feat(api): AI-powered multi-language menu translation

Adds enabled_languages on restaurants and translations JSONB on menu categories/items. New /restaurants/:id/languages endpoints bulk-translate the full menu via Gemini/GPT-4o-mini (reusing the ai-scanner dual-provider pattern) when a language is enabled. New categories/items are auto- translated in the background into any already-enabled languages. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-29 01:46:19 +03:00
parent 739de7de5c
commit 00195ae7d7
6 changed files with 378 additions and 0 deletions
@@ -0,0 +1,148 @@
+import { env } from "../env.js";
+
+export interface TranslatableItem {
+  id: string;
+  name: string;
+  description: string | null;
+}
+
+export interface TranslatableCategory {
+  id: string;
+  name: string;
+  items: TranslatableItem[];
+}
+
+export interface TranslatedItem {
+  id: string;
+  name: string;
+  description: string | null;
+}
+
+export interface TranslatedCategory {
+  id: string;
+  name: string;
+  items: TranslatedItem[];
+}
+
+const LANGUAGE_NAMES: Record<string, string> = {
+  en: "English",
+  de: "German",
+  ar: "Arabic",
+  ru: "Russian",
+  fr: "French",
+};
+
+function buildPrompt(targetLanguageName: string): string {
+  return `Sen profesyonel bir restoran menüsü çevirmenisin. Sana Türkçe bir restoran menüsü (kategori adları, ürün adları ve açıklamaları) JSON olarak verilecek.
+Bunları ${targetLanguageName} diline çevir. Yemek isimlerini o mutfağın doğal terimleriyle çevir (örn. "Adana Kebap" -> "Adana Kebab", tamamen literal çeviri yapma, restoran menüsü diline uygun doğal bir üslup kullan).
+Her kategori ve ürünün "id" alanını AYNEN koru, sadece "name" ve "description" alanlarını çevir. description null ise null bırak.
+
+SADECE aşağıdaki JSON formatında geçerli bir JSON yanıtı ver, başka hiçbir metin ekleme:
+{
+  "categories": [
+    { "id": "...", "name": "çevrilmiş kategori adı", "items": [ { "id": "...", "name": "çevrilmiş ürün adı", "description": "çevrilmiş açıklama veya null" } ] }
+  ]
+}`;
+}
+
+function cleanAndParse(text: string): { categories: TranslatedCategory[] } {
+  const cleaned = text
+    .replace(/^```json\s*/i, "")
+    .replace(/^```\s*/i, "")
+    .replace(/\s*```$/i, "")
+    .trim();
+  const parsed = JSON.parse(cleaned) as { categories: TranslatedCategory[] };
+  if (!parsed.categories || !Array.isArray(parsed.categories)) {
+    throw new Error("Invalid structure from translator: categories array missing");
+  }
+  return parsed;
+}
+
+async function translateWithGemini(
+  categories: TranslatableCategory[],
+  targetLanguageName: string,
+  apiKey: string,
+): Promise<TranslatedCategory[]> {
+  const url = `https://generativelanguage.googleapis.com/v1beta/models/gemini-1.5-flash:generateContent?key=${apiKey}`;
+  const response = await fetch(url, {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify({
+      contents: [
+        {
+          parts: [
+            { text: buildPrompt(targetLanguageName) },
+            { text: JSON.stringify({ categories }) },
+          ],
+        },
+      ],
+      generationConfig: { response_mime_type: "application/json", temperature: 0.2 },
+    }),
+  });
+
+  if (!response.ok) {
+    throw new Error(`Gemini translate error (${response.status}): ${await response.text()}`);
+  }
+
+  const data = (await response.json()) as {
+    candidates?: { content?: { parts?: { text?: string }[] } }[];
+  };
+  const rawText = data.candidates?.[0]?.content?.parts?.[0]?.text;
+  if (!rawText) throw new Error("No text response from Gemini translate");
+  return cleanAndParse(rawText).categories;
+}
+
+async function translateWithOpenAI(
+  categories: TranslatableCategory[],
+  targetLanguageName: string,
+  apiKey: string,
+): Promise<TranslatedCategory[]> {
+  const response = await fetch("https://api.openai.com/v1/chat/completions", {
+    method: "POST",
+    headers: { "Content-Type": "application/json", Authorization: `Bearer ${apiKey}` },
+    body: JSON.stringify({
+      model: "gpt-4o-mini",
+      response_format: { type: "json_object" },
+      messages: [
+        { role: "system", content: buildPrompt(targetLanguageName) },
+        { role: "user", content: JSON.stringify({ categories }) },
+      ],
+      temperature: 0.2,
+    }),
+  });
+
+  if (!response.ok) {
+    throw new Error(`OpenAI translate error (${response.status}): ${await response.text()}`);
+  }
+
+  const data = (await response.json()) as { choices?: { message?: { content?: string } }[] };
+  const content = data.choices?.[0]?.message?.content;
+  if (!content) throw new Error("No message content from OpenAI translate");
+  return cleanAndParse(content).categories;
+}
+
+export function resolveLanguageName(code: string): string {
+  return LANGUAGE_NAMES[code] ?? code;
+}
+
+export async function translateMenu(
+  categories: TranslatableCategory[],
+  languageCode: string,
+): Promise<TranslatedCategory[]> {
+  if (categories.length === 0) return [];
+  const targetLanguageName = resolveLanguageName(languageCode);
+
+  if (env.GEMINI_API_KEY) {
+    try {
+      return await translateWithGemini(categories, targetLanguageName, env.GEMINI_API_KEY);
+    } catch (err) {
+      console.warn("Gemini translate failed, falling back:", err);
+    }
+  }
+
+  if (env.OPENAI_API_KEY) {
+    return translateWithOpenAI(categories, targetLanguageName, env.OPENAI_API_KEY);
+  }
+
+  throw new Error("No translation provider configured (GEMINI_API_KEY / OPENAI_API_KEY missing)");
+}