//Ben Anderson
//Chris Guernsey
/*---------------------------------------------------------------------------*/
/*  Usage:  			                                     */
/*                                                                           */
/*  Runs an instance of a new shell that restricts runable commands          */
/*    based on the UID of user						     */
/*---------------------------------------------------------------------------*/

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


#define MAXDATASIZE 8192 // max number of bytes we can get at once 

extern int optind;
extern char *optarg;


int getField(int fd, char *buf){
	    int i,ret;
	    char ch;

	     ch=' ';
	     i=0;
	     
	    while(ch!=EOF){
	    ret=read(fd,&ch,1);
	    buf[i++]=ch;
	    if(i >= 8000 && ch == '\n'){
		return (0);
		}
	    if(ret==0){ return(1);}

		}
	    
	    buf[--i]='\0';
	    return(0);
	}
   int FileSize( const char * szFileName ) 
		{ 
		 struct stat fileStat; 
		int err = stat( szFileName, &fileStat ); 
		if (0 != err) return 0; 
		return fileStat.st_size; 
		}

char * listFiles(int sockfd){
    msg_buffer buffer;
    int rec;
    
		    bzero((char*)buffer.data,8192);
		    buffer.opcode = op_list_directory;
		    buffer.ack_nack = 0;
		    buffer.subcode = 0;
		    buffer.length = 0;
		    write(sockfd, (char *)&buffer, buffer.length+6);
		    bzero((char*)buffer.data,8192);
		    rec = read(sockfd,(char *)&buffer,8192);
		    if(rec<0){
                    perror("ERROR reading from socket");
                    }
		    //if(rec!=-1){
		    //printf("%s\n",(char*)buffer.data);
		    //printf("File list successful\n");
                    //}
		    
		return (char *) buffer.data;
    
    }


int readFile(int sockfd, char *filename){
    
    msg_buffer buffer;
    int rec,response;    

		    bzero((char*)buffer.data,8192);
		    buffer.opcode = op_open_file_input;
		    buffer.ack_nack = 0;
		    buffer.subcode = 0;
		    buffer.length = strlen(filename);
		    strcpy((char *)buffer.data,filename);
		    write(sockfd, (char *)&buffer, buffer.length+6);
		    bzero((char*)buffer.data,8192);
		    rec = read(sockfd,(char *)&buffer,8192);
		    if(rec<0){
                    perror("ERROR reading from socket");
                    }
		    if(rec!=-1){
		    printf("%s\n",(char*)buffer.data);
		    printf("File opened for input\n");
		    response = buffer.subcode;
                    
			}   
		    printf("%d\n",response);
   		    response = buffer.subcode;
		    bzero((char*)buffer.data,8192);
		    buffer.opcode = op_read_file;
		    buffer.ack_nack = 0;
		    buffer.subcode = response;
		    buffer.length = 8192;
		    write(sockfd, (char *)&buffer, buffer.length+6);
		    bzero((char*)buffer.data,8192);
		    rec = read(sockfd,(char *)&buffer,8192);
		    if(rec<0){
                    perror("ERROR reading from socket");
                    }
		    if(rec!=-1){
		    printf("%s\n",(char*)buffer.data);
		    printf("File read successful\n");
                    }

    
    }
int xfer(int sockfd, char * filename, char * filedata,bool first,int response){
    	    int rec,r;
	    msg_buffer buffer;
	    msg_buffer buffer2;
	    char message[100];
	    char * files = listFiles(sockfd);
	    char * temp = strstr(files,filename);
	    
	    if(first){
		    if(temp != NULL){
	    temp[strlen(temp)-1] = '\0';
		}
	    else if(temp == NULL){
		temp = "";
		}
	    	    if(strcmp(temp,filename)!=0){
		    bzero((char*)buffer.data,8192);
		    buffer.opcode = op_open_file_output;
		    buffer.ack_nack = 0;
		    buffer.subcode = 0;
		    buffer.length = strlen(filename);
		    strcpy((char *)buffer.data,filename);
		    write(sockfd, (char *)&buffer, buffer.length+6);
		    bzero((char*)buffer.data,8192);
		    rec = read(sockfd,(char *)&buffer,8192);
		    if(rec<0){
                    perror("ERROR reading from socket");
                    }
		    strcpy(message,(char*)buffer.data);
		    if(rec!=-1){
		    printf("%s\n",(char*)buffer.data);
		    printf("File opened for output\n");
                    }   
		    response = buffer.subcode;
		    		}

