package db

import "fmt"

//-----------------------------------------------------------------------------
// Main entry

const (
	LevelDBBackendStr   = "leveldb" // legacy, defaults to goleveldb unless +gcc
	CLevelDBBackendStr  = "cleveldb"
	GoLevelDBBackendStr = "goleveldb"
	MemDBBackendStr     = "memdb"
	FSDBBackendStr      = "fsdb" // using the filesystem naively
)

type dbCreator func(name string, dir string) (DB, error)

var backends = map[string]dbCreator{}

func registerDBCreator(backend string, creator dbCreator, force bool) {
	_, ok := backends[backend]
	if !force && ok {
		return
	}
	backends[backend] = creator
}

func NewDB(name string, backend string, dir string) DB {
	db, err := backends[backend](name, dir)
	if err != nil {
		panic(fmt.Sprintf("Error initializing DB: %v", err))
	}
	return db
}