#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdint.h>
#include <getopt.h>
#include <termios.h>
#include <error.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/signal.h>
#include <fcntl.h>
#include <poll.h>

#define false 0
#define FALSE 0
#define true 1
#define TRUE 1


// SERIAL
char MODEMDEVICE[64];
FILE *tapout_fd = NULL;
int is_outfile = 0;
int baud_rate = 0;
int wait_us = 200;
#define FILENAME_LENGTH 400
char output_dump_file[FILENAME_LENGTH];
char tap_file[FILENAME_LENGTH];
unsigned char in_buff[65538];
unsigned char *p_buff;
unsigned int is_continue = 1;
unsigned int is_binary = 0;
struct pollfd spolfd_serial[1];	  // pole descriptoru pro poll

static int inp_indx = 0;
int serial_fd;
size_t out_indx;
struct sigaction saterm;           /* definition of signal action */

float width;		// width of terminal
long pos = 0;
int scp = 0;
int is_scp_read = 0;

typedef struct {
	uint16_t block_len;
	uint8_t  block_xor;
	uint8_t  block_sum;
} __attribute__((packed))  fi_sum;

typedef struct {
	uint16_t length;		// delka dat ve fileinfo
	uint8_t h_xor;			// xor bajtu fileinfa od fi_numblocks
	uint8_t h_sum;			// sum bajtu fileinfa od fi_numblocks
	uint8_t fi_numblocks;	// pocet bloku
	uint8_t fi_name[64];	// jmeno souboru - prozatim musi byt ve fromatu 8.3 - kvuli esxdosu
	uint8_t fi_date[8];		// nepouzito
	uint8_t fi_time[8];		// nepouzito
	fi_sum fi_blocks[256];	// delky a soucty bloku
} __attribute__((packed)) FILEINFO;

FILEINFO fileinfo;


void usage(void) {
	printf ("Tap file over serial port uploader/downloader. (c)2012-2015 Pavel Vymetálek <pavel@vym.cz>\n");
	printf ("Based on utility tapheader: http://zeroteam.sk/tapheader.html (c)2012 Michal Jurica <mike@zeroteam.sk>\n");
	printf ("Usage:\ntaptoser [-v] [-h] [-o filename.tap] [-b|--baud baud_rate] -d /dev/serial tap_file\n");
	printf ("\t-v, --version\tShow version info\n");
	printf ("\t-h, --help\tShow this text\n");
	printf ("\t-d, --device\tCommunication device\n");
	printf ("\t-w, --wait\tWaiting in microseconds between transmitted bytes. Default is -w 200us\n");
	printf ("\t-b, --baud\tSet the communication speed. 4800Bd, 9600Bd, 19200Bd and 57600Bd (default) are supported\n");
	printf ("\t-B, --binary\tBinary output - received tap from ZX Spectrum will save without all tap's specific mishmash\n");
	printf ("\t-o, --outfile\tOutput file. Usualy *.tap or *.bin with in --binary mode\n");
}

void Set_DTR(unsigned short level) {
	int status;
	ioctl(serial_fd, TIOCMGET, &status);
	if (level) {
		status |= TIOCM_DTR;
	} else {
		status &= ~TIOCM_DTR;
	}
	ioctl(serial_fd, TIOCMSET, &status);
}

void TestCts(void) {
	int status;
	do {
		ioctl(serial_fd, TIOCMGET, &status);
		if (status & 0x20) break;
		usleep (100);
		if (is_continue == 0) return;
		//		printf ("status: %X\n",status);
	} while (1);
}


