload = "Drone '" + droneId + "' not found.";
        }

        _ = caller ->send(payload);
        _ = caller ->complete();
    }
}