Enhance authentication flow by adding return URL support

This commit updates the authentication process to include a return URL parameter, allowing users to be redirected back to their original page after logging in. Changes were made to the AuthController, Login component, and Routes component to handle the return URL appropriately. Additionally, improvements were made to the TeamScheduler and TeamSchedulerSolution classes for better team and student management. These enhancements improve user experience and navigation within the application.

WebApp/Authentication/AuthController.cs

@@ -26,7 +26,8 @@ namespace WebApp.Authentication
         public async Task<IActionResult> CookieLogin(
             [FromForm] string email,
             [FromForm] string password,
-            [FromForm] bool rememberMe = false)
+            [FromForm] bool rememberMe = false,
+            [FromForm] string? returnUrl = null)
         {
             try
             {
@@ -42,7 +43,10 @@ namespace WebApp.Authentication
                         ipAddress, remaining);
 
                     var errorMsg = Uri.EscapeDataString($"Too many failed attempts. Try again in {remaining?.Minutes ?? 15} minutes.");
-                    return Redirect($"/login?error={errorMsg}");
+                    var redirectUrl = string.IsNullOrEmpty(returnUrl) 
+                        ? $"/login?error={errorMsg}" 
+                        : $"/login?error={errorMsg}&returnUrl={Uri.EscapeDataString(returnUrl)}";
+                    return Redirect(redirectUrl);
                 }
 
                 // Validate credentials
@@ -57,7 +61,10 @@ namespace WebApp.Authentication
                         "Failed login attempt for {Email} from {IpAddress}",
                         email, ipAddress);
 
-                    return Redirect("/login?error=Invalid%20email%20or%20password.");
+                    var redirectUrl = string.IsNullOrEmpty(returnUrl) 
+                        ? "/login?error=Invalid%20email%20or%20password." 
+                        : $"/login?error=Invalid%20email%20or%20password.&returnUrl={Uri.EscapeDataString(returnUrl)}";
+                    return Redirect(redirectUrl);
                 }
 
                 // Success - clear rate limit tracking
@@ -89,13 +96,22 @@ namespace WebApp.Authentication
                     "Successful login for {Email} ({Role}) from {IpAddress}",
                     result.Email, result.Role, ipAddress);
 
+                // Validate return URL is local to prevent open redirect attacks
+                if (!string.IsNullOrEmpty(returnUrl) && Url.IsLocalUrl(returnUrl))
+                {
+                    return Redirect(returnUrl);
+                }
+
                 return Redirect("/");
             }
             catch (Exception ex)
             {
                 _logger.LogError(ex, "Error during login process");
                 TempData["LoginError"] = "An error occurred. Please try again.";
-                return Redirect("/login");
+                var redirectUrl = string.IsNullOrEmpty(returnUrl) 
+                    ? "/login" 
+                    : $"/login?returnUrl={Uri.EscapeDataString(returnUrl)}";
+                return Redirect(redirectUrl);
             }
         }