#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

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

#include "../errlib


#define MAX_File_number_to_request 5
#define RequestCmd_length 1000
#define BUFLEN	128 /* BUFFER LENGTH */

int main(int argc ,char * argv[])
{
//check arg number
	if(argc<=3)
	{
		fprintf(stderr,"missing parmeters. goy only %d . but expected at least 3",argc);
	}

//get port number
	int port =atoi(argv[2]);//Convert string to integer



//check if a vlaid ip address ofr not
	//struct hostent *Gethostbyname (const char *hostname);
	//gethostbyname() function returns a structure of type hostent for the given host name.
	//hostname--> is either a hostname or an IPv4 address in standard dot notation
	struct hostent *server;
	const char *hostname=argv[1];//???why  index 1 . why not 0???

	server =gethostbyname(hostname);
	if(server==NULL)
	{
		fprintf(stderr,"gethostbyname() failed for : %s \n",hostname);
		exit(1);
	}

//get ipaddress number

	//#include <arpa/inet.h>
	//int inet_aton(const char *cp, struct in_addr *addr);
	//inet_aton()-convert Internet dot address to network address

    struct in_addr	serverIPaddr_struct; 	/* server IP addr. structure */
	int result = inet_aton(hostname, &serverIPaddr_struct);
	if (!result)
	{
		fprintf(stderr,"Invalid address.quitting \n");
		//err_quit("Invalid address");
	}


//file names
	char files2Request[MAX_File_number_to_request];
	int n=argc-2;

	if(n>MAX_File_number_to_request)
		fprintf(stderr,"only 50 file can be asked at a time. U asked for  %d . so 1st %d  i will be asked",n,MAX_File_number_to_request);


	for (int i=0;i<n;i++)
	{
		files2Request[i]=argv[i+2];


		printf("%s\n",files2Request[i]);


	}
//construct request command
	char cmds[RequestCmd_length][500];
	//char * strcpy ( char * destination, const char * source );
	for ( i=0;i<n;i++)
	{
		bzero(cmds[i],RequestCmd_length);
		strcpy(cmds[i],"GET");//ASCII characters “GET”
		strcat(cmds[i]," ");// ASCII space character
		strcat(cmds[i],files2Request[i]);// ASCII characters of the file name
		strcat(cmds[i],"\r");//ASCII carriage return (CR)
		strcat(cmds[i],"\n");//ASCII line feed (LF)

		fprintf(stderr,"CMD-%s : %s \n",cmd[i]);
	}

    /* create the socket */
    printf("Creating socket\n");
 int   sockfd = Socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    printf("done. Socket fd number: %d\n",sockfd);




	  /* prepare address structure */
	 struct sockaddr_in	serv_addr;
    bzero(&serv_addr, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port   =  htons(port); //The htons() function converts the unsigned short integer hostshort from host byte order to network byte order.
    serv_addr.sin_addr   = serverIPaddr_struct;


	   /* connect */
    //showAddr("Connecting to target address", &serv_addr);
	 printf("Connecting to target address\n");
    //Connect(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
    //printf("done.\n");

	if(connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr))<0){
		error("Connection Failed");
	}
	else
	{
			printf("Client: Connecting...\n");
	}


	// a file descriptor (FD, less frequently fildes) is an abstract indicator (handle) used to access a file or other input/output resource, such as a pipe or network socket

	//The write() function shall attempt to write nbyte bytes from the buffer pointed to by buf to the file associated with the open file descriptor, fildes
	Write(sockfd, cmds[0], strlen(buf));

	/* reads exactly "n" bytes from a descriptor */
	//ssize_t readn (int fd, void *vptr, size_t n)

	int indexCount;
	char	   receivedData[BUFLEN];
	//read 1st 3 character -->"+ O K"
	int character_read_count=readn(sockfd, receivedData, 3);///why 5 bit ??? why not 3 bit

	//+ O K CR LF B1 B2 B3 B4 T1 T2 T3 T4 File content
	//read fist 3 character "+ O K"
	char *t= "+OK";
	int g=strlen(t);
	if( strncmp(receivedData,t,g)   ==  0  )
	{
		//read next 2 character. CR LF  . useless . but we need to read increase the ptr
		character_read_count=readn(sockfd, receivedData, 2);


		//read next 4 bit. B1 B2 B3 B4
			uint32_t file_bytes;
			int n = readn(sockfd, &file_bytes, 4);
			file_bytes = ntohl(file_bytes);
			printf("file_bytes: %d\n",file_bytes);



		//read next 4 bit. T1 T2 T3 T4
			uint32_t file_tm;
			n = readn(sockfd, &file_tm, 4);
			file_tm = ntohl(file_tm);
			printf("file_tm: %d\n",file_tm);


			//Writes an array of count elements, each one with a size of size bytes, from the block //of memory pointed by ptr to the current position in the stream.
			//size_t fwrite ( const void * ptr, size_t size, size_t count, FILE * stream );

			char *fileContent;
			fileContent=(char*)malloc(file_bytes* sizeof(char));

			n = readn(sockfd, fileContent, file_bytes);

			if(character_read_count != file_bytes)
			{
				printf("wrong number of byte received \n");
			}
			else
			{

				char *fname;
				fname=files2Request[0];
				strcat(fname,"_Recieved");

				FILE *fp;
				fp = fopen(fname, "w");
				if(NULL == fp)
				{
					printf("Error opening file");
					return 1;
				}
				else
				{
					fwrite(fileContent, sizeof(char), fileContent, fp);
					fclose(fp);
				}
			}



	}

	  Write(sockfd, "QUIT/r/n", 6);
	close(sockfd);

	 printf("===========================================================\n");

}