Budget Planning Assistant (Advanced Version)

A web-based financial assistant to manage monthly budgets, track categorized expenses, and visualize spending. Built with Flask (REST API + Jinja2), MySQL, SQLAlchemy, and Chart.js.

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Features

• Create, read, update, delete (CRUD) budgets and expenses
• Categorize expenses (food, bills, travel, etc.)
• RESTful API (Flask-RESTful)
• Data stored in MySQL
• Data visualization with Chart.js (frontend)

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Prerequisites

• Python 3.8+
• MySQL Server (running on localhost:3306)
• pip (Python package manager)

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Database Setup

1. Start MySQL server.
2. Create the database:

   CREATE DATABASE budjet_planning_assistant;

3. (Optional) Create user: If you want a user other than root, create and grant privileges:

   CREATE USER 'youruser'@'localhost' IDENTIFIED BY 'yourpassword';
   GRANT ALL PRIVILEGES ON budjet_planning_assistant.* TO 'youruser'@'localhost';
   FLUSH PRIVILEGES;

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Backend Setup

1. Navigate to backend folder:

   cd backend

2. Create .env file (if not present):

   DATABASE_URL=mysql://root:rootpassword@localhost:3306/budjet_planning_assistant
   

3. Install dependencies:

   pip install -r requirements.txt

4. Initialize the database tables: Open a Python shell in the backend folder:

   from app import db
   db.create_all()

5. Run the backend server:

   python app.py

   The API will be available at http://localhost:5000/api/

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Frontend Setup

1. Navigate to frontend folder:

   cd ../frontend

2. Install Flask (if needed):

   pip install Flask

3. Run the frontend server:

   python app.py

   The frontend will be available at http://localhost:5001/

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API Testing

• Use Postman or similar tool to test endpoints:
  • GET/POST/PUT/DELETE http://localhost:5000/api/budgets
  • GET/POST/PUT/DELETE http://localhost:5000/api/expenses

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Notes

• Update .env with your actual MySQL credentials if different.
• For custom SQL, use backend/mysql_connector.py.
• Data visualization (charts) is handled in the frontend (to be implemented).

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Project Structure

BTech1stYear-BudgetPlanningAssistant/
  backend/
    app.py
    models.py
    db.py
    resources/
    requirements.txt
    mysql_connector.py
    .env
  frontend/
    app.py
    templates/
    static/
  README.md

Known Bugs and How to Fix Them

This project intentionally contains 4 bugs for learning and debugging practice. Here are the bugs and how to solve them:

1. Backend: Budget Creation Allows Negative Amounts

Bug: You can create a budget with a negative amount via the API or frontend. How to Fix:

• In resources/budget.py, add a check in the post and put methods to reject negative amounts and return an error message.

2. Backend: Expense Date Not Validated

Bug: The API accepts any string for the expense date, even invalid dates (e.g., 'not-a-date'). How to Fix:

• In resources/expense.py, validate the date field using datetime.strptime and return an error if the format is invalid.

3. Frontend: Budgets Page Crashes if Backend is Down

Bug: If the backend API is not running, the /budgets page throws an unhandled exception and shows an error page. How to Fix:

• In frontend/app.py, wrap the requests.get call in a try/except block and show a user-friendly error message if the backend is unreachable.

4. Frontend: Expense Edit Form Does Not Pre-fill Values on Error

Bug: If you try to edit an expense and the backend returns an error (e.g., invalid data), the form reloads but does not pre-fill the previous values. How to Fix:

• In frontend/app.py, when handling the edit POST, if the backend returns an error, re-render the form with the submitted values and the error message.

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For more details, see the code comments in the relevant files.