fix: label system overhaul - sync dual storage, fix suggestions

- Replace broken upsert (nbScope ?? '') with findFirst+create for null notebookId
- Remove aggressive orphan cleanup that deleted notebook labels after save
- Add syncNoteLabels() to update both Note.labels JSON and labelRelations
- Fix createNote, updateNote, auto-labeling to use syncNoteLabels
- Add fallback: suggestFromExistingLabels → suggestNewLabels if empty
- Lower confidence threshold 0.6→0.3, max suggestions 3→5
- Case-insensitive label matching in suggestions

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

memento-note/app/actions/notes.ts

@@ -99,85 +99,55 @@ function collectLabelNamesFromNote(note: {
 }
 
 /**
- * Sync Label rows with Note.labels.
- * Optimisé: createMany (bulk) + delete en parallèle — uniquement 3-4 requêtes au lieu de N+2.
+ * Upsert Label rows and return their IDs.
+ * No orphan cleanup — labels are only deleted via the label management dialog.
  */
-async function syncLabels(userId: string, noteLabels: string[] = [], notebookId?: string | null) {
+async function syncLabels(userId: string, noteLabels: string[] = [], notebookId?: string | null): Promise<{ id: string; name: string }[]> {
   try {
     const nbScope = notebookId ?? null
 
-    // 1. Bulk-upsert les nouveaux labels via upsert en transaction
     if (noteLabels.length > 0) {
       const trimmedNames = [...new Set(
         noteLabels.map(name => name?.trim()).filter((n): n is string => Boolean(n))
       )]
-
-      if (trimmedNames.length > 0) {
-        await prisma.$transaction(
-          trimmedNames.map(name =>
-            prisma.label.upsert({
-              where: { notebookId_name: { notebookId: nbScope ?? '', name } as any },
-              update: {},
-              create: {
-                userId,
-                name,
-                color: getHashColor(name),
-                notebookId: nbScope,
-              },
-            })
-          )
-        )
+      for (const name of trimmedNames) {
+        const existing = await prisma.label.findFirst({
+          where: { userId, name, notebookId: nbScope },
+        })
+        if (!existing) {
+          await prisma.label.create({
+            data: { userId, name, color: getHashColor(name), notebookId: nbScope },
+          })
+        }
       }
     }
 
-    // 2. Récupérer les labels utilisés par toutes les notes de l'utilisateur
-    const [allNotes, allLabels] = await Promise.all([
-      prisma.note.findMany({
-        where: { userId },
-        select: {
-          notebookId: true,
-          labels: true,
-          labelRelations: { select: { name: true } },
-        },
-      }),
-      prisma.label.findMany({
-        where: { userId },
-        select: { id: true, name: true, notebookId: true },
-      })
-    ])
-
-    const usedLabelsSet = new Set<string>()
-    for (const note of allNotes) {
-      for (const name of collectLabelNamesFromNote(note)) {
-        const key = labelScopeKey(note.notebookId, name)
-        if (key) usedLabelsSet.add(key)
-      }
-    }
-
-    // 3. Supprimer les labels orphelins
-    const orphanIds = allLabels
-      .filter(label => {
-        const key = labelScopeKey(label.notebookId, label.name)
-        return key && !usedLabelsSet.has(key)
-      })
-      .map(label => label.id)
-
-    if (orphanIds.length > 0) {
-      // Dissocier les relations avant la suppression
-      await prisma.label.updateMany({
-        where: { id: { in: orphanIds } },
-        data: {} // Nécessaire pour trigger le middleware
-      })
-      // Supprimer en une seule requête
-      await prisma.label.deleteMany({
-        where: { id: { in: orphanIds } }
-      })
-    }
+    if (noteLabels.length === 0) return []
+    const uniqueNames = [...new Set(noteLabels.map(n => n.trim().toLowerCase()).filter(Boolean))]
+    return prisma.label.findMany({
+      where: { userId, notebookId: nbScope, name: { in: uniqueNames } },
+      select: { id: true, name: true },
+    })
   } catch (error) {
     console.error('Fatal error in syncLabels:', error)
+    return []
   }
 }
 
