grpcServer.ts

import { IDatabase, IServer } from "../interfaces";
import grpc from "@grpc/grpc-js";

const PROTO_PATH = "../proto/app.proto";

export default class GrpcServer implements IServer {
  server: any;
  db: IDatabase

  constructor(db: IDatabase) {
    this.db = db;

    const protoLoader = require("@grpc/proto-loader"); // Cannot convert this to an import
    const packageDefinition = protoLoader.loadSync(PROTO_PATH, {
      keepCase: true,
      longs: String,
      enums: String,
      defaults: true,
      oneofs: true,
    });
    const { app } = grpc.loadPackageDefinition(packageDefinition);
    this.server.addService((app as any).App.service, {
      getRandomProduct: randomProduct,
      getAllProducts: allProducts,
      getProduct: product,
      getAllCategories: categories,
      getAllOrders: allOrders,
      getAllUserOrders: ordersByUser,
      getOrder: order,
      getUser: user,
      getAllUsers: users,
      postOrder: postOrder,
      patchAccountDetails: accountDetails,
    });
    this.server = new grpc.Server();
  }

  start() {

    this.server.bindAsync(
      "0.0.0.0:3001",
      grpc.ServerCredentials.createInsecure(),
      () => {
        console.log("App ready and listening on port 3001");
        this.server.start();
      },
    );
  }
};

async function randomProduct(call, callback) {
  const randProd = await this.db.queryRandomProduct();
  callback(null, randProd);
}

async function allProducts(call, callback) {
  const products = await this.db.queryAllProducts();
  callback(null, { products });
}

async function product(call, callback) {
  const { product_id } = call.request;
  const product = await this.db.queryProductById(product_id);
  callback(null, product);
}

async function categories(call, callback) {
  const categories = await this.db.queryAllCategories();
  callback(null, { categories });
}

async function allOrders(call, callback) {
  const orders = await this.db.queryAllOrders();
  callback(null, { orders });
}

async function ordersByUser(call, callback) {
  const { id } = call.request;
  const orders = await this.db.queryOrdersByUser(id);
  callback(null, { orders });
}

async function order(call, callback) {
  const { order_id } = call.request;
  const order = await this.db.queryOrderById(order_id);
  callback(null, order);
}

async function user(call, callback) {
  const { id } = call.request;
  const user = await this.db.queryUserById(id);
  callback(null, user);
}

async function users(call, callback) {
  const users = await this.db.queryAllUsers();
  callback(null, { users });
}

async function postOrder(call, callback) {
  ///TODO: Implement this
}

async function accountDetails(call, callback) {
  const { id } = call.request;
  delete call.request.id;
  const user = await this.db.updateUser(id, call.request);
  callback(null, user);
}

/**
 * Starts an RPC server that receives requests for the Greeter service at the
 * sample server port
 */