subrouters

internal/server/api/auth/router.go

@@ -0,0 +1,107 @@
+package auth
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"ruben/inventory2/internal/domains/authentication"
+	"ruben/inventory2/internal/server/cookies"
+	"ruben/inventory2/internal/server/response"
+	"ruben/inventory2/internal/server/router"
+)
+
+type loginSubrouter struct {
+	log  *slog.Logger
+	auth *authentication.Authenticator
+	router.Subrouter
+}
+
+func NewLoginSubrouter(logger *slog.Logger, auth *authentication.Authenticator) *loginSubrouter {
+	mux := router.NewSubMux(logger)
+
+	ls := &loginSubrouter{
+		log:       logger,
+		auth:      auth,
+		Subrouter: mux,
+	}
+
+	mux.Handle("GET /login", ls.loginPage)
+	mux.Handle("GET /login/callback", ls.loginCallback)
+	mux.Handle("GET /logout", ls.logoutPage)
+
+	return ls
+}
+
+func (s *loginSubrouter) newLoginSubrouter(logger *slog.Logger) router.Subrouter {
+	mux := router.NewSubMux(logger)
+
+	ls := &loginSubrouter{
+		log:       s.log,
+		auth:      s.auth,
+		Subrouter: mux,
+	}
+
+	mux.Handle("GET /login", ls.loginPage)
+	mux.Handle("GET /login/callback", ls.loginCallback)
+	mux.Handle("GET /logout", ls.logoutPage)
+
+	return ls
+}
+
+func (s *loginSubrouter) loginPage(r *http.Request) (response.Response, error) {
+	ctx := r.Context()
+
+	u, err := NewLoginURL(ctx, s.auth, "/")
+	if err != nil {
+		return nil, err
+	}
+
+	return response.TemporaryRedirect(u), nil
+}
+
+func NewLoginURL(ctx context.Context, auth *authentication.Authenticator, targetURI string) (string, error) {
+	state, err := auth.NewState(ctx, targetURI)
+	if err != nil {
+		return "", fmt.Errorf("failed to generate random state: %w", err)
+	}
+
+	base64EncodedState := fmt.Sprintf("%x", state[:])
+
+	return auth.AuthCodeURL(base64EncodedState), nil
+}
+
+func (s *loginSubrouter) loginCallback(r *http.Request) (response.Response, error) {
+	ctx := r.Context()
+	q := r.URL.Query()
+
+	// obtain token and profile
+
+	accessToken, targetURI, expiration, err := s.auth.Exchange(ctx, q.Get("state"), q.Get("code"))
+	if err != nil {
+		return nil, response.Unauthorized().
+			Msg(fmt.Sprintf("Failed to exchange an authorization code for a token")).
+			Wrap(err)
+	}
+
+	// set access_token cookie and redirect to a reasonable place
+
+	return response.TemporaryRedirect(targetURI).
+		Cookie(cookies.AccessToken(accessToken, expiration)), nil
+}
+
+func (s *loginSubrouter) logoutPage(r *http.Request) (response.Response, error) {
+	host := r.Header.Get("X-Forwarded-Host")
+	if host == "" {
+		host = r.Host
+	}
+
+	if ck, err := r.Cookie("access_token"); err == nil && ck != nil {
+		if err := s.auth.DeleteOAuthTokens(r.Context(), ck.Value); err != nil {
+			s.log.Error("failed to delete auth token", "error", err)
+		}
+	}
+
+	return response.TemporaryRedirect(s.auth.GetLogoutURL(host).String()).
+		Cookie(cookies.Expired("access_token")), nil
+}