From 77674b0730575813abd31ccf57fdb7c5e3b698ef Mon Sep 17 00:00:00 2001
From: M66B <M66B@users.noreply.github.com>
Date: Mon, 18 Jan 2021 22:57:15 +0100
Subject: [PATCH] cld3 binding

---
 .../main/java/eu/faircode/email/TextHelper.java | 12 ++++++++++++
 app/src/main/jni/fairemail.cc                   | 17 +++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/app/src/main/java/eu/faircode/email/TextHelper.java b/app/src/main/java/eu/faircode/email/TextHelper.java
index aef3e28bd0..7e9ed51d7e 100644
--- a/app/src/main/java/eu/faircode/email/TextHelper.java
+++ b/app/src/main/java/eu/faircode/email/TextHelper.java
@@ -41,11 +41,23 @@ import java.util.Locale;
 import java.util.Set;
 
 public class TextHelper {
+    static {
+        System.loadLibrary("fairemail");
+    }
+
+    private static native String jni_language(byte[] octets);
+
     static Locale detectLanguage(Context context, String text) {
         // Why not ML kit? https://developers.google.com/ml-kit/terms
         if (TextUtils.isEmpty(text))
             return null;
 
+        if (BuildConfig.DEBUG) {
+            // https://github.com/google/cld3
+            String lang = jni_language(text.getBytes());
+            return Locale.forLanguageTag(lang);
+        }
+
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q)
             return null;
 
diff --git a/app/src/main/jni/fairemail.cc b/app/src/main/jni/fairemail.cc
index 886594e0cd..89918230c4 100644
--- a/app/src/main/jni/fairemail.cc
+++ b/app/src/main/jni/fairemail.cc
@@ -7,6 +7,7 @@
 #include <netinet/tcp.h>
 
 #include "compact_enc_det/compact_enc_det.h"
+#include "cld_3/src/nnet_language_identifier.h"
 
 void log_android(int prio, const char *fmt, ...) {
     if (prio >= ANDROID_LOG_DEBUG) {
@@ -57,6 +58,22 @@ Java_eu_faircode_email_CharsetHelper_jni_1detect(JNIEnv *env, jclass type, jbyte
             (jboolean) is_reliable);
 }
 
+extern "C"
+JNIEXPORT jstring JNICALL
+Java_eu_faircode_email_TextHelper_jni_1language(JNIEnv *env, jclass clazz, jbyteArray _octets) {
+    int len = env->GetArrayLength(_octets);
+    jbyte *octets = env->GetByteArrayElements(_octets, nullptr);
+
+    std::string text(reinterpret_cast<char const *>(octets), len);
+
+    chrome_lang_id::NNetLanguageIdentifier lang_id(0, 1000);
+    const chrome_lang_id::NNetLanguageIdentifier::Result result = lang_id.FindLanguage(text);
+
+    env->ReleaseByteArrayElements(_octets, octets, JNI_ABORT);
+
+    return env->NewStringUTF(result.language.c_str());
+}
+
 extern "C"
 JNIEXPORT jint JNICALL
 Java_eu_faircode_email_EmailService_jni_1socket_1keep_1alive(