#include <stdio.h>   
#include <stdlib.h>
#include <string.h>  
#include <unistd.h>  
#include <fcntl.h>   
#include <errno.h>   
#include <termios.h> 
#include <ctype.h>

#include "serial_io.h"


char	*param_file_name;
int	param_baud;
int	param_parity;	// not implemented yet
int	param_size;
int	param_flow;		// not implemented yet



serial_io::serial_io(char *args){
	struct	termios
		options;
	int	error;
	int	i;

	param_file_name = NULL;
	param_baud = B9600;	// set defaults
	param_size = CS8;
	char	temp[200];
	int	len, last, cnt;

	error = NO_ERROR;
	strcpy(temp, args);
	len = strlen(args);
	last = 0;
	cnt = 0;
	for(i = 0; (i < len) && (error == NO_ERROR); i++){
		if(temp[i] == ','){
			temp[i] = 0;
			error = decode_param(&(temp[last]));
			cnt++;
			last = i + 1;
		} else if(i == (len-1)){
			error = decode_param(&(temp[last]));
			cnt++;
		}
	}

	if((error == NO_ERROR) && (param_file_name != NULL)){
		if((fd = open(param_file_name /*args[0] port "/dev/ttyS0"*/, O_RDWR | O_NOCTTY | O_NDELAY)) < 0){
			printf("Unable to open serial port\n");
			fd = -1;
		} else {
			fcntl(fd, F_SETFL, FNDELAY); 
			/* Configure port reading */
			tcgetattr(fd, &options);	  
			/* Get the current options for the port */

			cfsetispeed(&options, param_baud);  /* Set the baud */
			cfsetospeed(&options, param_baud);

			options.c_cflag |= (CLOCAL | CREAD);
			// enable receiver and set local mode

			options.c_cflag &= ~PARENB;
			// Mask the character size to 8 bits, no parity
			options.c_cflag &= ~CSTOPB;

			options.c_cflag &= ~CSIZE;
			// set data size
			options.c_cflag |=  param_size;
			// set number of data bits

//			options.c_cflag &= ~CRTSCTS;
			// Disable hardware flow control
// 			options.c_lflag &= ~(ICANON | ECHO | ISIG);
			// process as raw input
			options.c_oflag |= OPOST;

			// Update settings
			tcsetattr(fd, TCSANOW, &options);
		}
	} else {
		fd = -1;
	}
}


serial_io::~serial_io(void)
{
	close(fd);
	fd = -1;
	if(param_file_name != NULL) delete param_file_name;
}


int serial_io::decode_param(char*parameter){
	int	error;
	int	temp;

	error = NO_ERROR;
	if(parameter[0] == 'F'){
		if(param_file_name != NULL) delete param_file_name;
		param_file_name = new char[strlen(parameter)];
		strcpy(param_file_name, &(parameter[1]));
	} else if(parameter[0] == 'B'){
		temp = atoi(&(parameter[1]));
		if(temp == 9600) param_baud = B9600;
		if(temp == 2400) param_baud = B2400;
		if(temp == 1200) param_baud = B1200;
	} else if(parameter[0] == 'D'){
		temp = atoi(&(parameter[1]));
		if(temp == 8) param_size = CS8;
		if(temp == 7) param_size = CS7;
	} else {
		printf("Did not recognize serial argument type - ignoring\n");
	}

	return error;
}


int serial_io::reader(char *text, int max){
	int	char_read,
		error,
		i, j;

	error = ERROR;
	if(fd >= 0){
		char_read = read(fd, text, max-1);
		if (char_read > 0){
			text[char_read] = 0;
			error = NO_ERROR;
			for(i = 0; i < char_read;){
				if((text[i] == 10 /*CR*/) || (text[i] == '\n')){
					for(j = i+1; j <= char_read; j++){
						text[j-1] = text[j];
					}
					char_read--;
				} else if(text[i] == '\t'){
					text[i] = ' ';
					i++;
				} else {
					i++;
				}
			}
		} else {
			text[0] = 0;
		}
	} else {
		printf("Serial port is not initialized\n");
	}

	return error;
}


int serial_io::writer(char *text)
{
	int	error,
		length = 0,
		count = 0;

	error = NO_ERROR;
	if(fd >= 0){
		length = strlen(text);
		for(count = 0; count < length; count++){
			write(fd, &(text[count]), 1);
		}
	} else {
		printf("Serial port not initialized\n");
		error = ERROR;
	}

	return error;
}