diff --git a/package.json b/package.json
index 171b0f2..c570318 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "translate-reboot",
-  "version": "0.4",
+  "version": "0.5",
   "description": "",
   "scripts": {
     "build": "tsc",
diff --git a/src/bot-hooks.ts b/src/bot-hooks.ts
index 1bf34d1..97460e4 100644
--- a/src/bot-hooks.ts
+++ b/src/bot-hooks.ts
@@ -32,6 +32,30 @@ function makeLines(text: string): string[] {
     return lines;
 }
 
+async function translate(text: string, dstLang: string): Promise<string> {
+    const srcLang: string = await detectGoogle(text);
+    dstLang = dstLang === 'ua' || dstLang === 'ru' ? 'uk' : dstLang;
+    if (srcLang === 'uk' || dstLang === 'uk') {
+        return translateGoogle(text, dstLang);
+    } else {
+        return await translateDeepL(text, srcLang, dstLang);
+    }
+}
+
+function makeResults(translated: string): Array<InlineQueryResultArticle> {
+    const results: Array<InlineQueryResultArticle> = [];
+    if (translated.length === 0) {
+        return;
+    } else if (translated.length < max) {
+        results.push(makeResult(translated, translated));
+    } else {
+        makeLines(translated).forEach((line: string) => {
+            results.push(makeResult(line, translated));
+        });
+    }
+    return results;
+}
+
 bot.on('inline_query', async (query: InlineQuery) => {
     const queryText = query.query;
     const length = queryText.length;
@@ -47,32 +71,18 @@ bot.on('inline_query', async (query: InlineQuery) => {
         queryText.endsWith(eol + 'it') ||
         queryText.endsWith(eol + 'ru')
     );
-    let lang: string;
+    let dstLang: string;
     let text: string;
     if (basicQuery) {
-        lang = 'de';
+        dstLang = 'de';
         text = queryText.slice(0, length - 2);
     } else if (customQuery) {
-        lang = queryText.slice(length - 2, length);
-        lang = lang === 'ua' || lang === 'ru' ? 'uk' : lang;
+        dstLang = queryText.slice(length - 2, length);
         text = queryText.slice(0, length - 4);
     } else {
         return;
     }
-    let translated: string;
-    const srcLang: string = await detectGoogle(text);
-    if (srcLang === 'uk' || lang === 'uk') {
-        translated = await translateGoogle(text, lang);
-    } else {
-        translated = await translateDeepL(text, srcLang, lang);
-    }
-    const results: Array<InlineQueryResultArticle> = [];
-    if (translated.length < max) {
-        results.push(makeResult(translated, translated));
-    } else {
-        makeLines(translated).forEach((line: string) => {
-            results.push(makeResult(line, translated));
-        });
-    }
+    const translated = await translate(text, dstLang);
+    const results = makeResults(translated);
     await bot.answerInlineQuery(query.id, results, {cache_time: 0, is_personal: true});
 });
diff --git a/src/deepl-translate-adapter.ts b/src/deepl-translate-adapter.ts
index aaaa555..ff21d91 100644
--- a/src/deepl-translate-adapter.ts
+++ b/src/deepl-translate-adapter.ts
@@ -1,9 +1,16 @@
-import { Translator} from 'deepl-node';
+import { Translator, TextResult } from 'deepl-node';
+import { DeeplInLang, DeeplOutLang } from './model';
+
 
 const translator = new Translator(require('../keys.json').DEEPL);
 
-export async function translate(text: string, srcLang:any, targetLang: any): Promise<string> {
-    targetLang = targetLang === 'en' ? 'en-US' : targetLang;
-    return translator.translateText(text, srcLang, targetLang)
-        .then((textResult => textResult.text));
+export async function translate(text: string, srcLang:any, dstLang: any): Promise<string> {
+    dstLang = dstLang === 'en' ? 'en-US' : dstLang;
+    if (!(srcLang in DeeplInLang)) { srcLang = 'en'; }
+    if (!(dstLang in DeeplOutLang)) { dstLang = 'en'; }
+    return translator.translateText(text, srcLang, dstLang)
+        .then(
+            (textResult: TextResult) => {return textResult.text;},
+            () => ''
+        );
 }
diff --git a/src/google-translate-adapter.ts b/src/google-translate-adapter.ts
index e4a7503..9f9e0f7 100644
--- a/src/google-translate-adapter.ts
+++ b/src/google-translate-adapter.ts
@@ -1,15 +1,23 @@
+import { GoogleLang } from './model';
+
 const {Translate} = require('@google-cloud/translate').v2;
 
 const projectId = 'translate-reebot';
 const translator = new Translate({projectId});
 translator.key = require('../keys.json').GOOGLE;
 
-export async function translate(text: string, targetLang: string): Promise<string> {
-    return translator.translate(text, targetLang)
-        .then(([result] : any) => result);
+export async function translate(text: string, dstLang: string): Promise<string> {
+    return translator.translate(text, dstLang)
+        .then(
+            ([result] : any) => result,
+            (error: any) => console.log(error)
+        );
 }
 
 export async function detect(text: string): Promise<string> {
     return translator.detect(text)
-        .then(([result] : any) => result.language === 'und' ? 'en' : result.language);
+        .then(
+            ([result] : any) => !(result.language in GoogleLang) ? 'en' : result.language,
+            (error: any) => console.log(error)
+        );
 }
diff --git a/src/model.ts b/src/model.ts
new file mode 100644
index 0000000..044e873
--- /dev/null
+++ b/src/model.ts
@@ -0,0 +1,14 @@
+// subset of https://cloud.google.com/translate/docs/languages
+export enum GoogleLang {
+    de, en, uk, es, fr, it, ru
+}
+
+// subset of https://www.deepl.com/docs-api/translating-text/
+export enum DeeplInLang {
+    de, en, es, fr, it, ru
+}
+
+// subset of https://www.deepl.com/docs-api/translating-text/
+export enum DeeplOutLang {
+    de, 'en-US', es, fr, it, ru
+}
diff --git a/src/results.ts b/src/results.ts
index 0a46310..23413de 100644
--- a/src/results.ts
+++ b/src/results.ts
@@ -2,11 +2,12 @@ import { InlineQueryResultArticle } from 'node-telegram-bot-api';
 
 let id = 0;
 
-export function makeResult(title: string, message: string) : InlineQueryResultArticle {
+export function makeResult(title: string, message: string): InlineQueryResultArticle {
+    if (id + 1 == Number.MAX_SAFE_INTEGER) { id = 0; }
     return {
         type: 'article',
         id: '' + ++id,
         title: title,
-        input_message_content: { message_text:  message}
+        input_message_content: {message_text: message}
     };
 }