server.ts

import path from 'path'
import * as grpc from '@grpc/grpc-js'
import * as protoLoader from '@grpc/proto-loader'
import {ProtoGrpcType} from './proto/random'
import { RandomHandlers } from './proto/randomPackage/Random'
import { TodoResponse } from './proto/randomPackage/TodoResponse'
import { TodoRequest } from './proto/randomPackage/TodoRequest'
import { ChatRequest } from './proto/randomPackage/ChatRequest'
import { ChatResponse } from './proto/randomPackage/ChatResponse'

const PORT = 8082
const PROTO_FILE = './proto/random.proto'

const packageDef = protoLoader.loadSync(path.resolve(__dirname, PROTO_FILE))
const grpcObj = (grpc.loadPackageDefinition(packageDef) as unknown) as ProtoGrpcType
const randomPackage = grpcObj.randomPackage

function main() {
  const server = getServer()

  server.bindAsync(`0.0.0.0:${PORT}`, grpc.ServerCredentials.createInsecure(),
  (err, port) => {
    if (err) {
      console.error(err)
      return
    }
    console.log(`Your server as started on port ${port}`)
    server.start()
  })
}

const todoList: TodoResponse = {todos :[] }
const callObjByUsername = new Map<string, grpc.ServerDuplexStream<ChatRequest, ChatResponse>>()

function getServer() {
  const server = new grpc.Server()
  server.addService(randomPackage.Random.service, {
    PingPong: (req, res) => {
      console.log(req.request)
      res(null, {message: "Pong"})
    },
    RandomNumbers: (call) => {
      const { maxVal = 10 } = call.request
      console.log({maxVal})

      let runCount = 0
      const id = setInterval(() => {
        runCount = ++runCount
        call.write({num: Math.floor(Math.random() * maxVal)})

        if(runCount >= 10) {
          clearInterval(id)
          call.end()
        }
      }, 500)
    },
    TodoList: (call, callback) => {
      call.on("data", (chunk: TodoRequest) => {
        todoList.todos?.push(chunk)
        console.log(chunk)
      })

      call.on("end", () => {
        callback(null, {todos: todoList.todos})
      })
    },
    Chat: (call) => {
      call.on("data", (req) => {
        const username = call.metadata.get('username')[0] as string
        const msg = req.message
        console.log(username, req.message)


        for(let [user, usersCall] of callObjByUsername) {
          if(username !== user) {
            usersCall.write({
              username: username,
              message: msg
            })
          }
        }

        if (callObjByUsername.get(username) === undefined) {
          callObjByUsername.set(username, call)
        }
      })

      call.on("end", () => {
        const username = call.metadata.get('username')[0] as string
        callObjByUsername.delete(username)
        for(let [user, usersCall] of callObjByUsername) {
            usersCall.write({
              username: username,
              message: "Has Left the Chat!"
            })
        }
        console.log(`${username} is ending their chat session`)

        call.write({
          username: "Server",
          message: `See you later ${username}`
        })

        call.end()
      })

    }
  } as RandomHandlers)

  return server
}

main()