add initial auth0 module

auth/auth0/middleware.go

@@ -0,0 +1,42 @@
+package auth0
+
+import (
+	"context"
+	"net/http"
+)
+
+type userContextKey struct{}
+
+type Middleware func(http.Handler) http.Handler
+
+func authenticatedMiddleware(deps *deps, next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		sessionUser := deps.sessions.Get(r.Context(), "user")
+		if sessionUser == nil {
+			state, err := generateRandomState()
+			if err != nil {
+				deps.log.Error("unable to generate random state", "error", err)
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+				return
+			}
+
+			if err = deps.sessions.Put(r.Context(), StateKey, state); err != nil {
+				deps.log.Error("unable to store state in session", "error", err)
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+				return
+			}
+
+			loginURL := deps.auth.AuthCodeURL(state)
+			http.Redirect(w, r, loginURL, http.StatusFound)
+
+			return
+		}
+
+		ctx := context.WithValue(r.Context(), userContextKey{}, sessionUser)
+		next.ServeHTTP(w, r.WithContext(ctx))
+	})
+}
+
+func CurrentUser(r *http.Request) any {
+	return r.Context().Value(userContextKey{})
+}