void TestArgs (int argc, char *argv[])
{
	int c;
	while (1) {
		int option_index = 0;
		static struct option long_options[] = {
 			{"outfile", required_argument, NULL, 'o'},
			{"device", required_argument, NULL, 'd'},
			{"baud", required_argument, NULL, 'b'},
			{"wait", required_argument, NULL, 'w'},
			{"scp", no_argument, NULL, 's'},
			{"read", no_argument, NULL, 'r'},
			{"binary", no_argument, NULL, 'B'},
			{"version", no_argument, NULL, 'v'},
			{"help", no_argument, NULL, 'h'},
			{0, 0, 0, 0}
		};
		c = getopt_long (argc, argv, "o:d:b:w:srBvh", long_options, &option_index);
		if (c == -1) {
			// konec parametru
			break;
		}
		switch (c) {
			case 'h':
				usage();
				exit(1);
				break;
			case 'b':
				baud_rate = atoi(optarg);
				break;
			case 'w':
				wait_us = atoi(optarg);
				break;
			case 's':
				printf ("Serial CP mode is activated\n");
				scp = 1;
				break;
			case 'r':
				printf ("scp read...\n");
				is_scp_read = 1;
				break;
			case 'd':
				strncpy(MODEMDEVICE, optarg, strlen(optarg));
// 				printf ("Serial port: %s\n", MODEMDEVICE);
				break;
			case 'o':
				strncpy (output_dump_file, optarg, strlen(optarg));
				is_outfile = 1;
				break;
			case 'B':
				printf ("Running in binary output mode\n");
				is_binary = 1;
				break;
			case 'v':
				printf ("Version 0.9.1 2015-07-22\n");
				exit(1);
				break;
			default:
				break;
		}
	}
	if (optind < argc) {
		while (optind < argc){
			strncpy (&tap_file[0], argv[optind++], 63);		// input tap file name - without option switch
		}
	}
}


// from tapheader utility
unsigned int h_len;

unsigned int getword(unsigned char* data) {
	return *data + 256 * (*(data + 1));
}

void tooshort(FILE *fd) {
	printf("Input file too short.\n\n");
	fclose(fd);
	exit(2);
}

// decode header1
void decode(unsigned char *header) {
	char name[11];
	unsigned int n;
	printf("\n");
	strncpy(name, (char*)(header+2), 10);
	name[10] = '\0';
	printf("Filename: %12s \n", name);
	printf("Flag: %4u ", (unsigned int)*header);
	n = getword(header+14);
	h_len = getword(header+12);

	switch(*(header+1)) {
		case '\0':
			printf("Type: 0 => program\nProgram length: %6u bytes ", h_len);
			if (n < 32768)	printf("Runs from line %5u\t", n);
			printf("Length without variables: %5u bytes ", getword(header+16));
			break;
		case '\1':
			printf("Type: 1 => number array\tLength: %6u bytes", h_len);
			break;
		case '\2':
			printf("Type: 2 => character array\tLength: %6u bytes", h_len);
			break;
		case '\3':
			if (n == 16384 && h_len == 6912)
				printf("Type: 3 => screen image\n");
			else
				printf("Type: 3 => bytes  "
					"Start address: %5u\t"
					"Length: %6u bytes\t3rd param: %4u",
					n, h_len, getword(header+16));
			break;
	}
	printf("\n");
}

void signal_handler_sigterm (int status) {
	// CTRL+C pressed
	is_continue = 0; 	// do not continue
}

int GetTerminalWidth(void) {
	struct winsize termsize;
	ioctl (STDOUT_FILENO, TIOCGWINSZ, &termsize);
	return (termsize.ws_col);
}

#define PROGRESS_PERCENT	0
#define PROGRESS_COMPLETTE	1
#define PROGRESS_ERROR_CSUM	2

void DoProgress(size_t pos, size_t max, unsigned char csum_ok) {
	width = GetTerminalWidth();
	float percent, p, m;
	int imax = width - 40;
	int ipercent;
	int px;
	char progress_char;
	p = pos;
	m = max;
	percent = 100 / m * p;
	ipercent = percent / 100 * imax;
	if (is_binary) progress_char = '#';
	else  progress_char = '=';
	printf ("Proceed bytes: %6d/%6d [", (int) pos, (int)max);
	for (px = 0; px < imax; px++) {
		if (px < ipercent) printf ("%c", progress_char);
		else printf (" ");
	}
	if (csum_ok == 0) {
		printf ("] %3d %%\r", (int)percent);
	} else if (csum_ok == 1) {
		printf ("]  OK  \r");
	} else {
		printf ("]  ERR \r");
	}
	fflush (stdout);
}

