# define NOT_SWITCH 'X'
# define DIR_SWITCH 'l'
# define GET_SWITCH 'g'
# define PUT_SWITCH 'p'
# define REP_SWITCH 'r'
# define DEL_SWITCH 'd'

# include <sys/types.h>
# include <sys/socket.h>
# include <netinet/in.h>
# include <arpa/inet.h>
# include <netdb.h>
# include <stdio.h>

const int BUFSIZE = 256;
const int BLOCKSIZE = 128;

int readLine(char buf[], const int BUFSIZE, FILE *recv);
int sftpLogin(FILE *send, FILE *receive);
char checkArg(char arg[], FILE *send, FILE *receive);
void eraseFile(FILE *send, FILE *receive, char filename[]);
void getTextFile(FILE *receive, FILE *writeFile);


int main (int argc, char *argv[])
{
	register struct hostent *hp = 0;
	struct sockaddr_in remoteaddr;
	struct servent *sp;
	FILE *send, *receive;
	int sock, port, status;
	char buffer[BUFSIZE];
	int bs = '\r';
	
	FILE *readFile, *writeFile;

	hp = gethostbyname (argv[1]);

	/* WHAT IF GETHOSTBYNAME FAILS? */
	if(hp == NULL)
	{
		printf("Could not locate %s, quitting...",argv[1]);
		exit(1);
	}

	/* Extract the remote address and put it into the structure for socket */
	remoteaddr.sin_family = hp->h_addrtype;
	bcopy (hp->h_addr_list[0], (caddr_t) &remoteaddr.sin_addr, hp->h_length);

	sock = socket (remoteaddr.sin_family, SOCK_STREAM, 0);

	if (sock < 0)
	{ 
		printf("Socket not created. Exiting...\n");
		exit (1);
	}

	sp = getservbyname ("comp347","tcp");
	if (sp == 0)
	{ 
		printf("Could not find sftp service in /etc/services...\n");
		exit (1);
	}
	else 
	{
		port = sp->s_port;
	}

	remoteaddr.sin_port = port;

	if (comp347_connect (sock, &remoteaddr, sizeof (remoteaddr)) < 0)
	{
		printf("Connect failed...\n");
		exit (1);
	}

	receive = fdopen (sock,"rb");
	send = fdopen (sock,"wb");


	//LOGIN HERE
	status = sftpLogin(send,receive);

	if(status != 0)
	{
		printf("Server error: %d ...quitting.\n", status);
		exit(1);
	}
	
	int i;
	for(i = 2; i < argc ; i++)
	{
		char currentC = '\r';

		switch(checkArg(argv[i],send,receive))
		{
			case NOT_SWITCH: break;

			case DIR_SWITCH: 

				printf("DIR\r\n");
				fprintf(send,"DIR\r\n");
				fflush(send);

				status = readLine(buffer,BUFSIZE,receive);

				currentC = '\r';
				
				if(status == 0)
				{
					/*while(currentC != '\0')
					{
						currentC = fgetc(receive);
						fputc(currentC,stdout);
					}*/
					getTextFile(receive,stdout);

				}
				break;

			case GET_SWITCH:

				printf("FETCH %s\r\n",argv[i+1]);
				fprintf(send,"FETCH %s\r\n",argv[i+1]);
				fflush(send);

				status = readLine(buffer,BUFSIZE,receive);

				if(status == 0)
				{
					currentC = '\r';
					
					writeFile = fopen(argv[i+1],"w");

					if(writeFile != NULL)
					{
						if(argv[i][2] == 'b' || argv[i][1] == 'b')
						{
							bs = '\r';

							while(bs != '\0')
							{
								bs = fgetc(receive);

								fread(buffer,bs,1,receive);
								fwrite(buffer,bs,1,writeFile);
							}

							fflush(writeFile);

						}
						else
						{
							/*while(currentC != '\0')
							{
								currentC = fgetc(receive);
								fputc(currentC,writeFile);
							}*/
							getTextFile(receive,writeFile);
						}

						fclose(writeFile);
					}
					else
					{
						printf("Could not open %s for writing. Quitting!\n",argv[i+1]);
					}
				}
				break;	

			case REP_SWITCH:
				
				eraseFile(send,receive,argv[i+1]);
				status = readLine(buffer,BUFSIZE,receive);

			case PUT_SWITCH:
					
				readFile = fopen(argv[i+1],"r");

				if(readFile == NULL)
				{
					printf("File %s not exist...\n",argv[i+1]);
					exit(1);
				}
				else
				{
					printf("STORE %s\r\n",argv[i+1]);
					fprintf(send,"STORE %s\r\n",argv[i+1]);
					fflush(send);
					status = readLine(buffer,BUFSIZE,receive);

