
#include <jni.h>
#include <string>
#include <termios.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>



#include "android/log.h"
static const char *TAG="serial_port";
#define LOGI(fmt, args...) __android_log_print(ANDROID_LOG_INFO,  TAG, fmt, ##args)
#define LOGD(fmt, args...) __android_log_print(ANDROID_LOG_DEBUG, TAG, fmt, ##args)
#define LOGE(fmt, args...) __android_log_print(ANDROID_LOG_ERROR, TAG, fmt, ##args)


static speed_t getBaudrate(jint baudrate)
{
    switch(baudrate) {
        case 0: return B0;
        case 50: return B50;
        case 75: return B75;
        case 110: return B110;
        case 134: return B134;
        case 150: return B150;
        case 200: return B200;
        case 300: return B300;
        case 600: return B600;
        case 1200: return B1200;
        case 1800: return B1800;
        case 2400: return B2400;
        case 4800: return B4800;
        case 9600: return B9600;
        case 19200: return B19200;
        case 38400: return B38400;
        case 57600: return B57600;
        case 115200: return B115200;
        case 230400: return B230400;
        case 460800: return B460800;
        case 500000: return B500000;
        case 576000: return B576000;
        case 921600: return B921600;
        case 1000000: return B1000000;
        case 1152000: return B1152000;
        case 1500000: return B1500000;
        case 2000000: return B2000000;
        case 2500000: return B2500000;
        case 3000000: return B3000000;
        case 3500000: return B3500000;
        case 4000000: return B4000000;
        default: return -1;
    }
}

static void throwException(JNIEnv *env, const char *name, const char *msg)
{
    jclass cls = env->FindClass(name);
    /* if cls is NULL, an exception has already been thrown */
    if (cls != NULL) {
        env->ThrowNew(cls, msg);
    }

    /* free the local ref */
    env->DeleteLocalRef(cls);
}

extern "C"
JNIEXPORT jobject JNICALL
Java_com_handset_serialportlib_SerialPort_open
        (JNIEnv *env, jobject instance, jstring path, jint baudrate,jint parity, jint dataBits, jint stopBit, jint flags)
{
    int fd;
    speed_t speed;
    jobject mFileDescriptor;

    /* Check arguments */
    {
        speed = getBaudrate(baudrate);
        if (speed == -1) {
            throwException(env, "java/lang/IllegalArgumentException", "Invalid baudrate");
            return NULL;
        }
        if (parity <0 || parity>2) {
            throwException(env, "java/lang/IllegalArgumentException", "Invalid parity");
            return NULL;
        }
        if (dataBits <5 || dataBits>8) {
            throwException(env, "java/lang/IllegalArgumentException", "Invalid dataBits");
            return NULL;
        }
        if (stopBit <1 || stopBit>2) {
            throwException(env, "java/lang/IllegalArgumentException", "Invalid stopBit");
            return NULL;
        }
    }

    /* Opening device */
    {
        jboolean iscopy;
        const char *path_utf = env->GetStringUTFChars(path, &iscopy);
        LOGD("Opening serial port %s with flags 0x%x", path_utf, O_RDWR | flags);
        fd = open(path_utf, O_RDWR | flags);
        LOGD("open() fd = %d", fd);
        env->ReleaseStringUTFChars(path, path_utf);
        if (fd == -1)
        {
            throwException(env, "java/io/IOException", "Cannot open port");
            return NULL;
        }
    }

    /* Configure device */
    {
        struct termios cfg;
        LOGD("Configuring serial port");
        if (tcgetattr(fd, &cfg))
        {
            LOGE("tcgetattr() failed");
            close(fd);
            throwException(env, "java/io/IOException", "tcgetattr() failed");
            return NULL;
        }

        cfmakeraw(&cfg);
        cfsetispeed(&cfg, speed);
        cfsetospeed(&cfg, speed);

        /* More attribute set */
        switch (parity) {
            case 0: break;
            case 1: cfg.c_cflag |= PARENB; break;
            case 2: cfg.c_cflag &= ~PARODD; break;
        }
        switch (dataBits) {
            case 5: cfg.c_cflag |= CS5; break;
            case 6: cfg.c_cflag |= CS6; break;
            case 7: cfg.c_cflag |= CS7; break;
            case 8: cfg.c_cflag |= CS8; break;
        }
        switch (stopBit) {
            case 1: cfg.c_cflag &= ~CSTOPB; break;
            case 2: cfg.c_cflag |= CSTOPB; break;
        }

        if (tcsetattr(fd, TCSANOW, &cfg))
        {
            LOGE("tcsetattr() failed");
            close(fd);
            /* TODO: throw an exception */
            return NULL;
        }
    }

    /* Create a corresponding file descriptor */
    {
        jclass cFileDescriptor = env->FindClass("java/io/FileDescriptor");
        jmethodID iFileDescriptor = env->GetMethodID(cFileDescriptor, "<init>", "()V");
        jfieldID descriptorID = env->GetFieldID(cFileDescriptor, "descriptor", "I");
        mFileDescriptor = env->NewObject(cFileDescriptor, iFileDescriptor);
        env->SetIntField(mFileDescriptor, descriptorID, (jint)fd);
    }

    return mFileDescriptor;
}


/*
 * Class:     cedric_serial_SerialPort
 * Method:    close
 * Signature: ()V
 */
extern "C"
JNIEXPORT void JNICALL Java_com_handset_serialportlib_SerialPort_close
        (JNIEnv *env, jobject thiz)
{
    jclass SerialPortClass = env->GetObjectClass( thiz);
    jclass FileDescriptorClass = env->FindClass( "java/io/FileDescriptor");

    jfieldID mFdID = env->GetFieldID(SerialPortClass, "mFd", "Ljava/io/FileDescriptor;");
    jfieldID descriptorID = env->GetFieldID(FileDescriptorClass, "descriptor", "I");

    jobject mFd = env->GetObjectField(thiz, mFdID);
    jint descriptor = env->GetIntField(mFd, descriptorID);

    LOGD("close(fd = %d)", descriptor);
    close(descriptor);
}
