Go E-Commerce API

This project provides a RESTful API for a basic e-commerce platform built using Go, Gin, and GORM. It includes endpoints for user management, product catalog, categories, wishlists, and shopping carts.

Table of Contents

• Features
• Technologies Used
• Prerequisites
• Setup
• Environment Variables
• Running the Application
• API Endpoints
  • User Management
  • Product Management
  • Category Management
  • Wishlist Management
  • Cart Management
• Database
• Error Handling
• Authentication/Authorization (TODO)
• Input Validation
• License

Features

• User Management: Create, list, get, update, and delete user accounts.
• Product Management: Create, list, get, update, and delete products.
• Category Management: Create, list, get, update, and delete product categories.
• Wishlist Management: Add products to a user's wishlist, view a user's wishlist, view all wishlists and remove items from a wishlist.
• Cart Management: Add products to a user's shopping cart, view a user's cart, update quantities of items in the cart, and remove items from the cart.
• Database Seeding: Seed initial categories and products for development/testing.
• Automatic Database Migrations: GORM automatically migrates the database schema based on the defined models.

Technologies Used

• Go: Programming language
• Gin: Web framework
• GORM: ORM (Object-Relational Mapper) for database interaction
• MySQL: Database (but easily adaptable to other databases supported by GORM)
• godotenv: For loading environment variables from a .env file

Prerequisites

• Go installed (version 1.18 or higher)
• MySQL database server running
• make command installed (optional, but recommended for convenience)

Setup

1. Clone the repository:

   git clone <repository_url>
   cd <project_directory>

2. Install dependencies:

   go mod download

3. Create a .env file:

   Copy the example .env.example file to .env and configure the database connection settings:

   cp .env.example .env

   Edit .env and fill in the appropriate values.

Environment Variables

The following environment variables are required:

• PORT: The port the application will listen on (e.g., 8080).
• DB_USER: The MySQL database user.
• DB_PASSWORD: The MySQL database password.
• DB_HOST: The MySQL database host (e.g., localhost).
• DB_PORT: The MySQL database port (e.g., 3306).
• DB_NAME: The MySQL database name.
• SEED_PRODUCT_COUNT: The number of products to seed when the application starts (optional).

Running the Application

1. Initialize the database:

   The application automatically runs database migrations on startup. Ensure your MySQL server is running and the connection details in .env are correct.

2. Run the application:

   go run main.go

   The application will start, and you can access the API endpoints.

API Endpoints

All API endpoints return JSON responses.

User Management

• POST /api/users: Create a new user. Requires JSON body with user details (firstName, lastName, email, password, phone, address).
• GET /api/users: List all users.
• GET /api/users/:userid: Get a single user by ID.
• PATCH /api/users/:userid: Update an existing user. Requires JSON body with the fields to update.
• DELETE /api/users/:userid: Delete a user.

Product Management

• POST /api/product: Create a new product. Requires JSON body with product details (SKU, name, description, price, categoryID).
• GET /api/product: List all products.
• GET /api/product/:productid/: Get a single product by ID.
• PATCH /api/product/:productid/: Update an existing product. Requires JSON body with the fields to update.
• DELETE /api/product/:productid/: Delete a product.

Category Management

• POST /api/categories: Create a new category. Requires JSON body with category details (name, description).
• GET /api/categories: List all categories.
• GET /api/categories/:categoryid/: Get a single category by ID.
• PATCH /api/categories/:categoryid/: Update an existing category. Requires JSON body with the fields to update (name, description).
• DELETE /api/categories/:categoryid/: Delete a category.

Wishlist Management

• POST /api/wishlists: Add a product to a user's wishlist. Requires JSON body with userID and productID.
• GET /api/wishlists/:userid/: View a user's wishlist.
• GET /api/wishlists: View all wishlists.
• DELETE /api/wishlists/:wishlistid/: Remove an item from a user's wishlist.

Cart Management

• POST /api/carts: Add a product to a user's shopping cart. Requires JSON body with userID, productID, and quantity.
• GET /api/carts/:userid/: View a user's shopping cart.
• PATCH /api/carts/:cartid/: Update the quantity of an item in a user's shopping cart. Requires JSON body with quantity.
• DELETE /api/carts/:cartid/: Remove an item from a user's shopping cart.

Database

The application uses a MySQL database. The database schema is automatically created and updated by GORM based on the model definitions in models/models.go. The following tables are created:

• users
• products
• categories
• wishlists
• carts

Error Handling

The API uses a consistent error handling pattern:

• 400 Bad Request: For invalid requests (e.g., missing required fields, invalid data types).
• 404 Not Found: For requests to non-existent resources.
• 500 Internal Server Error: For unexpected server errors.

Error messages are returned in JSON format with a message field.

Authentication/Authorization (TODO)

Important: Currently, there is NO authentication or authorization implemented in this project. All API endpoints are publicly accessible.

Future development should include:

• User Authentication: Implement user login/registration using a secure authentication mechanism (e.g., JWTs - JSON Web Tokens).
• Authorization: Implement authorization rules to restrict access to resources based on user roles and permissions.

Input Validation

The API uses Gin's binding and validation features to validate input data. The binding:"required" tag is used to mark required fields. Custom validation logic can be added as needed.

License

This project is licensed under the MIT License.