Math Student app

/*
    The student.app consumes math functions exposed by MathTutor app.
    The student.app uses dataBridges RPC (call-response), functionality.
    You need to run the math tutor app [ NodeJS, Python, .NET].
    If you run multiple instances of math tutor app, dataBridges will automatically load-balance the rpc.function calls.

    dataBridges supports 2 types of RPC interactions
        Unary RPC: the client sends a request and receives a single response.
        Server streaming RPC: the client sends a request and in return, the receives multiple responses.

    The student app will be consuming 2 Unary RPC functions :-> add, multiple
                            consume a single server streaming RPC function :-> AllMathFunctions
                            and will receive 4 math operations reply.

    We will be using databridges-sio-client-lib in student app.

*/
// Include dataBridges client library package
const dBridges = require('databridges-sio-client-lib');

// Initialize dataBridges client
const dbridge = new dBridges();

// Replace your application key below, which you have received from dataBridges management portal.
// use environmental variables for greater security of your keys
dbridge.appkey = '____appKey______';

// Replace your authentication url below, which you have received from dataBridges management portal.
// example https://endpoint01.databridges.io/client/v1/authenticate
// use environmental variables for greater security of your keys
dbridge.auth_url = '_____URL_____';


// Connect to dataBridges. If any runtime error it will be caught in catch().
dbridge.connect().catch((err) => {
    console.log('\n', 'dataBridges Connection exception..', err.source, err.code, err.message);
});

//Bind to disconnected event, to get intimation about dataBridges network disconnection.
dbridge.connectionstate.bind("disconnected", () => {
    console.log('\n', 'Disconnected from dataBridges real-time network');
});

dbridge.connectionstate.bind("connected", () => {
    console.log('\n', 'Connected to dataBridges real-time network !!!');
    let mathFunctions = null;

    try {
        // We need to inform dataBridges network that the app want to consume 'mathTutor's functions.
        mathFunctions = dbridge.rpc.connect('MathTutor');
    } catch (err) {
        // Connect errors will be handled here.
        console.log('\n', 'Connecting to MathTutor RPC server faced an exception : ', err.source, err.code, err.message);
    }

    // We will bind to rpc server connection success event. On success, we will call remote functions.
    mathFunctions.bind("dbridges:rpc.server.connect.success", () => {
        console.log('\n', 'dataBridges granted access to MathTutor RPC server');

        // Create Random numbers for "a" and "b"
        const a = Math.floor(Math.random() * 100) + 1;
        const b = Math.floor(Math.random() * 100) + 1;
        const funParam = { a: a, b: b };

        // Unary RPC: The client sends a request and receives a single response.
        mathFunctions.call('add', JSON.stringify(funParam), 1000 * 60 * 2).then((response) => {
            console.log('\n', 'Received response for mathFunctions.call(add) : ', response)
        }).catch((err) => {
            // Catch exception for .call
            console.log('\n', 'Error was encountered while executing mathFunctions.call(add) : ', err.source, err.code, err.message);
        });

        // Unary RPC: The client sends a request and receives a single response.
        mathFunctions.call('multiply', JSON.stringify(funParam), 1000 * 60 * 2).then((response) => {
            console.log('\n', 'Received response for mathFunctions.call(multiply) : ', response)
        }).catch((err) => {
            // Catch exception for .call
            console.log('\n', 'Error was encountered while executing mathFunctions.call(multiply) : ', err.source, err.code, err.message);
        });

        // Server streaming RPC: the client sends a request and in return, the receives multiple responses.
        mathFunctions.call('AllMathFunction', JSON.stringify(funParam), 1000 * 60 * 2, (response) => {
            console.log('\n', 'Received response for mathFunctions.call(AllMathFunction) : ', response)
        }).then((response) => {
            console.log('\n', 'FINAL response for mathFunctions.call(AllMathFunction) : ', response)
        }).catch((err) => {
            // Catch exception for .call
            console.log('\n', 'Error was encountered while executing mathFunctions.call(AllMathFunction) : ', err.source, err.code, err.message);
        });

    });

    // Bind to server.connect.fail event to understand if any issues in Math Server Connection.
    mathFunctions.bind("dbridges:rpc.server.connect.fail", (payload, metadata) => {
        console.log('\n', 'MathTutor RPC server faced an issue : ', payload.source, payload.code, payload.message)
    });

});