package database

import (
	"log"

	"github.com/joho/godotenv"
	"github.com/spf13/viper"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
)

var shared_db_connection *gorm.DB

func initDB() *gorm.DB {
	// load .env into environment (so viper can read them)
	if err := godotenv.Load(); err != nil {
		log.Println(".env not found or could not be loaded; proceeding with existing environment variables")
	}

	viper.AutomaticEnv() // read from environment

	sql_dsn := viper.GetString("SQL_DSN")

	if sql_dsn == "" {
		log.Fatal("SQL_DSN must be set in .env or environment")
	}

	db, err := gorm.Open(mysql.Open(sql_dsn), &gorm.Config{})
	if err != nil {
		log.Fatalf("failed to connect to MySQL Server: %v", err)
	}

	log.Println("connected to MySQL Server")
	return db
}

func Init() *gorm.DB {
	if shared_db_connection == nil {
		shared_db_connection = initDB()
	}
	return shared_db_connection
}