Fixed Template cache invalidation issue

Author: FrostyApeOne

src/DfE.ExternalApplications.Web/Pages/RenderForm.cshtml.cs

@@ -170,6 +170,7 @@ public async Task<IActionResult> OnGetAutocompleteAsync(string endpoint, string
 
         private async Task LoadTemplateAsync()
         {
+            _logger.LogDebug("Loading template {TemplateId} for RenderForm", TemplateId);
             Template = await _templateProvider.GetTemplateAsync(TemplateId);
         }
 

src/DfE.ExternalApplications.Web/Pages/TemplateManager.cshtml.cs

@@ -91,7 +91,10 @@ public async Task<IActionResult> OnPostAsync()
         try
         {
             await CreateNewTemplateVersionAsync(templateId);
-            InvalidateTemplateCache(templateId);
+            
+            await Task.Delay(2000);
+            
+            await InvalidateTemplateCacheAsync(templateId);
 
             _logger.LogInformation("Successfully created template version {NewVersion} for {TemplateId}", 
                 NewVersion, templateId);
@@ -121,14 +124,22 @@ private async Task LoadTemplateDataAsync(string templateId)
     {
         try
         {
+            _logger.LogDebug("Loading template data for {TemplateId}", templateId);
+            
             var apiResponse = await _templatesClient.GetLatestTemplateSchemaAsync(new Guid(templateId));
             CurrentVersionNumber = apiResponse.VersionNumber;
 
+            _logger.LogDebug("API returned template version {VersionNumber} for {TemplateId}", 
+                CurrentVersionNumber, templateId);
+            
             CurrentTemplate = await _formTemplateProvider.GetTemplateAsync(templateId);
             if (CurrentTemplate != null)
             {
                 var options = new JsonSerializerOptions { WriteIndented = true };
                 CurrentTemplateJson = JsonSerializer.Serialize(CurrentTemplate, options);
+                
+                _logger.LogDebug("Successfully loaded template {TemplateId} with {TaskGroupCount} task groups", 
+                    templateId, CurrentTemplate.TaskGroups?.Count ?? 0);
             }
         }
         catch (Exception ex)
@@ -183,20 +194,41 @@ await _templatesClient.CreateTemplateVersionAsync(new Guid(templateId),
             new CreateTemplateVersionRequest(VersionNumber: NewVersion!, JsonSchema: base64Schema));
     }
 
-    private void InvalidateTemplateCache(string templateId)
+    private async Task InvalidateTemplateCacheAsync(string templateId)
     {
         try
         {
             var cacheKey = $"FormTemplate_{CacheKeyHelper.GenerateHashedCacheKey(templateId)}";
+            _logger.LogInformation("Attempting to invalidate cache for template {TemplateId} with key {CacheKey}", 
+                templateId, cacheKey);
+            
             _cacheService.Remove(cacheKey);
-            _logger.LogDebug("Invalidated cache for template {TemplateId} with key {CacheKey}", templateId, cacheKey);
+            _logger.LogInformation("Successfully invalidated cache for template {TemplateId} with key {CacheKey}", 
+                templateId, cacheKey);
+            
+            // Verify the new template version is available by attempting to load it
+            await VerifyNewTemplateVersionAsync(templateId);
         }
         catch (Exception ex)
         {
             _logger.LogWarning(ex, "Failed to invalidate cache for template {TemplateId}", templateId);
             // Don't throw - cache invalidation failure shouldn't break the operation
         }
     }
+    
+    private async Task VerifyNewTemplateVersionAsync(string templateId)
+    {
+        try
+        {
+            // Try to load the new template version to ensure it's available
+            var newTemplate = await _formTemplateProvider.GetTemplateAsync(templateId);
+            _logger.LogDebug("Successfully verified new template version is available for {TemplateId}", templateId);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Failed to verify new template version for {TemplateId}", templateId);
+        }
+    }
 
     private void HandleApiError(Exception exception)
     {

src/DfE.ExternalApplications.Web/appsettings.json

@@ -2,7 +2,8 @@
   "Logging": {
     "LogLevel": {
       "Default": "Information",
-      "Microsoft.AspNetCore": "Warning"
+      "Microsoft.AspNetCore": "Warning",
+      "DfE.ExternalApplications": "Debug"
     }
   },
   "AllowedHosts": "*",