Logto Integration Attempt 1.

backend/internal/handlers/logto.go

@@ -0,0 +1,110 @@
+package handlers
+
+import (
+	"net/http"
+	"os"
+
+	"github.com/gin-contrib/sessions"
+	"github.com/gin-gonic/gin"
+	"github.com/logto-io/go/client"
+)
+
+// SessionStorage implements Logto's Storage interface using Gin sessions
+// Avoid cookie-based sessions due to size limits; use memory-based sessions for demo
+// In production, use Redis/MongoDB
+
+type SessionStorage struct {
+	session sessions.Session
+}
+
+func (s *SessionStorage) GetItem(key string) string {
+	value := s.session.Get(key)
+	if value == nil {
+		return ""
+	}
+	str, ok := value.(string)
+	if !ok {
+		return ""
+	}
+	return str
+}
+
+func (s *SessionStorage) SetItem(key, value string) {
+	s.session.Set(key, value)
+	s.session.Save()
+}
+
+// getLogtoConfig returns Logto config from environment variables
+func getLogtoConfig() *client.LogtoConfig {
+	return &client.LogtoConfig{
+		Endpoint:  os.Getenv("LOGTO_ENDPOINT"),
+		AppId:     os.Getenv("LOGTO_APP_ID"),
+		AppSecret: os.Getenv("LOGTO_APP_SECRET"),
+	}
+}
+
+// HomeHandler shows auth state and sign-in/sign-out links
+func HomeHandler(ctx *gin.Context) {
+	session := sessions.Default(ctx)
+	logtoClient := client.NewLogtoClient(getLogtoConfig(), &SessionStorage{session: session})
+	authState := "You are not logged in to this website. :("
+	if logtoClient.IsAuthenticated() {
+		authState = "You are logged in to this website! :)"
+	}
+	homePage := "<h1>Hello Logto</h1>" +
+		"<div>" + authState + "</div>" +
+		`<div><a href="/service/auth/sign-in">Sign In</a></div>` +
+		`<div><a href="/service/auth/sign-out">Sign Out</a></div>`
+	ctx.Data(http.StatusOK, "text/html; charset=utf-8", []byte(homePage))
+}
+
+// SignInHandler starts the Logto sign-in flow
+func SignInHandler(ctx *gin.Context) {
+	session := sessions.Default(ctx)
+	logtoClient := client.NewLogtoClient(getLogtoConfig(), &SessionStorage{session: session})
+	redirectUri := os.Getenv("LOGTO_REDIRECT_URI")
+	signInUri, err := logtoClient.SignIn(redirectUri)
+	if err != nil {
+		ctx.String(http.StatusInternalServerError, err.Error())
+		return
+	}
+	ctx.Redirect(http.StatusTemporaryRedirect, signInUri)
+}
+
+// CallbackHandler handles the Logto sign-in callback
+func CallbackHandler(ctx *gin.Context) {
+	session := sessions.Default(ctx)
+	logtoClient := client.NewLogtoClient(getLogtoConfig(), &SessionStorage{session: session})
+	err := logtoClient.HandleSignInCallback(ctx.Request)
+	if err != nil {
+		ctx.String(http.StatusInternalServerError, err.Error())
+		return
+	}
+	// Redirect to the frontend page instead of the backend auth page
+	ctx.Redirect(http.StatusTemporaryRedirect, os.Getenv("BASE_URL"))
+}
+
+// SignOutHandler starts the Logto sign-out flow
+func SignOutHandler(ctx *gin.Context) {
+	session := sessions.Default(ctx)
+	logtoClient := client.NewLogtoClient(getLogtoConfig(), &SessionStorage{session: session})
+	postSignOutRedirectUri := os.Getenv("LOGTO_POST_SIGN_OUT_REDIRECT_URI")
+	signOutUri, err := logtoClient.SignOut(postSignOutRedirectUri)
+	if err != nil {
+		ctx.String(http.StatusOK, err.Error())
+		return
+	}
+	ctx.Redirect(http.StatusTemporaryRedirect, signOutUri)
+}
+
+// UserIdTokenClaimsHandler returns the user's ID token claims as JSON
+func UserIdTokenClaimsHandler(ctx *gin.Context) {
+	session := sessions.Default(ctx)
+	logtoClient := client.NewLogtoClient(getLogtoConfig(), &SessionStorage{session: session})
+	idTokenClaims, err := logtoClient.GetIdTokenClaims()
+	if err != nil {
+		ctx.String(http.StatusOK, err.Error())
+		return
+	}
+	ctx.JSON(http.StatusOK, idTokenClaims)
+}