#define HEADER_RAW_LEN	21

void RecvTap() {
	unsigned int err;
	size_t len;
	int result;
	size_t block_pos = 0, last_block_pos = 0;
	size_t block_len = 10000;
	size_t tap_pos = 0;
	unsigned char xor_csum, xor_csum_ok;
	unsigned char *p_write;
	unsigned char block_type;				// typ bloku 255 data  0 - hlavicka
	unsigned char recv_status = 0;			// 0 - zacatek, 1 - hlavicka nactena,  2 - blok se nacita, 3- header less
	tapout_fd = fopen (output_dump_file, "a");
	if (tapout_fd == NULL) {
		err = errno;
		error (1, err, "can't open output file");
	}
	printf("Output file is: %s\n", output_dump_file);
	p_buff = in_buff;
	p_write = in_buff;
	while (is_continue) {
		result = poll (spolfd_serial, 1, 200);		// 200ms timeout
		if (result == 0) {
			// nic neprislo
			continue;
		}
		if (spolfd_serial[0].revents & POLLIN) {
			len = read (serial_fd, p_buff, 256);
			block_pos += len;
			p_buff += len;
			if (is_binary == 0) {
				// ulozeni dat ze seriaku jako tap file
				while (len) {
					fputc(*p_write, tapout_fd);
					p_write++;
					len--;
				}
			}
			if (block_pos != last_block_pos && recv_status >= 2) {
				last_block_pos = block_pos;
				DoProgress(block_pos, block_len+2, PROGRESS_PERCENT);
			}
			if (block_pos >= HEADER_RAW_LEN && recv_status == 0) {
				recv_status = 1;		// hlavicka nactena
				block_len = getword(in_buff);
				block_type = *(in_buff + 2);
				if (block_type == 0) {
					// Hlavicka komplet
					decode (in_buff + 2);
					block_len = 0;
					block_pos = 0;
					xor_csum = 0;
					recv_status = 0;
					p_buff = in_buff;
					p_write = in_buff;
				} else if (block_type == 255) {
					// data block
					printf ("Data block len: %6zu\n", block_len-2);
					recv_status = 3;
				}
				continue;
			}
			if (block_pos > HEADER_RAW_LEN + 3 && recv_status == 1) {
				// nactena delka dalsiho bloku
				recv_status = 2;
				block_len = getword(in_buff + HEADER_RAW_LEN);
				block_type = *(in_buff + HEADER_RAW_LEN + 2);
				printf ("Block len: %zu Block type: %d\n", block_len, block_type);
				continue;
			}
			if (block_len + 2 == block_pos && recv_status > 2) {
				// Blok komplet nacten cekej novy
				block_len = getword(in_buff);
				block_type = *(in_buff + 2);
				for (tap_pos = 0; tap_pos < block_len -1; tap_pos++) {
					xor_csum ^= *(in_buff + 2 + tap_pos);
				}
				xor_csum_ok = *(in_buff + 2 + block_len - 1);
				if (xor_csum == xor_csum_ok) {
					DoProgress(block_pos, block_len+2, PROGRESS_COMPLETTE);	// vypis jeste OK
					if (is_binary == 1) {
						// binarni vystup do souboru
						for (tap_pos = 0; tap_pos < block_len - 2; tap_pos++){
							fputc(*(in_buff + 3 + tap_pos), tapout_fd);	// uloz do souboru
						}
						DoProgress(tap_pos, block_len - 2, PROGRESS_COMPLETTE);
					}
// 					printf ("Checksum OK\n");
				} else {
					DoProgress(block_pos, block_len+2, PROGRESS_ERROR_CSUM);	// vypis error CSUM
				}
				block_len = 0;
				block_pos = 0;
				xor_csum = 0;
				recv_status = 0;
				p_buff = in_buff;
				p_write = in_buff;
				continue;
			}
		}
	}
	fclose (tapout_fd);
	printf ("\n\nulozeno...\n");
}

