Cashback Calculator

A Flask-based web application for analyzing credit card transactions, calculating cashback rewards, and comparing against bank statements.

Features

• PDF Parsing: Extract transactions from credit card PDF statements
• Cashback Calculation: Automatically calculate cashback based on spending categories
• CSV/Excel Import: Upload transaction sheets in CSV or Excel format
• Multi-Card Support: Track multiple credit cards/issuers
• Spending Analytics: View spending breakdown by category, issuer, and month
• Cashback Comparison: Compare calculated cashback vs. stated amounts

UI Overview

The application features a dark-themed interface with four main tabs:

Overview Tab

Displays a summary dashboard with key metrics:

• Total transactions count
• Purchases (DR) and Credits (CR) breakdown
• Total spend amount
• Earned cashback amount
• Number of statements processed

Each card issuer can be expanded to show transactions grouped by month, with spend and cashback summaries per month.

Dashboard Tab

Interactive visual analytics:

• Spending by Category: Pie chart showing spending distribution across categories
• Monthly Cashback Trend: Line chart tracking cashback earnings over time
• Top Spending Categories: Bar chart ranking categories by spending
• Category Details: Expandable table with per-category statistics

Cards Tab

View all credit cards in one place:

• Each card shows total transactions, spending, and cashback
• Click to expand and see monthly breakdown
• Per-month statistics with spend and cashback totals

Transactions Tab

Complete transaction history with advanced filtering:

• Date range filter (From/To month selectors)
• Year-based filtering for each card
• Expandable month groups showing individual transactions
• Cashback comparison columns: Calculated vs Earned vs Credited
• Percentage difference indicator for each month
• Detailed transaction table with date, type, description, amount, category, rate, and cashback

UI Functionality

Navigation

• Overview: High-level summary with expandable issuer/month groups
• Dashboard: Visual charts and analytics
• Cards: Per-card transaction views
• Transactions: Complete transaction list with filtering

Header Actions

• Upload PDF: Drag and drop or click to upload credit card statements
• Clear All: Remove all data from the system
• Reload: Re-process all uploaded PDFs

Date Filtering

• Select From/To months to filter all views
• Click "All" to show complete transaction history
• Filters apply across Overview, Dashboard, and Transactions tabs

Transaction Details

Each transaction displays:

• Date and description
• Transaction type (DR = Purchase, CR = Credit)
• Amount in local currency
• Auto-detected category
• Cashback rate applied
• Calculated cashback amount

Cashback Rates

Category	Rate
Grocery	10%
Dining	10%
Utilities	10%
Airtel	25%
Fuel	1%
Travel	1%
Entertainment	1%
Shopping	1%
Default	1%

Note: Airtel cashback is capped at Rs. 250 per month.

Project Structure

Cashback Calculator/
├── app.py              # Flask application and API endpoints
├── requirements.txt    # Python dependencies
├── backend/
│   ├── pdf_parser.py         # PDF statement parser
│   ├── cashback_calculator.py # Cashback calculation logic
│   └── data_manager.py        # Data storage and organization
├── data/
│   └── transactions.json      # Transaction data storage
├── uploads/             # Uploaded PDF files
└── static/              # Frontend files

Setup

1. Create virtual environment:

   python -m venv venv

2. Activate virtual environment:

   • Windows: venv\Scripts\activate
   • Mac/Linux: source venv/bin/activate

3. Install dependencies:

   pip install -r requirements.txt

Run

python app.py

The application runs at http://localhost:5000

API Endpoints

Method	Endpoint	Description
GET	/api/transactions	Get all transactions with organized data
GET	/api/transactions/csv	Get transactions from JSON file
POST	/api/upload-pdf	Upload and parse a PDF statement
POST	/api/upload-sheet	Upload CSV/Excel sheet
POST	/api/reload-data	Reload all transactions from PDFs
GET	/api/compare	Compare calculated vs stated cashback
POST	/api/clear	Clear all stored data
GET	/api/debug	Debug info about stored data

Transaction Data Format

Transactions are stored in data/transactions.json:

{
  "date": "2026-03-15",
  "description": "AMAZON MARKETPLACE",
  "amount": 45.99,
  "transaction_type": "DR",
  "card_issuer": "Chase Sapphire",
  "category": "Shopping",
  "is_credit": false,
  "calculated_cashback": 0.46
}

License

MIT