Accounting Module for POS System

A comprehensive Accounting Module for a Point-of-Sale (POS) system built using Spring Boot. This module implements double-entry bookkeeping and covers core accounting functionalities such as invoice processing, payment processing, expense tracking, and more. It is designed to be robust, scalable, and production-ready, serving the needs of both small businesses and large enterprises.

Overview

This repository contains a Spring Boot microservice that manages accounting transactions for a POS system. It demonstrates how to:

• Create invoices that automatically generate balanced journal entries.
• Process payments against invoices.
• Record operational expenses.
• Generate essential financial reports such as Income Statements, Balance Sheets, and Cash Flow Statements.
• (Optionally) Integrate with inventory and supplier management for a complete financial solution.

The module adheres to double-entry accounting principles—ensuring every transaction is recorded with equal debits and credits.

Features

• Invoice Processing:

  • Capture invoice details (invoice number, subtotal, tax rate).
  • Calculate VAT and total amount.
  • Automatically generate journal entries (Debit: Accounts Receivable; Credits: Sales Revenue and VAT Payable).

• Payment Processing:

  • Record customer payments against invoices.
  • Update invoice status ("Partially Paid" or "Paid") and adjust journal entries (Debit: Cash/Bank; Credit: Accounts Receivable).

• Expense Tracking:

  • Log operational expenses and generate corresponding accounting entries.

• Purchase Orders & Accounts Payable:

  • Record credit purchases from suppliers.
  • Process supplier payments with proper accounting entries.

• Financial Reporting:

  • Generate standard financial reports (Income Statement, Balance Sheet, Cash Flow Statement) based on aggregated journal entries.

• Advanced Tax Management:

  • Extend tax calculations to support multiple tax types.
  • Generate detailed tax reports for compliance.

• Multi-Currency Support (Optional):

  • Record transactions in different currencies.
  • Integrate with exchange rate services for currency conversion.

• Audit Trails:

  • Log every transaction with timestamps and user identifiers for complete traceability.

Roadmap

Phase 1: Core Accounting Functionalities

• Invoice Processing:
  Implement invoice creation with automatic journal entry generation.
• Payment Processing:
  Create a PaymentService to process payments and update invoice statuses.
• Expense Recording:
  Develop an ExpenseService to record and categorize business expenses.

Phase 2: Integration with Inventory and Supplier Management

• Inventory Management:
  Integrate inventory adjustments and COGS calculations during invoice processing.
• Accounts Payable:
  Build a PurchaseService to manage credit purchases and supplier payments.

Phase 3: Advanced Reporting and Tax Management

• Financial Reporting:
  Implement services for generating Income Statements, Balance Sheets, and Cash Flow Statements.
• Tax Reporting:
  Enhance tax logic and generate detailed tax reports.

Phase 4: Reconciliation and Multi-Currency Support

• Bank Reconciliation:
  Develop a service to match system records with bank statements.
• Multi-Currency Support:
  Enable transactions in multiple currencies and implement real-time currency conversion.

Phase 5: Audit and Automation

• Audit Trails:
  Integrate comprehensive logging for all transactions.
• Automation & Integration:
  Use an event-driven architecture to automate accounting entries across POS modules.

Dependencies

Key Maven dependencies include:

• Spring Boot Starter Web: For RESTful API development.
• Spring Boot Starter Data JPA: For ORM and database interactions.
• Spring Boot Starter Validation: For validating request data.
• Spring Boot Starter Actuator: For monitoring and health checks.
• springdoc-openapi-starter-webmvc-ui: For generating API documentation (Swagger UI).
• Lombok: To reduce boilerplate code.
• H2 (or MySQL/PostgreSQL): For persistence (H2 is used for development).
• Spring Boot DevTools: For hot reloading during development.
• Spring Boot Starter Test: For unit and integration testing.

Refer to the pom.xml for complete details.

How to Run

Development Mode

1. Database Configuration:
   • Use H2 for development (or configure MySQL/PostgreSQL in application.properties).
2. Run the Application:

   mvn spring-boot:run

3. Access the Endpoints:
   • API: http://localhost:8080/api/
   • Swagger UI: http://localhost:8080/swagger-ui.html
   • H2 Console (if used): http://localhost:8080/h2-console (JDBC URL: jdbc:h2:mem:accountingdb)

Production Deployment

• Configure production database settings in application.properties.
• Package the application:

  mvn clean package

• Deploy the jar using your preferred method (Docker, cloud services, etc.).

Testing

• Unit Tests: Use JUnit 5 and Mockito to test business logic.
• Integration Tests: Simulate HTTP requests using Spring Boot Test.
• Data Seeding: data.sql seeds essential accounts so that the system is immediately operational.

Contributing

Contributions are welcome! Please fork the repository and submit pull requests. Make sure your changes adhere to the project’s coding standards and include tests where applicable.

License

This project is licensed under Amar