#include "ansi.h"

#include <termios.h>  	/* POSIX terminal control definitions */
#include <stdio.h>
#include <stdlib.h>			// atoi
#include <fcntl.h>			// File control definitions
#include <sys/ioctl.h>		// ioctl
#include <unistd.h>			// read, close
#include <string.h>  		// memset
#include <linux/i2c-dev.h>	// I2C_SLAVE, __u8 reg
#include <errno.h>

#define PORTNAME 				"/dev/ttyBF1"
#define GOODBYE 				200
#define BUFFERSIZE 				16
#define I2C_DEVICE_FILE			"/dev/i2c-0"
#define I2C_DEVICE_ADDRESS		0x4C
//#define I2C_DEVICE_ADDRESS	0x48
#define I2C_REGISTER_ADDRESS	0x40



int i2c_open(const char* file,unsigned int addr){

	//device file
	int fd = open( file, O_RDWR );
	if (fd < 0)	{
		cprintf(RED,"Warning: Unable to open file %s\n",file);
		return -1;
	}

	//device address
	if( ioctl( fd, I2C_SLAVE, addr&0x7F ) < 0 )	{
		cprintf(RED,"Warning: Unable to set slave address:0x%x \n",addr);
		return -2;
	}
	return fd;
}


int i2c_read(){

	int fd = i2c_open(I2C_DEVICE_FILE, I2C_DEVICE_ADDRESS);
	__u8 reg = I2C_REGISTER_ADDRESS & 0xff;

	unsigned char buf = reg;
	if (write(fd, &buf, 1)!= 1){
		cprintf(RED,"Warning: Unable to write read request to register %d\n", reg);
		return -1;
	}
	//read and update value (but old value read out)
	if(read(fd, &buf, 1) != 1){
		cprintf(RED,"Warning: Unable to read register %d\n", reg);
		return -2;
	}
	//read again to read the updated value
	if(read(fd, &buf, 1) != 1){
		cprintf(RED,"Warning: Unable to read register %d\n", reg);
		return -2;
	}
	close(fd);
	return buf;
}


int i2c_write(unsigned int value){

	__u8 val = value & 0xff;

	int fd = i2c_open(I2C_DEVICE_FILE, I2C_DEVICE_ADDRESS);
	if(fd < 0)
		return fd;

	__u8 reg = I2C_REGISTER_ADDRESS & 0xff;
	char buf[3];
	buf[0] = reg;
	buf[1] = val;
	if (write(fd, buf, 2) != 2) {
		cprintf(RED,"Warning: Unable to write %d to register %d\n",val, reg);
		return -1;
	}

	close(fd);
	return 0;
}





int main(int argc, char* argv[]) {

	int fd = open(PORTNAME, O_RDWR | O_NOCTTY | O_SYNC);
	if(fd < 0){
		cprintf(RED,"Warning: Unable to open port %s\n", PORTNAME);
		return -1;
	}
	cprintf(GREEN,"opened port at %s\n",PORTNAME);

	struct termios serial_conf;
	// reset structure
	memset(&serial_conf,0,sizeof(serial_conf));
	// control options
	serial_conf.c_cflag = B2400 | CS8 | CREAD | CLOCAL;
	// input options
	serial_conf.c_iflag = IGNPAR;
	// output options
	serial_conf.c_oflag = 0;
	// line options
	serial_conf.c_lflag = ICANON;
	// flush input
	if(tcflush(fd, TCIOFLUSH) < 0){
		cprintf(RED,"Warning: error form tcflush %d\n", errno);
		return 0;
	}
	// set new options for the port, TCSANOW:changes occur immediately without waiting for data to complete
	if(tcsetattr(fd, TCSANOW, &serial_conf) < 0){
		cprintf(RED,"Warning: error form tcsetattr %d\n", errno);
		return 0;
	}

	if(tcsetattr(fd, TCSAFLUSH, &serial_conf) < 0){
		cprintf(RED,"Warning: error form tcsetattr %d\n", errno);
		return 0;
	}

	int ret = 0;
	int n = 0;
	int ival= 0;
	char buffer[BUFFERSIZE];
	memset(buffer,0,BUFFERSIZE);
	buffer[BUFFERSIZE-1] = '\n';
	cprintf(GREEN,"Ready...\n");


	while(ret != GOODBYE){
		memset(buffer,0,BUFFERSIZE);
		n = read(fd,buffer,BUFFERSIZE);
#ifdef VERBOSE
		cprintf(BLUE,"Received %d Bytes\n", n);
#endif
		cprintf(BLUE,"Got message: '%s'\n",buffer);

		switch(buffer[0]){
		case '\0':
			cprintf(GREEN,"Got Start (Detector restart)\n");
			break;
		case 's':
			cprintf(GREEN,"Got Start \n");
			break;
		case 'p':
			if (!sscanf(&buffer[1],"%d",&ival)){
				cprintf(RED,"Warning: cannot scan voltage value\n");
				break;
			}
			// ok/ fail
			memset(buffer,0,BUFFERSIZE);
			buffer[BUFFERSIZE-1] = '\n';
			if(i2c_write(ival)<0)
				strcpy(buffer,"fail ");
			else
				strcpy(buffer,"success ");
			cprintf(GREEN,"Sending: '%s'\n",buffer);
			n = write(fd, buffer, BUFFERSIZE);
#ifdef VERBOSE
			cprintf(GREEN,"Sent %d Bytes\n", n);
#endif
			break;

		case 'g':
			ival = i2c_read();
			//ok/ fail
			memset(buffer,0,BUFFERSIZE);
			buffer[BUFFERSIZE-1] = '\n';
			if(ival < 0)
				strcpy(buffer,"fail ");
			else
				strcpy(buffer,"success ");
			n = write(fd, buffer, BUFFERSIZE);
			cprintf(GREEN,"Sending: '%s'\n",buffer);
#ifdef VERBOSE
			cprintf(GREEN,"Sent %d Bytes\n", n);
#endif
			//value
			memset(buffer,0,BUFFERSIZE);
			buffer[BUFFERSIZE-1] = '\n';
			if(ival >= 0){
				cprintf(GREEN,"Sending: '%d'\n",ival);
				sprintf(buffer,"%d ",ival);
				n = write(fd, buffer, BUFFERSIZE);
#ifdef VERBOSE
				cprintf(GREEN,"Sent %d Bytes\n", n);
#endif
			}else cprintf(RED,"%s\n",buffer);
			break;

		case 'e':
			printf("Exiting Program\n");
			ret = GOODBYE;
			break;
		default:
			cprintf(RED,"Unknown Command. buffer:'%s'\n",buffer);
			break;
		}
	}

	close(fd);
	printf("Goodbye Serial Communication for HV(9M)\n");
	return 0;
}