Dating App Backend

A backend system for a dating app (similar to T*nder/B*mble) built using Golang and the Echo framework. The app includes features like profile management, swipe functionality, subscriptions, and payments. The backend uses PostgreSQL as the primary database and GORM for ORM.

Features

• User Registration & Authentication (JWT)
• Profile Management with verification label for premium users
• Swipe functionality with swipe quota limit and view restriction
• Premium feature subscriptions with options for verified label or no swipe quota
• Database schema with constraints and relationships to support complex functionalities
• Custom middleware for authentication

Prerequisites

• Golang >= 1.18
• PostgreSQL >= 13

Setup & Installation

1. Clone the Repository:

   git clone https://github.com/fanajib5/kopelko-dating-app-backend.git
   cd kopelko-dating-app-backend

2. Install Dependencies:

   go mod download

3. Environment Variables: Create a .env file at the root level with the following variables:

   # Application configuration
   API_PORT=3000
   LIMIT_SWIPE=10
   
   # Database credentials
   DB_HOST=localhost
   DB_USER=yourusername
   DB_PASSWORD=yourpassword
   DB_NAME=yourdatabase
   DB_PORT=5432
   DB_TIMEZONE=youtimezone
   
   # JWT credential
   JWT_SECRET=yourjwtsecret

4. Database Setup: Run migrations to set up the PostgreSQL database tables and enum types:

   go run databases/migrations/migrate.go

   Run seeders for initial premium feature records:

   go run databases/seeders/seed.go

5. Run the Application: Start the server using:

   go run main.go

   The API will be available at http://localhost:8080.

Code Structure

Kopelko-Dating-App/
├── .env                        # Environment variables for sensitive data
├── .env.example                # Sample environment file for reference
├── .gitignore                  # Git ignore file to avoid committing unnecessary files
├── go.mod                      # Go module file, manages project dependencies
├── go.sum                      # Dependency checksum file
├── main.go                     # Main entry point for the application
├── README.md                   # Documentation for the project setup, structure, and usage
├── config/                     # Configuration files and setup
│   └── config.go               # Loads and parses environment variables
├── controllers/                # Handles HTTP request processing and response generation
│   ├── auth.go                 # Controller for authentication endpoints
│   ├── profile.go              # Controller for profile-related endpoints
│   ├── subscription.go         # Controller for subscription-related endpoints
│   └── swipe.go                # Controller for swipe functionality
├── databases/                  # Database migration and seeding management
│   ├── migrations/             # Database migration files
│   │   ├── migration.go        # Migration setup that execute the SQL file
│   │   └── schema.sql          # SQL script for initial schema setup
│   └── seeders/                # Seed data setup for initial database population
│       ├── seeder.go           # Seed management that execute the SQL file
│       └── seeder.sql          # SQL file for initial data
├── dto/                        # Data Transfer Objects for request and response validation
│   ├── login_request.go        # DTO for login request validation
│   └── register_request.go     # DTO for register request validation
├── middlewares/                # Custom middleware functions for the app
│   ├── httphelper.go           # Helper functions for HTTP responses
│   ├── middleware.go           # Authentication and logging middleware setup
│   └── validator.go            # Custom validator functions
├── models/                     # Defines database schemas using GORM models
│   ├── premium_feature.go      # Premium feature model
│   ├── profile.go              # Profile model
│   ├── profile_view.go         # Profile view model
│   ├── subscription.go         # Subscription model
│   ├── swipe.go                # Swipe model
│   └── user.go                 # User model
├── repositories/               # Data access layer to manage database interactions
│   ├── premium_feature.go      # Repository for premium feature operations
│   ├── profile.go              # Repository for profile operations
│   ├── profile_view.go         # Repository for profile view operations
│   ├── subscription.go         # Repository for subscription operations
│   ├── swipe.go                # Repository for swipe operations
│   └── user.go                 # Repository for user operations
├── routes/                     # API route registration
│   └── routes.go               # Define and group routes for each resource
├── services/                   # Core business logic for different functionalities
│   ├── auth.go                 # Service for authentication logic
│   ├── match.go                # Service for match-related logic
│   ├── profile.go              # Service for profile-related logic
│   ├── subscription.go         # Service for subscription-related logic
│   └── swipe.go                # Service for swipe functionality
├── tests/                      # Testing resources
│   └── Kopelko_Dating_App.postman_collection.json  # Postman tests for API endpoints
└── utils/                      # Utility functions for the app
    ├── db.go                   # Database connection setup
    └── jwt.go                  # JWT token generation and verification

Explanation of Key Components

• Main Application (main.go): The main entry point sets up the Echo framework and initializes configuration, routing, and middleware. It brings together the components in controllers, routes, and middlewares.

• Configuration (config): This package loads environment variables from .env and manages app configuration using config.go.

• Controllers: These files contain HTTP handler functions for different routes. Each controller organizes endpoint logic (authentication, profile handling, subscriptions, and swipes), calling corresponding services.

• Database Management (databases): Contains migration and seeding scripts. The migrations folder holds database schema creation scripts, while the seeders folder provides initial data for testing or development purposes.

• Data Transfer Objects (dto): Defines structures to handle data validation for incoming requests, allowing separation between request validation and business logic.

• Middleware: Manages cross-cutting concerns like logging, authentication, and request validation, applied globally or to specific routes.

• Models: Represents the database schema using GORM. Each model maps to a table and defines relationships (e.g., User model, Profile model).

• Repositories: The data access layer interacts with the database, separating raw data operations (e.g., queries, CRUD operations) from business logic.

• Routes: Registers and groups the application's endpoints, simplifying route management and separation between API layers.

• Services: Encapsulates business logic for each feature. For example, auth.go handles authentication processes (e.g., registration, login), while profile.go manages profile operations (e.g., viewing profiles).

• Tests: The tests folder contains resources and tools for testing, including Postman collections for automated API testing.

• Utilities: Shared functions, such as database initialization (db.go) and token management (jwt.go).

Testing

Unit and integration tests are located in the tests folder. The sqlmock package is used for mocking database operations with GORM.

To run tests:

go test ./...

Linting

Code linting is handled by golangci-lint. To run linting, make sure golangci-lint is installed:

go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest

Then, run linting:

golangci-lint run

API Endpoints

• Authentication:
  • POST /api/register: Register a new user
  • POST /api/login: User login
• Profile:
  • GET /api/users/profiles/me: View the authenticated profile itselg
  • GET /api/users/profiles/random: Get the other profile randomly
• Swipe:
  • POST /users/swipes/:target_user_id: Swipe left (pass) or right (like) on a profile
• Subscription:
  • POST /users/subscriptions: Purchase a premium feature

Sample Requests

More examples is on the Postman JSON file: Kopelko_Dating_App.postman_collection.json.

Swipe Example

To swipe on a profile:

POST /users/swipes/2
Content-Type: application/json
Authorization: Bearer <JWT>

{
    "type": "like"
}

Subscription Example

To purchase a subscription:

POST /users/subscriptions
Content-Type: application/json
Authorization: Bearer <JWT>

{
    "feature_id": 1
}

License

This project is licensed under the MIT License. See the LICENSE file for more details.

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With this README.md, you should have a comprehensive guide covering all aspects of setup, usage, testing, deployment, and contributing guidelines for the dating app backend.