import { SSEClientObjInterface } from 'sse-service';
import { fastify } from 'fastify';

const server = fastify({ logger: true });

server.route({
  method: 'GET',
  url: '/sse',
  handler: async (req, res) => {
    sse.connectSSE({
      clientId: 'unique id', // this is a primary key of how your client connection could be retrieved, could be ommited, library will take care of creating unique id  
      // client id could be retrieved from the JWT token for example
      req: req.raw, // here we link to raw NodeJS request object, because its wrapped by Fastify
      res: res.raw, // the same as for request
      originalResHeaders: res.getHeaders(), // sometimes you need to pass through response headers added by Fastify, this headers will be added to raw NodeJS response stream
      onDisconnectCb: () => {
        // ....
      }, // sometimes you need to perform some actions when user disconnects
    });
  },
});

// someService.ts

import { sendSSEToClient } from 'sse-service';

// ....

// some function that handles update from DB or whatever
const processUpdate = (update) => {
  const { userId, ...payload } = update;
  
  sendSSEToClient(userId, payload); // this will send payload to every connection that user with userId has
  
  // OR send update to all:

  sendSSEToAll(payload);
}; 

// sse.controller.ts

import { connectSSE } from 'sse-service';

// ...

export class SseController {

    // ...
  
    public sse(@Req() req, @Res() res) {
      connectSSE({
        clientId: req.user.id, // this is a primary key of how your client connection could be retrieved, could be ommited, library will take care of creating unique id  
        // client id could be retrieved from the JWT token for example
        req,
        res,
        originalResHeaders: res.getHeaders(), // sometimes you need to pass through response headers added by Nest (actually it is Fastify or Express under the hood), this headers will be added to raw NodeJS response stream
        onDisconnectCb: () => {
          // ... 
        }, // sometimes you need to perform some actions when user disconnects
      });
    }
}

// someService.ts

import { sendSSEToClient } from 'sse-service';

// ....

// some function that handles update from DB or whatever
const processUpdate = (update) => {
  const { userId, ...payload } = update;
  
  sendSSEToClient(userId, payload); // this will send payload to every connection that user with userId has

  // OR send update to all:

  sendSSEToAll(payload);
}; 

var express = require('express')
var app = express()

app.get('/sse', function (req, res) {
  connectSSE({
    clientId: req.user.id, // this is a primary key of how your client connection could be retrieved, could be ommited, library will take care of creating unique id  
    // client id could be retrieved from the JWT token for example
    req,
    res,
    originalResHeaders: res.getHeaders(), // sometimes you need to pass through response headers added by Express, this headers will be added to raw NodeJS response stream
    onDisconnectCb: () => {
      // ... 
    }, // sometimes you need to perform some actions when user disconnects
  });
})

app.listen(3000);

// someService.ts

import { sendSSEToClient } from 'sse-service';

// ....

// some function that handles update from DB or whatever
const processUpdate = (update) => {
  const { userId, ...payload } = update;
  
  sendSSEToClient(userId, payload); // this will send payload to every connection that user with userId has

  // OR send update to all:

  sendSSEToAll(payload);
}; 

npm install sse-service

{
  req: HttpRequest; // NodeJS raw request object
  
  res: HttpResponse; // NodeJS raw response object
  
  originalResHeaders: HttpResponseHeaders; // response headers from the response object of you framework,
  // for example Fastify wraps original response object and could add additional headers,
  // so if you want to pass them through call .getHeaders() on the framework's response object and pass here 
  
  meta?: Record<string, any>; // any metadata to be persisted in client object that will be created 
  
  clientId?: string; // this is a primary key of how your client connection could be retrieved, 
  // could be ommited, library will take care of creating unique id  
  // client id could be retrieved from the JWT token for example
  
  onDisconnectCb?: () => void; // sometimes you need to perform some actions when user disconnects
  
  groupName?: string; // this param allows you to add this user connection to some specific group(namespace)
  // so later you could send a SSE message for all users connections from this group
  // by default all connections being added to default group name
}

 {
    client: {
        connections: HttpResponse[]; // array of raw NodeJS responses, 
        // will contain more then one if we add few connections by the same clientId param
        meta?: Record<string, any>; // any meta you have added by meta param
        clientId: string; // client id you passed to or the one generated by lib
    };
    currConnection: HttpResponse // raw NodeJS response object that was esatablished by this specific connectSSE method call 
 }
 

 {
    connections: HttpResponse[]; // array of raw NodeJS responses,
    // will contain more then one if we add few connections by the same clientId param
    meta?: Record<string, any>; // any meta you have added by meta param
    clientId: string; // client id you passed to or the one generated by lib
 };

 Array<{
    connections: HttpResponse[]; // array of raw NodeJS responses,
    // will contain more then one if we add few connections by the same clientId param
    meta?: Record<string, any>; // any meta you have added by meta param
    clientId: string; // client id you passed to or the one generated by lib
 }>;

 {
    connections: HttpResponse[]; // array of raw NodeJS responses,
    // will contain more then one if we add few connections by the same clientId param
    meta?: Record<string, any>; // any meta you have added by meta param
    clientId: string; // client id you passed to or the one generated by lib
 };k