+/** Sync both Note.labels (JSON) AND labelRelations for a single note. */
+async function syncNoteLabels(noteId: string, labelNames: string[], notebookId: string | null, userId: string) {
+  const uniqueNames = [...new Set(labelNames.map(n => n.trim()).filter(Boolean))]
+  const labelRows = await syncLabels(userId, uniqueNames, notebookId)
+  const labelIds = labelRows.map(l => l.id)
+  await prisma.note.update({
+    where: { id: noteId },
+    data: {
+      labels: uniqueNames.length > 0 ? JSON.stringify(uniqueNames) : null,
+      labelRelations: { set: labelIds.map(id => ({ id })) },
+    },
+  })
+}
+
 /** Après déplacement via API : rattacher les étiquettes de la note au bon carnet */
 export async function reconcileLabelsAfterNoteMove(noteId: string, newNotebookId: string | null) {
   const session = await auth()
@@ -198,7 +168,7 @@ export async function reconcileLabelsAfterNoteMove(noteId: string, newNotebookId
       /* ignore */
     }
   }
-  await syncLabels(session.user.id, labels, newNotebookId)
+  await syncNoteLabels(noteId, labels, newNotebookId, session.user.id)
 }
 
 // Get all notes (non-archived by default)
@@ -441,7 +411,7 @@ export async function createNote(data: {
         color: data.color || 'default',
         type: data.type || 'text',
         checkItems: data.checkItems ? JSON.stringify(data.checkItems) : null,
-        labels: data.labels && data.labels.length > 0 ? JSON.stringify(data.labels) : null,
+        labels: null, // set by syncNoteLabels below
         images: data.images ? JSON.stringify(data.images) : null,
         links: data.links ? JSON.stringify(data.links) : null,
         isArchived: data.isArchived || false,
@@ -454,9 +424,9 @@ export async function createNote(data: {
       }
     })
 
-    // Sync user-provided labels immediately (étiquettes rattachées au carnet de la note)
+    // Sync labels (JSON + labelRelations + Label rows) in one call
     if (data.labels && data.labels.length > 0) {
-      await syncLabels(session.user.id, data.labels, data.notebookId ?? null)
+      await syncNoteLabels(note.id, data.labels, data.notebookId ?? null, session.user.id)
     }
 
     if (!data.skipRevalidation) {
@@ -528,11 +498,22 @@ export async function createNote(data: {
               .map(s => s.label)
 
             if (appliedLabels.length > 0) {
-              await prisma.note.update({
+              // Merge with existing labels
+              const existing = await prisma.note.findUnique({
                 where: { id: noteId },
-                data: { labels: JSON.stringify(appliedLabels) }
+                select: { labels: true },
               })
-              await syncLabels(userId, appliedLabels, notebookId ?? null)
+              let existingNames: string[] = []
+              if (existing?.labels) {
+                try {
+                  const parsed = existing.labels as unknown
+                  existingNames = Array.isArray(parsed)
+                    ? parsed.filter((n): n is string => typeof n === 'string' && n.trim().length > 0)
+                    : []
+                } catch { existingNames = [] }
+              }
+              const merged = [...new Set([...existingNames, ...appliedLabels])]
+              await syncNoteLabels(noteId, merged, notebookId ?? null, userId)
               if (!data.skipRevalidation) {
                 revalidatePath('/')
               }
@@ -616,7 +597,8 @@ export async function updateNote(id: string, data: {
     }
 
     if ('checkItems' in data) updateData.checkItems = data.checkItems ? JSON.stringify(data.checkItems) : null
-    if ('labels' in data) updateData.labels = data.labels ? JSON.stringify(data.labels) : null
+    // labels handled by syncNoteLabels below
+    delete updateData.labels
     if ('images' in data) updateData.images = data.images ? JSON.stringify(data.images) : null
     if ('links' in data) updateData.links = data.links ? JSON.stringify(data.links) : null
     if ('notebookId' in data) updateData.notebookId = data.notebookId
@@ -637,14 +619,14 @@ export async function updateNote(id: string, data: {
       data: updateData
     })
 
