add bridge native code

app/src/main/cpp/native-lib.cpp

@@ -0,0 +1,60 @@
+#include <jni.h>
+#include <string>
+
+#include <android/log.h>
+
+#include "consts.h"
+#include "api.h"
+
+std::unique_ptr<Connector> connector = nullptr;
+
+void setup(JNIEnv* env, jobject isoDepObj);
+void initSessionViaBAC();
+
+extern "C" JNIEXPORT jint JNICALL
+Java_com_bshield_cccc_MainActivity_initNFCScan(
+        JNIEnv* env,
+        jobject /* this */,
+        jobject isoDepObj) {
+
+    setup(env, isoDepObj);
+    if (!connector) return 0;
+
+    connector->selectDf1();
+    connector->initBAC();
+    connector->readEFCOM();
+    return 1;
+}
+
+void setup(JNIEnv* env, jobject isoDepObj) {
+    // Get the IsoDep class and its methods
+    jclass isoDepClass = env->FindClass("android/nfc/tech/IsoDep");
+
+    jmethodID connectMethod = env->GetMethodID(isoDepClass, "connect", "()V");
+    jmethodID closeMethod = env->GetMethodID(isoDepClass, "close", "()V");
+    jmethodID transceiveMethod = env->GetMethodID(isoDepClass, "transceive", "([B)[B");
+    jmethodID isConnectedMethod = env->GetMethodID(isoDepClass, "isConnected", "()Z");
+
+    // formalize api to vector<uint8_t> to remove platform dependency
+    // use closure to capture values to work on transceive api easily
+    auto transceive = [env, isoDepObj, transceiveMethod](std::vector<uint8_t> data) {
+        jbyteArray command = env->NewByteArray(data.size());
+        env->SetByteArrayRegion(command, 0, data.size(), reinterpret_cast<const jbyte*>(data.data()));
+        auto b = (jbyteArray)env->CallObjectMethod(isoDepObj, transceiveMethod, command);
+
+        jsize length = env->GetArrayLength(b);
+        jbyte* elements = env->GetByteArrayElements(b, NULL);
+        std::vector<uint8_t> vec(length);
+        memcpy(&vec[0], elements, length);
+        env->ReleaseByteArrayElements(b, elements, JNI_ABORT);
+
+        return vec;
+    };
+
+    connector.reset(new Connector(transceive));
+
+    // cannot remove, must call connect to connect
+    env->CallVoidMethod(isoDepObj, connectMethod);
+//    jboolean isConnected = env->CallBooleanMethod(isoDepObj, isConnectedMethod);
+    return;
+};