<div class="Objective_card card-content-body"><p>Building a chat tool with a simple command-line interface which supports multiple chat rooms.</p></div>

Objective

<div class="Project_Context_card card-content-body"><p>Most often than not, we run heavy GUI-based applications for the simplest of tasks. One such simple task is instant messaging or chatting. Chat tools enable users to start chatting with other users in real-time. It also enables users to transmit text messages, images, videos, and hyperlinks.
<br/>
<br/></p><p>In this project, we aim to build a simple command-line chat tool which is easy to use and also has a very minimal interface.
<br/></p></div>

Project Context

<div class="Project_Stages_card card-content-body"><ul>
<li>Understanding how to use <code>socket</code> and <code>threading</code> modules in Python.</li>
<li>Implementing a simple client-server chat tool in Python.</li>
<li>Incorporating multiple chat rooms functionality into the chat tool.</li>
</ul><p>The diagram below shows the basic architecture of the chat tool. The server should be connected to all the clients directly but should be able to categorize them into their respective chat rooms and broadcast messages only to the sender's chat room.
<br/></p><p>For example: If Client A sends a message, the message should only be broadcasted to clients B and C and not any other clients.</p><p><img alt="expected_outcome" src="https://storage.googleapis.com/crio-content-container-assets/ME_ME_PROJECT_CLI_CHAT_MODULE_ME_PROJECT_CLI_CHAT_MODULE_CLI_CHAT_2_expected_outcome.jpg" style="max-width:750px;"/></p></div>

Project Stages

<div class="High-level_Approach_card card-content-body"><p>The diagram below shows a high level approach used to build and develop the chat tool.
<img alt="high_level_approach" src="https://storage.googleapis.com/crio-content-container-assets/ME_ME_PROJECT_CLI_CHAT_MODULE_ME_PROJECT_CLI_CHAT_MODULE_CLI_CHAT_1_high_level_approach.jpg" style="max-width:750px;"/>
<br/></p><p>The desired end result of the project is like this:
<div class="video"><iframe allowfullscreen="allowfullscreen" class="iframe-video" height="350px" mozallowfullscreen="mozallowfullscreen" msallowfullscreen="msallowfullscreen" oallowfullscreen="oallowfullscreen" src="https://www.youtube.com/embed/HnnBJsr6fBs" webkitallowfullscreen="webkitallowfullscreen" width="600px"></iframe></div></p></div>

High-level Approach

<div class="Primary_goals_card card-content-body"><ul>
<li>Understand socket programming how it can be used to build an application.</li>
<li>Understand multithreading and how it helps a program to maximum utilize the CPU time.</li>
<li>Build a fully functioning chat tool that allows multiple users to communicate with each other.</li>
<li>Incorporate multiple chat rooms(or groups) functionality into the chat tool.</li>
</ul></div>

Primary goals

<div class="Applications_card card-content-body"><ul>
<li>Chat tools enable instant messaging and can be used in a number of scenarios.</li>
<li>Command-line tools are often preferred over GUI applications by software developers.</li>
</ul></div>

Applications

<div class="Multithreading_card card-content-body"><p>A thread is a light-weight smallest part of a process that can run concurrently with the other parts(other threads) of the same process. Threads are independent because they all have separate paths of execution. All threads of a process share the common memory. The process of executing multiple threads simultaneously is known as multithreading. (definition source: <a href="https://beginnersbook.com/" target="_blank">beginnersbook.com</a>)
<br/>
<br/></p><p>In this milestone, you need to understand the concepts of multithreading and learn how to implement multithreading in Python.</p></div>

Multithreading

<div class="Requirements_card card-content-body"><ul>
<li>Understand the concept of multithreading.</li>
<li>Familiarize yourself with basics of the <code>threading</code> module in Python.</li>
<li>Implement a simple multithreaded program in Python.
<ul>
<li>Create a simple function in Python.</li>
<li>Call the function with different arguments in different threads.</li>
</ul>
</li>
</ul><div class="References"><h3>References</h3><ul>
<li><a href="https://en.wikipedia.org/wiki/Multithreading_(computer_architecture)" target="_blank">Multithreading</a></li>
<li><a href="https://www.geeksforgeeks.org/multithreading-python-set-1/" target="_blank">Multithreading in Python</a></li>
</ul></div></div>

Requirements

<div class="Expected_Outcome_card card-content-body"><p>You should be able to understand how to implement multithreading in Python using the <code>threading</code> library.
<br/></p></div>

Expected Outcome

<div class="Socket_Programming_card card-content-body"><p>Sockets allow communication between two different processes on the same or different machines. To be more precise, it's a way to talk to other computers using standard Unix file descriptors. In Unix, every I/O action is done by writing or reading a file descriptor. A file descriptor is just an integer associated with an open file and it can be a network connection, a text file, a terminal, or something else. To a programmer, a socket looks and behaves much like a low-level file descriptor. This is because commands such as read() and write() work with sockets in the same way they do with files and pipes. (definition source: <a href="https://www.tutorialspoint.com/index.htm" target="_blank">tutorialspoint.com</a>)
<br/>
<br/></p><p>In this milestone, you have to understand socket programming and have to implement a simple client-server program and establish a connection between the client and server.</p></div>

