#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <netdb.h>
#include <time.h>
#include <poll.h>

#include <sys/timerfd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <sys/time.h>
#include <sys/poll.h>
#include <openssl/md5.h>

#define buffer_gets 114688

typedef struct
{
	unsigned char md5[MD5_DIGEST_LENGTH];
} md5struct;

void printMD5(unsigned char* md5)
{
    	for(int i=0; i<MD5_DIGEST_LENGTH; i++){
        	printf("%02x", md5[i]);
    	}
    	printf("\n");
}

char* Parameters(int argc, char* argv[], int* count, float* r_delay, float* s_delay, long* port);
int change_to_int(char* number);
float change_to_float(char* number);
int hostname_to_ip(char* hostname, char* ip);

struct itimerspec value;

int main(int argc, char* argv[])
{
	int count = 0;
	long port = 0;
	float r_delay = 0;
	float s_delay = 0;
	char* address = NULL;
	address = Parameters(argc, argv, &count, &r_delay, &s_delay, &port);

	//printf("Count = %d\nr_delay = %f\ns_delay = %f\nAddres & Port = %s:%ld\n", count, r_delay, s_delay, address, port);
	int len, fd, sfd;
	char send_buf[5] = "abcd";
	char recv_buf[buffer_gets];
	struct sockaddr_in addr;
	char server[25];

	struct sockaddr_in* saddr = (struct sockaddr_in*)&addr;
	inet_ntop(AF_INET, &saddr->sin_addr, server, INET6_ADDRSTRLEN);

	int createClock = timerfd_create(CLOCK_REALTIME, 0);
	if(createClock == -1)
	{
		printf("Problem with clock.\n");
		exit(1);
	}
    if(r_delay){
        value.it_value.tv_sec = (long)r_delay;
        value.it_value.tv_nsec = (r_delay-(float)value.it_value.tv_sec)*1000000000;
        value.it_interval.tv_sec = (long)r_delay;
        value.it_interval.tv_nsec = (r_delay-(float)value.it_value.tv_sec)*1000000000;
    }
    else{
        value.it_value.tv_sec = (long)s_delay;
        value.it_value.tv_nsec = (s_delay-(float)value.it_value.tv_sec)*1000000000;
        value.it_interval.tv_sec = 0;
        value.it_interval.tv_nsec = 0;
    }
	if(timerfd_settime(createClock, 0, &value, NULL) == -1)
	{
		printf("problem with timerfd_settime\n");
		exit(1);
	}

	if((sfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
	{
		printf("Problem with socket()\n");
		exit(-1);
	}

	hostname_to_ip(address, server);

	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = inet_addr(server);
	addr.sin_port = htons(port);

	fd = connect(sfd, (struct sockaddr*)&addr, sizeof(addr));
	if(fd < 0)
	{
		printf("fd = %d", fd);
		printf("Problem with connect");
		exit(-1);
	}

	struct pollfd fds[10];
	memset(fds, 0, sizeof(fds));
	fds[0].fd = sfd;
	fds[0].events = POLLIN;
	fds[1].fd = createClock;
	fds[1].events = POLLIN;
	int extra;
    	int writeCount = 0;
    	int readCount = 0;
    	MD5_CTX CTX;

    	md5struct blocks[count];
	int timeout = (300000);
	while(1){
		extra = poll(fds, 2, timeout);
		if(extra < 0){
			printf("Problem with poll\n");
			break;
		}
		else if(extra == 0){
			printf("End a program\n");
			break;
		}
		if(fds[0].fd == sfd && fds[0].revents == POLLIN){
	    		MD5_Init(&CTX);
	    		int tsiz = 0;
                //Gettime tab[readCount].secoundTS
	    		for(int i=0; i<buffer_gets/1024; i++){
	        		len = recv(sfd, recv_buf+(i*1024), 1024, 0);
	        		tsiz += len;
	        		MD5_Update(&CTX, recv_buf+(i*1024), len);
	    		}
                //Gettime tab[readCount].thirdTS
			MD5_Final(blocks[readCount].md5, &CTX);
	    	readCount++;
            printf("%d -- %d\n", readCount, count);
            if(readCount != count){
                if(s_delay){
                    if(timerfd_settime(createClock, 0, &value, NULL) == -1)
                    {
                        printf("problem with timerfd_settime\n");
                        exit(1);
                    }
                }
            }
            else{
                value.it_value.tv_sec = 0;
                value.it_value.tv_nsec = 0;
                value.it_interval.tv_sec = 0;
                value.it_interval.tv_nsec = 0;
                if(timerfd_settime(createClock, 0, &value, NULL) == -1)
                {
                    printf("problem with timerfd_settime\n");
                    exit(1);
                }
            }
		}
		else if(fds[1].fd == createClock && fds[1].revents == POLLIN){
			char buf[8];
			read(createClock, buf, 8);

