package model

import (
	"crypto/rand"
	"crypto/sha256"
	"crypto/subtle"
	"encoding/base64"
)

func NewVisitorToken() (string, string, error) {
	bytes := make([]byte, 32)
	if _, err := rand.Read(bytes); err != nil {
		return "", "", err
	}

	token := base64.RawURLEncoding.EncodeToString(bytes)
	return token, HashVisitorToken(token), nil
}

func HashVisitorToken(token string) string {
	hash := sha256.Sum256([]byte(token))
	return base64.RawURLEncoding.EncodeToString(hash[:])
}

func VerifyVisitorToken(session *Session, token string) bool {
	if token == "" || session.VisitorTokenHash == "" {
		return false
	}
	return subtle.ConstantTimeCompare([]byte(session.VisitorTokenHash), []byte(HashVisitorToken(token))) == 1
}