Mongo Calculator

A console-based calculator that saves and loads operations using MongoDB. Supports addition, subtraction, multiplication, and division, with persistent storage for previously run operations.

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✨ Features

• Run calculations directly in the console (CLI).
• Supports +, -, *, /.
• Each operation is stored as a MongoDB document.
• Load and re-run previous operations from the database.
• Simple, lightweight code structure.

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📦 Technologies

• Java 17+
• MongoDB (as storage backend)
• Lombok (for boilerplate reduction)
• BSON (MongoDB document format)

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📂 Project Structure

me.wabuein.calc
 └── operation
      ├── Operation.java        # Represents a calculation, can be saved/loaded
      ├── OperationType.java    # Enum: ADD, SUBTRACT, MULTIPLY, DIVIDE
      └── OperationStage.java   # Enum for input stages (A, B, Operation type)

• Operation – Holds operands (a, b), operation type, and can convert to/from MongoDB Document.
• OperationType – Enum of supported operations.
• OperationStage – Guides user input stages (setting first number, second number, operation).

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⚡ Usage

1. Clone the repository:

   git clone https://github.com/<your-username>/<repo-name>.git
   cd <repo-name>

2. Ensure you have MongoDB running locally (mongodb://localhost:27017 by default).

3. Build & run the project:

   ./mvnw clean install
   java -jar target/mongo-calculator.jar

4. Follow console prompts to:

   • Enter number A
   • Enter number B
   • Choose an operation type

5. The result is printed and saved to MongoDB.

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🗂 Example Mongo Document

Each operation is stored like this:

{
  "a": 10,
  "b": 5,
  "type": "ADD"
}

📄 Configuration File (config.txt)

mongo:
  uri-mode: false
  normal:
    host: 127.0.0.1
    port: 27017
    auth:
      enabled: false
      username: ''
      password: ''
  uri:
    database: Calculator
    connection-string: mongodb://127.0.0.1:27017/Calculator

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📜 License

MIT – feel free to use and adapt.