Rocket.Chat/app/autotranslate/server/googleTranslate.js

/**
 * @author Vigneshwaran Odayappan <vickyokrm@gmail.com>
 */

import { TAPi18n } from 'meteor/rocketchat:tap-i18n';
import { HTTP } from 'meteor/http';
import _ from 'underscore';

import { AutoTranslate,	TranslationProviderRegistry } from './autotranslate';
import { SystemLogger } from '../../logger/server';
import { settings } from '../../settings';

/**
 * Represents google translate class
 * @class
 * @augments AutoTranslate
 */

class GoogleAutoTranslate extends AutoTranslate {
	/**
	 * setup api reference to Google translate to be used as message translation provider.
	 * @constructor
	 */
	constructor() {
		super();
		this.name = 'google-translate';
		this.apiEndPointUrl = 'https://translation.googleapis.com/language/translate/v2';
		// Get the service provide API key.
		settings.get('AutoTranslate_GoogleAPIKey', (key, value) => {
			this.apiKey = value;
		});
	}

	/**
	 * Returns metadata information about the service provider
	 * @private implements super abstract method.
	 * @returns {object}
	 */
	_getProviderMetadata() {
		return {
			name: this.name,
			displayName: TAPi18n.__('AutoTranslate_Google'),
			settings: this._getSettings(),
		};
	}

	/**
	 * Returns necessary settings information about the translation service provider.
	 * @private implements super abstract method.
	 * @returns {object}
	 */
	_getSettings() {
		return {
			apiKey: this.apiKey,
			apiEndPointUrl: this.apiEndPointUrl,
		};
	}

	/**
	 * Returns supported languages for translation by the active service provider.
	 * Google Translate api provides the list of supported languages.
	 * @private implements super abstract method.
	 * @param {string} target : user language setting or 'en'
	 * @returns {object} code : value pair
	 */
	getSupportedLanguages(target) {
		if (!this.apiKey) {
			return [];
		}

		if (this.supportedLanguages[target]) {
			return this.supportedLanguages[target];
		}

		let result;
		const params = {
			key: this.apiKey,
		};

		if (target) {
			params.target = target;
		}

		try {
			result = HTTP.get('https://translation.googleapis.com/language/translate/v2/languages', {
				params,
			});
		} catch (e) {
			// Fallback: Get the English names of the target languages
			if (e.response && e.response.statusCode === 400 && e.response.data && e.response.data.error && e.response.data.error.status === 'INVALID_ARGUMENT') {
				params.target = 'en';
				target = 'en';
				if (!this.supportedLanguages[target]) {
					result = HTTP.get('https://translation.googleapis.com/language/translate/v2/languages', {
						params,
					});
				}
			}
		}

		if (this.supportedLanguages[target]) {
			return this.supportedLanguages[target];
		}
		this.supportedLanguages[target || 'en'] = result?.data?.data?.languages;
		return this.supportedLanguages[target || 'en'];
	}

	/**
	 * Send Request REST API call to the service provider.
	 * Returns translated message for each target language in target languages.
	 * @private
	 * @param {object} message
	 * @param {object} targetLanguages
	 * @returns {object} translations: Translated messages for each language
	 */
	_translateMessage(message, targetLanguages) {
		const translations = {};
		let msgs = message.msg.split('\n');
		msgs = msgs.map((msg) => encodeURIComponent(msg));

		const query = `q=${ msgs.join('&q=') }`;
		const supportedLanguages = this.getSupportedLanguages('en');

		targetLanguages.forEach((language) => {
			if (language.indexOf('-') !== -1 && !_.findWhere(supportedLanguages, { language })) {
				language = language.substr(0, 2);
			}

			try {
				const result = HTTP.get(this.apiEndPointUrl, {
					params: {
						key: this.apiKey,
						target: language,
					},
					query,
				});

				if (result.statusCode === 200 && result.data && result.data.data && result.data.data.translations && Array.isArray(result.data.data.translations) && result.data.data.translations.length > 0) {
					const txt = result.data.data.translations.map((translation) => translation.translatedText).join('\n');
					translations[language] = this.deTokenize(Object.assign({}, message, { msg: txt }));
				}
			} catch (e) {
				SystemLogger.error('Error translating message', e);
			}
		});
		return translations;
	}

	/**
	 * Returns translated message attachment description in target languages.
	 * @private
	 * @param {object} attachment
	 * @param {object} targetLanguages
	 * @returns {object} translated attachment descriptions for each target language
	 */
	_translateAttachmentDescriptions(attachment, targetLanguages) {
		const translations = {};
		const query = `q=${ encodeURIComponent(attachment.description || attachment.text) }`;
		const supportedLanguages = this.getSupportedLanguages('en');

		targetLanguages.forEach((language) => {
			if (language.indexOf('-') !== -1 && !_.findWhere(supportedLanguages, { language })) {
				language = language.substr(0, 2);
			}

			try {
				const result = HTTP.get(this.apiEndPointUrl, {
					params: {
						key: this.apiKey,
						target: language,
					},
					query,
				});

				if (result.statusCode === 200 && result.data && result.data.data && result.data.data.translations && Array.isArray(result.data.data.translations) && result.data.data.translations.length > 0) {
					translations[language] = result.data.data.translations.map((translation) => translation.translatedText).join('\n');
				}
			} catch (e) {
				SystemLogger.error('Error translating message', e);
			}
		});
		return translations;
	}
}

// Register Google translation provider.
TranslationProviderRegistry.registerProvider(new GoogleAutoTranslate());