void SendByte(unsigned char *p_dato) {
	TestCts();
	write (serial_fd, p_dato, 1);
// 	tcdrain(serial_fd);		// better solution, but usleep at the next line is
	usleep (wait_us);			// faster solution, TODO change sleep time according to serial communication speed  200us is for 57600Bd
}

void SendTap() {
	FILE *tap_fd;
	unsigned int err, no, len;
	struct stat st;
	unsigned char header[19];

	no = stat(tap_file, &st);
	if (no != 0) {
		err = errno;
		error(1, err, "can't stat input file");
	}

	tap_fd = fopen(tap_file, "r");
	if (tap_fd == NULL)	{
		err = errno;
		error(1, err, "can't open input file");
	}
	while (pos < st.st_size) {
		if (is_continue == 0) break;
		pos += no = fread(header, 1, 2, tap_fd);
		if (no != 2)
			tooshort(tap_fd);
		for (out_indx = 0; out_indx < 2; out_indx++) {
			SendByte(&header[out_indx]);
		}
		no = getword(header);
		if (no == 19) /* HEADER */
		{
			pos += no = fread(header, 1, 19, tap_fd);
			if (no != 19)
				tooshort(tap_fd);
// 			printf ("Header len: %d\n", no);
			decode(header);
			for (out_indx = 0; out_indx < 19; out_indx++) {
				SendByte(&header[out_indx]);
			}
		} else {
			if (h_len != no - 2) { /* zobrazuj iba bloky bez hl. */
				len = no;
				printf ("NO datablock without header: %d\n", no);
				printf("Type: datablock\nLength: %u\n", len - 2);
				pos += no = fread(header, 1, 1, tap_fd);
				SendByte(header);
				DoProgress(1, no, PROGRESS_PERCENT);
				if (no != 1) tooshort(tap_fd);
				printf("Flag: %u\n\n", (int)*header);
				len--;
			} else {
				len = no;
			}
			pos += len;
			for (out_indx = 0; out_indx < len; out_indx++) {
				fread(header, 1, 1, tap_fd);
				SendByte(header);
				DoProgress(out_indx+1, len, PROGRESS_PERCENT);
				if (is_continue == 0) break;
			}
			printf ("\n");
			usleep (800000);
		}
	}
	fclose(tap_fd);
}


int CheckFileInfo(FILEINFO* p_fi) {
	unsigned char *p_fiinfo = (unsigned char*)p_fi;
	uint16_t fi_len;
	uint8_t fi_xor = 0;
	uint8_t fi_sum = 0;
	fi_len = p_fi->length;
	p_fiinfo += 4;			// suma se bude pocitat od offsetu 4
	for (uint16_t indx = 0; indx < (fi_len-4); indx++) {
		fi_xor ^= *p_fiinfo;
		fi_sum += *p_fiinfo;
		p_fiinfo++;
	}
	if (fi_xor == p_fi->h_xor && fi_sum == p_fi->h_sum) {
		return 0;
	}
	return -1;
}

int CheckSumBlock(FILEINFO* p_fi, uint8_t block_indx, uint8_t *p_buffer) {
	uint16_t block_len;
	uint8_t b_xor = 0;
	uint8_t b_sum = 0;
	uint8_t block_xor;
	uint8_t block_sum;
	block_len = p_fi->fi_blocks[block_indx].block_len;
	block_sum = p_fi->fi_blocks[block_indx].block_sum;
	block_xor = p_fi->fi_blocks[block_indx].block_xor;
	for (uint16_t indx = 0; indx < block_len; indx++) {
		b_xor ^= *p_buffer;
		b_sum += *p_buffer;
		p_buffer++;
	}
	if (b_xor == block_xor && b_sum == block_sum) {
		return 0;	// vrat se, je to v poradku
	}
	return -1;		// vrat se s chybou bloku
}

