# ClientServer

A Java-based ☕️↔️ UDP client-server chat 💬 system with automatic 🔄 text-to-emoji 😊 conversion using Mistral API.

## Features

### Available Commands

- `/list` : Display connected clients list
- `/msg <nickname> <message>` : Send private message to specific client
- `/help` : Display help with all available commands
- `/disconnect` : Clean server disconnection
- `<message>` : Broadcast message translated to emojis to all connected clients

### Technical Features

- UDP Communication
- Multi-threading for client handling
- Mistral API for text-to-emoji conversion
- Disconnection handling

## Build

```bash
./gradlew build
```

## Run

### Client

```bash
./gradlew runClient
```

The client will ask for a pseudo, an IP (type `localhost` if server and clients are on the same machine), and a port (type `6666` by default).

### Server

```bash
./gradlew runServer
```

## Configuration

Create a `config.properties` file at project root (`ClientServer/app/config.properties`) with:

```properties
mistral.api.key=your_api_key
```

Replace `your_api_key` with your actual Mistral API key. Create one for free at https://console.mistral.ai/api-keys. If no API key is provided, the server will not be able to convert broadcasted messages to emojis and empty broadcasted messages will be sent.

## Documentation

### Sequence Diagram

```mermaid
sequenceDiagram
    participant MainServer

    participant Alice
    Note over Alice: Creates DatagramSocket
    Alice->>+MainServer: Sends username "Alice"
    Note over MainServer: Creates new socket<br/>for AliceHandler
    create participant AliceHandler
    MainServer->>AliceHandler: Create new handler thread
    MainServer->>-Alice: PORT:{AlicePort}

    participant Bob
    Bob->>+MainServer: Sends username "Bob"
    Note over MainServer: Creates new socket<br/>for BobHandler
    create participant BobHandler
    MainServer->>BobHandler: Create new handler thread
    MainServer->>-Bob: PORT:{BobPort}

    rect rgb(200, 200, 255)
        Note over Alice,Bob: Chat loop
        Alice->>+AliceHandler: "Hi everyone!"
        Note over AliceHandler: Converts to emojis
        AliceHandler->>+BobHandler: Broadcast message
        BobHandler->>-Bob: "Alice: 👋👩‍👩🌍🎉"
        AliceHandler->>-Alice: Message sent

        Bob->>+BobHandler: "Hello Alice, how are you?"
        Note over BobHandler: Converts to emojis
        BobHandler->>+AliceHandler: Broadcast message
        AliceHandler->>-Alice: "Bob: 👋🏻👩🏼‍🦰🐰🤔👩🏼‍🦰🐇💬👩🏼‍🦰🐰👍🏻😊👩🏼‍🦰🐇👋🏻"
        BobHandler->>-Bob: Message sent
    end

    Alice->>+AliceHandler: /disconnect
    Note over AliceHandler: Removes Alice<br/>from map
    AliceHandler->>-Alice: Disconnection confirmation
    AliceHandler->>MainServer: Thread terminated
    MainServer-->>AliceHandler: destroy

    Bob->>+BobHandler: /disconnect
    Note over BobHandler: Removes Bob<br/>from map
    BobHandler->>-Bob: Disconnection confirmation
    BobHandler->>MainServer: Thread terminated
    MainServer-->>BobHandler: destroy

    Note over Alice,Bob: Close sockets
```