Socket Programming

<div class="Requirements_card card-content-body"><ul>
<li>Understand the concept of socket programming.</li>
<li>Familiarize yourself with basics of <code>socket</code> module in Python.</li>
<li>Implement a simple client-server program in Python using the <code>socket</code> module.
<ul>
<li>Start a chat server and accept connections from clients.</li>
<li>Connect to the server from a client (using a different terminal on the same machine or a different machine on the same local network).</li>
<li>Once the connection is successful, send a message from client to server or vice-versa and close the connection.</li>
</ul>
</li>
</ul><div class="References"><h3>References</h3><ul>
<li><a href="https://medium.com/swlh/understanding-socket-connections-in-computer-networking-bac304812b5c" target="_blank">Understanding Socket Connections in Computer Networking</a></li>
<li><a href="https://www.geeksforgeeks.org/socket-programming-python/" target="_blank">Socket Programming in Python</a></li>
<li><a href="https://www.youtube.com/watch?v=u4kr7EFxAKk" target="_blank">Socket Programming in Python (Video)</a></li>
</ul></div></div>

<div class="Expected_Outcome_card card-content-body"><p>You should be able to implement a simple client-server program in Python using the <code>socket</code> module.
<br/></p></div>

<div class="Building_a_chat_application_card card-content-body"><p>In this milestone you'll be developing a simple chat application. Extend the previously built client-server program to allow server to accept connections from multiple clients. Also, allow the server the to accept messages from all the client and broadcast the messages to all the clients.</p></div>

Building a chat application

<div class="Requirements_card card-content-body"><ul>
<li>Extend the program developed as part of previous task to allow connections from multiple clients to the server.</li>
<li>Come up with a way to identify unique clients on the server.</li>
<li>Allow the clients to send messages to the server.</li>
<li>Broadcast the messages from the sender to all other clients through the server.</li>
</ul><div class="References"><h3>References</h3><ul>
<li><a href="https://www.geeksforgeeks.org/socket-programming-multi-threading-python/" target="_blank">Socket Programming with Multithreading - 1</a></li>
<li><a href="https://www.tutorialspoint.com/socket-programming-with-multi-threading-in-python" target="_blank">Socket Programming with Multithreading - 2</a></li>
</ul></div><div class="Note"><h3>Note</h3><ul>
<li>The clients shouldn't communicate with each other directly. The clients should only be connected to the server and therefore they should only send and receive messages to and from the server.</li>
</ul></div></div>

<div class="Expected_Outcome_card card-content-body"><p>You should be able to achieve the following:</p><ul>
<li>Chat tool implemented in Python.</li>
<li>Multiple clients should be able to communicate with each other through the chat server.
<br/></li>
</ul></div>

<div class="Extending_the_chat_tool_card card-content-body"><p>Extend the functionality of the chat tool so it supports multiple chat rooms. The server should be able to manage multiple users in multiple chat rooms at a given time.</p></div>

Extending the chat tool

<div class="Requirements_card card-content-body"><ul>
<li>Extend the chat tool to support multiple chat rooms (i.e., the clients should be able to join or create a chat room)</li>
<li>When the client connects to the server, the client should be presented with a few options
<ul>
<li>List all existing chat rooms - This allows the client to list all the existing chat rooms.</li>
<li>Create a new chat room - This allows the client to create a new chat room.</li>
<li>Join an existing chat room - This allows the client to join an existing chat room.</li>
</ul>
</li>
<li>A client should only be able to join only one chat room.</li>
<li>After joining a chat room, all messages sent by the client should only be broadcasted to other clients in the same room.</li>
</ul><div class="Tip"><h3>Tip</h3><ul>
<li>Use unique identifiers to identify the chat room (for example: Room ID or Room Number).</li>
</ul></div><div class="Note"><h3>Note</h3><ul>
<li>Remember to cover boundary cases such as
<ul>
<li>Clients creating a new chat room with an already existing Room ID or Room Number</li>
<li>Clients trying to join an invalid room</li>
</ul>
</li>
</ul></div></div>

<div class="Bring_it_On!_card card-content-body"><ul>
<li>Limit the number of clients that can join a chat room.</li>
<li>Add functionality to create private chat rooms.
<ul>
<li>These chat rooms shouldn't be listed when the user chooses to list all the existing chat rooms.</li>
</ul>
</li>
</ul></div>

Bring it On!