unsigned char buff[32768];

uint32_t GetOverallLen(FILEINFO *p_fi) {
	uint32_t overall_len = 0;
	uint8_t block_num = p_fi->fi_numblocks;
	for (uint8_t indx = 0; indx < block_num; indx++) {
		overall_len += p_fi->fi_blocks[indx].block_len;
	}
	return overall_len;
}

void RecvSCP(void) {
	int recv_phase = 0;			// 0 - fileinfo, 1 - blok 16kiB, 2 - posledni blok
	uint8_t block_index = 0;
	int result;
	uint16_t len;
	uint16_t length = 0;
	uint16_t expected_len = 0;
// 	uint8_t expected_xor;
// 	uint8_t expected_sum;
	uint32_t overall_length = 0;		// celkova delka souboru
	uint32_t recv_length = 0;			// zatim prijatych dat ze souboru
	int err;

	FILEINFO *p_fileinfo = &fileinfo;
	unsigned char *p_buff = buff;
	tapout_fd = NULL;

	memset (p_fileinfo, 0, sizeof(fileinfo));
	while (is_continue) {
		result = poll (spolfd_serial, 1, 200);		// 200ms timeout
		if (result == 0) {
			// nic neprislo
			continue;
		}
		switch (recv_phase) {
			case 0:
				// prijem fileinfo
				if (spolfd_serial[0].revents & POLLIN) {
					len = read (serial_fd, p_buff, sizeof(fileinfo));
					p_buff += len;
					length += len;
					if (length == sizeof(fileinfo)) {
						memcpy((unsigned char*) p_fileinfo, buff, sizeof(fileinfo));
						if (CheckFileInfo(p_fileinfo) == 0) {
							printf("Prijato fileinfo\n");
							overall_length = GetOverallLen(p_fileinfo);
							printf("Nazev souboru: \"%s\" pocet bloku:%d, delka souboru: %u\n", p_fileinfo->fi_name, p_fileinfo->fi_numblocks, overall_length);
							recv_phase++;			// priste se uz prijimaji bloky
							block_index = 0;		// zacina se prvnim blokem
							p_buff = buff;			// buffer na zacatek
							length = 0;
							expected_len = p_fileinfo->fi_blocks[block_index].block_len;


							tapout_fd = fopen ((char*)p_fileinfo->fi_name, "w");
							if (tapout_fd == NULL) {
								err = errno;
								error (1, err, "can't open output file");
							}
// 							expected_xor = p_fileinfo->fi_blocks[block_index].block_xor;
// 							expected_sum = p_fileinfo->fi_blocks[block_index].block_sum;
						} else {
							printf("Fileinfo neni v cajku. Koncim...\n");
							break;
						}
						break;
					} else if (length > sizeof(fileinfo)){
						len = read (serial_fd, p_buff, sizeof(fileinfo));
						printf("Nejaky bordel. Koncim...\n");
						break;
					}
				}
				break;
			case 1:
				// prijem datoveho bloku - max. delka 16kiB
				if (spolfd_serial[0].revents & POLLIN) {
					len = read (serial_fd, p_buff, expected_len);
					p_buff += len;
					expected_len -= len;
					length += len;
					recv_length += len;
					DoProgress(recv_length, overall_length, PROGRESS_PERCENT);
					if (length == p_fileinfo->fi_blocks[block_index].block_len) {
						// prijaty prvni block
// 						printf("Prijaty blok c.%d delky: %d\n", block_index, length);
						if (CheckSumBlock(p_fileinfo, block_index, buff) == 0) {
							// blok je v cajku - zapsat do souboru
							if (tapout_fd) fwrite(buff, length, 1, tapout_fd);
						}
						length = 0;
						p_buff = buff;
						block_index++;
						expected_len = p_fileinfo->fi_blocks[block_index].block_len;
					}
					if (expected_len == 0 || block_index == 255) {
						printf ("\nKonec prenosu\n");
						recv_phase++;
						is_continue = 0;
						break;
					}
				} else if (length > 16384) {
						len = read (serial_fd, p_buff, 16384);
						printf("Nejaky bordel. Koncim...\n");
						break;
				}
			}
	}
	if (tapout_fd) fclose (tapout_fd);
	printf ("\n\nulozeno...\n");
}

