package database

import (
	"fmt"
	"os"

	"gorm.io/driver/mysql"
	"gorm.io/gorm"
)

var (
	db     *gorm.DB
	config mysql.Config
)

func Init() {
	config = mysql.Config{
		DSN: fmt.Sprintf(
			"%s:%s@tcp(%s:%s)/%s?charset=utf8&parseTime=True&loc=Local",
			fallback(os.Getenv("MYSQL_USERNAME"), "root"),
			fallback(os.Getenv("MYSQL_PASSWORD"), "root"),
			fallback(os.Getenv("MYSQL_HOST"), "127.0.0.1"),
			fallback(os.Getenv("MYSQL_PORT"), "3306"),
			fallback(os.Getenv("MYSQL_DATABASE"), "app"),
		),
		DefaultStringSize:         256,
		DisableDatetimePrecision:  true,
		DontSupportRenameIndex:    true,
		DontSupportRenameColumn:   true,
		SkipInitializeWithVersion: false,
	}
}

func GetDb() *gorm.DB {
	var err error

	if db == nil {
		db, err = gorm.Open(mysql.New(config))

		if err != nil {
			panic(err)
		}
	}

	gdb, err := db.DB()

	if err != nil {
		db = nil

		return GetDb()
	}

	if err = gdb.Ping(); err != nil {
		db = nil

		return GetDb()
	}

	return db
}

func fallback(value string, fb string) string {
	if value == "" {
		return fb
	}

	return value
}