Invoice Management System (IMS) CLI

Overview

A CLI-based Invoice Management System for small businesses. Supports user authentication, company and client management, invoice processing, and company user administration.

---

Features

👤 User Management

• Register and login with secure password hashing (BCrypt)
• Masked email logging
• Account deletion with cascade cleanup

🏢 Company Management

• Create companies with unique organization numbers
• Multi-user associations
• Manage company info (address, contact details)

👥 Client Management

• CRUD operations for clients
• Company-scoped clients
• Store name, address, email, and phone

📄 Invoice Management

• Full lifecycle: CREATED → SENT → PAID → OVERDUE → CANCELLED
• Add items with quantity and pricing
• Automatic total calculation
• Client-specific invoice tracking

🔐 Validation & Security

• Email format validation
• Business rule enforcement
• Entity existence validation
• SQL injection prevention via JPA

---

Architecture

Domain Model:

User ↔ CompanyUser ↔ Company ↔ Client
↳ Invoice ↔ InvoiceItem

Entities:

• User: System credentials
• Company: Business entity with unique org number
• CompanyUser: Many-to-many relationships
• Client: Company-associated customer
• Invoice: Financial document
• InvoiceItem: Line items

Design Patterns: Repository, DTO, Dependency Injection, Builder

---

Getting Started

Prerequisites:

• Java 21+
• Maven 3.6+
• Docker

Installation:

git clone https://github.com/ithsjava25/project-jpa-grupp-3-d.git
cd project-jpa-grupp-3-d
mvn clean compile
mvn exec:java -Dexec.mainClass="org.example.InvoiceManagementApplication"

Usage Guide

1. Authentication
Register or login
Password validation ≥8 chars
Email format check

2. Company Setup
Create new company (auto-associate creator)
Select existing company
Manage company information

3. Main Operations
Client Management: CRUD clients
Invoice Management: Create invoices, add items, update status
Company Users: Invite/remove users
Company Settings: Update info

4. Invoice Workflow
Select client
Enter invoice number & due date
Add items
Review totals & save

Project Structure

src/main/java/org/example/
├── auth/        # Authentication services
├── entity/      # Domain entities & DTOs
│   ├── user/
│   ├── company/
│   ├── client/
│   └── invoice/
├── repository/  # Data access
├── service/     # Business logic
├── exception/   # Custom exceptions
└── util/        # Utilities

Testing

mvn test

• Unit & integration tests
• Business rule validation
• Exception handling

Configuration

• Database: MySQL 9.5.0, auto-generated schema, UUID PKs, timestamp auditing
• Logging: SLF4J with debug/info, masked emails, transaction logs

Sample Operations

Invoice

• Select client
• Enter invoice number & due date
• Add line items
• Save & review total

Company Users

• List company users
• Invite by email
• Remove user from a company

Invoice Status Flow

CREATED → SENT → PAID
         ↘ OVERDUE
         ↘ CANCELLED

Business Rules

• Unique company org numbers
• Unique invoice numbers per company
• Users cannot remove themselves
• Clients belong to a single company
• Invoice requires ≥1 item