-    // Sync Label rows (carnet + noms) quand les étiquettes changent ou que la note change de carnet
+    // Sync labels (JSON + labelRelations + Label rows)
     const notebookMoved =
       data.notebookId !== undefined && data.notebookId !== oldNotebookId
     if (data.labels !== undefined || notebookMoved) {
       const labelsToSync = data.labels !== undefined ? (data.labels || []) : oldLabels
       const effectiveNotebookId =
         data.notebookId !== undefined ? data.notebookId : oldNotebookId
-      await syncLabels(session.user.id, labelsToSync, effectiveNotebookId ?? null)
+      await syncNoteLabels(id, labelsToSync, effectiveNotebookId ?? null, session.user.id)
     }
 
     // Only revalidate for STRUCTURAL changes that affect the page layout/lists

memento-note/lib/ai/services/contextual-auto-tag.service.ts

@@ -55,10 +55,12 @@ export class ContextualAutoTagService {
 
     // CASE 1: Notebook has existing labels → suggest from them (IA2)
     if (notebook.labels.length > 0) {
-      return await this.suggestFromExistingLabels(noteContent, notebook, language)
+      const existing = await this.suggestFromExistingLabels(noteContent, notebook, language)
+      if (existing.length > 0) return existing
+      // Fallback: no existing label matched → suggest new ones too
     }
 
-    // CASE 2: Notebook has NO labels → suggest NEW labels to create
+    // CASE 2: No labels in notebook (or none matched) → suggest NEW labels
     return await this.suggestNewLabels(noteContent, notebook, language)
   }
 
@@ -126,20 +128,23 @@ export class ContextualAutoTagService {
         return []
       }
 
-      // Filter and map suggestions
+      // Filter and map suggestions (case-insensitive)
+      const lowerAvailable = availableLabels.map((l: string) => l.toLowerCase())
       const suggestions = suggestionsArray
         .filter((s: any) => {
-          // Must be in available labels
-          return availableLabels.includes(s.label) && s.confidence > 0.6
+          return s.label && lowerAvailable.includes(s.label.toLowerCase()) && (s.confidence || 0) > 0.3
         })
-        .map((s: any) => ({
-          label: s.label,
+        .map((s: any) => {
+          const originalLabel = availableLabels.find((l: string) => l.toLowerCase() === s.label.toLowerCase()) || s.label
+          return {
+            label: originalLabel,
           confidence: Math.round(s.confidence * 100),
           reasoning: s.reasoning || '',
           isNewLabel: false,
-        }))
+          }
+        })
         .sort((a: any, b: any) => b.confidence - a.confidence)
-        .slice(0, 3) // Max 3 suggestions
+        .slice(0, 5)
 
       return suggestions as LabelSuggestion[]
     } catch (error) {
@@ -213,7 +218,7 @@ export class ContextualAutoTagService {
       // Filter and map suggestions
       const suggestions = suggestionsArray
         .filter((s: any) => {
-          return s.label && s.label.length > 0 && s.confidence > 0.6
+          return s.label && s.label.length > 0 && (s.confidence || 0) > 0.3
         })
         .map((s: any) => ({
           label: s.label,
@@ -222,7 +227,7 @@ export class ContextualAutoTagService {
           isNewLabel: true, // Mark as new label suggestion
         }))
         .sort((a: any, b: any) => b.confidence - a.confidence)
-        .slice(0, 3) // Max 3 suggestions
+        .slice(0, 5)
 
       return suggestions as LabelSuggestion[]
     } catch (error) {