<div class="Expected_Outcome_card card-content-body"><p>You should be able to achieve the following:</p><ul>
<li>Chat tool with multiple room functionality.</li>
<li>The clients should be able to do the following
<ul>
<li>List all the existing chat rooms.</li>
<li>Create a new chat room.</li>
<li>Join an existing chat room.</li>
</ul>
</li>
<li>Messages in sent by a client in a chat room should be only broadcasted to same chat room.</li>
<li>Multiple chat rooms should be able to function at the same time.
<ul>
<li>Each chat room should allow communication between multiple clients.
<br/></li>
</ul>
</li>
</ul></div>

<div class="Spice_it_up!_card card-content-body"><p>As the basic implementation is all done, for all the curious cats out there, these are some of the line items which can be implemented to spice up the existing functionality.
<br/></p><p>[<strong>NOTE</strong>: This is not a mandatory milestone.]</p></div>

Spice it up!

<div class="Requirements_card card-content-body"><ul>
<li>Saving the chat history on disk for later use.</li>
<li>Store the chat history of each chat separately.</li>
<li>The chat history can be saved in multiple ways
<ul>
<li>Custom objects(<code>dict</code> or objects of a class) can be created with a specified format and saved using Python's <code>pickle</code> module.</li>
<li>It can be saved as JSON-like objects using NoSQL databases such as TinyDB or MongoDB.</li>
<li>It can also be saved in a table-like structure using relational databases such as SQLite or MySQL.</li>
</ul>
</li>
</ul><div class="References"><h3>References</h3><ul>
<li><a href="https://docs.python.org/3/library/pickle.html" target="_blank">Pickle Module in Python - Documentation</a></li>
<li><a href="https://pypi.org/project/tinydb/" target="_blank">TinyDB - Documentation</a></li>
<li><a href="https://www.w3schools.com/python/python_mongodb_getstarted.asp" target="_blank">MongoDB Getting started guide</a></li>
<li><a href="https://docs.python.org/3/library/sqlite3.html" target="_blank">SQLite - Documentations</a></li>
<li><a href="https://www.w3schools.com/python/python_mysql_getstarted.asp" target="_blank">MySQL with Python - Getting started guide</a></li>
</ul></div><div class="Tip"><h3>Tip</h3><ul>
<li>Use a well-defined structure (containing sender name, message, etc.) to store each message in the chat history.</li>
</ul></div></div>

<div class="Expected_Outcome_card card-content-body"><p>The chat history for all the chat rooms should be stored in files or databases.
<br/></p></div>

<div class="Spice_it_up_X2!_card card-content-body"><p>As the basic implementation is all done, for all the curious cats out there, these are some of the line items which can be implemented to spice up the existing functionality.
<br/>
<br/></p><p>[<strong>NOTE</strong>: This is not a mandatory milestone.]
[<strong>P. S.</strong> : This milestone is independent of milestone 5. Meaning, you can skip milestone 5 and implement this one if you want to.]</p></div>

Spice it up X2!

<div class="Requirements_card card-content-body"><ul>
<li>Setup Port forwarding on your router and modify the server program accordingly.
<ul>
<li>Forward the incoming requests to router from Port X to Port Y of the local machine.</li>
</ul>
</li>
<li>Make sure all the chat tool functionality is working as expected over the internet as well.</li>
</ul><div class="References"><h3>References</h3><ul>
<li><a href="https://en.wikipedia.org/wiki/Port_forwarding" target="_blank">Port Forwarding</a></li>
<li><a href="https://stackoverflow.com/a/35385941/10861907" target="_blank">Socket Connection over Internet - 1</a></li>
<li><a href="https://stackoverflow.com/a/55196585" target="_blank">Socket Connection over Internet - 2</a></li>
</ul></div></div>

<div class="Expected_Outcome_card card-content-body"><ul>
<li>Clients on a different network should be able to connect to chat server using the server's public IP.</li>
<li>The chat tool should function as expected over the internet.
<br/></li>
</ul></div>

CONTAINER_REGULAR_TASK_ME_PROJECT_CLI_CHAT_MODULE_CLI_CHAT_TASK_1

Introduction to Multithreading in Python

CONTAINER_REGULAR_TASK_ME_PROJECT_CLI_CHAT_MODULE_CLI_CHAT_TASK_2

Introduction to Socket Programming in Python

CONTAINER_REGULAR_TASK_ME_PROJECT_CLI_CHAT_MODULE_CLI_CHAT_TASK_3

Implementing a chat tool in Python

CONTAINER_REGULAR_TASK_ME_PROJECT_CLI_CHAT_MODULE_CLI_CHAT_TASK_4

Incorporating multiple chat room functionality into the chat tool

CONTAINER_REGULAR_TASK_ME_PROJECT_CLI_CHAT_MODULE_CLI_CHAT_TASK_5

Saving chat history on the server

CONTAINER_REGULAR_TASK_ME_PROJECT_CLI_CHAT_MODULE_CLI_CHAT_TASK_6

Connecting to the chat tool over the internet

Realtime Video Processing using ChromaKey (GreenScreen) Effect

Companion App: A mental health tracker built using Flutter and Firebase.

Exploratory Analysis of Geolocational Data

Learn to create apps on Kubernetes - for beginners.

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