refactor: simply DittoTranslator interface and classes that implement it

src/controllers/api/translate.ts

@@ -1,14 +1,15 @@
+import { LanguageCode } from 'iso-639-1';
 import { z } from 'zod';
 
 import { AppController } from '@/app.ts';
-import { languageSchema } from '@/schema.ts';
-import { dittoTranslations, dittoTranslationsKey } from '@/translators/translator.ts';
+import { localeSchema } from '@/schema.ts';
+import { dittoTranslations, dittoTranslationsKey, MastodonTranslation } from '@/translators/translator.ts';
 import { parseBody } from '@/utils/api.ts';
 import { getEvent } from '@/queries.ts';
 import { renderStatus } from '@/views/mastodon/statuses.ts';
 
 const translateSchema = z.object({
-  lang: languageSchema,
+  lang: localeSchema,
 });
 
 const translateController: AppController = async (c) => {
@@ -24,7 +25,8 @@ const translateController: AppController = async (c) => {
     return c.json({ error: 'No translator configured.' }, 500);
   }
 
-  const { lang } = result.data;
+  const lang = result.data.lang.language.slice(0, 2) as LanguageCode;
+
   const id = c.req.param('id');
 
   const event = await getEvent(id, { signal });
@@ -39,6 +41,9 @@ const translateController: AppController = async (c) => {
   }
 
   const status = await renderStatus(event, { viewerPubkey });
+  if (!status?.content) {
+    return c.json({ error: 'Bad request.', schema: result.error }, 400);
+  }
 
   const translatedId = `${lang}-${id}` as dittoTranslationsKey;
   const translationCache = dittoTranslations.get(translatedId);
@@ -55,18 +60,79 @@ const translateController: AppController = async (c) => {
   }) ?? [];
 
   try {
-    const translation = await translator.translate(
-      status?.content ?? '',
-      status?.spoiler_text ?? '',
-      mediaAttachments,
-      null,
-      event.language,
-      lang,
-      { signal },
-    );
-    dittoTranslations.set(translatedId, translation);
-    return c.json(translation.data, 200);
-  } catch (_) {
+    const texts: string[] = [];
+
+    const mastodonTranslation: MastodonTranslation = {
+      content: '',
+      spoiler_text: '',
+      media_attachments: [],
+      poll: null,
+      detected_source_language: event.language ?? 'en',
+      provider: translator.getProvider(),
+    };
+
+    if ((status?.poll as MastodonTranslation['poll'])?.options) {
+      mastodonTranslation.poll = { id: (status?.poll as MastodonTranslation['poll'])?.id!, options: [] };
+    }
+
+    type TranslationIndex = {
+      [key: number]: 'content' | 'spoilerText' | 'poll' | { type: 'media'; id: string };
+    };
+    const translationIndex: TranslationIndex = {};
+    let index = 0;
+
+    // Content
+    translationIndex[index] = 'content';
+    texts.push(status.content);
+    index++;
+
+    // Spoiler text
+    if (status.spoiler_text) {
+      translationIndex[index] = 'spoilerText';
+      texts.push(status.spoiler_text);
+      index++;
+    }
+
+    // Media description
+    for (const [mediaIndex, value] of mediaAttachments.entries()) {
+      translationIndex[index + mediaIndex] = { type: 'media', id: value.id };
+      texts.push(mediaAttachments[mediaIndex].description);
+      index += mediaIndex;
+    }
+
+    // Poll title
+    if (status?.poll) {
+      for (const [pollIndex] of (status?.poll as MastodonTranslation['poll'])!.options.entries()) {
+        translationIndex[index + pollIndex] = 'poll';
+        texts.push((status.poll as MastodonTranslation['poll'])!.options[pollIndex].title);
+        index += pollIndex;
+      }
+    }
+
+    const data = await translator.translate(texts, event.language, lang, { signal });
+    const translatedTexts = data.results;
+
+    for (let i = 0; i < texts.length; i++) {
+      if (translationIndex[i] === 'content') {
+        mastodonTranslation.content = translatedTexts[i];
+      } else if (translationIndex[i] === 'spoilerText') {
+        mastodonTranslation.spoiler_text = translatedTexts[i];
+      } else if (translationIndex[i] === 'poll') {
+        mastodonTranslation.poll?.options.push({ title: translatedTexts[i] });
+      } else {
+        const media = translationIndex[i] as { type: 'media'; id: string };
+        mastodonTranslation.media_attachments.push({
+          id: media.id,
+          description: translatedTexts[i],
+        });
+      }
+    }
+
+    mastodonTranslation.detected_source_language = data.source_lang;
+
+    dittoTranslations.set(translatedId, { data: mastodonTranslation });
+    return c.json(mastodonTranslation, 200);
+  } catch {
     return c.json({ error: 'Service Unavailable' }, 503);
   }
 };