add folders structure

app/controllers/dashboard_controller.rb

@@ -6,17 +6,56 @@ class DashboardController < ApplicationController
   before_action :maybe_redirect_product_url
   before_action :maybe_render_landing
 
+  load_and_authorize_resource :template_folder, parent: false
   load_and_authorize_resource :template, parent: false
 
-  def index
-    @templates = @templates.active.preload(:author).order(id: :desc)
-    @templates = Templates.search(@templates, params[:q])
+  SHOW_TEMPLATES_FOLDERS_THRESHOLD = 9
+  TEMPLATES_PER_PAGE = 12
+  FOLDERS_PER_PAGE = 18
 
-    @pagy, @templates = pagy(@templates, items: 12)
+  def index
+    @template_folders = filter_template_folders(@template_folders)
+
+    @pagy, @template_folders = pagy(
+      @template_folders,
+      items: FOLDERS_PER_PAGE,
+      page: @template_folders.count > SHOW_TEMPLATES_FOLDERS_THRESHOLD ? params[:page] : 1
+    )
+
+    if @pagy.count > SHOW_TEMPLATES_FOLDERS_THRESHOLD
+      @templates = @templates.none
+    else
+      @template_folders = @template_folders.reject { |e| e.name == TemplateFolder::DEFAULT_NAME }
+      @templates = filter_templates(@templates)
+
+      items =
+        if @template_folders.size < 4
+          TEMPLATES_PER_PAGE
+        else
+          (@template_folders.size < 7 ? 9 : 6)
+        end
+
+      @pagy, @templates = pagy(@templates, items:)
+    end
   end
 
   private
 
+  def filter_template_folders(template_folders)
+    rel = template_folders.joins(:active_templates)
+                          .order(id: :desc)
+                          .distinct
+
+    TemplateFolders.search(rel, params[:q])
+  end
+
+  def filter_templates(templates)
+    rel = templates.active.preload(:author).order(id: :desc)
+                   .where(folder_id: current_account.default_template_folder.id)
+
+    Templates.search(rel, params[:q])
+  end
+
   def maybe_redirect_product_url
     return if !Docuseal.multitenant? || signed_in?