package captcha

import (
	"fmt"
	"math"
	"math/rand/v2"
	"time"
)

type Generator interface {
	Generate() string
}

type stringCaptchaGenerator struct {
	length int
}

func NewStringCaptchaGenerator(length int) Generator {
	return &stringCaptchaGenerator{
		length: length,
	}
}

func (s *stringCaptchaGenerator) Generate() string {
	n := math.Pow(10, float64(s.length))
	r := rand.New(rand.NewPCG(uint64(time.Now().UnixNano()), 2)).IntN(int(n))
	return fmt.Sprintf("%0*d", s.length, r)
}