Vendor Management System

A comprehensive Django REST Framework-based Vendor Management System with JWT authentication, automated reminders, and full CRUD operations for vendors and their services/contracts.

Installation & Setup

Prerequisites

• Python 3.8 or higher
• pip (Python package manager)

Step 1: Clone/Download the Project

cd /path/to/assignment

Step 2: Create Virtual Environment (Recommended)

# Linux/Mac
python3 -m venv venv
source venv/bin/activate

# Windows
python -m venv venv
venv\Scripts\activate

Step 3: Install Dependencies

pip install -r requirements.txt

Step 4: Run Migrations

python manage.py makemigrations
python manage.py migrate

Step 5: Create Superuser (Optional)

python manage.py createsuperuser

This allows you to access the Django admin panel at /admin/

Step 6: Run Development Server

python manage.py runserver

The API will be available at http://127.0.0.1:8000/

Step 7: Configure Email Settings (Optional)

Edit project/settings.py and uncomment/configure SMTP settings for production:

EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'
EMAIL_HOST = 'smtp.gmail.com'
EMAIL_PORT = 587
EMAIL_USE_TLS = True
EMAIL_HOST_USER = 'your-email@gmail.com'
EMAIL_HOST_PASSWORD = 'your-password'
DEFAULT_FROM_EMAIL = 'your-email@gmail.com'
ADMIN_EMAIL = 'admin@example.com'  # For reminder notifications

Step 8: Insert Dummy Data

python manage.py insert_dummy_data.py

Authentication

JWT Authentication

All vendor and service management endpoints require JWT authentication. Include the access token in the Authorization header:

Authorization: Bearer <access_token>

Authentication Endpoints

1. Register a New User

POST /api/register/
No authentication required

Request Body:

{
  "username": "johndoe",
  "email": "john@example.com",
  "password": "securepassword123",
  "password2": "securepassword123",
  "first_name": "John",
  "last_name": "Doe"
}

2. Obtain JWT Token (Login)

POST /api/token/
No authentication required

Request Body:

{
  "username": "johndoe",
  "password": "securepassword123"
}

Response:

{
  "access": "eyJ0eXAiOiJKV1QiLCJhbGc...",
  "refresh": "eyJ0eXAiOiJKV1QiLCJhbGc..."
}

3. Refresh JWT Token

POST /api/token/refresh/

Request Body:

{
  "refresh": "eyJ0eXAiOiJKV1QiLCJhbGc..."
}

Returns a new access token.

4. Verify JWT Token

POST /api/token/verify/

Request Body:

{
  "token": "eyJ0eXAiOiJKV1QiLCJhbGc..."
}

Token Configuration

• Access Token Lifetime: 1 hour
• Refresh Token Lifetime: 7 days
• Token Rotation: Enabled
• Header Format: Authorization: Bearer <token>

Add Cron Jobs to send expired and payment due emails

0 9 * * * /path/to/assignment/venv/bin/python manage.py check_reminders --days 15

API Documentation

Base URL

All API endpoints are prefixed with /api/

Note: All endpoints below require JWT authentication unless otherwise specified.

Pagination

All list endpoints support pagination with a default page size of 20 items.

Query Parameters:

• ?page=1 - Get specific page
• ?page_size=20 - Change page size

Response Format:

{
  "count": 100,
  "next": "http://localhost:8000/api/vendors/?page=2",
  "previous": null,
  "results": [...]
}

Vendors Endpoints

List All Vendors (Paginated)

GET /api/vendors/
Requires authentication

Returns paginated list of vendors with their services.

Query Parameters: ?page=1&page_size=20

Get Vendor Details

GET /api/vendors/{id}/
Requires authentication

Returns vendor with all services.

Create Vendor

POST /api/vendors/
Requires authentication

Request Body:

{
  "name": "Vendor Name",
  "contact_person": "John Doe",
  "email": "vendor@example.com",
  "phone": "+1234567890",
  "status": "Active"
}

Update Vendor

PUT/PATCH /api/vendors/{id}/
Requires authentication

Delete Vendor

DELETE /api/vendors/{id}/
Requires authentication

List Vendors with Active Services Only (Paginated)

GET /api/vendors/list_with_active_services/
Requires authentication

Returns paginated list of vendors with only their active services.

Query Parameters: ?page=1&page_size=20

Services Endpoints

List All Services (Paginated)

GET /api/services/
Requires authentication

Returns paginated list of services with vendor information.

Query Parameters: ?page=1&page_size=20

Get Service Details

GET /api/services/{id}/
Requires authentication

Returns service with vendor information and status color.

Create Service

POST /api/services/
Requires authentication

Request Body:

{
  "vendor": 1,
  "service_name": "Service Name",
  "start_date": "2024-01-01",
  "expiry_date": "2024-12-31",
  "payment_due_date": "2024-12-15",
  "amount": "1000.00"
}

Update Service

PUT/PATCH /api/services/{id}/
Requires authentication

Delete Service

DELETE /api/services/{id}/
Requires authentication

Get Services Expiring in Next 15 Days (Paginated)

GET /api/services/expiring_soon/
Requires authentication

Returns paginated list of services expiring within 15 days.

Query Parameters: ?page=1&page_size=20

Get Services with Payment Due in Next 15 Days (Paginated)

GET /api/services/payment_due_soon/
Requires authentication

Returns paginated list of services with payment due within 15 days.

Query Parameters: ?page=1&page_size=20

Check and Send Reminders

GET/POST /api/services/check_reminders/
Requires authentication

POST /api/services/check_reminders/ with body: {"days": 15}
GET /api/services/check_reminders/ (uses default 15 days)

Checks services and sends email notifications for those expiring or with payment due within the specified number of days (default: 15).

Get Services Grouped by Color Codes

GET /api/services/services_by_color/
Requires authentication

Returns services grouped by status color:

• red: Expired services
• orange: Payment overdue
• yellow: Expiring/payment due soon (within 15 days)
• green: Active and healthy
• gray: Other statuses

Dependencies

See requirements.txt for complete list:

• Django 5.2.8
• djangorestframework 3.16.1
• djangorestframework-simplejwt 5.5.1
• PyJWT 2.10.1
• pandas 2.3.3

License

This project is part of an assignment for vendor management system implementation.