package utl

import (
	"github.com/mojocn/base64Captcha"
)

var (
	store = base64Captcha.DefaultMemStore
)

// Used for generating and verify the digital captcha
type DigitCaptcha struct {
	h *base64Captcha.Captcha
}

// Initializer. length is the length of the digitals
func NewDigitCatpcha(length int) *DigitCaptcha {
	driver := &base64Captcha.DriverDigit{
		Height:   80,
		Width:    240,
		Length:   length,
		MaxSkew:  0.7,
		DotCount: 80,
	}
	return &DigitCaptcha{
		h: base64Captcha.NewCaptcha(driver, store),
	}
}

// Generate a new captcha image
//
// return
// 		id: is the id of the new captcha image
//		b64: captcha image in base64 format
// 		err: any error
func (self *DigitCaptcha) Gen() (id, b64 string, err error) {
	id, b64, err = self.h.Generate()
	return
}

// Verify if the user input is the same as digits in captcha.
func (self *DigitCaptcha) Verify(id, value string) bool {
	return store.Verify(id, value, true)
}