package keys

import (
	"crypto/rand"
	"encoding/base64"
)

var alphaNumericTable = []byte("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ")
var alphaNumericTableFull = []byte("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789")

func GetRandomAlphaNumeric(size int) ([]byte, error) {
	alpha := make([]byte, size)
	_, err := rand.Read(alpha)
	if err != nil {
		return nil, err
	}

	for i := 0; i < size; i++ {
		alpha[i] = alphaNumericTable[alpha[i]%byte(len(alphaNumericTable))]
	}
	return alpha, nil
}

func GetRandomAlphaNumericFull(size int) ([]byte, error) {
	alphaFull := make([]byte, size)
	_, err := rand.Read(alphaFull)
	if err != nil {
		return nil, err
	}
	for i := 0; i < size; i++ {
		alphaFull[i] = alphaNumericTableFull[alphaFull[i]%byte(len(alphaNumericTableFull))]
	}
	return alphaFull, nil
}

func GetRandomBase64(size int) ([]byte, error) {
	rb := make([]byte, size)
	_, err := rand.Read(rb)
	if err != nil {
		return nil, err
	}
	dest := base64.StdEncoding.EncodeToString(rb)
	return []byte(dest), nil
}