💳 RFID Payment & Safety Tracker Backend API

A production-ready RESTful API backend built in Go (Golang) using the Gin Web Framework and GORM (PostgreSQL). This system manages RFID card-based payments, balance accounts, and doubles as an IoT safety tracker for facilities like theme parks, playgrounds, or events.

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🚀 Key Features

• RFID Card Payment Engine: Manages card holder registration, balance status updates, and handles transactions (e.g., balance check, pay, and top-up operations).
• Safety & GPS Tracker Integration: Features a tracker subsystem (UserTracker) designed to map physical cards/phones to GPS devices, customize emergency alarm blast modes, manage visibility, and save critical emergency medical data (blood type, allergies, illness history).
• Audit Logging: Detailed logging tables for both transaction histories (HistoryTransactions) and top-up operations (HistoryTopup) to ensure full financial auditing.
• ORM Auto-Migrations: Integrated GORM auto-migrations to deploy PostgreSQL tables automatically on startup.
• Environment-Driven Configuration: Separation of code and configuration settings via godotenv.

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🧠 Database Schema

The database model is configured via GORM to model real-world account structures:

erDiagram
    User {
        int id PK
        string rfid_card_id UK
        string user_name
        string user_phone UK
        double user_balance
        string user_status
        string user_email
        string user_password
        timestamp balance_update_time
    }
    UserTracker {
        int id PK
        string wallet_number UK
        string first_name
        string sure_name
        string email
        string mobile_number
        timestamp dob
        string nationality
        string NIK
        string gender
        string blood_type
        string illness
        string alergic
        string alarm_blast_mode
        string gps_device
        boolean visibility
        string registry_number
    }
    Admins {
        int id PK
        string admins_id UK
        string user_name
        string user_phone UK
        string user_email
        string password
    }
    HistoryTransactions {
        int id PK
        string rfid_card_id
        string user_name
        string user_phone
        double user_balance
        double transaction_amount
        double balance_before
        string transaction_status
        timestamp transaction_time
        string playground_name
    }
    HistoryTopup {
        int id PK
        string rfid_card_id
        string user_name
        string user_phone
        double user_balance
        double topup_amount
        double balance_before
        timestamp topup_time
        string playground_name
        string waitres_name
    }

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🛣️ API Endpoints

All endpoints accept JSON payloads and return JSON responses.

Category	HTTP Method	Endpoint	Description
User	POST	/user/add_new_user	Register a new user & link RFID card
User	POST	/user/delete_user	Remove user record
Admin	POST	/admin/new_admin	Create a new administrator account
Admin	POST	/admin/delete_admin	Delete an administrator account
Transaction	POST	/transaction/topup	Perform a card balance top-up
Transaction	POST	/transaction/pay	Process a payment at a terminal
Tracker	POST	/tracker/add_new_user	Register user details on the GPS safety tracker

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📁 Project Structure

• main.go - System entry point, loads environment variables, initializes database, and starts the HTTP router.
• blueprints/ - Defines Gin routing schemas and maps paths to services.
• services/ - Contains business logic handlers for transactions, user profiles, and trackers.
• db/ - Manages GORM initialization, connection pools, and GORM database schemas.
• schema/ - Holds API request and response payload validation structs.
• logger/ - Custom logging utilities.

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⚙️ Setup and Installation

1. Prerequisites

• Go 1.18 or higher
• PostgreSQL Database instance

2. Configure Environment Variables

Create a .env file in the root folder with the following variables:

SQLALCHEMY_DATABASE_URI=postgres://username:password@localhost:5432/dbname?sslmode=disable
SERVER_PORT=8080

3. Install Packages

go mod download

4. Run Server

go run main.go

The GORM ORM will auto-create the necessary tables in your PostgreSQL database, and the server will start listening on the configured SERVER_PORT.

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🛡️ License

Distributed under the MIT License. See LICENSE for more information.