Initial commit: Custom Start Page application with authentication and DynamoDB storage

internal/middleware/auth.go

@@ -0,0 +1,52 @@
+package middleware
+
+import (
+	"context"
+	"net/http"
+)
+
+// SessionStore defines the interface for session validation
+type SessionStore interface {
+	ValidateSession(r *http.Request) bool
+	GetUserID(r *http.Request) (string, error)
+}
+
+// contextKey is a custom type for context keys to avoid collisions
+type contextKey string
+
+const userIDContextKey contextKey = "user_id"
+
+// GetUserIDContextKey returns the context key for user ID (for testing)
+func GetUserIDContextKey() contextKey {
+	return userIDContextKey
+}
+
+// RequireAuth is a middleware that ensures the user is authenticated
+func RequireAuth(sessionStore SessionStore) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			// Validate session
+			if !sessionStore.ValidateSession(r) {
+				http.Redirect(w, r, "/login", http.StatusSeeOther)
+				return
+			}
+
+			// Get user ID and add to context
+			userID, err := sessionStore.GetUserID(r)
+			if err != nil {
+				http.Redirect(w, r, "/login", http.StatusSeeOther)
+				return
+			}
+
+			// Add user ID to request context
+			ctx := context.WithValue(r.Context(), userIDContextKey, userID)
+			next.ServeHTTP(w, r.WithContext(ctx))
+		})
+	}
+}
+
+// GetUserIDFromContext retrieves the user ID from the request context
+func GetUserIDFromContext(ctx context.Context) (string, bool) {
+	userID, ok := ctx.Value(userIDContextKey).(string)
+	return userID, ok
+}