📚 Advanced Library Management System (LMS)

A high-performance, industry-standard Library Management System (LMS) developed in Modern C++17. This project demonstrates a complete architectural overhaul of a traditional monolithic system, transforming it into a decoupled, polymorphic, and persistent application. It is designed as a premier educational resource for mastering Object-Oriented Programming (OOP), memory safety, and professional CLI user interface design.

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🌟 Key Features

🖥️ Professional Console Interface

• Clean Transitions: Integrated screen-clearing logic (clearScreen) ensures a modern UI where previous module data does not clutter the screen.
• Controlled Workflow: "Press Enter to Continue" prompts allow users to review system output before moving to the next action.
• Robust Input Handling: Custom template-based validation (getValidInput<T>) eliminates crashes and infinite loops caused by invalid character input.

👥 Hierarchical User Management

• Contextual Modes: Separate workflows for Teachers (Faculty), Students, and Staff.
• Borrowing Rules Logic:
  • Faculty: 90-day duration limit.
  • Students: 7-day duration limit.
  • Staff: 21-day duration limit.
• Profile Tracking: Manages Account Numbers, Names, Contact Info, DOB, and accumulated Fines.

📖 Polymorphic Inventory System

• Universal Document Support: Unified management of Books, Journals, Magazines, and Newspapers.
• Full Stock Lifecycle: Advanced features for adding stock, searching by library code, checking availability status, and deleting records.
• Transaction Tracking: Automatically records who a document was issued to, the issue date, and the expected return date.

💾 Complete Data Persistence (File Handling)

• Automatic State Recovery: Loads all users and documents from disk upon startup.
• Persistent Storage: Saves the entire library state to users.txt and docs.txt on a clean exit.
• System Security Persistence: Administrator passwords are saved in admin_pass.txt, ensuring changes to security settings are remembered across sessions.

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🏗️ Technical Architecture

The project follows professional software engineering patterns to ensure scalability and maintainability:

• Repository Pattern: Centralized data management in DirectoryUser and DirectoryDocument classes, completely separating the Business Logic from the UI (Source.cpp).
• Dynamic Memory Safety: Utilizes std::unique_ptr and std::vector to manage object lifecycles automatically, preventing memory leaks and allowing for unlimited growth of the library database.
• True Polymorphism: Uses base class interfaces (User and Document) to handle derived types uniformly, reducing code duplication by over 80%.
• Type Safety: Leverages enum class for all categorical data to prevent errors associated with "magic strings" or integers.

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🛠️ Installation & Build Guide

Prerequisites

• A C++17 compliant compiler (Visual Studio 2019/2022, GCC, or Clang).
• CMake (Version 3.10 or higher).

Method 1: Visual Studio (Recommended for Windows)

1. Open LibraryManagementSystem.sln by double-clicking it.
2. Right-click the project in the Solution Explorer and select Build.
3. Press F5 to run the application.

Method 2: CMake (Cross-Platform CLI)

# Navigate to the project root
mkdir build
cd build

# Configure and compile
cmake ..
cmake --build .

# Run the system (Executable is generated in the root directory)
../LibraryManagementSystem (or ..\LibraryManagementSystem.exe on Windows)

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📂 Project Structure

├── LibraryManagementSystem/      # Core Class Library
│   ├── DirectoryDocument.h/cpp   # Document Repository & Transactions
│   ├── DirectoryUser.h/cpp       # User Repository & Accounting
│   ├── User.h/cpp                # Base User Logic (Inheritance)
│   ├── Document.h/cpp            # Base Document Logic (Inheritance)
│   ├── Types.h/cpp               # Global Enums & Utilities
│   └── ... (Derived Classes)     # Student, Book, Journal, Staff, etc.
├── Source.cpp                    # Main Application Entry Point
├── CMakeLists.txt                # Cross-Platform Build Logic
├── README.md                     # Comprehensive Documentation
└── LibraryManagementSystem.sln   # Visual Studio Solution File

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⚖️ License & Contribution

It is open-source and intended for educational use. Students are encouraged to fork the repository to experiment with advanced C++ features or to add new modules such as a Graphical User Interface (GUI) or an SQL backend.