1 files changed, 41 insertions, 0 deletions
diff --git a/names/translate.js b/names/translate.js
index 5382711..36ab8cf 100644
--- a/names/translate.js
+++ b/names/translate.js
@@ -80,3 +80,44 @@ export async function translate(text, target, source = 'auto') {
     return out;
   } finally { release(); }
 }
+
+// DeepL, with the reader's own API key (sent per request; never stored, and
+// not part of the cache key beyond the provider). DeepL refuses browsers
+// (no CORS), which is the only reason this passes through here. A free key
+// ends in ":fx" and has its own host.
+const DEEPL_TARGET = { en: 'EN-US', pt: 'PT-BR', zh: 'ZH-HANS' };
+export async function translateDeepl(text, target, key, fetchImpl = fetch) {
+  text = String(text || '');
+  target = norm(target);
+  if (!text.trim()) return { text: '', source: null };
+  if (text.length > MAX_CHARS) throw Object.assign(new Error('too long'), { status: 413 });
+  if (!/^[0-9a-f-]{20,}(:fx)?$/i.test(key)) throw Object.assign(new Error('bad DeepL key'), { status: 401 });
+  const ck = createHash('sha256').update('deepl|' + target + '|' + text).digest('hex');
+  const hit = cache.get(ck);
+  if (hit) { cache.delete(ck); cache.set(ck, hit); return hit; }
+  const { prose, tags } = translatable(text, target);
+  if (!prose.length && !tags.length) return { text, source: null, nothing: true };
+  const host = /:fx$/i.test(key) ? 'https://api-free.deepl.com' : 'https://api.deepl.com';
+  let from = null;
+  const translated = await translatePieces(text, async (qs) => {
+    const r = await fetchImpl(host + '/v2/translate', {
+      method: 'POST',
+      headers: { 'content-type': 'application/json', authorization: 'DeepL-Auth-Key ' + key },
+      body: JSON.stringify({ text: qs, target_lang: DEEPL_TARGET[target] || target.toUpperCase() }),
+      signal: AbortSignal.timeout(20_000),
+    });
+    if (r.status === 403 || r.status === 401) throw Object.assign(new Error('DeepL refused the key'), { status: 401 });
+    if (r.status === 456) throw Object.assign(new Error('DeepL quota exceeded'), { status: 402 });
+    if (r.status === 400) throw Object.assign(new Error('DeepL can’t translate into that language'), { status: 422 });
+    if (!r.ok) throw Object.assign(new Error('DeepL ' + r.status), { status: 502 });
+    const j = await r.json();
+    const out = (j.translations || []).map((x) => x.text);
+    from ||= norm(j.translations?.[0]?.detected_source_language) || null;
+    if (out.length !== qs.length) throw Object.assign(new Error('DeepL answered short'), { status: 502 });
+    return out;
+  }, target);
+  const out = { text: from === target ? text : translated, source: from };
+  cache.set(ck, out);
+  if (cache.size > CACHE_MAX) cache.delete(cache.keys().next().value);
+  return out;
+}