// Jeremiah Schultz
// CS 176B Winter 2016
// HW2: mftp.c - FTP Client

#include "mftp.h"

// print error message to stderr & exit with proper error code
void exitCode(int errCode){

	switch(errCode){
		case 0 :
			fprintf(stderr, "exit-code %i: Operation successfully completed\n", errCode);
			break;
		case 1 :
			fprintf(stderr, "exit-code %i: Can't connect to server\n", errCode);
			break;
		case 2 :
			fprintf(stderr, "exit-code %i: Authentication failed\n",errCode);
			break;
		case 3 :
			fprintf(stderr, "exit-code %i: File not found\n", errCode);
			break;
		case 4 :
			fprintf(stderr, "exit-code %i: Syntax error in client request\n", errCode);
			break;
		case 5 :
			fprintf(stderr, "exit-code %i: Command not implemented by server\n", errCode);
			break;
		case 6 :
			fprintf(stderr, "exit-code %i: Operation not allowed by server\n", errCode);
			break;
		case 7 :
			fprintf(stderr, "exit-code %i: Generic error\n", errCode);
			break;
	}

	exit(errCode);
}

// display working version of client
void printVersion(){
	printf("App: mftp client\nVersion: 0.1\nAuthor: Jeremiah");

}

// display proper usage ofr mftp client
void printHelp(){
	printf("Usage: ./mftp [FLAGS]\n");

	//print all possible flag options
	printf("FLAGS:\n");
	printf("  -a, --active                 	Forces active behavior (default: passive)\n");
	printf("  -f, --file [file]        		Specifies the file to download\n");
	printf("  -h, --help                   	Displays this help information and exits\n");
	printf("  -l, --log [logfile]     		Logs all the FTP commands exchanged with server to file ('-' will log to stdout)\n");
	printf("  -m, --mode [mode]            	Specifies the mode to be used for the transfer (ASCII or binary) (default: binary)\n");
	printf("  -n, --username [user]    		Specifies the username to use when logging into the FTP server (default: anonymous)\n");
	printf("  -p, --port [port]            	Specifies the port to be used when contacting the server (default: 21)\n");
	printf("  -P, --password [password]    	Specifies the password to use when logging into the FTP server (default: user@localhost.localnet)\n");
	printf("  -s, --server [hostname]      	Specifies the server to download the file from\n");
	printf("  -v, --version                	Prints version information and exits\n");
	printf("  -w, --swarm [swarm-file]		Enables swarming mode\n(use with optional -b [num-bytes] to force download in segments of size num_bytes)\n");

}


// MAIN | MAIN | MAIN | MAIN //
int main(int argc, char* argv[]){

	// myData initialization
	myData.active = false;
	myData.filename = NULL;
	myData.logfile = NULL;
	myData.logSet = false;
	myData.mode = 0;
	myData.user = "anonymous";
	myData.portNum = 21;
	myData.pass = "user@localhost.localnet";
	myData.server = NULL;
	myData.swarmfile = NULL;

	// check usage and display help if needed
	if (argc == 1){
		printHelp();
		exitCode(0);
	}

	// parse command line options
	int optIndex = 0;
	int opt = 0;

	opt = getopt_long(argc, argv, flags, longOptions, &optIndex);

	while (opt != -1){

		switch(opt){
			case 'a' :
				// active mode
				fprintf(stdout, "active mode\n");
				break;
			case 'f' :
				// store filename
				myData.filename = optarg;
				break;
			case 'h' :
				// display help info
				printHelp();
				break;
			case 'l' :
				// update logfile path
				if (!strcmp(optarg, "-")){
					myData.logfile = stdout;
					myData.logSet = true;
					printf("Printing to stdout\n");
				}
				else{
					if((myData.logfile = fopen(optarg, "w")) == NULL){
						fprintf(stderr, "Logfile could not be created\n");
						exitCode(7);
					}
					myData.logSet = true;
					printf("Logfile %s created successfully\n", optarg);
				}
				break;
			case 'm' :
				// set transfer mode to binary (0) or ASCII (1)
				if (!strcasecmp(optarg, "binary")){
					myData.mode = 0;
					printf("Binary transfer mode enabled\n");
				}
				else if (!strcasecmp(optarg, "ASCII")){
					myData.mode = 1;
					printf("ASCII transfer mode enabled\n");
				}
				else{
					// invalid mode provided
					printf("Invalid mode\n");
					exitCode(4);
				}
				break;
			case 'n' :
				// store username
				myData.user = optarg;
				break;
			case 'p' :
				// store port number
				myData.portNum = atoi(optarg);
				break;
			case 'P' :
				// store password
				myData.pass = optarg;
				break;
			case 's' :
				// store servername
				myData.server = optarg;
				break;
			case 'v' :
				// display version info
				printVersion();
				break;
		}
		opt = getopt_long(argc, argv, flags, longOptions, &optIndex);
	}


	// setup control connection
	int sockfd = 0;
	int bytesBack = 0;
	char recvBuf[SIZE];
	char sendBuf[SIZE];
	char echo[SIZE];
	struct sockaddr_in serv_addr;
	struct hostent* server;

	memset(recvBuf, '0', SIZE);
	memset(sendBuf, '0', SIZE);
	memset(&serv_addr, '0', sizeof(serv_addr));


	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0) < 0)){
		fprintf(stderr, "Error opening socket\n");
		exitCode(7);
	}





	if ((server = gethostbyname(myData.server)) == NULL){
		// can't connect to server
		exitCode(1);
	}



	//bzero((char *) &serv_addr, sizeof(serv_addr));
	memcpy(&server->h_addr, server->h_addr_list[0], server->h_length);
	serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(myData.portNum);

    if (connect(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0){
        exitCode(1);
    }

    if ((bytesBack = recv(sockfd, recvBuf, sizeof(recvBuf), 0)) < 0){
    	fprintf(stderr, "No greeting received from server\n");
    	exitCode(7);
    }

    printf("Received from server: %s", recvBuf);



	exitCode(0);
	return 0;
}