src/lib/ai-tagger.ts

@@ -3,7 +3,7 @@ import path from 'path'
 import type { Library, Tag, TagCategory } from '@/types'
 import { getDb } from './db'
 import { getAiConfig } from './app-settings'
-import { getTags, getCategories, addTagToItem } from './tags'
+import { getTags, getCategories, addTagToItem, getActiveCategoryIdsForLibrary, getResolvedTagsForItem } from './tags'
 import { getThumbnailPath } from './thumbnails'
 import { findFile } from './media-utils'
 import { getLibrary, resolveLibraryRoot } from './libraries'
@@ -89,8 +89,10 @@ function resolveItemImage(libraryRoot: string, item: MediaItemRow): string | nul
 
 /**
  * Build the system prompt that instructs the LLM to select matching tags.
+ * If currentTags are provided they are included as context to help the model
+ * understand the image before selecting additional tags.
  */
-function buildTagPrompt(tags: Tag[], categories: TagCategory[]): string {
+function buildTagPrompt(tags: Tag[], categories: TagCategory[], currentTags?: Tag[]): string {
   const categoryMap = new Map(categories.map((c) => [c.id, c.name]))
 
   const grouped: Record<string, { id: string; name: string }[]> = {}
@@ -105,14 +107,24 @@ function buildTagPrompt(tags: Tag[], categories: TagCategory[]): string {
     lines.push(`[${catName}] ${tagList}`)
   }
 
-  return [
+  const parts: string[] = [
     'You are an image tagger. Given the image, select which of the following tags apply.',
-    'Return ONLY a JSON array of tag IDs that match the image. Do not invent new tags.',
-    'If no tags match, return an empty array: []',
-    '',
-    'Available tags:',
-    ...lines,
-  ].join('\n')
+    'Return ONLY a JSON array of tag IDs that match the image (e.g., ["tag-apple", "tag-orange"]). Do not invent new tags. Do not return any text other than what is inside the JSON array.',
+    'If no tags match, return an empty array (e.i., [])',
+  ]
+
+  if (currentTags && currentTags.length > 0) {
+    const currentTagNames = currentTags.map((t) => t.name).join(', ')
+    parts.push('')
+    parts.push(`This image already has the following tags applied: ${currentTagNames}`)
+    parts.push('Use these as context to better understand the image when selecting tags.')
+  }
+
+  parts.push('')
+  parts.push('Available tags:')
+  parts.push(...lines)
+
+  return parts.join('\n')
 }
 
 /**
@@ -148,7 +160,7 @@ async function callVisionApi(
             ],
           },
         ],
-        max_tokens: 512,
+        max_tokens: 8192,
         temperature: 0.1,
       }),
     })
@@ -184,12 +196,15 @@ export async function runAiTagging(library: Library, libraryRoot: string): Promi
   const config = getAiConfig()
   if (!config.enabled || !config.endpoint || !config.model) return
 
-  const tags = getTags()
-  const categories = getCategories()
+  const activeCategoryIds = new Set(getActiveCategoryIdsForLibrary(library.id))
+  const allTags = getTags()
+  const allCategories = getCategories()
+
+  const tags = allTags.filter((t) => activeCategoryIds.has(t.categoryId))
+  const categories = allCategories.filter((c) => activeCategoryIds.has(c.id))
   if (tags.length === 0) return
 
   const validTagIds = new Set(tags.map((t) => t.id))
-  const systemPrompt = buildTagPrompt(tags, categories)
 
   const db = getDb()
   const untaggedItems = db
@@ -227,6 +242,9 @@ export async function runAiTagging(library: Library, libraryRoot: string): Promi
       const thumbnailPath = await getThumbnailPath(imagePath, library.id, 'image')
       const base64 = fs.readFileSync(thumbnailPath, 'base64')
 
+      const { tags: currentItemTags } = getResolvedTagsForItem(item.item_key)
+      const systemPrompt = buildTagPrompt(tags, categories, currentItemTags)
+
       const suggestedIds = await callVisionApi(config.endpoint, config.model, base64, systemPrompt)
 
       // Filter to valid tags only
@@ -263,14 +281,19 @@ export async function tagSingleItem(itemKey: string): Promise<string[]> {
     throw Object.assign(new Error('AI tagging endpoint and model are not configured'), { code: 'NOT_CONFIGURED' })
   }
 
-  const tags = getTags()
-  const categories = getCategories()
+  const libraryId = itemKey.split(':')[0]
+
+  const activeCategoryIds = new Set(getActiveCategoryIdsForLibrary(libraryId))
+  const allTags = getTags()
+  const allCategories = getCategories()
+
+  const tags = allTags.filter((t) => activeCategoryIds.has(t.categoryId))
+  const categories = allCategories.filter((c) => activeCategoryIds.has(c.id))
   if (tags.length === 0) {
     return []
   }
 
   const validTagIds = new Set(tags.map((t) => t.id))
-  const systemPrompt = buildTagPrompt(tags, categories)
 
   const db = getDb()
   const item = db
@@ -280,8 +303,6 @@ export async function tagSingleItem(itemKey: string): Promise<string[]> {
   if (!item) {
     throw Object.assign(new Error(`Item not found: ${itemKey}`), { code: 'NOT_FOUND' })
   }
-
-  const libraryId = itemKey.split(':')[0]
   const library = getLibrary(libraryId)
   if (!library) {
     throw Object.assign(new Error(`Library not found: ${libraryId}`), { code: 'NOT_FOUND' })
@@ -296,7 +317,10 @@ export async function tagSingleItem(itemKey: string): Promise<string[]> {
   const thumbnailPath = await getThumbnailPath(imagePath, libraryId, 'image')
   const base64 = fs.readFileSync(thumbnailPath, 'base64')
 
-  const suggestedIds = await callVisionApi(config.endpoint, config.model, base64, systemPrompt)
+  const { tags: currentItemTags } = getResolvedTagsForItem(itemKey)
+  const systemPromptWithContext = buildTagPrompt(tags, categories, currentItemTags)
+
+  const suggestedIds = await callVisionApi(config.endpoint, config.model, base64, systemPromptWithContext)
   const validIds = suggestedIds.filter((id) => validTagIds.has(id))
 
   for (const tagId of validIds) {

src/lib/tags.ts

@@ -18,6 +18,25 @@ export function getCategories(): TagCategory[] {
   return db.prepare('SELECT id, name FROM tag_categories ORDER BY name').all() as TagCategory[]
 }
 
+/**
+ * Returns the distinct category IDs that have at least one tag assigned to any
+ * item in the given library. Used by the AI tagger to restrict the tag prompt
+ * to categories that are actually in use within the target library.
+ */
+export function getActiveCategoryIdsForLibrary(libraryId: string): string[] {
+  const db = getDb()
+  const rows = db
+    .prepare(
+      `SELECT DISTINCT t.category_id
+       FROM tags t
+       JOIN media_tags mt ON mt.tag_id = t.id
+       JOIN media_items mi ON mi.item_key = mt.item_key
+       WHERE mi.library_id = ?`
+    )
+    .all(libraryId) as { category_id: string }[]
+  return rows.map((r) => r.category_id)
+}
+
 export function addCategory(name: string): TagCategory {
   const trimmed = name.trim()
   if (!trimmed) throw new Error('Category name is required.')