#include<sys/socket.h>
#include<sys/types.h>
#include<netinet/ip.h>
#include<arpa/inet.h>
#include<stdio.h>
#include<unistd.h>
#include<stdlib.h>
#include<string.h>
#include<pthread.h>

// A global that is a list of clients
int* client_list;
size_t client_list_size = 0;
size_t client_list_mem;

struct ctparam {
	size_t clpos;
	char ipaddr[16];
};

void* client_thread(void* param){
	struct ctparam *ctp = (struct ctparam*)param;
	int cfd = client_list[ctp->clpos];
	// Handle interaction with one particular client
	char buffer[1024];
	ssize_t readlen;
	for(;;){
		readlen = read(cfd, buffer, 1024);
		if(readlen <= 0)
			break;
		for(size_t i = 0; i < client_list_size; i++){
			if(client_list[i] > 2){
				write(client_list[i], ctp->ipaddr, strlen(ctp->ipaddr));
				write(client_list[i], ":  ", 3);
				write(client_list[i], buffer, readlen);
			}
		}
	}
	// If the client disconnects, we need to deal with that!
	close(cfd);
	client_list[ctp->clpos] = 2;
	free(ctp);
	return 0;
}

int main(int args, char ** argv){
	struct sockaddr_in sad;
	sad.sin_port = htons(5141);
	sad.sin_addr.s_addr = INADDR_ANY;
	sad.sin_family = AF_INET;

	int skt = socket(AF_INET, SOCK_STREAM, 0);
	bind(skt, (struct sockaddr *)(&sad), sizeof(struct sockaddr_in));
	listen(skt, 5);
	int client_fd;
	struct sockaddr_in client_addr;
	client_list = (int*)malloc(sizeof(int) * 1024);
	client_list_mem = 1024;
	for(;;){
		socklen_t client_address_length;
		client_fd = accept(skt, (struct sockaddr*)&client_addr, &client_address_length);
		printf("Accepted a connection from %s\n", inet_ntoa(client_addr.sin_addr));
		client_list[client_list_size++] = client_fd;
		if(client_list_size >= client_list_mem){
			client_list = (int*)realloc(client_list, sizeof(int) * (client_list_mem + 1024));
			client_list_mem += 1024;
		}
		// Start a thread to talk to that client
		pthread_t thread;
		struct ctparam *ctp = (struct ctparam*)malloc(sizeof(struct ctparam));
		ctp->clpos = client_list_size - 1;
		strncpy(ctp->ipaddr, inet_ntoa(client_addr.sin_addr), 16);
		pthread_create(&thread, 0, client_thread, ctp);
	}
	close(skt);
	return 0;
}