refactor(ux): consolidate BMAD skills, update design system, and clean up Prisma generated client

keep-notes/lib/ai/services/chat.service.ts

@@ -0,0 +1,141 @@
+/**
+ * Chat Service
+ * Handles conversational AI with context retrieval (RAG)
+ */
+
+import { semanticSearchService } from './semantic-search.service'
+import { getChatProvider } from '../factory'
+import { getSystemConfig } from '@/lib/config'
+import { prisma } from '@/lib/prisma'
+import { auth } from '@/auth'
+import { loadTranslations, getTranslationValue, SupportedLanguage } from '@/lib/i18n'
+
+// Default untitled text for fallback
+const DEFAULT_UNTITLED = 'Untitled'
+
+export interface ChatMessage {
+  role: 'user' | 'assistant' | 'system'
+  content: string
+}
+
+export interface ChatResponse {
+  message: string
+  conversationId?: string
+  suggestedNotes?: Array<{ id: string; title: string }>
+}
+
+export class ChatService {
+  /**
+   * Main chat entry point with context retrieval
+   */
+  async chat(
+    message: string,
+    conversationId?: string,
+    notebookId?: string,
+    language: SupportedLanguage = 'en'
+  ): Promise<ChatResponse> {
+    const session = await auth()
+    if (!session?.user?.id) {
+      throw new Error('Unauthorized')
+    }
+    const userId = session.user.id
+
+    // Load translations for the requested language
+    const translations = await loadTranslations(language)
+    const untitledText = getTranslationValue(translations, 'notes.untitled') || DEFAULT_UNTITLED
+    const noNotesFoundText = getTranslationValue(translations, 'chat.noNotesFoundForContext') || 
+      'No relevant notes found for this question. Answer with your general knowledge.'
+
+    // 1. Manage Conversation
+    let conversation: any
+    if (conversationId) {
+      conversation = await prisma.conversation.findUnique({
+        where: { id: conversationId },
+        include: { messages: { orderBy: { createdAt: 'asc' }, take: 10 } }
+      })
+    }
+
+    if (!conversation) {
+      conversation = await prisma.conversation.create({
+        data: {
+          userId,
+          notebookId,
+          title: message.substring(0, 50) + '...'
+        },
+        include: { messages: true }
+      })
+    }
+
+    // 2. Retrieval (RAG)
+    // We search for relevant notes based on the current message or notebook context
+    // Lower threshold for notebook-specific searches to ensure we find relevant content
+    const searchResults = await semanticSearchService.search(message, {
+      notebookId,
+      limit: 10,
+      threshold: notebookId ? 0.3 : 0.5
+    })
+
+    const contextNotes = searchResults.map(r => 
+      `NOTE [${r.title || untitledText}]: ${r.content}`
+    ).join('\n\n---\n\n')
+
+    // 3. System Prompt Synthesis
+    const systemPrompt = `Tu es l'Assistant IA de Memento. Tu accompagnes l'utilisateur dans sa réflexion.
+Tes réponses doivent être concises, premium et utiles.
+${contextNotes.length > 0 ? `Voici des extraits de notes de l'utilisateur qui pourraient t'aider à répondre :\n\n${contextNotes}\n\nUtilise ces informations si elles sont pertinentes, mais ne les cite pas mot pour mot sauf si demandé.` : noNotesFoundText}
+Si l'utilisateur pose une question sur un carnet spécifique, reste focalisé sur ce contexte.`
+
+    // 4. Call AI Provider
+    const history = (conversation.messages || []).map((m: any) => ({
+      role: m.role,
+      content: m.content
+    }))
+    
+    const currentMessages = [...history, { role: 'user', content: message }]
+    
+    const config = await getSystemConfig()
+    const provider = getChatProvider(config)
+    const aiResponse = await provider.chat(currentMessages, systemPrompt)
+
+    // 5. Save Messages to DB
+    await prisma.chatMessage.createMany({
+      data: [
+        { conversationId: conversation.id, role: 'user', content: message },
+        { conversationId: conversation.id, role: 'assistant', content: aiResponse.text }
+      ]
+    })
+
+    return {
+      message: aiResponse.text,
+      conversationId: conversation.id,
+      suggestedNotes: searchResults.map(r => ({ id: r.noteId, title: r.title || untitledText }))
+    }
+  }
+
+  /**
+   * Get conversation history
+   */
+  async getHistory(conversationId: string) {
+    return prisma.conversation.findUnique({
+      where: { id: conversationId },
+      include: {
+        messages: {
+          orderBy: { createdAt: 'asc' }
+        }
+      }
+    })
+  }
+
+  /**
+   * List user conversations
+   */
+  async listConversations(userId: string) {
+    return prisma.conversation.findMany({
+      where: { userId },
+      orderBy: { updatedAt: 'desc' },
+      take: 20
+    })
+  }
+}
+
+export const chatService = new ChatService()