discourse-translator/services/discourse_translator/yandex.rb

# frozen_string_literal: true

require_relative "base"

module DiscourseTranslator
  class Yandex < Base
    TRANSLATE_URI = "https://translate.yandex.net/api/v1.5/tr.json/translate"
    DETECT_URI = "https://translate.yandex.net/api/v1.5/tr.json/detect"

    # Hash which maps Discourse's locale code to Yandex Translate's language code found in
    # https://yandex.com/dev/translate/doc/dg/concepts/api-overview.html
    SUPPORTED_LANG_MAPPING = {
      pt_BR: "pt",
      pl_PL: "pl",
      no_NO: "no",
      fa_IR: "fa",
      zh_CN: "zh",
      zh_TW: "zh",
      tr_TR: "tr",
      en: "en",
      en_US: "en",
      en_GB: "en",
      az: "az",
      ml: "ml",
      sq: "sq",
      mt: "mt",
      am: "am",
      mk: "mk",
      mi: "mi",
      ar: "ar",
      mr: "mr",
      hy: "hy",
      mhr: "mhr",
      af: "af",
      mn: "mn",
      eu: "eu",
      de: "de",
      ba: "ba",
      ne: "ne",
      be: "be",
      no: "no",
      bn: "bn",
      pa: "pa",
      my: "my",
      pap: "pap",
      bg: "bg",
      fa: "fa",
      bs: "bs",
      pl: "pl",
      cy: "cy",
      pt: "pt",
      hu: "hu",
      ro: "ro",
      vi: "vi",
      ru: "ru",
      ht: "ht",
      ceb: "ceb",
      gl: "gl",
      sr: "sr",
      nl: "nl",
      si: "si",
      mrj: "mrj",
      sk: "sk",
      el: "el",
      sl: "sl",
      ka: "ka",
      sw: "sw",
      gu: "gu",
      su: "su",
      da: "da",
      tg: "tg",
      he: "he",
      th: "th",
      yi: "yi",
      tl: "tl",
      id: "id",
      ta: "ta",
      ga: "ga",
      tt: "tt",
      it: "it",
      te: "te",
      is: "is",
      tr: "tr",
      es: "es",
      udm: "udm",
      kk: "kk",
      uz: "uz",
      kn: "kn",
      uk: "uk",
      ca: "ca",
      ur: "ur",
      ky: "ky",
      fi: "fi",
      zh: "zh",
      fr: "fr",
      ko: "ko",
      hi: "hi",
      xh: "xh",
      hr: "hr",
      km: "km",
      cs: "cs",
      lo: "lo",
      sv: "sv",
      la: "la",
      gd: "gd",
      lv: "lv",
      et: "et",
      lt: "lt",
      eo: "eo",
      lb: "lb",
      jv: "jv",
      mg: "mg",
      ja: "ja",
      ms: "ms",
    }

    def self.access_token_key
      "yandex-translator"
    end

    def self.access_token
      SiteSetting.translator_yandex_api_key ||
        (raise TranslatorError.new("NotFound: Yandex API Key not set."))
    end

    def self.detect(topic_or_post)
      topic_or_post.custom_fields[DiscourseTranslator::DETECTED_LANG_CUSTOM_FIELD] ||= begin
        query = default_query.merge("text" => get_text(topic_or_post))

        uri = URI(DETECT_URI)
        uri.query = URI.encode_www_form(query)

        response_body = result(uri.to_s, "", default_headers)

        response_body["lang"]
      end
    end

    def self.translate(topic_or_post)
      detected_lang = detect(topic_or_post)

      if !SUPPORTED_LANG_MAPPING.keys.include?(detected_lang.to_sym) &&
           !SUPPORTED_LANG_MAPPING.values.include?(detected_lang.to_s)
        raise TranslatorError.new(I18n.t("translator.failed"))
      end

      translated_text =
        from_custom_fields(topic_or_post) do
          query =
            default_query.merge(
              "lang" => "#{detected_lang}-#{locale}",
              "text" => get_text(topic_or_post),
              "format" => "html",
            )

          uri = URI(TRANSLATE_URI)
          uri.query = URI.encode_www_form(query)

          response_body = result(uri.to_s, "", default_headers)
          response_body["text"][0]
        end

      [detected_lang, translated_text]
    end

    private

    def self.locale
      SUPPORTED_LANG_MAPPING[I18n.locale] || (raise I18n.t("translator.not_supported"))
    end

    def self.post(uri, body, headers = {})
      Excon.post(uri, body: body, headers: headers)
    end

    def self.result(uri, body, headers)
      response = post(uri, body, headers)
      response_body = JSON.parse(response.body)

      if response.status != 200
        raise TranslatorError.new(response_body)
      else
        response_body
      end
    end

    def self.default_headers
      { "Content-Type" => "application/x-www-form-urlencoded" }
    end

    def self.default_query
      { key: access_token }
    end
  end
end