package httpserver

import (
	"crypto/sha256"
	"encoding/base64"
	"math/rand"
	"time"
)

func init() {
	rand.Seed(time.Now().UnixNano())
}

type TokenGenerator interface {
	GenerateToken(n int) string
}

var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")

type RandomTokenGenerator struct{}

func (g RandomTokenGenerator) GenerateToken(n int) string {
	b := make([]rune, n)
	for i := range b {
		b[i] = letters[rand.Intn(len(letters))]
	}
	return string(b)
}

func encodeSHA256(s string) string {
	enc := sha256.Sum256([]byte(s))
	return base64.RawURLEncoding.EncodeToString(enc[:])
}