feat(AI Assistant): query rewriting for enhanced context retrieval

admin/app/controllers/ollama_controller.ts

@@ -5,6 +5,8 @@ import { chatSchema, getAvailableModelsSchema } from '#validators/ollama'
 import { inject } from '@adonisjs/core'
 import type { HttpContext } from '@adonisjs/core/http'
 import { SYSTEM_PROMPTS } from '../../constants/ollama.js'
+import logger from '@adonisjs/core/services/logger'
+import type { Message } from 'ollama'
 
 @inject()
 export default class OllamaController {
@@ -25,9 +27,8 @@ export default class OllamaController {
   async chat({ request }: HttpContext) {
     const reqData = await request.validateUsing(chatSchema)
 
-    /**If there are no system messages in the chat
-     *(i.e. first message from the user)inject system prompts
-     **/
+    // If there are no system messages in the chat
+    // (i.e. first message from the user) inject system prompts
     const hasSystemMessage = reqData.messages.some((msg) => msg.role === 'system')
     if (!hasSystemMessage) {
       const systemPrompt = {
@@ -37,18 +38,22 @@ export default class OllamaController {
       reqData.messages.unshift(systemPrompt)
     }
 
-    // Get the last user message to use for RAG context retrieval
-    const lastUserMessage = [...reqData.messages].reverse().find((msg) => msg.role === 'user')
-
-    if (lastUserMessage) {
-      // Search for relevant context in the knowledge base
-      // Using lower threshold (0.3) with improved hybrid search
-      const relevantDocs = await this.ragService.searchSimilarDocuments(
-        lastUserMessage.content,
-        5, // Retrieve top 5 most relevant chunks
-        0.3 // Minimum similarity score of 0.3 (lowered from 0.7 for better recall)
+    // Query rewriting for better RAG retrieval with manageable context
+    // Will return user's latest message if no rewriting is needed
+    const rewrittenQuery = await this.rewriteQueryWithContext(
+      reqData.messages,
+      reqData.model
     )
 
+    if (rewrittenQuery) {
+      const relevantDocs = await this.ragService.searchSimilarDocuments(
+        rewrittenQuery,
+        5, // Top 5 most relevant chunks
+        0.3 // Minimum similarity score of 0.3
+      )
+
+      logger.debug(`[RAG] Retrieved ${relevantDocs.length} relevant documents for query: "${rewrittenQuery}"`)
+
       // If relevant context is found, inject as a system message
       if (relevantDocs.length > 0) {
         const contextText = relevantDocs
@@ -91,4 +96,56 @@ export default class OllamaController {
   async installedModels({ }: HttpContext) {
     return await this.ollamaService.getModels()
   }
+
+  private async rewriteQueryWithContext(
+    messages: Message[],
+    model: string
+  ): Promise<string | null> {
+    try {
+      // Get recent conversation history (last 6 messages for 3 turns)
+      const recentMessages = messages.slice(-6)
+
+      // If there's only one user message, no rewriting needed
+      const userMessages = recentMessages.filter(msg => msg.role === 'user')
+      if (userMessages.length <= 1) {
+        return userMessages[0]?.content || null
+      }
+
+      const conversationContext = recentMessages
+        .map(msg => {
+          const role = msg.role === 'user' ? 'User' : 'Assistant'
+          // Truncate assistant messages to first 200 chars to keep context manageable
+          const content = msg.role === 'assistant'
+            ? msg.content.slice(0, 200) + (msg.content.length > 200 ? '...' : '')
+            : msg.content
+          return `${role}: "${content}"`
+        })
+        .join('\n')
+
+      const response = await this.ollamaService.chat({
+        model,
+        messages: [
+          {
+            role: 'system',
+            content: SYSTEM_PROMPTS.query_rewrite,
+          },
+          {
+            role: 'user',
+            content: `Conversation:\n${conversationContext}\n\nRewritten Query:`,
+          },
+        ],
+      })
+
+      const rewrittenQuery = response.message.content.trim()
+      logger.info(`[RAG] Query rewritten: "${rewrittenQuery}"`)
+      return rewrittenQuery
+    } catch (error) {
+      logger.error(
+        `[RAG] Query rewriting failed: ${error instanceof Error ? error.message : error}`
+      )
+      // Fallback to last user message if rewriting fails
+      const lastUserMessage = [...messages].reverse().find(msg => msg.role === 'user')
+      return lastUserMessage?.content || null
+    }
+  }
 }

admin/app/services/chat_service.ts

@@ -4,7 +4,6 @@ import logger from '@adonisjs/core/services/logger'
 import { DateTime } from 'luxon'
 import { inject } from '@adonisjs/core'
 import { OllamaService } from './ollama_service.js'
-import { ChatRequest } from 'ollama'
 import { SYSTEM_PROMPTS } from '../../constants/ollama.js'
 import { toTitleCase } from '../utils/misc.js'
 
@@ -12,15 +11,6 @@ import { toTitleCase } from '../utils/misc.js'
 export class ChatService {
   constructor(private ollamaService: OllamaService) {}
 
-  async chat(chatRequest: ChatRequest & { stream?: false }) {
-    try {
-      return await this.ollamaService.chat(chatRequest)
-    } catch (error) {
-      logger.error(`[ChatService] Chat error: ${error instanceof Error ? error.message : error}`)
-      throw new Error('Chat processing failed')
-    }
-  }
-
   async getAllSessions() {
     try {
       const sessions = await ChatSession.query().orderBy('updated_at', 'desc')
@@ -230,9 +220,6 @@ export class ChatService {
     }
   }
 
-  /**
-   * Delete all chat sessions and messages
-   */
   async deleteAllSessions() {
     try {
       await ChatSession.query().delete()

admin/constants/ollama.ts

@@ -107,5 +107,35 @@ The suggestions should be in title case.
 Ensure that your suggestions are comma-seperated with no conjunctions like "and" or "or".
 Do not use line breaks, new lines, or extra spacing to separate the suggestions.
 Format: suggestion1, suggestion2, suggestion3
+`,
+  query_rewrite: `
+You are a query rewriting assistant. Your task is to reformulate the user's latest question to include relevant context from the conversation history.
+
+Given the conversation history, rewrite the user's latest question to be a standalone, context-aware search query that will retrieve the most relevant information.
+
+Rules:
+1. Keep the rewritten query concise (under 150 words)
+2. Include key entities, topics, and context from previous messages
+3. Make it a clear, searchable query
+4. Do NOT answer the question - only rewrite the user's query to be more effective for retrieval
+5. Output ONLY the rewritten query, nothing else
+
+Examples:
+
+Conversation:
+User: "How do I install Gentoo?"
+Assistant: [detailed installation guide]
+User: "Is an internet connection required to install?"
+
+Rewritten Query: "Is an internet connection required to install Gentoo Linux?"
+
+---
+
+Conversation:
+User: "What's the best way to preserve meat?"
+Assistant: [preservation methods]
+User: "How long does it last?"
+
+Rewritten Query: "How long does preserved meat last using curing or smoking methods?"
 `,
 }