package database

import (
	"database/sql"
	"embed"
	"sync"

	"git.ipao.vip/rogeecn/mp-qvyun/conf"
	"github.com/gofiber/fiber/v3/log"
	_ "github.com/lib/pq"
	"github.com/pkg/errors"
)

//go:embed migrations/*
var MigrationFS embed.FS

var (
	mutex sync.Mutex
	db    *sql.DB
)

func Close() error {
	if db == nil {
		return nil
	}
	return db.Close()
}

func GetDB(config conf.Database) (*sql.DB, error) {
	mutex.Lock()
	defer mutex.Unlock()

	if db != nil {
		return db, nil
	}

	once := sync.OnceValues(func() (*sql.DB, error) {
		log.Debugf("connect postgres with dsn: '%s'", config.DSN())
		db, err := sql.Open("postgres", config.DSN())
		if err != nil {
			return nil, errors.Wrap(err, "connect database")
		}

		if err := db.Ping(); err != nil {
			db.Close()
			return nil, errors.Wrap(err, "ping database")
		}

		return db, err
	})

	var err error
	db, err = once()
	if err != nil {
		return nil, err
	}

	return db, err
}