Blackjack 21 P2P Game Architecture

Core Components

1. Game Objects

• Card: Represents a playing card with suit and value
• Deck: Collection of 52 cards, with shuffle and draw capabilities
• Hand: Collection of cards for a player or dealer, with calculation methods
• Player: Represents a user with properties like name, balance, and current hand
• Dealer: Special player that follows specific rules for playing
• Game: Manages the game state, rules, and flow

2. Network Components

• Socket Manager: Handles P2P connections between players
• Message Handler: Processes and routes game messages between clients
• Serialization Layer: Converts game state to transferable format

3. Game Logic

• Rules Engine: Implements blackjack rules (hit, stand, split, double down)
• Bet Manager: Handles coin transactions and bet placement
• Game State Manager: Tracks the current state of the game (waiting, dealing, player turns, etc.)
• Turn Manager: Controls whose turn it is and what actions are valid

4. Data Management

• Player Profile Store: Stores player information and coin balances
• Game History: Records game outcomes and significant events
• Session Manager: Manages active game sessions

Architecture Decisions

Technology Stack

• Backend: Python with socket programming for P2P connectivity
• Frontend: Pygame for game visualization and user interaction
• Data Storage: SQLite for persistent player data
• Networking: Custom socket implementation using Python's socket library

Application Structure

blackjack_p2p/
├── client/
│   ├── ui/                  # Pygame UI components
│   ├── network/             # Socket client implementation
│   └── game_client.py       # Client entry point
├── server/
│   ├── matchmaking.py       # Optional matchmaking server
│   └── lobby_server.py      # Minimal central server for discovery
├── shared/
│   ├── models/              # Game object definitions
│   │   ├── card.py
│   │   ├── deck.py
│   │   ├── hand.py
│   │   ├── player.py
│   │   └── game.py
│   ├── game_logic/          # Game rules and mechanics
│   │   ├── rules.py
│   │   ├── bet_manager.py
│   │   └── state_manager.py
│   ├── network/             # Network protocol definitions
│   │   ├── message.py
│   │   ├── serializer.py
│   │   └── p2p_manager.py
│   └── utils/               # Shared utilities
├── data/
│   ├── database.py          # Database interface
│   └── file_storage.py      # File-based storage
└── main.py                  # Application entry point

P2P Network Architecture

• Hybrid P2P Model: Use a lightweight central server for discovery, then direct P2P for gameplay
• Host-Based Games: One player hosts the game (acts as server), others connect as clients
• Fallback Mechanism: If direct P2P fails, relay through the minimal central server

Communication Protocol

• Custom message format for game events:

  {
    "type": "GAME_ACTION",
    "action": "HIT",
    "player_id": "uuid",
    "timestamp": 1234567890,
    "game_id": "uuid"
  }

Data Management Strategy

Player Data

• Store core player information (username, uuid, balance) in SQLite
• Encrypt sensitive data like balance to prevent cheating

Game State

• In-memory during active games
• Serialized for network transmission
• Basic game logs stored in text files for auditing

Session Management

• Temporary game sessions stored in memory
• Option to persist incomplete games to files for recovery