FIX: Bring back empty state message when appropriate (#1446)

The Today section was added always, but a side-effect was that we hid the empty state component. This commit brings back the empty state

assets/javascripts/discourse/services/ai-conversations-sidebar-manager.js

@@ -84,6 +84,13 @@ export default class AiConversationsSidebarManager extends Service {
     );
   }
 
+  addEmptyStateClass() {
+    document.body.classList.toggle(
+      "has-empty-ai-conversations-sidebar",
+      !this.topics.length
+    );
+  }
+
   forceCustomSidebar() {
     document.body.classList.add("has-ai-conversations-sidebar");
     if (!this.sidebarState.isForcingSidebar) {
@@ -100,6 +107,7 @@ export default class AiConversationsSidebarManager extends Service {
 
     // don't render sidebar multiple times
     if (this._didInit) {
+      this.addEmptyStateClass();
       return true;
     }
 
@@ -107,6 +115,7 @@ export default class AiConversationsSidebarManager extends Service {
 
     this.fetchMessages().then(() => {
       this.sidebarState.setPanel(AI_CONVERSATIONS_PANEL);
+      this.addEmptyStateClass();
     });
 
     return true;
@@ -140,6 +149,7 @@ export default class AiConversationsSidebarManager extends Service {
 
   stopForcingCustomSidebar() {
     document.body.classList.remove("has-ai-conversations-sidebar");
+    document.body.classList.remove("has-empty-ai-conversations-sidebar");
 
     const isAdmin = this.sidebarState.currentPanel?.key === ADMIN_PANEL;
     if (this.sidebarState.isForcingSidebar && !isAdmin) {

assets/stylesheets/modules/ai-bot-conversations/common.scss

@@ -23,8 +23,20 @@ body.has-ai-conversations-sidebar {
     }
   }
 
-  // we always have the "today" section rendered at the top of the sidebar but hide it when empty
+  // When the sidebar is empty, we want to hide the "Today" header
-  .sidebar-section[data-section-name="today"]:has(.ai-bot-sidebar-empty-state) {
+  // and only show the empty state component
+  &.has-empty-ai-conversations-sidebar
+    .sidebar-section[data-section-name="today"]
+    .sidebar-section-header-wrapper {
+    display: none;
+  }
+
+  // When the sidebar isn't empty, BUT "today" is empty, hide
+  // the entire section
+  &:not(.has-empty-ai-conversations-sidebar)
+    .sidebar-section[data-section-name="today"]:has(
+      .ai-bot-sidebar-empty-state
+    ) {
     display: none;
   }
 

spec/system/ai_bot/homepage_spec.rb

@@ -226,6 +226,22 @@ RSpec.describe "AI Bot - Homepage", type: :system do
           expect(sidebar).to have_section_link(pm.title)
         end
 
+        it "shows empty state when no PMs exist" do
+          pm.destroy!
+
+          visit "/"
+          header.click_bot_button
+
+          expect(page).to have_css(".sidebar-section .ai-bot-sidebar-empty-state", visible: true)
+        end
+
+        it "doesn't show empty state when a PM exists" do
+          visit "/"
+          header.click_bot_button
+
+          expect(page).to have_no_css(".sidebar-section .ai-bot-sidebar-empty-state")
+        end
+
         it "displays last_7_days label in the sidebar" do
           pm.update!(last_posted_at: Time.zone.now - 5.days)
           visit "/"