Wallet Transaction System

The Wallet Transaction System is a Ruby on Rails API application designed to handle wallet-based financial transactions. It provides endpoints for managing wallets, creating different types of transactions (credit, debit, and transfer), and ensuring secure access through JWT authentication.

Features

• JWT Authentication: Secure authentication with JSON Web Tokens (JWT).
• Polymorphic Wallet Model: Each user can have a wallet with a polymorphic association to allow for flexibility.
• Transaction Types: Supports multiple transaction types such as credit, debit, and transfer.
• Balance Calculation: Calculates wallet balance based on transactions.
• Validation: Ensures transactions are correctly validated based on type (e.g., debit transactions ensure sufficient funds).

Installation

1. Clone the Repository:

   git clone <repository-url>
   cd wallet_transaction_system

2. Install Dependencies: Make sure you have Ruby and Bundler installed, then run:

   bundle install

3. Database Setup: Set up the database by running the migrations:

   rails db:create
   rails db:migrate

4. Environment Variables:

   • Set the SECRET_KEY_BASE for JWT encoding/decoding. You can generate one with:

     rails secret

   • Add this key to your environment variables, e.g., in .env:

     SECRET_KEY_BASE=<your-secret-key>
     

5. Run the Server: Start the Rails server:

   rails server

API Endpoints

Authentication

• Register: POST /register

  • Parameters: username, password
  • Returns: User information upon successful registration.

• Login: POST /sessions

  • Parameters: username, password
  • Returns: JWT token on successful login.

Wallets

• List Transactions: GET /wallet_transactions

  • Requires JWT token.
  • Returns: List of all transactions for the authenticated user’s wallet.

• Create Transaction: POST /wallet_transactions

  • Parameters:
    • amount: Decimal
    • transaction_type: String (one of credit, debit, transfer)
    • target_wallet_id (for transfers)
  • Requires JWT token.
  • Returns: Success or error message based on transaction validation.

Stock API

• List Available Stocks: GET /stocks

  • Requires JWT token.
  • Returns: List of available stocks.

• Purchase Stock: POST /stocks/purchase

  • Parameters:
    • stock_id: ID of the stock
    • quantity: Number of shares to purchase
  • Requires JWT token.
  • Returns: Confirmation of purchase or error message if validation fails.

Models

User

• Fields:
  • username: Unique identifier for the user.
  • password_digest: Encrypted password (handled via has_secure_password).

Wallet

• Polymorphic association with User.
• Methods:
  • transaction_balance: Returns the total balance based on transactions.

WalletTransaction

• Fields:
  • amount: Decimal
  • transaction_type: Enum (credit, debit, transfer)
• Validations:
  • Ensures amount is non-zero.
  • Custom validations for positive/negative amounts based on transaction_type.

Transaction Subclasses

• CreditTransaction: Ensures amount is positive.
• DebitTransaction: Ensures amount is negative and user has sufficient balance.
• TransferTransaction: Checks for valid target wallet and balance.

Testing

1. Run All Tests:

   rails test

2. Controller Tests: Ensure the API endpoints work as expected.

3. Model Tests: Test validations, associations, and custom logic.

Usage

1. Register a user to create an account.
2. Authenticate to obtain a JWT token.
3. Use the JWT token in the Authorization header for all subsequent requests.
4. Create transactions by specifying an amount and transaction_type. For transfer transactions, specify the target_wallet_id.

License

This project is open-source under the MIT License.