package entity

import (
	"strings"

	"github.com/teris-io/shortid"
)

const (
	qrTokenMin = 9
	qrTokenMax = 20
)

// NewQRCode is an opaque scan ticket from shortid. It is not uid, spark_id, or a Redis key.
func NewQRCode() (string, error) {
	return shortid.Generate()
}

func ValidQRCode(s string) bool {
	s = strings.TrimSpace(s)
	n := len(s)
	if n < qrTokenMin || n > qrTokenMax {
		return false
	}
	for i := 0; i < n; i++ {
		if !strings.ContainsRune(shortid.DefaultABC, rune(s[i])) {
			return false
		}
	}
	return true
}