#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>

#define PORT 29012
#define SIZE (20 * sizeof(int))
#define FILEPATH "clients.bin"

struct shared_data {
  int data;
  int clients[20];
};

int main(){

	int sockfd, ret;
	struct sockaddr_in serverAddr;
	int newSocket;
	struct sockaddr_in newAddr;
	socklen_t addr_size;
	char buffer[1024];
	pid_t childpid;
	int fd, result;
	int number=-1;
	///////////////
	struct shared_data *shared_clients, *child;
	const char *shm_name = "projekt";
	int shm_fd = shm_open(shm_name, O_CREAT | O_RDWR, 0666);
	int child_fd;
	int cli_number = 0;
	ftruncate(shm_fd, sizeof(struct shared_data));
	shared_clients = mmap(0, sizeof(struct shared_data), PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);
	if (shared_clients == MAP_FAILED) {
		printf("mmap - failed.\n");
		return -1;
	}
	shared_clients->data = 0;

	//int *clients = mmap(NULL, SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0);

	/* wspoldzielony plik z klientami
	fd = open(FILEPATH, O_RDWR | O_CREAT | O_TRUNC, (mode_t)0600);
    if (fd == -1) {
	    perror("Error opening file for writing");
	    exit(EXIT_FAILURE);
    }
	lseek(fd, SIZE-1, SEEK_SET);
    result = lseek(fd, SIZE-1, SEEK_SET);
    if (result == -1) {
	    close(fd);
	    perror("Error calling lseek() to 'stretch' the file");
	    exit(EXIT_FAILURE);
    }
	write(fd, "", 1);
    result = write(fd, "", 1);
    if (result != 1) {
	    close(fd);
	    perror("Error writing last byte of the file");
	    exit(EXIT_FAILURE);
    }
	clients = mmap(0, SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (clients == MAP_FAILED) {
	    close(fd);
	    perror("Error mmapping the file");
	    exit(EXIT_FAILURE);
    }
    if (munmap(clients, SIZE) == -1) {
	        perror("Error un-mmapping the file");
	        /* Decide here whether to close(fd) and exit() or not. Depends...
    }
    close(fd); */
	////////////////////////////////////////

	sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if(sockfd < 0){
		printf("Error in connection.\n");
		exit(1);
	}
	printf("Server Socket is created.\n");

	memset(&serverAddr, '\0', sizeof(serverAddr));
	serverAddr.sin_family = AF_INET;
	serverAddr.sin_port = htons(PORT);
	serverAddr.sin_addr.s_addr = htonl(INADDR_ANY);

	ret = bind(sockfd, (struct sockaddr*)&serverAddr, sizeof(serverAddr));
	if(ret < 0){
		printf("Error in binding.\n");
		exit(1);
	}
	printf("Bind to port %d\n", PORT);

	if(listen(sockfd, 10) == 0){
		printf("Listening....\n");
	}else{
		printf("Error in binding.\n");
	}


	while(1){

		newSocket = accept(sockfd, (struct sockaddr*)&newAddr, &addr_size);
		if(newSocket < 0){
			exit(1);
		}
		cli_number++;
        printf("Connection accepted from %s:%d\n", inet_ntoa(newAddr.sin_addr), ntohs(newAddr.sin_port));
		/************************************/
		sprintf(shared_clients->clients[cli_number-1], newSocket);
		shared_clients->data = cli_number;
		/************************************/



		// ten kawa\u0142ek zmieni\u0142am //
		/*fd = open(FILEPATH, O_RDWR | O_CREAT);
		number=number+1;
	clients[number] = newSocket;
		for (int i=0; i<=number; ++i)
            printf("c: %d: %d\n", i, clients[i]);
        if (munmap(clients, SIZE) == -1) {
	        perror("Error un-mmapping the file");
	        /* Decide here whether to close(fd) and exit() or not. Depends...
        }
        close(fd); */

		////////////////////////////


		if((childpid = fork()) == 0){
			close(sockfd);
			child_fd = shm_open(shm_name, O_RDONLY, 0666);
			child = mmap(0, sizeof(struct shared_data), PROT_READ , MAP_SHARED, child_fd, 0);
			if (child == MAP_FAILED) {
				printf("mmap - failed (in child).\n");
				return -1;
			}
			int my_clients = child->data;

			while(1){
				recv(newSocket, buffer, 1024, 0);
				if(strcmp(buffer, ":exit") == 0){
					printf("Disconnected from %s:%d\n", inet_ntoa(newAddr.sin_addr), ntohs(newAddr.sin_port));
					break;
				}else{
					printf("Client: %s\n", buffer);
					printf("Number of logged clients: %s\n", child->data);

					//// ten kawa\u0142ek zmieni\u0142am ///
					/*fd = open(FILEPATH, O_RDONLY);
                    if (fd == -1) {
	                        perror("Error opening file for reading");
	                        exit(EXIT_FAILURE);
                    }
                    clients = mmap(0, SIZE, PROT_READ, MAP_SHARED, fd, 0);
                    if (clients == MAP_FAILED) {
	                    close(fd);
	                    perror("Error mmapping the file");
	                    exit(EXIT_FAILURE);
                    }*/
					for(int i=0; i < child->data; i=i+1) {
						send(child->clients[i], buffer, strlen(buffer), 0);
					}
					/*
                    if (munmap(clients, SIZE) == -1) {
	                        perror("Error un-mmapping the file");
                    }
                    close(fd);*/
					//send(newSocket, buffer, strlen(buffer), 0);
					//////////////////////////////
					bzero(buffer, sizeof(buffer));
				}
			}
		}
	}

	close(newSocket);

	return 0;
}