💳 Electronic Wallet System

A robust, console-based electronic wallet system implemented in C++17. This project demonstrates systems engineering principles by simulating a distributed financial environment where two distinct processes (Admin & Client) operate concurrently on a shared persistent state.

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🏗️ System Architecture

The system mimics a real-world distributed application where an administrative backend and a user-facing frontend share a synchronized data source.

graph TD
    User((User)) -->|Commands| Client[Remote Wallet API]
    Admin((Admin)) -->|Management| Manager[Wallet Manager API]
    
    subgraph "Persistence Layer"
        CSV[(cards.csv)]
        Log[transactions.txt]
    end
    
    Client -->|Read/Write| CSV
    Manager -->|Read/Write| CSV
    
    Client -.->|Append Logs| Log
    Manager -.->|Append Logs| Log

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✨ Key Features

🏢 Wallet Manager (wallet_manager)

• Card Issuance: Create new cards with owner details, expiration dates, and unique card numbers.
• Fund Management: Load money directly onto existing cards.
• Persistence: Automatically saves all card data to cards.csv to ensure data retention between sessions.
• System Overview: List and inspect all issued cards within the system.

🏧 Remote Wallet (remote_wallet)

• Transaction Processing: Simulate spending money at a point-of-sale.
• P2P Transfers: Securely transfer funds between two distinct cards.
• Robust Input Sanitization: Prevents data corruption via strict type checking and negative value rejection.
• Activity Logging: Every action (Transfer, Load, Spend) is timestamped and recorded in transactions.txt.

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🛠️ Technical Implementation

• Language: C++17 (utilizing STL containers, streams, and exception handling)
• Architecture: Decoupled processes interacting via shared file storage.
• Data Storage: Custom CSV parser/serializer for lightweight persistence.
• Safety: Implements try-catch blocks for robust error handling against malformed inputs.

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🚀 Getting Started

1. Prerequisites

• Compiler: GCC/G++ supporting C++17.
• OS: Windows, Linux, or macOS.

2. Compilation

For Windows Users: Run the batch file to build both executables in the bin/ directory:

.\build.bat

For Linux/Unix Users: Use the makefile to build the project:

make

3. Usage

Important: Run all commands from the project root directory so the executables can locate cards.csv.

🔧 Wallet Manager (Admin)

# Add a new card
./bin/wallet_manager.exe add_card "Visa" "1001" "John Doe" "12/28"

# Load money onto a card
./bin/wallet_manager.exe load_money "1001" 500.00

# List all cards
./bin/wallet_manager.exe list_cards

💸 Remote Wallet (User)

# Spend money from a card
./bin/remote_wallet.exe spend "1001" 25.50

# Transfer money between cards
./bin/remote_wallet.exe transfer "1001" "2002" 100.00

# View card details
./bin/remote_wallet.exe view_card "1001"

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📂 Project Structure

l4aaa-electronic_wallet_system/
├── bin/                 # Compiled executables
├── include/             # Header files (Card.h, Wallet.h, etc.)
├── src/                 # Source code (Implementation logic)
├── cards.csv            # Persistent card database
├── transactions.txt     # Transaction history log
├── build.bat            # Windows build script
├── makefile             # Linux build script
└── README.md            # Documentation

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📝 License

Distributed under the MIT License. See LICENSE for more information.