/**
 * File:
 *  sr.c
 *
 * Notes:
 *  This file contains native routines for sending and receiving data from
 *  a specified serial device.
 *
 * History:
 *  2013/07/06 Written by Simon Platten
 */
#include <errno.h>
#include <fcntl.h>
#include <termios.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include "sr.h"
// Constants
#define BUFFER_SIZE   12
/*
 * Opens the specified device
 */
static int openDevice(const char* strDevice, int intModes, jboolean blnDebug) {
// Try to open the port
	int intFD = open(strDevice, intModes | O_NOCTTY | O_NDELAY);

	if ( intFD >= 0 ) {
		fcntl(intFD, F_SETFL, 0);
	}
	struct termios options;
// Get the current options for the port...
	tcgetattr(intFD, &options);
// Set the baud rates to 115200...
	cfsetispeed(&options, B115200);
	cfsetospeed(&options, B115200);
// Enable the receiver and set local mode...
	options.c_cflag |= (CLOCAL | CREAD);
	options.c_cflag &= ~PARENB;
	options.c_cflag &= ~CSTOPB;
	options.c_cflag &= ~CSIZE;
	options.c_cflag |= CS8;
// disable hardware flow control
	options.c_cflag &= ~CRTSCTS;
// disable XON XOFF (for transmit and receive)
	options.c_iflag &= ~(IXON | IXOFF | IXANY);
//options.c_cflag |= CRTSCTS;                    // enable hardware flow control
// min carachters to be read
	options.c_cc[VMIN] = 0;
// Time to wait for data (tenths of seconds)
	options.c_cc[VTIME] = 0;
// Set the new options for the port...
// tcsetattr(fd, TCSANOW, &options);
//Set the new options for the port...
	tcflush(intFD, TCIFLUSH);
	if ( tcsetattr(intFD, TCSANOW, &options) == -1 ) {
		perror("On tcsetattr:");
	}
	if ( intFD < 0 && blnDebug == JNI_TRUE ) {
		printf("%s, port not ready\n", strDevice);
	}
	return intFD;
}
/*
 * Class:     cantley_co_uk_clsMain
 * Method:    receive
 * Signature: (I)Ljava/lang/String;
 */
JNIEXPORT jbyteArray JNICALL Java_cantley_co_uk_clsMain_receive
  (JNIEnv* pEnv, jobject obj, jstring strDevice, jboolean blnDebug) {
	const char *pstrDevice	= (*pEnv)->GetStringUTFChars(pEnv, strDevice, NULL);
	jbyteArray aryRC = NULL;

	if ( pstrDevice ) {
		int intFD = openDevice(pstrDevice, O_RDONLY | O_NONBLOCK, blnDebug);

		if ( intFD >= 0 ) {
			aryRC = (*pEnv)->NewByteArray(pEnv, BUFFER_SIZE);

			if ( aryRC ) {
printf("receive aaa\n");
				char arycData[BUFFER_SIZE];
				int intIdx = 0;

				while( read(intFD, &arycData[intIdx], 1) != -1 ) {
					if ( ++intIdx >= BUFFER_SIZE ) {
						break;
					}
				}
printf("receive bbb: %d\n", intIdx);
				(*pEnv)->SetByteArrayRegion(pEnv, aryRC, 0, intIdx, (jbyte*)arycData);

				if ( blnDebug == JNI_TRUE ) {
					int i;
					printf("%s, receive[%d]: ", pstrDevice, intIdx);
					for( i=0; i<intIdx; i++ ) {
						printf("%c", arycData[i]);
					}
					printf("\n");
				}
			}
// Close the device
			close(intFD);
		}
	}
	(*pEnv)->ReleaseStringUTFChars(pEnv, strDevice, pstrDevice);
	return aryRC;
}
/*
 * Class:     cantley_co_uk_clsMain
 * Method:    send
 * Signature: (ILjava/lang/String;)V
 */
JNIEXPORT void JNICALL Java_cantley_co_uk_clsMain_send
  (JNIEnv* pEnv, jobject obj, jstring strDevice, jstring strData, jboolean blnDebug) {
	const char *pstrDevice	= (*pEnv)->GetStringUTFChars(pEnv, strDevice, NULL);
	const char *pstrData = (*pEnv)->GetStringUTFChars(pEnv, strData, NULL);
	int intLength;

	if ( pstrDevice && pstrData && (intLength = strlen(pstrData)) > 0 ) {
		int intFD = openDevice(pstrDevice, O_WRONLY, blnDebug);

		if ( intFD >= 0 ) {
// Write to the device
			int intWritten = write(intFD, pstrData, intLength);

			if ( blnDebug == JNI_TRUE ) {
				printf("%s, send[%d]: %s\n", pstrDevice, intWritten, pstrData);
			}
// Close the device
			close(intFD);
		}
	}
	(*pEnv)->ReleaseStringUTFChars(pEnv, strDevice, pstrDevice);
	(*pEnv)->ReleaseStringUTFChars(pEnv, strData, pstrData);
}