		    
		  /*  bzero((char*)buffer.data,8192);
		    buffer.opcode = op_open_file_input;
		    buffer.ack_nack = 0;
		    buffer.subcode = 0;
		    buffer.length = strlen(filename);
		    strcpy((char *)buffer.data,filename);
		    write(sockfd, (char *)&buffer, buffer.length+6);
		    bzero((char*)buffer.data,8192);
		    rec = read(sockfd,(char *)&buffer,8192);
		    if(rec<0){
                    perror("ERROR reading from socket");
                    }
		    if(rec!=-1){
		    printf("%s\n",(char*)buffer.data);
		    printf("File opened for input\n");
                    }   
		    r = buffer.subcode;
		    printf("r = %d and response = %d\n",r,response);
		    */
		    bzero(buffer2.data,8192);
		    buffer2.opcode = op_write_file;
		    buffer2.ack_nack = 0;
		    if(response !=0){
		    buffer2.subcode = response;
			}
		    else{
			buffer2.subcode = r;
			}
		    buffer2.length = strlen(filedata);
		    strcpy((char *)buffer2.data,filedata);
		    //printf("%s\n",filedata);
		    write(sockfd, (char *)&buffer2, buffer2.length+6);
		    bzero((char*)buffer2.data,8192);
		    rec = read(sockfd,(char *)&buffer2,8192);
		    if(rec<0){
                    perror("ERROR reading from socket");
                    }
		    if(rec!=-1){
		    printf("%s\n",(char*)buffer2.data);
		    printf("File write successful\n");
                    }   
		    
		    
		    
		    if(response !=0){
		    return response;
			}
		    else{
			return  r;
			}
		}
	    else{
	    
	     
		 /*   bzero((char*)buffer.data,8192);
		    buffer.opcode = op_open_file_input;
		    buffer.ack_nack = 0;
		    buffer.subcode = 0;
		    buffer.length = strlen(filename);
		    strcpy((char *)buffer.data,filename);
		    write(sockfd, (char *)&buffer, buffer.length+6);
		    bzero((char*)buffer.data,8192);
		    rec = read(sockfd,(char *)&buffer,8192);
		    if(rec<0){
                    perror("ERROR reading from socket");
                    }
		    if(rec!=-1){
		    printf("%s\n",(char*)buffer.data);
		    printf("File opened for input\n");
                    }   
		    r = buffer.subcode;
		    printf("r = %d and response = %d\n",r,response);
		   */ 
		    bzero(buffer2.data,8192);
		    buffer2.opcode = op_write_file;
		    buffer2.ack_nack = 0;
		    if(response !=0){
		    buffer2.subcode = response;
			}
		    else{
			buffer2.subcode = r;
			}
		    buffer2.length = strlen(filedata);
		    strcpy((char *)buffer2.data,filedata);
		    //printf("%s\n",filedata);
		    write(sockfd, (char *)&buffer2, buffer2.length+6);
		    bzero((char*)buffer2.data,8192);
		    rec = read(sockfd,(char *)&buffer2,8192);
		    if(rec<0){
                    perror("ERROR reading from socket");
                    }
		    if(rec!=-1){
		    printf("%s\n",(char*)buffer2.data);
		    printf("File write successful\n");
                    }   
		    
		    bzero((char*)buffer.data,8192);
		    buffer.opcode = op_close_file;
		    buffer.ack_nack = 0;
		    if(response !=0){
		    buffer2.subcode = response;
			}
		    else{
			buffer2.subcode = r;
			}

		    buffer.length = strlen(filename);
		    strcpy((char *)buffer.data,filename);
		    write(sockfd, (char *)&buffer, buffer.length+6);
		    bzero((char*)buffer.data,8192);
		    rec = read(sockfd,(char *)&buffer,8192);
		    if(rec<0){
                    perror("ERROR reading from socket");
                    }
		    if(rec!=-1){
		    printf("%s\n",(char*)buffer.data);
		    printf("File close successful\n");
                    }   
		    
		    
		    if(response !=0){
		    return response;
			}
		    else{
			return  r;
			}

		}

		
    }


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

    int i,t,fd,rec,filelength,endofFile,response,PORT,rep;
    char *opts="hpiafld:";
    int sockfd, numbytes;  
    char buf[MAXDATASIZE];
    struct hostent *hostname;
    struct sockaddr_in their_addr; 
    struct sockaddr_in my_addr;
    int print=0;
    char * filename = "";
    char ch;
    char * userID= "";
    char * opcode = "";
    char message[100];
    bool r1 = false;
    bool r2 = false;
    bool r3 = false;
    bool transfer = false;
    bool list = false;
    bool del = false;
    bool logged = false;
    bool resolved = false;
    bool first = false;
    bool readme = false;
    bool dorl = false;
    bool fused = false;
    char filedata[8192];
    int addrlen=sizeof(their_addr);
    msg_buffer buffer;
    msg_buffer buffer2;
    msg_buffer buffer3;
    i=0;
    while ((ch=getopt(argc,argv,opts))!=-1){

        if (ch=='h') 
                {
		if(!r1){
                i+=2;
                if ((hostname=gethostbyname(argv[i])) == NULL) {  // get the host info 
                herror("gethostbyname");
                exit(1);
		r1=true;
		    }
		}
		else{
		    printf("Host already defined\n");
		    exit(1);
		    }
                

                r1=true;
                }
        if (ch=='p') 
                {
		if(r2==0){
                i+=2;
                PORT = atoi(argv[i]);
                r2=true;
			}
		    else{
		    printf("Port already defined\n");
		    exit(1);
		    }

