package rand

import (
	crand "crypto/rand"
	"math/big"
)

const base62 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"

// Base62 returns a cryptographically random base62 string of length n.
func Base62(n int) (string, error) {
	out := make([]byte, n)
	for i := range out {
		idx, err := crand.Int(crand.Reader, big.NewInt(int64(len(base62))))
		if err != nil {
			return "", err
		}
		out[i] = base62[idx.Int64()]
	}
	return string(out), nil
}