Captcha implementation was moved off to pkg directory to be able to be used as an external library.

internal/captcha/dwelling_captcha.go

@@ -3,6 +3,7 @@ package captcha
 import (
 	"crypto/rand"
 	"image"
+	"justcaptcha/pkg/captcha"
 	"math/big"
 	"time"
 
@@ -15,14 +16,14 @@ const (
 )
 
 type DwellingCaptcha struct {
-	Captcha
+	captcha.Captcha
 }
 
 func NewDwellingCaptcha(expiry time.Duration) *DwellingCaptcha {
 	return &DwellingCaptcha{
-		Captcha: Captcha{
-			Answer:   GenerateAnswer(),
-			ExpireIn: ExpiryDate(expiry)}}
+		Captcha: captcha.Captcha{
+			Answer:   captcha.GenerateAnswer(),
+			ExpireIn: captcha.ExpiryDate(expiry)}}
 }
 
 func (c *DwellingCaptcha) generateImage() *image.Image {
@@ -72,3 +73,20 @@ func (c *DwellingCaptcha) GetImage() *image.Image {
 
 	return &c.Image
 }
+
+func (c *DwellingCaptcha) GetAnswer() captcha.Answer {
+	return c.Answer
+}
+
+func (c *DwellingCaptcha) Solve(answer captcha.Answer) bool {
+	c.Solved = c.Answer == answer
+	return c.Solved
+}
+
+func (c *DwellingCaptcha) IsSolved() bool {
+	return c.Solved
+}
+
+func (c *DwellingCaptcha) Expiry() time.Time {
+	return c.ExpireIn
+}

internal/captcha/instance.go

@@ -2,29 +2,30 @@ package captcha
 
 import (
 	"image"
+	"justcaptcha/pkg/captcha"
 	"time"
 )
 
-var captchaDb CaptchaDB = CaptchaDB{
-	DB: make(map[ID]ICaptcha)}
+var captchaDb captcha.CaptchaDB = captcha.CaptchaDB{
+	DB: make(map[captcha.ID]captcha.ICaptcha)}
 
 func Init(expiry time.Duration) {
 	captchaDb.SetExpiry(expiry)
 }
 
-func New(data string, captcha ICaptcha) (ICaptcha, ID) {
+func New(data string, captcha captcha.ICaptcha) (captcha.ICaptcha, captcha.ID) {
 	return captchaDb.New(data, captcha)
 }
 
-func Image(id ID) (*image.Image, error) {
+func Image(id captcha.ID) (*image.Image, error) {
 	return captchaDb.Image(id)
 }
 
-func Solve(id ID, answer Answer) (bool, error) {
+func Solve(id captcha.ID, answer captcha.Answer) (bool, error) {
 	return captchaDb.Solve(id, answer)
 }
 
-func IsSolved(id ID) (bool, error) {
+func IsSolved(id captcha.ID) (bool, error) {
 	return captchaDb.IsSolved(id)
 }
 

internal/handlers/handlers.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"image/png"
 	"justcaptcha/internal/captcha"
+	pcaptcha "justcaptcha/pkg/captcha"
 	"justcaptcha/pkg/server"
 	"net/http"
 )
@@ -22,7 +23,7 @@ func (h *CaptchaHandlers) New(w http.ResponseWriter, r *http.Request) {
 }
 
 func (h *CaptchaHandlers) Image(w http.ResponseWriter, r *http.Request) {
-	captchaID := captcha.ID(server.GetURLParam(r, "captcha"))
+	captchaID := pcaptcha.ID(server.GetURLParam(r, "captcha"))
 
 	captchaImage, err := captcha.Image(captchaID)
 	if err != nil {
@@ -43,10 +44,10 @@ func (h *CaptchaHandlers) Image(w http.ResponseWriter, r *http.Request) {
 func (h *CaptchaHandlers) Solve(w http.ResponseWriter, r *http.Request) {
 	r.ParseForm()
 
-	captchaID := captcha.ID(server.GetURLParam(r, "captcha"))
-	answer := captcha.Answer(r.FormValue("answer"))
+	captchaID := pcaptcha.ID(server.GetURLParam(r, "captcha"))
+	answer := pcaptcha.Answer(r.FormValue("answer"))
 
-	ok, err := captcha.Solve(captcha.ID(captchaID), answer)
+	ok, err := captcha.Solve(pcaptcha.ID(captchaID), answer)
 	if err != nil {
 		w.WriteHeader(http.StatusNotFound)
 		return
@@ -58,7 +59,7 @@ func (h *CaptchaHandlers) Solve(w http.ResponseWriter, r *http.Request) {
 }
 
 func (h *CaptchaHandlers) IsSolved(w http.ResponseWriter, r *http.Request) {
-	captchaID := captcha.ID(server.GetURLParam(r, "captcha"))
+	captchaID := pcaptcha.ID(server.GetURLParam(r, "captcha"))
 
 	solved, err := captcha.IsSolved(captchaID)
 	if err != nil {

pkg/captcha/captcha.go

@@ -33,6 +33,18 @@ type Captcha struct {
 	ExpireIn time.Time
 }
 
+func (c *Captcha) generateImage() *image.Image {
+	return nil
+}
+
+func (c *Captcha) GetImage() *image.Image {
+	if c.Image == nil {
+		return c.generateImage()
+	}
+
+	return &c.Image
+}
+
 func (c *Captcha) Solve(answer Answer) bool {
 	c.Solved = c.Answer == answer
 	return c.Solved