main.py

import random

from flask import Flask, render_template, request
from flask_socketio import SocketIO, emit

app = Flask(__name__)
socketio = SocketIO(app)


# Store connected users. key: socket_id, value: username & avatar
users = {}


@app.route('/')
def index():
    return render_template("index.html")


# listening for the connect event
@socketio.on("connect")
def handle_connect():
    username = f"User_{random.randint(1000,9999)}"
    gender = random.choice(["girl","boy"])
    # https://avatar.iran.liara.run/public/boy?username=User_123
    avatar_url = f" https://avatar.iran.liara.run/public/{gender}?username={username}"

    users[request.sid] = { "username":username,"avatar":avatar_url}

    emit("user_joined", {"username":username,"avatar":avatar_url},broadcast=True)

    emit("set_username", {"username":username})


@socketio.on("disconnect")
def handle_disconnect():
    user = users.pop(request.sid, None)
    if user:
      emit("user_left", {"username":user["username"]},broadcast=True)


@socketio.on("send_message")
def handle_message(data):
    user = users.get(request.sid)
    if user:
        emit("new_message", {
            "username":user["username"],
            "avatar":user["avatar"],
            "message":data["message"]
        }, broadcast=True)


@socketio.on("update_username")
def handle_update_username(data):
    old_username = users[request.sid]["username"]
    new_username = data["username"]
    users[request.sid]["username"] = new_username

    emit("username_updated", {
        "old_username":old_username,
        "new_username":new_username
    }, broadcast=True)


if __name__ == "__main__":
    socketio.run(app)