# include <stdio.h>
# include <stdlib.h>
# include <unistd.h>
# include <string.h>
# include <errno.h>
# include <sys/socket.h>
# include <sys/types.h>
# include <netinet/in.h>
#include <dirent.h>
#include <netdb.h>
#include <fcntl.h>


# define PORT 12345
# define BUFSIZE 128


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


	int sd=socket(AF_INET,SOCK_STREAM,0);
	long val =1;
	if(setsockopt(sd,SOL_SOCKET,SO_REUSEADDR,&val,sizeof(long))==-1){
		perror("setsockopt");
		exit(1);
	}
	int client_sd;
	struct sockaddr_in server_addr;
	struct sockaddr_in client_addr;
	memset(&server_addr,0,sizeof(server_addr));
	server_addr.sin_family=AF_INET;
	server_addr.sin_addr.s_addr=htonl(INADDR_ANY);
	int x = atoi(argv[1]);
	server_addr.sin_port=htons(x);
	if(bind(sd,(struct sockaddr *) &server_addr,sizeof(server_addr))<0){
		printf("bind error: %s (Errno:%d)\n",strerror(errno),errno);
		exit(0);
	}
	if(listen(sd,3)<0){
		printf("listen error: %s (Errno:%d)\n",strerror(errno),errno);
		exit(0);
	}
	int addr_len=sizeof(client_addr);
	if((client_sd=accept(sd,(struct sockaddr *) &client_addr,&addr_len))<0){
		printf("accept erro: %s (Errno:%d)\n",strerror(errno),errno);
		exit(0);
	}

	while(1){
		char buff[100];
		int len;
		if((len=recv(client_sd,buff,sizeof(buff),0))<0){
			printf("receive error: %s (Errno:%d)\n", strerror(errno),errno);
			exit(0);
		}
		buff[len]='\0';
		printf("RECEIVED INFO: ");
		if(strlen(buff)!=0)printf("%s\n",buff);

		if(strcmp("list",buff)==0){

			struct dirent *de;
			DIR *dr = opendir(".");

			if (dr == NULL)  // opendir returns NULL if couldn't open directory
    			{
        			printf("Could not open current directory" );
       				 return 0;
   			 }

    			while ((de = readdir(dr)) != NULL) {
				if((len=send(client_sd,de->d_name,strlen(de->d_name),0))<0){

					printf("Error: %s (Errno:%d)\n",strerror(errno),errno);
					exit(0);
				}else{
					send(client_sd,"\n",strlen("\n"),0);
					printf("%s\n", de->d_name);
				}
			}

    			closedir(dr);
   			break;

		}



		if(strcmp(buff, "put") == 0){
		    char fname[50];
		    char buf[100];
		    int n;
		    if((len=recv(client_sd,fname,sizeof(fname),0))<0){
			printf("receive error: %s (Errno:%d)\n", strerror(errno),errno);
			exit(0);
		    }
		    int fd;
		    printf("File name is :%s\n", fname);
		    fd=open(fname,O_WRONLY|O_CREAT,S_IRWXU);

		    while ( (n = read(client_sd, buf, strlen(buf)-1)) > 0)
		    {

		        buf[n] = '\0';
		        write(fd,buf,n);
		        if( n < BUFSIZE-2)
		            break;
		    }

		    printf("file receiving completed \n");
		    close(client_sd);
		    close(fd);
		}
	}
	close(sd);
	return 0;
}