[Slack bot] Show which assistant is chosen + link to help (#7921)

* [Slack bot] Show which assistant is chosen + link to help

Description
---
Fixes dust-tt/tasks#1417

Risks
---
a little bit slower to show the thinking message, but should be fine

Deploy
---
connectors

* fix

connectors/src/connectors/slack/bot.ts

@@ -276,14 +276,6 @@ async function botAnswerMessage(
     }
   );
 
-  const mainMessage = await slackClient.chat.postMessage({
-    ...makeMessageUpdateBlocksAndText(null, {
-      isThinking: true,
-    }),
-    channel: slackChannel,
-    thread_ts: slackMessageTs,
-  });
-
   // Slack sends the message with user ids when someone is mentionned (bot or user).
   // Here we remove the bot id from the message and we replace user ids by their display names.
   // Example: <@U01J9JZQZ8Z> What is the command to upgrade a workspace in production (cc
@@ -415,6 +407,18 @@ async function botAnswerMessage(
     }
   }
 
+  const mainMessage = await slackClient.chat.postMessage({
+    ...makeMessageUpdateBlocksAndText(
+      null,
+      {
+        isThinking: true,
+      },
+      mention?.assistantName
+    ),
+    channel: slackChannel,
+    thread_ts: slackMessageTs,
+  });
+
   const messageReqBody = {
     content: message,
     mentions: mentions.map((m) => {

connectors/src/connectors/slack/chat/blocks.ts

@@ -11,6 +11,9 @@ import type { SlackMessageFootnotes } from "@connectors/connectors/slack/chat/ci
  */
 export const MAX_SLACK_MESSAGE_LENGTH = 2950;
 
+export const SLACK_CHOOSE_BOT_HELP_URL =
+  "https://docs.dust.tt/docs/slack#calling-an-assistant-in-slack";
+
 function makeConversationLinkContextBlock(conversationUrl: string) {
   return {
     type: "context",
@@ -23,13 +26,16 @@ function makeConversationLinkContextBlock(conversationUrl: string) {
   };
 }
 
-export function makeThinkingBlock() {
+export function makeThinkingBlock(assistantName: string | undefined) {
+  const thinkingText =
+    (assistantName ? `@${assistantName} is thinking...` : "Thinking...") +
+    `  <${SLACK_CHOOSE_BOT_HELP_URL}| Select which assistant replies>`;
   return {
     type: "context",
     elements: [
       {
-        type: "plain_text",
-        text: "Thinking...",
+        type: "mrkdwn",
+        text: thinkingText,
       },
     ],
   };
@@ -98,13 +104,14 @@ export type SlackMessageUpdate =
 
 export function makeMessageUpdateBlocksAndText(
   conversationUrl: string | null,
-  messageUpdate: SlackMessageUpdate
+  messageUpdate: SlackMessageUpdate,
+  assistantName: string | undefined
 ) {
   const { isThinking, text, footnotes } = messageUpdate;
 
   return {
     blocks: [
-      isThinking ? makeThinkingBlock() : makeMarkdownBlock(text),
+      isThinking ? makeThinkingBlock(assistantName) : makeMarkdownBlock(text),
       ...makeContextSectionBlocks(conversationUrl, footnotes),
     ],
     // TODO(2024-06-17 flav) We should not return markdown here.

connectors/src/connectors/slack/chat/stream_conversation_handler.ts

@@ -73,7 +73,11 @@ export async function streamConversationToSlack(
     }
 
     const response = await slackClient.chat.update({
-      ...makeMessageUpdateBlocksAndText(conversationUrl, messageUpdate),
+      ...makeMessageUpdateBlocksAndText(
+        conversationUrl,
+        messageUpdate,
+        assistantName
+      ),
       channel: slackChannelId,
       thread_ts: slackMessageTs,
       ts: mainMessage.ts as string,