Daily Expenses Sharing Application

Overview

This is a backend service for managing and sharing daily expenses between users. The application allows users to add expenses and split them in three different ways: equally, by exact amounts, or by percentage. It also manages user details, validates input, and generates a downloadable balance sheet.

Key Features:

• User Management: Create, retrieve, and manage users.
• Expense Management: Add expenses with various split methods.
• Balance Sheet: Track individual expenses, total expenses, and download balance sheets.

Project Structure

├── README.md
├── app
│   ├── api
│   │   ├── users.py            # API logic for user management
│   │   ├── expenses.py         # API logic for expenses
│   │   └── users.py            # API logic for balance management
│   ├── core
│   │   └── database.py         # Database connection setup
│   ├── main.py                 # Application entry point
│   ├── models
│   │   └── models.py           # Database models for users, expenses, and balances
│   └── schemas
│       ├── users.py            # Pydantic models for user creation
│       ├── expenses.py         # Pydantic models for expense creation
│       └── balance.py          # Pydantic models for balance creation
└── requirements.txt            # Required Python packages

Setup and Installation

1. Clone the repository

git clone <repository-url>
cd <repository-directory>

2. Install dependencies

Ensure you have Python 3.9+ installed. Install the required packages:

pip install -r requirements.txt

3. Database Setup

This application uses PostgreSQL as the database. Make sure PostgreSQL is installed and running on your machine.

Create a new PostgreSQL database and update the SQLALCHEMY_DATABASE_URL in app/core/database.py to match your PostgreSQL credentials:

SQLALCHEMY_DATABASE_URL = "postgresql://<username>:<password>@localhost:5432/<database>"

4. Run the Application

Start the FastAPI server:

uvicorn app.main:app --reload

The application will be available at http://127.0.0.1:8000.

6. Data Models

Users

• User: Contains id, name, email, and mobile.

Expenses

• Expense: Contains id, amount, description, paid_by, split_method, and user_ids.

Balance

• Balance: Tracks the balance for each user, including the user_id, user_name, and amount_owed.

5. API Endpoints

The API endpoints are organized as follows:

User Endpoints:

• POST /users/: Create a new user.
• GET /users/{user_id}: Retrieve details of a specific user.
• GET /users/: Retrieve all users.

Expense Endpoints:

• POST /expenses/: Add a new expense.
• GET /expenses/{user_id}: Retrieve individual expenses for a user.
• GET /expenses/: Retrieve overall expenses.

Balance Sheet Endpoints:

• GET /balance/{user_id}: Retrieve the balance sheet for a specific user.
• GET /balance/: Retrieve overall balances for all users.
• GET /download: Download the balance sheet as a file.

6. Example Usage

Add Users

Users Table

Add Expenses

Expenses Table

Retrieve overall expenses.

Retrieve individual user expenses.

Balance Table

Balance Sheet - Show overall expenses for all users.

Download Balance Sheet

7. Interacting with the API

To interact with the API, you can use the automatically generated FastAPI documentation, which provides a user-friendly interface to explore and test the endpoints.

FastAPI Documentation UI FastAPI provides an interactive documentation UI, which can be accessed at the following paths after running the application:

Swagger UI: Navigate to http://127.0.0.1:8000/docs to access Swagger, which allows you to interact with the API directly from your browser. ReDoc: Alternatively, you can use http://127.0.0.1:8000/redoc for a different style of documentation.

License

This project is licensed under the MIT License.