Fis-Retransmission/test/grpc2.ts

import * as fs from 'fs'
import { Subject, groupBy, mergeMap, take, toArray } from 'rxjs';
import { ColorCode, Message, MessageLog, ReportStatus } from '../interfaces/general.interface';
import { GrpcService } from '../services/grpc.service';
import { FisRetransmissionService } from '../services/fis.retransmission.service';
import { GrpcServiceMethod } from '../services/service.method';

// Subject for bidirectional communication
const errorHandlingService: FisRetransmissionService = new FisRetransmissionService()
const grpcService: GrpcService = new GrpcService(new GrpcServiceMethod())
const messagesJSON: any = fs.readFileSync('payload.json')
let incomingMessages: Subject<any> = grpcService.getIncomingMessage()
let parsedMessages: any[] = JSON.parse(messagesJSON) // load the fake messages generated for this trial 
let messageToBeReleased: Subject<any> = new Subject() // Sample message to be transmitted over to target server
let applicationOutgoingResponse: Subject<Message> = new Subject()
let statusControl: Subject<ReportStatus> = new Subject() // Listening for error events and states
let targetserver: string = 'localhost:3000'
let hostServer: string = 'localhost:3001'
let array: any[] = []// Used for testing

// Handler for the incoming Messages from the other side. 
incomingMessages.subscribe({
  next: request => {
    // Application logic comes here. This is where the asortment takes place, of decidiing whose messages it belongs of what it is
    if ((request.message as MessageLog).appData.msgPayload == 'Query') {
      generateFakeStreamResponse(request).subscribe({
        next: (responseMessage) => {
          // console.log(`Processing request:${request.id}....`)
          applicationOutgoingResponse.next(responseMessage)
        },
        error: error => console.error(error),
        complete: () => {
          console.log(`Stream request for ${request.id} is queued.`) // shpuld be indefinite
        }
      })
    } else {
      array.push(request)
      console.log(`Received messages from the other side: ${(request.message as MessageLog).appData.msgId}`)
    }
  },
  error: error => console.error(error),
  complete: () => console.log(`Response for incoming generated. But this will never stop, and should not either.`)
})

// Open channel for sending messages across.
errorHandlingService.handleMessage(applicationOutgoingResponse, statusControl).subscribe((messages) => {
  messageToBeReleased.next(messages)
})
grpcService.createGrpcInstance(hostServer, statusControl, { instanceType: 'server', serviceMethod: 'server streaming' }, messageToBeReleased)

grpcService.createGrpcInstance(targetserver, statusControl, { instanceType: 'client', serviceMethod: 'server streaming' })

setTimeout(() => {
  let message = {
    id: parsedMessages[10].appData.msgId,
    message: parsedMessages[10] // Choose this number, because i purposely use the 11th message and change the msgPayload property to query to emulate a request
  }
  applicationOutgoingResponse.next(message)
}, 2000)
setTimeout(() => {
  let message = {
    id: parsedMessages[11].appData.msgId,
    message: parsedMessages[11]// Choose this number, because i purposely use the 11th message and change the msgPayload property to query to emulate a request
  }
  applicationOutgoingResponse.next(message)
}, 3000)
setTimeout(() => {
  console.log(`All received data: ${array.length}`)
}, 10000)
setTimeout(() => {
  console.log(`All received data: ${array.length}`)
}, 20000)


// this is just to publish an array of fake data as a Subject
function stream(): Subject<any> {
  let result: Subject<any> = new Subject()
  let messages: any[] = parsedMessages
  let count = 0
  const intervalId = setInterval(() => {
    result.next(messages[count]);
    count++;
    if (count >= 1000) {
      clearInterval(intervalId);
      result.complete();
    }
  }, 500)
  return result
}

function generateFakeStreamResponse(request: any): Subject<any> {
  let res: Subject<any> = new Subject()
  stream().pipe(take(5)).subscribe({
    next: element => {
      let message = {
        id: request.id, // Caller's 
        message: element
      }
      res.next(message)
    },
    error: error => console.error(error),
    complete: () => console.log(`Stream response for ${request.id} has been prepared.`)
  })
  return res
}