FIX: clear uploads after successfully posting new PM (#1307)

This PR addresses a bug where uploads weren't being cleared after successfully posting a new private message in the AI bot conversations interface. Here's what the changes do:

## Main Fix:
- Makes the `prepareAndSubmitToBot()` method async and adds proper error handling
- Adds `this.uploads.clear()` after successful submission to clear all uploads
- Adds a test to verify that the "New Question" button properly resets the UI with no uploads

## Additional Improvements:
1. **Dynamic Character Length Validation**:
   - Uses `siteSettings.min_personal_message_post_length` instead of hardcoded 10 characters
   - Updates the error message to show the dynamic character count
   - Adds proper pluralization in the localization file for the error message

2. **Bug Fixes**:
   - Adds null checks with optional chaining (`link?.topic?.id`) in the sidebar code to prevent potential errors

3. **Code Organization**:
   - Moves error handling from the service to the controller for better separation of concerns

Author: SamSaffron

assets/javascripts/discourse/controllers/discourse-ai-bot-conversations.js

@@ -3,6 +3,7 @@ import Controller from "@ember/controller";
 import { action } from "@ember/object";
 import { getOwner } from "@ember/owner";
 import { service } from "@ember/service";
+import { popupAjaxError } from "discourse/lib/ajax-error";
 import UppyUpload from "discourse/lib/uppy/uppy-upload";
 import UppyMediaOptimization from "discourse/lib/uppy-media-optimization-plugin";
 import { clipboardHelpers } from "discourse/lib/utilities";
@@ -172,10 +173,15 @@ export default class DiscourseAiBotConversations extends Controller {
   }
 
   @action
-  prepareAndSubmitToBot() {
+  async prepareAndSubmitToBot() {
     // Pass uploads to the service before submitting
     this.aiBotConversationsHiddenSubmit.uploads = this.uploads;
-    this.aiBotConversationsHiddenSubmit.submitToBot();
+    try {
+      await this.aiBotConversationsHiddenSubmit.submitToBot();
+      this.uploads.clear();
+    } catch (error) {
+      popupAjaxError(error);
+    }
   }
 
   _autoExpandTextarea() {

assets/javascripts/discourse/services/ai-bot-conversations-hidden-submit.js

@@ -3,7 +3,6 @@ import { next } from "@ember/runloop";
 import Service, { service } from "@ember/service";
 import { tracked } from "@ember-compat/tracked-built-ins";
 import { ajax } from "discourse/lib/ajax";
-import { popupAjaxError } from "discourse/lib/ajax-error";
 import { getUploadMarkdown } from "discourse/lib/uploads";
 import { i18n } from "discourse-i18n";
 
@@ -13,6 +12,7 @@ export default class AiBotConversationsHiddenSubmit extends Service {
   @service composer;
   @service dialog;
   @service router;
+  @service siteSettings;
 
   @tracked loading = false;
 
@@ -33,10 +33,14 @@ export default class AiBotConversationsHiddenSubmit extends Service {
 
   @action
   async submitToBot() {
-    if (this.inputValue.length < 10) {
+    if (
+      this.inputValue.length <
+      this.siteSettings.min_personal_message_post_length
+    ) {
       return this.dialog.alert({
         message: i18n(
-          "discourse_ai.ai_bot.conversations.min_input_length_message"
+          "discourse_ai.ai_bot.conversations.min_input_length_message",
+          { count: this.siteSettings.min_personal_message_post_length }
         ),
         didConfirm: () => this.focusInput(),
         didCancel: () => this.focusInput(),
@@ -89,8 +93,6 @@ export default class AiBotConversationsHiddenSubmit extends Service {
       });
 
       this.router.transitionTo(response.post_url);
-    } catch (e) {
-      popupAjaxError(e);
     } finally {
       this.loading = false;
     }

assets/javascripts/initializers/ai-conversations-sidebar.js

@@ -319,7 +319,7 @@ export default {
 
               // force Glimmer to re-render that one link
               this.links = this.links.map((link) =>
-                link.topic.id === topic.id
+                link?.topic?.id === topic.id
                   ? new AiConversationLink(topic)
                   : link
               );

config/locales/client.en.yml

@@ -726,7 +726,9 @@ en:
           disclaimer: "Generative AI can make mistakes. Verify important information."
           placeholder: "Ask a question..."
           new: "New Question"
-          min_input_length_message: "Message must be longer than 10 characters"
+          min_input_length_message:
+            one: "Message must be 1 character or longer"
+            other: "Message must be %{count} characters or longer"
           messages_sidebar_title: "Conversations"
           today: "Today"
           last_7_days: "Last 7 days"

spec/system/ai_bot/homepage_spec.rb

@@ -131,6 +131,10 @@
             expect(topic_page).to have_content("Here are two image attachments")
             expect(page).to have_css(".cooked img", count: 2)
           end
+
+          find(".ai-new-question-button").click
+          expect(ai_pm_homepage).to have_homepage
+          expect(page).to have_no_css(".ai-bot-upload")
         end
 
         it "allows removing an upload before submission" do

spec/system/page_objects/components/ai_pm_homepage.rb

@@ -20,7 +20,11 @@ def submit
       def has_too_short_dialog?
         page.find(
           ".dialog-content",
-          text: I18n.t("js.discourse_ai.ai_bot.conversations.min_input_length_message"),
+          text:
+            I18n.t(
+              "js.discourse_ai.ai_bot.conversations.min_input_length_message",
+              count: SiteSetting.min_personal_message_post_length,
+            ),
         )
       end