web-chat/backend/socket.js

const { Server } = require("socket.io");
const jwt = require("jsonwebtoken");
const jwtSecret = process.env.JWT_SECRET;
const { db } = require("./db.js");
const { json } = require("express");

function initializeSocket(server) {
  const io = new Server(server, {
    cookie: {
      httpOnly: true,
      sameSite: "strict",
      maxAge: 30 * 24 * 60 * 60 * 1000,
    },
  });

  io.use((socket, next) => {
    // user auth
    const token = socket.handshake.auth.token;
    if (token) {
      jwt.verify(token, jwtSecret, (err, user) => {
        if (err) {
          console.log(err);
          return next(new Error("Authentication error"));
        }
        socket.user = user;
        next();
      });
    } else {
      next(new Error("Not logged in"));
    }
  });

  // open main socket connection
  io.on("connection", (socket) => {
    if (!socket.user) {
      socket.emit("socket error", "User not authenticated");
      socket.disconnect();
      return;
    }
    const username = socket.user.username;
    // Join a room with the user's username
    socket.join(username);

    io.to(username).emit("username", username);

    // chat message event
    socket.on("chat message", async (msgData) => {
      const { content, recipient } = msgData;
      let insertedId;
      try {
        // Insert the new message into the database
        const result = await db.query(
          "INSERT INTO messages (content, username, recipient) VALUES ($1, $2, $3) RETURNING id",
          [content, username, recipient],
        );
        insertedId = result.rows[0].id;
      } catch (err) {
        console.error("Error inserting message:", err);
        socket.emit(
          "socket error",
          "Error inserting message, try refreshing the page",
        );
        return;
      }

      // Fetch the newly inserted message from the database
      try {
        const query =
          "SELECT id, content, username, recipient FROM messages WHERE id = $1";
        const result = await db.query(query, [insertedId]);

        if (result.rows.length > 0) {
          const newMessage = result.rows[0];

          // Emit message to the sender's and recipient's rooms
          io.to(username).to(recipient).emit("chat message", {
            username: newMessage.username,
            recipient: newMessage.recipient,
            content: newMessage.content,
          });
        }
      } catch (err) {
        console.error("Error fetching inserted message:", err);
        socket.emit("socket error", "Failed to send message");
      }
    });

    socket.on("get messages", async (recipient) => {
      const username = socket.user.username;
      try {
        const query = `
            SELECT id, content, username, recipient
            FROM messages
            WHERE (username = $1 AND recipient = $2) OR (username = $2 AND recipient = $1)
            ORDER BY id ASC
        `;
        const result = await db.query(query, [username, recipient]);

        if (result.rows.length > 0) {
          //const { username: sender, recipient: receiver, content: content, id: id } = result.rows;

          io.to(username).emit("messages history", result.rows);
        } else {
          io.to(username).emit("no messages");
        }
      } catch (e) {
        console.error("Error retrieving messages:", e);
        socket.emit(
          "socket error",
          "Error retrieving messages, refresh the page (server error)",
        );
      }
    });

    // Contacts socket
    socket.on("contacts", async (contactUsername) => {
      const username = socket.user.username;
      const status = contactUsername.status === "read" ? "read" : "unread";

      // Update contact list in db
      try {
        const query = `
            INSERT INTO contacts (username, contact, status)
            SELECT $1, $2, $3
            WHERE NOT EXISTS (
                SELECT 1 FROM contacts WHERE username = $1 AND contact = $2
            )
            `;
        await db.query(query, [username, contactUsername.contact, status]);
      } catch (err) {
        console.error("Failed to update contacts ", err);
        socket.emit("socket error", "Failed to update contacts (server error)");
      }
      // Get contact list from db
      try {
        const query = `
            SELECT contact, username, status
            FROM contacts
            WHERE username = $1
            `;
        const result = await db.query(query, [username]);
        io.to(username).emit("contacts", result.rows);
      } catch (err) {
        console.error("Failed to get contacts from db");
        io.to(username).emit(
          "socket error",
          "Failed to get contacts (server error)",
        );
      }
    });

    socket.on("get contacts", async () => {
      const username = socket.user.username;
      try {
        const query = `
            SELECT contact, username, status
            FROM contacts
            WHERE username = $1
        `;
        const result = await db.query(query, [username]);
        io.to(username).emit("contacts", result.rows);
      } catch (err) {
        console.error("Failed to get contacts from db");
        io.to(username).emit(
          "socket error",
          "Failed to get contacts (server error)",
        );
      }
    });
    socket.on("delete contact", async (contactUsername) => {
      const username = socket.user.username;
      try {
        const query =
          "DELETE FROM contacts WHERE (username = $1 AND contact = $2)";
        await db.query(query, [username, contactUsername]);
      } catch (err) {
        console.error("Failed to remove contact from db");
        io.to(username).emit(
          "socket error",
          "Failed to remove contact (server error)",
        );
      }
    });

    socket.on("status", async (username) => {
      const userUsername = socket.user.username;
      const status = "unread";
      try {
        const query =
          "UPDATE contacts SET status = $1 WHERE username = $2 AND contact = $3";
        await db.query(query, [status, userUsername, username]);
        io.to(userUsername).emit("status", username);
      } catch (err) {
        console.error("Failed to update unread status:", err);
      }
    });

    socket.on("read", async (contactUsername) => {
      const userUsername = socket.user.username;
      const status = "read";
      try {
        const query =
          "UPDATE contacts SET status = $1 WHERE username = $2 AND contact = $3";
        await db.query(query, [status, userUsername, contactUsername]);
        io.to(userUsername).emit("status", contactUsername);
      } catch (err) {
        console.error("Failed to update unread status:", err);
      }
    });
    // disconnect event
    socket.on("disconnect", () => {
      console.log(socket.id, " disconnected");
      return "Disconnected";
    });
  });

  return io;
}

module.exports = { initializeSocket };