void SendSCP(void) {

}

int main(int argc, char** argv, char** env)
{
	// osetreni breaku ^C
	saterm.sa_handler = signal_handler_sigterm;
	saterm.sa_flags = 0;
	sigaction (SIGINT, &saterm, NULL);
	width = GetTerminalWidth();

	// nastaveni serioveho portu
	struct termios oldtio, newtio;
	inp_indx = 0;
	if (argc < 3) {
		printf("You must specify the Serial device and file\n");
		usage();
		exit(1);
	}
	TestArgs (argc, argv);
	/* open the device to be non-blocking (read will return immediatly) */
	serial_fd = open(MODEMDEVICE, O_RDWR | O_NOCTTY | O_NONBLOCK);
	if (serial_fd < 0) {
		perror(MODEMDEVICE);
		return(-1);
	}
	tcgetattr(serial_fd, &oldtio); /* save current port settings */
	switch (baud_rate){
		default:
			baud_rate = 57600;			// default speed
			newtio.c_cflag = B57600 | CS8 | CLOCAL | CREAD | CSTOPB;// | CRTSCTS;
			break;
		case 115200:
			newtio.c_cflag = B115200 | CS8 | CLOCAL | CREAD | CSTOPB | CRTSCTS;
			break;
		case 57600:
			newtio.c_cflag = B57600 | CS8 | CLOCAL | CREAD | CSTOPB | CRTSCTS;
			break;
		case 38400:
			newtio.c_cflag = B38400 | CS8 | CLOCAL | CREAD | CRTSCTS;	// dva stopbity jsou nastaveny vsude
			break;
		case 19200:
			newtio.c_cflag = B19200 | CS8 | CLOCAL | CREAD | CSTOPB | CRTSCTS;
			break;
		case 9600:
			newtio.c_cflag = B9600 | CS8 | CLOCAL | CREAD | CSTOPB | CRTSCTS;
			break;
		case 4800:
			newtio.c_cflag = B4800 | CS8 | CLOCAL | CREAD | CSTOPB | CRTSCTS;
			break;
		case 2400:
			newtio.c_cflag = B2400 | CS8 | CLOCAL | CREAD | CSTOPB | CRTSCTS;
			break;
		case 1200:
			newtio.c_cflag = B1200 | CS8 | CLOCAL | CREAD | CSTOPB | CRTSCTS;
			break;
	}
	printf ("Serial device: %s, communication speed is: %d Bd\n", MODEMDEVICE, baud_rate);
// 	newtio.c_iflag &= ~(IXON | IXOFF | IXANY);	// vypne XON/XOFF
	newtio.c_iflag = 0;IGNPAR | IXOFF;
	newtio.c_oflag = 0;
// 	newtio.c_oflag &= ~OPOST;
	newtio.c_lflag = 0; //NOFLSH;
	newtio.c_cc[VMIN] = 0;
	newtio.c_cc[VTIME] = 10;
	tcsetattr(serial_fd, TCSANOW, &newtio);
	tcflush(serial_fd, TCIOFLUSH);
	spolfd_serial[0].fd = serial_fd;		// nastaveni hlidaneho descriptoru
	spolfd_serial[0].events = POLLIN;		// hlidaji se data na vstupu

	if (scp) {
		// serial copy activated
		if (is_scp_read) {
			RecvSCP();
		} else {
			SendSCP();
		}
	} else {
		Set_DTR(true);		// PC can read data from speccy everytime
		if (is_outfile) {
			RecvTap();	// cteni tap souboru ze seriaku a zapis na disk pocitace
		} else {
			SendTap();	// poslat na seriak tap soubor do spectra
		}
	}
	close (serial_fd);
	return 0;
}