package k8s_manager

import (
	"fmt"
	"github.com/sirupsen/logrus"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
	"sync"
)

var instance *gorm.DB = nil
var lock sync.Mutex

func opendb() *gorm.DB {
	if instance == nil {
		lock.Lock()
		if instance == nil {
			db_host := GetConfig().DBHost
			db_user := GetConfig().DBUser
			db_pass := GetConfig().DBPassword
			dsn := fmt.Sprintf("%s:%s@tcp(%s:3306)/k8s?charset=utf8mb4&parseTime=True&loc=Local", db_user, db_pass, db_host)
			var err error
			instance, err = gorm.Open(mysql.Open(dsn), &gorm.Config{})
			if err != nil {
				logrus.WithError(err).Error("Cannot open database.")
				instance = nil
			}
		}
		lock.Unlock()
	}
	return instance
}

func checkdb(cnt int) *gorm.DB {
	ans := opendb()
	if ans == nil {
		return nil
	}
	db, err := ans.DB()
	if err != nil {
		logrus.WithError(err).Error("Cannot get *sql.DB.")
		db = nil
	}
	if db != nil {
		err = db.Ping()
		if err != nil {
			logrus.WithError(err).Errorf("Ping error %d.", cnt)
			err = db.Close()
			if err != nil {
				logrus.WithError(err).Errorf("Close error %d.", cnt)
			}
			instance = nil
			ans = nil
		}
	}
	return ans
}

func DB() *gorm.DB {
	ans := checkdb(1)
	if ans != nil {
		return ans
	}
	instance = nil
	return checkdb(2)
}