Return language detection result

app/src/main/java/eu/faircode/email/TextHelper.java

@@ -45,7 +45,7 @@ public class TextHelper {
         System.loadLibrary("fairemail");
     }
 
-    private static native String jni_detect_language(byte[] octets);
+    private static native DetectResult jni_detect_language(byte[] octets);
 
     static Locale detectLanguage(Context context, String text) {
         // Why not ML kit? https://developers.google.com/ml-kit/terms
@@ -54,8 +54,9 @@ public class TextHelper {
 
         if (BuildConfig.DEBUG) {
             // https://github.com/google/cld3
-            String lang = jni_detect_language(text.getBytes());
-            return Locale.forLanguageTag(lang);
+            DetectResult result = jni_detect_language(text.getBytes());
+            Log.i("Language=" + result);
+            return Locale.forLanguageTag(result.language);
         }
 
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q)
@@ -121,4 +122,23 @@ public class TextHelper {
 
         return tcm.getTextClassifier().suggestConversationActions(request);
     }
+
+    private static class DetectResult {
+        String language;
+        float probability;
+        boolean is_reliable;
+        float proportion;
+
+        DetectResult(String language, float probability, boolean is_reliable, float proportion) {
+            this.language = language;
+            this.probability = probability;
+            this.is_reliable = is_reliable;
+            this.proportion = proportion;
+        }
+
+        @Override
+        public String toString() {
+            return language + " p=" + probability + " r=" + is_reliable + " pr=" + proportion;
+        }
+    }
 }

app/src/main/jni/fairemail.cc

@@ -21,7 +21,8 @@ void log_android(int prio, const char *fmt, ...) {
 }
 
 extern "C" JNIEXPORT jobject JNICALL
-Java_eu_faircode_email_CharsetHelper_jni_1detect_1charset(JNIEnv *env, jclass type, jbyteArray _octets) {
+Java_eu_faircode_email_CharsetHelper_jni_1detect_1charset(JNIEnv *env, jclass type,
+                                                          jbyteArray _octets) {
     int len = env->GetArrayLength(_octets);
     jbyte *octets = env->GetByteArrayElements(_octets, nullptr);
 
@@ -59,8 +60,9 @@ Java_eu_faircode_email_CharsetHelper_jni_1detect_1charset(JNIEnv *env, jclass ty
 }
 
 extern "C"
-JNIEXPORT jstring JNICALL
-Java_eu_faircode_email_TextHelper_jni_1detect_1language(JNIEnv *env, jclass clazz, jbyteArray _octets) {
+JNIEXPORT jobject JNICALL
+Java_eu_faircode_email_TextHelper_jni_1detect_1language(JNIEnv *env, jclass clazz,
+                                                        jbyteArray _octets) {
     int len = env->GetArrayLength(_octets);
     jbyte *octets = env->GetByteArrayElements(_octets, nullptr);
 
@@ -71,7 +73,15 @@ Java_eu_faircode_email_TextHelper_jni_1detect_1language(JNIEnv *env, jclass claz
 
     env->ReleaseByteArrayElements(_octets, octets, JNI_ABORT);
 
-    return env->NewStringUTF(result.language.c_str());
+    jclass cls = env->FindClass("eu/faircode/email/TextHelper$DetectResult");
+    jmethodID ctor = env->GetMethodID(cls, "<init>", "(Ljava/lang/String;FZF)V");
+    jstring jlanguage = env->NewStringUTF(result.language.c_str());
+    return env->NewObject(
+            cls, ctor,
+            jlanguage,
+            (jfloat) result.probability,
+            (jint) result.is_reliable,
+            (jfloat) result.is_reliable);
 }
 
 extern "C"