			len = send(sfd, send_buf, sizeof(send_buf), 0);
			if(len != sizeof(send_buf))
				printf("Problem with size of send\n");
            //Gettime tab[writeCount].firstTS
            writeCount++;
            if(writeCount >= count){
                fds[1].fd = -1;
            }
		}
		if(readCount == count){
			struct timespec ts;
			clock_gettime(CLOCK_REALTIME, &ts);
			long ts1 = ts.tv_sec;
			clock_gettime(CLOCK_MONOTONIC, &ts);
			long ts2 = ts.tv_sec;
			fprintf(stderr, "WallTime: %ld\nMonotonic: %ld\nPID of a process: %d\nAddress IP: %s\nMD5:\n", ts1, ts2, getpid(), server);
            		for(int i=0; i<count; i++){
                		printMD5(blocks[i].md5);
            		}
			close(sfd);
			exit(0);
		}
	}

	return 0;
}

char* Parameters(int argc, char* argv[], int* count, float* r_delay, float* s_delay, long* port)
{
	char* address;
	int c;
	char* count_pom = NULL;
	char* r_pom = NULL;
	char* s_pom = NULL;

	while((c = getopt(argc, argv, "#:r:s:")) != -1)
	{
		switch(c)
		{
			case '#':
				count_pom = optarg;
				*count = change_to_int(count_pom);
				break;
			case 'r':
				r_pom = optarg;
				*r_delay = change_to_float(r_pom);
				break;
			case 's':
				s_pom = optarg;
				*s_delay = change_to_float(s_pom);
				break;
		}
	}
	if(*count == 0)
	{
		printf("-# is mandatory..\n");
		exit(1);
	}
	if((*r_delay == 0 && *s_delay == 0) || (*r_delay != 0 && *s_delay != 0))
	{
		printf("You can\'t use -s and -r together\n");
		exit(1);
	}
	if(optind != (argc - 1))
	{
		printf("Not enough parameters\n");
		exit(1);
	}

	char* pEnd;
	char* tmp = argv[optind];
	address = strtok(tmp, "[]:");
	tmp = strtok(NULL, "[]:");
	if(tmp == NULL)
	{
		*port = strtol(address, &pEnd, 10);
		if(*port == 0)
		{
			printf("Wrong port...\n");
			exit(1);
		}
		strcpy(address, "localhost");
	}
	else
	{
		*port = strtol(tmp, &pEnd, 10);
		if(*port == 0)
		{
			printf("Wrong port...\n");
			exit(1);
		}
	}

	return address;
}

int change_to_int(char* tmp)
{
	char tmp_copy[10];
	strcpy(tmp_copy, tmp);
	int l1 = 0;
	int l2 = 0;
	char* pEnd;

	char* tmp1 = strtok(tmp_copy, ":");
	char* tmp2 = strtok(NULL, ":");
	char* tmp3 = strtok(NULL, ":");

	l1 = strtol(tmp1, &pEnd, 0);
	if(tmp3 != NULL)
	{
		printf("L1:L2:L3.\tYou can\'t have more than two parameters here.\n");
		exit(1);
	}
	if(l1 <= 0)
	{
		printf("L1 in -#.\tThis parameter can\'t be lower than 0.\n");
		exit(1);
	}
	if(tmp2 == NULL)
		return l1;
	else
	{
		l2 = strtol(tmp2, &pEnd, 0);
		if(l2 <= 0)
		{
			printf("L2 in -#.\tThis parameter can\'t be lower than 0.\n");
			exit(1);
		}

		if(l2 < l1)
		{
			printf("L1 and L2 in -#.\tFirst parameter has to be lower than the second one.\n");
			exit(1);
		}
		if(l1 == l2)
			return l1;
		int t;
		time_t tt;
		t = time(&tt);
		srand(t);
		return (rand() % (l2 - l1) + 1) + l1;

	}
}

float change_to_float(char* tmp)
{
	char tmp_copy[50];
	strcpy(tmp_copy, tmp);
	float l1 = 0;
	float l2 = 0;

	char* pEnd;

	char* tmp1 = strtok(tmp_copy, ":");
	char* tmp2 = strtok(NULL, ":");
	char* tmp3 = strtok(NULL, ":");

	l1 = strtof(tmp1, &pEnd);
	if(tmp3 != NULL)
	{
		printf("Problem with tmp3\n");
		exit(1);
	}
	if(l1 <= 0)
	{
		printf("L1 in -r or -s.\tThis parameter has to be bigger than 0.\n");
		exit(1);
	}
	if(tmp2 == NULL)
		return l1;
	else
	{
		l2 = strtof(tmp2, &pEnd);
		if(l2 <= 0)
		{
			printf("L2 in -r or -s.\tThis parameter has to be bigger than 0.\n");
			exit(1);
		}

		int tim;
		time_t tt;
		tim = time(&tt);
		srand(tim);
		if(l1 == l2)
			return l1;
		else if(l1 > l2)
		{
			printf("L1 and L2 in -r or -s.\tFirst parameter has to be lower than the second one.\n");
			exit(1);
		}
		else
			return (((float)rand() / RAND_MAX) * (l2 - l1 + 1) + l1);
	}
	return -1;
}
int hostname_to_ip(char* hostname, char* ip)
{
	struct hostent *he;
	struct in_addr **addr_list;

	if((he = gethostbyname(hostname)) == NULL)
	{
		printf("Problem with gethostbyname\n");
		exit(1);
	}
	addr_list = (struct in_addr**)he->h_addr_list;
	for(int i = 0; addr_list[i] != NULL; i++)
	{
		strcpy(ip, inet_ntoa(*addr_list[i]));
		return 0;
	}
	return 1;
}