1 files changed, 112 insertions, 0 deletions
diff --git a/MLEB/Translate/webservices/GoogleTranslateWebService.php b/MLEB/Translate/webservices/GoogleTranslateWebService.php
new file mode 100644
index 00000000..abb435ea
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+++ b/MLEB/Translate/webservices/GoogleTranslateWebService.php
@@ -0,0 +1,112 @@
+<?php
+/**
+ * Contains a class for querying external translation service.
+ *
+ * @file
+ * @author Carsten Schmitz / LimeSurvey GmbH
+ * @license GPL-2.0-or-later
+ */
+
+/**
+ * Implements support for Google Translate API
+ * @see https://cloud.google.com/translate/docs/reference/rest
+ * @ingroup TranslationWebService
+ * @since 2020.05
+ */
+class GoogleTranslateWebService extends TranslationWebService {
+	private const PUBLIC_API = 'https://translation.googleapis.com/language/translate/v2';
+
+	/** @inheritDoc */
+	public function getType() {
+		return 'mt';
+	}
+
+	/** @inheritDoc */
+	protected function mapCode( $code ) {
+		if ( $code === 'be-tarask' ) {
+			$code = 'be';
+		}
+		return $code;
+	}
+
+	/** @inheritDoc */
+	public function isSupportedLanguagePair( $from, $to ) {
+		$pairs = $this->getSupportedLanguagePairs();
+		$from = $this->mapCode( $from );
+		$to = $this->mapCode( $to );
+
+		// As long as the source & target language exist at Google it is fine
+		return isset( $pairs[$from] ) && isset( $pairs[$to] ) && $from !== $to;
+	}
+
+	/** @inheritDoc */
+	protected function doPairs() {
+		if ( !isset( $this->config['key'] ) ) {
+			throw new TranslationWebServiceConfigurationException( 'API key is not set' );
+		}
+
+		$api = $this->config['pairs'] ?? self::PUBLIC_API . '/languages';
+		$params = [
+			'key' => $this->config['key'],
+		];
+
+		$json = Http::get(
+			wfAppendQuery( $api, wfArrayToCgi( $params ) ),
+			[ 'timeout' => $this->config['timeout'] ],
+			__METHOD__
+		);
+		$response = FormatJson::decode( $json );
+
+		if ( !is_object( $response ) ) {
+			$exception = 'Malformed reply from remote server: ' . (string)$json;
+			throw new TranslationWebServiceException( $exception );
+		}
+
+		$pairs = [];
+		foreach ( $response->data->languages as $language ) {
+			// Google can translate from any language to any language
+			$pairs[$language->language] = true;
+		}
+
+		return $pairs;
+	}
+
+	/** @inheritDoc */
+	protected function getQuery( $text, $from, $to ) {
+		if ( !isset( $this->config['key'] ) ) {
+			throw new TranslationWebServiceConfigurationException( 'API key is not set' );
+		}
+		# https://cloud.google.com/translate/docs/reference/translate
+		if ( strlen( $text ) > 10000 ) {
+			// There is no limitation but we don't want the translation service to be abused, don't we?
+			throw new TranslationWebServiceInvalidInputException( 'Source text too long' );
+		}
+
+		$url = $this->config['url'] ?? self::PUBLIC_API;
+		$text = trim( $text );
+		$text = $this->wrapUntranslatable( $text );
+
+		return TranslationQuery::factory( $url )
+			->timeout( $this->config['timeout'] ?? 3 )
+			->postWithData( wfArrayToCgi( [
+				'key' => $this->config['key'],
+				'q' => $text,
+				'target' => $to,
+				'source' => $from,
+				'format' => 'html',
+			] ) );
+	}
+
+	/** @inheritDoc */
+	protected function parseResponse( TranslationQueryResponse $reply ) {
+		$body = $reply->getBody();
+		$response = FormatJson::decode( $body );
+		if ( !is_object( $response ) ) {
+			throw new TranslationWebServiceException( 'Invalid json: ' . serialize( $body ) );
+		}
+		$text = Sanitizer::decodeCharReferences( $response->data->translations[0]->translatedText );
+		$text = $this->unwrapUntranslatable( $text );
+
+		return trim( $text );
+	}
+}