feat: regenerate in Chat, agent and Chatflow app (#7661)

web/app/components/base/chat/utils.ts

@@ -1,7 +1,11 @@
+import { addFileInfos, sortAgentSorts } from '../../tools/utils'
+import { UUID_NIL } from './constants'
+import type { ChatItem } from './types'
+
 async function decodeBase64AndDecompress(base64String: string) {
   const binaryString = atob(base64String)
   const compressedUint8Array = Uint8Array.from(binaryString, char => char.charCodeAt(0))
-  const decompressedStream = new Response(compressedUint8Array).body.pipeThrough(new DecompressionStream('gzip'))
+  const decompressedStream = new Response(compressedUint8Array).body?.pipeThrough(new DecompressionStream('gzip'))
   const decompressedArrayBuffer = await new Response(decompressedStream).arrayBuffer()
   return new TextDecoder().decode(decompressedArrayBuffer)
 }
@@ -15,6 +19,57 @@ function getProcessedInputsFromUrlParams(): Record<string, any> {
   return inputs
 }
 
+function appendQAToChatList(chatList: ChatItem[], item: any) {
+  // we append answer first and then question since will reverse the whole chatList later
+  chatList.push({
+    id: item.id,
+    content: item.answer,
+    agent_thoughts: addFileInfos(item.agent_thoughts ? sortAgentSorts(item.agent_thoughts) : item.agent_thoughts, item.message_files),
+    feedback: item.feedback,
+    isAnswer: true,
+    citation: item.retriever_resources,
+    message_files: item.message_files?.filter((file: any) => file.belongs_to === 'assistant') || [],
+  })
+  chatList.push({
+    id: `question-${item.id}`,
+    content: item.query,
+    isAnswer: false,
+    message_files: item.message_files?.filter((file: any) => file.belongs_to === 'user') || [],
+  })
+}
+
+/**
+ * Computes the latest thread messages from all messages of the conversation.
+ * Same logic as backend codebase `api/core/prompt/utils/extract_thread_messages.py`
+ *
+ * @param fetchedMessages - The history chat list data from the backend, sorted by created_at in descending order. This includes all flattened history messages of the conversation.
+ * @returns An array of ChatItems representing the latest thread.
+ */
+function getPrevChatList(fetchedMessages: any[]) {
+  const ret: ChatItem[] = []
+  let nextMessageId = null
+
+  for (const item of fetchedMessages) {
+    if (!item.parent_message_id) {
+      appendQAToChatList(ret, item)
+      break
+    }
+
+    if (!nextMessageId) {
+      appendQAToChatList(ret, item)
+      nextMessageId = item.parent_message_id
+    }
+    else {
+      if (item.id === nextMessageId || nextMessageId === UUID_NIL) {
+        appendQAToChatList(ret, item)
+        nextMessageId = item.parent_message_id
+      }
+    }
+  }
+  return ret.reverse()
+}
+
 export {
   getProcessedInputsFromUrlParams,
+  getPrevChatList,
 }