                     
                }
        if (ch=='i') 
                {
		    if(!r3){
                i+=2;
                userID = argv[i];
                r3=true;
			}
		    else{
		    printf("User already defined\n");
		    exit(1);
		    }

                     
                }
        if (ch=='f') 
                {
		if(!dorl){
		transfer = true;
                i+=2;
                filename = argv[i];
		filelength = FileSize(filename);
		fd = open(filename, O_RDONLY);
		fused = true;
		    }
		else{
		    printf("-f can not be used with -d or -l\n");
		    exit(1);

		    }
		
                }
        if (ch=='l') 
                {
		if(!fused){
                i++;
		list = true;   
		dorl = true;
		    }
		else{
		    printf("-l can not be used with -f\n");
		    exit(1);

		    }

                }
        if (ch=='d') 
                {
		if(!fused){
                i++;
		del = true;
		dorl = true;
		    }
                else{
		    printf("-d can not be used with -f\n");
		    exit(1);

		    }
    
                }
	if(ch == 'a'){
	    i+=2;
	    filename = argv[i];
	    readme = true;
	    }
        }
        if(r1 && r2 && r3){
           
            if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
                perror("socket");
                exit(1);
		}

                their_addr.sin_family = AF_INET;    // host byte order 
                their_addr.sin_port = htons(PORT);  // short, network byte order 
                their_addr.sin_addr = *((struct in_addr *)hostname->h_addr);
                if (connect(sockfd, (struct sockaddr *)&their_addr,sizeof(struct sockaddr)) == -1) {
                perror("connect");
                exit(1);
                }
                strcpy(message,opcode);
                strcat(message,userID);
                buffer.opcode = op_hello;
                buffer.ack_nack = 1;
                buffer.subcode = 0;
                buffer.length = strlen(message);
                strcpy((char*)buffer.data,message);
		write(sockfd, (char *)&buffer, buffer.length+6);
		bzero((char*)buffer.data,8192);
		rec = read(sockfd,(char *)&buffer,8192);
		if(rec<0){
                    perror("ERROR reading from socket");
                    }
		strcpy(message,(char*)buffer.data);
                if(rec!=-1){
                    printf("%s\n",message);
		    printf("Login successful\n");
                    }     
		resolved = true;

	    }


	else if(r1 && r2 && !r3){
	/*	if(fork() == 0) {
		execvp("/usr/bin/clear", argv);
		exit(1);}*/
		while(!logged){



		userID = getpass("Enter your user id\n");
		printf("%s \n", userID);

		if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
                perror("socket");
                exit(1);
		}
                their_addr.sin_family = AF_INET;    // host byte order 
                their_addr.sin_port = htons(PORT);  // short, network byte order 
                their_addr.sin_addr = *((struct in_addr *)hostname->h_addr);
                if (connect(sockfd, (struct sockaddr *)&their_addr,sizeof(struct sockaddr)) == -1) {
                perror("connect");
                exit(1);
                }
                strcpy(message,opcode);
                strcat(message,userID);
                buffer.opcode = op_hello;
                buffer.ack_nack = 1;
                buffer.subcode = 0;
                buffer.length = strlen(message);
                strcpy((char*)buffer.data,message);
		write(sockfd, (char *)&buffer, buffer.length+6);
		bzero((char*)buffer.data,8192);
		rec = read(sockfd,(char *)&buffer,8192);
		if(rec<0){
                    perror("ERROR reading from socket");
                    }
		strcpy(message,(char*)buffer.data);
		if(buffer.ack_nack==1){
		    logged = true;
		    }
 
		
		    }
		resolved = true;
		}

		
		if(list){
		     
		    char * templist = listFiles(sockfd);
		    printf("%s\n",templist);

		    }
		if(del){
		    bzero((char*)buffer.data,8192);
		    buffer.opcode = op_erase_files;
		    buffer.ack_nack = 0;
		    buffer.subcode = 0;
		    buffer.length = 0;
		    write(sockfd, (char *)&buffer, buffer.length+6);
		    bzero((char*)buffer.data,8192);
		    rec = read(sockfd,(char *)&buffer,8192);
		    if(rec<0){
                    perror("ERROR reading from socket");
                    }
		    if(rec!=-1){
		    printf("%s\n",(char*)buffer.data);
		    printf("File remove successful\n");

                    }
		    response = buffer.length;

		    
		    }
		    
                bzero(message,80);
                            
          	if(transfer){
		i=0;    
		t=0;
		while(true){
		
		endofFile=getField(fd,filedata);
		//printf("%s\n",filedata);

		if(i>0){
		    first = false;
		    }
		else{
		    first = true;
		    }
		t = xfer(sockfd,filename,filedata,first,t);
		bzero(filedata,strlen(filedata));
		if(endofFile){
		    break;
		    }
		    i++;
		}

		}
		
		if(readme){
			readFile(sockfd,filename);
			
			}
	        close(sockfd);
	
    return 0;
}