iFitness Backend

A RESTful service for managing gym memberships and billing structures.

Overview

Fitness+ offers gym memberships with various billing structures. Some memberships are annual with a single upfront payment, while others have monthly dues. Additionally, members can subscribe to optional add-on services (personal training sessions, towel rentals) with separate monthly charges. Here's the twist:

• For new members, the first invoice combines the annual membership fee with the first month's charges for any add-on services they choose.

• In subsequent months, only the monthly charges for the add-on services are billed.

Task

Develop a backend system that implements the following functionalities based on your expertise in these frameworks to build a robust and scalable backend API. Consider Nest.js, Postgresql, well-documented RESTful APIs and you can use your Gmail SMTP server to send out the mails.

1. Data Model:

• Design a data model to store information about gym memberships, including:

  • Membership ID (unique identifier)
  • First Name
  • Last Name
  • Membership type (e.g., Annual Basic, Monthly Premium)
  • Start date
  • Due date (for annual memberships) or monthly due date (for add-on services)
  • Total amount (for annual memberships) or monthly amount (for add-on services)
  • Member email address
  • IsFirstMonth (boolean flag indicating if it's the first month of the membership)
  • (Optional) Link to the detailed membership invoice

2. Cron Job Implementation:

• Develop a cron job that will run periodically (e.g., daily) to check for upcoming membership fees.

• The cron job should:

  • Query the database for memberships with upcoming due dates.

  • Differentiate between annual memberships and add-on services, considering the isFirstMonth flag.

  • For new members (first month):

    • Calculate the reminder date (e.g., 7 days before the due date) based on the annual membership due date.

    • Send an email reminder with the membership type, total amount for the combined annual fee and first month's add-on service charges, and a link to the full invoice detailing both.

  • For existing members (subsequent months):

    • Check if the current date falls within the month for which the add-on service applies.

    • If yes, send an email reminder with the service name, monthly amount, and a link to the invoice for that specific month's add-on service charge.

3. Email Functionality:

   • Implement a mechanism to send email reminders using an email service provider (ESP) or a local mail server (your choice).

   • The email should contain:

     • Subject: Fitness+ Membership Reminder - [Membership Type]

     • Body: A message reminding the member about the upcoming payment, including the membership details (type, due date for annual or month for add-on services), and a link to the relevant invoice. Clearly differentiate between the first month's combined invoice and subsequent month's add-on service invoices in the message.

Project Structure

Overall, the project is designed to be scalable, maintainable and extensible. The use of a modular monolithic architecture, where all key features are modularized. This can easily spin off to a micro-service that easily promotes code organization and separation of concerns.

Tech Stack

• Node.js
• NestJS
• TypeScript
• TypeORM
• PostgreSQL
• Redis for caching.
• Bull for handling email queue notifications

Application Requirements

• Docker
• Git
• Postman
• Mailtrap or any free email delivery platform to manage email infrastructure.

Rename.env.dev to .env and populate variables only with ****

Installation 📦

   $ git clone https://github.com/sheygs/iFitness-backend.git
   $ cd iFitness-backend
   $ yarn

Seeding

• Run yarn run:migration to seed tables with sample data

Using Docker (Recommended)

• Run docker-compose up -d.
• Open the browser and visit http://localhost:3001

Test

# unit tests
$ yarn run test

API Documentation

• Navigate to http://localhost:3001/api-docs on your computer to view the openapi documentation.