					if(status == 0)
					{
						long readSize;
						size_t readResult;
						
						fseek(readFile,0,SEEK_END);
						readSize = ftell(readFile);
						rewind(readFile);

						if(argv[i][2] == 'b' || argv[i][1] == 'b')
						{
							bs = BLOCKSIZE;
							char readBuffer[bs];
							
							fseek(readFile,0,SEEK_END);
							readSize = ftell(readFile);
							rewind(readFile);

							while(readSize != 0)
							{
								if(readSize < BLOCKSIZE)
									bs = readSize;
								fread(readBuffer,bs,1,readFile);
								fputc(bs,send);
								fflush(send);
								fwrite(readBuffer,bs,1,send);
								
								readSize -= bs;
							}
							fputc('\0',send);

							free(readBuffer);

						}
						else
						{
							char *readBuffer;
							readBuffer = (char*) malloc (sizeof(char)*readSize);
							fread(readBuffer,1,readSize,readFile);
							char currentC = '\r';
							int currentI;
			
							int i;
							for(i = 0; i < readSize; i++)
							{
								currentI = (unsigned int) readBuffer[i];
								if( (currentI > 31 && currentI < 127) || (currentI > 8 && currentI < 14 && currentI != 12))
								{
									fprintf(send,"%c",readBuffer[i]);
								}
							}
							fputc('\0',send);

						}

						fflush(send);
						fclose(readFile);
						status = readLine(buffer,BUFSIZE,receive);
					}
				}

				break;

			case DEL_SWITCH:

				eraseFile(send,receive,argv[i+1]);
				status = readLine(buffer,BUFSIZE,receive);

				break;
		}

	}

	// QUIT //
	printf("QUIT\r\n");
	fprintf(send,"QUIT\r\n");
	fflush(send);
	status = readLine(buffer,BUFSIZE,receive);
		
	return 0;
}

int readLine(char buf[], const int BUFSIZE, FILE *receive)
{
	bzero(buf,BUFSIZE);
	fgets(buf,BUFSIZE-1,receive);
	printf("%s",buf);
	
	int status;
	char statmsg[20];
	sscanf(buf,"%s %d",statmsg,&status);

	return status;
}

int sftpLogin(FILE *send, FILE *receive)
{
	const int SLEEPTIME = 3;
	const int BUSYERR = 500;

	char buffer[BUFSIZE];
	char loginname[BUFSIZE];
	int status = '\0';

	bzero(buffer,BUFSIZE); bzero(loginname,BUFSIZE);

	status = readLine(buffer,BUFSIZE,receive);

	if(status == 0)
	{
		getlogin_r(loginname,sizeof(loginname));

		printf("USER %s\r\n",loginname);	
		fprintf(send,"USER %s\r\n",loginname);
		fflush(send);

		status = readLine(buffer,BUFSIZE,receive);

		while(status == BUSYERR) 
		{
			printf("Server busy, reconnecting in %d seconds...\n",SLEEPTIME);
			sleep(SLEEPTIME);
			printf("USER %s\r\n",loginname);	
			fprintf(send,"USER %s\r\n",loginname);
			fflush(send);
			status = readLine(buffer,BUFSIZE,receive);
		}
	}
	
	free(buffer);
	free(loginname);

	return status;
}


void eraseFile(FILE *send, FILE *receive, char filename[])
{
	printf("ERASE %s\r\n",filename);
	fprintf(send,"ERASE %s\r\n",filename);
	fflush(send);
}

char checkArg(char arg[], FILE *send, FILE *receive)
{
	char switchcode;
	if(arg[0] == '-')
	{
		char buffer[BUFSIZE];
		int status ='\0';
		
		if(arg[1] == 'b' || arg[2] == 'b')
		{
			printf("MODE BINARY\r\n");
			fprintf(send,"MODE BINARY\r\n");
			fflush(send);
			status = readLine(buffer,BUFSIZE,receive);

			if(arg[1] == 'b')
				switchcode = arg[2];
			else
				switchcode = arg[1];
		}
		else
		{
			printf("MODE TEXT\r\n");
			fprintf(send,"MODE TEXT\r\n");
			fflush(send);
			status = readLine(buffer,BUFSIZE,receive);

			switchcode = arg[1];
		}

		free(buffer);
	}
	else
		switchcode = NOT_SWITCH;

	return switchcode;
}

void getTextFile(FILE *receive, FILE *writeFile)
{
	int currentC = '\r';

	while(currentC != '\0')
	{
		currentC = fgetc(receive);
		fputc(currentC,writeFile);
	}

}