server.ts

import { createServer } from "node:http";
import next from "next";
import { Server } from "socket.io";
import { PrismaClient } from "@prisma/client";
import { User } from "./src";

const dev = process.env.NODE_ENV !== "production";
const hostname = "localhost";
const port = 3000;
// when using middleware `hostname` and `port` must be provided below
const app = next({ dev, hostname, port });
const handler = app.getRequestHandler();

app.prepare().then(() => {
  const httpServer = createServer(handler);

  const io = new Server(httpServer);
  const db = new PrismaClient();

  let users: User[] = [];

  io.on("connection", (socket) => {
    socket.on("newUser", (data) => {
      // Ignore new user subscription when user is Anonymous (initial zustand value for session context)
      if (
        data.name !== "Anonymous" &&
        (!users.some((user) => user.name === data.name) || data.socketID)
      ) {
        socket.join(data.space);
        // Update socket when duplicate is found elsewhere just push the new user
        users = users.some((user) => user.name === data.name)
          ? users.map((user) => {
              if (user.name === data.name) {
                return data;
              }
              return user;
            })
          : [...users, data];
        io.to(data.space).emit(
          "newUserResponse",
          users.filter((user) => user.space === data.space),
        );
      }
    });
    socket.on("message", async (data) => {
      // When new message is sended persist it into database and broadcast it into the space
      socket.join(data.message.spaceId);
      await db.message.create({
        data: data.insertToDB,
      });
      io.to(data.message.spaceId).emit("messageResponse", data.message);
    });
    socket.on("disconnect", () => {
      // Remove user reference
      users = users.map((user) => {
        if (user.socketID === socket.id) {
          return {
            ...user,
            socketID: false,
          };
        }
        return user;
      });
      io.emit("newUserResponse", users);
      socket.disconnect();
    });
  });

  httpServer
    .once("error", (err) => {
      console.error(err);
      process.exit(1);
    })
    .listen(port, () => {
      console.log(`> Ready on http://${hostname}:${port}`);
    });
});