Add user content translations with configurable backends (#19218)

1 files changed, 53 insertions, 0 deletions

diff --git a/app/lib/translation_service/deepl.rb b/app/lib/translation_service/deepl.rb
new file mode 100644
index 000000000..89ccf01e5
--- /dev/null
+++ b/app/lib/translation_service/deepl.rb
@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+class TranslationService::DeepL < TranslationService
+  include JsonLdHelper
+
+  def initialize(plan, api_key)
+    super()
+
+    @plan    = plan
+    @api_key = api_key
+  end
+
+  def translate(text, source_language, target_language)
+    request(text, source_language, target_language).perform do |res|
+      case res.code
+      when 429
+        raise TooManyRequestsError
+      when 456
+        raise QuotaExceededError
+      when 200...300
+        transform_response(res.body_with_limit)
+      else
+        raise UnexpectedResponseError
+      end
+    end
+  end
+
+  private
+
+  def request(text, source_language, target_language)
+    req = Request.new(:post, endpoint_url, form: { text: text, source_lang: source_language.upcase, target_lang: target_language, tag_handling: 'html' })
+    req.add_headers('Authorization': "DeepL-Auth-Key #{@api_key}")
+    req
+  end
+
+  def endpoint_url
+    if @plan == 'free'
+      'https://api-free.deepl.com/v2/translate'
+    else
+      'https://api.deepl.com/v2/translate'
+    end
+  end
+
+  def transform_response(str)
+    json = Oj.load(str, mode: :strict)
+
+    raise UnexpectedResponseError unless json.is_a?(Hash)
+
+    Translation.new(text: json.dig('translations', 0, 'text'), detected_source_language: json.dig('translations', 0, 'detected_source_language')&.downcase)
+  rescue Oj::ParseError
+    raise UnexpectedResponseError
+  end
+end