#include "w_main.h"

/**
 * File Name: w_server.cpp
 * Author   : Edison Chindrawaly
 * Course   : CSCI 4330 TCP/IP Fall 2001
 * Desc     : It sends report to w_client regarding the
 *            current load of the CSP server through
 *            TCP's connection.
 * Usage    : ./w_server 1080
 */

char* performCheck(char *);
char* strtrim(char*);

void main(int argc, char *argv[])
{
 int s,so;
 struct sockaddr_in server;
 int port = atoi(argv[1]);
 int n_bytes;
 char rmessage[MAXSIZE];
 char store[MAXSIZE];

 if((so=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP)) == ERROR)
   cerr<<"Error in opening socket"<<endl;

 memset(&server,0,sizeof(server));
 server.sin_family = AF_INET;
 server.sin_port = htons((unsigned short)port);
 server.sin_addr.s_addr = INADDR_ANY;

 if(bind(so,(struct sockaddr *)&server,sizeof(server)) == ERROR)
 {
   cerr<<"Error in bind"<<endl;
   exit(0);
 }

 if(listen(so,5) == ERROR)
    cerr<<"Error in listen"<<endl;

 if((s=accept(so,(struct sockaddr *)&server,
                 (socklen_t *)sizeof(server))) == ERROR)
    cerr<<"Error in accept"<<endl;
 char* sign = performCheck(store);
 if(sign != NULL)
   strcpy(rmessage,store);
 if((n_bytes=send(s,rmessage,sizeof(rmessage),0)) == ERROR)
    cerr<<"Error in send"<<endl;
}

/**
 * performCheck(): To do the reporting of the current
 * load balance of the server.
 * @param  char* store - variable that stores
 * @return char* the current load - else NULL if error occurs
 */
char* performCheck(char* store)
{
 int maxlength = 256;
 FILE *fpin;
 char buffer[maxlength];
 char *token, *strpos;
 char cmd[2] = "w";
 bool flag;
 if((fpin = popen(cmd,"r")) == NULL)
   return NULL;
 while(fgets(buffer, maxlength, fpin) != NULL)
 {
  flag = false;
  strpos = buffer;
  while((token=strsep(&strpos,":"))!=NULL)
  {
   if(flag == true)
   {
     strtrim(token);
     strcpy(store,token);
     return store;
   } 
   if(strstr(token,"average") != NULL)
     flag = true;
  }
 }
 return NULL;
}

/**
 * strtrim(): To delete the leading blank space of the string.
 *            Courtesy of DonR (lecture of UNT CSCI)
 * @param  char* string - to be trim
 * @return char* string - else NULL if error
 */
char* strtrim(char *s)
{
 if(s == NULL)
   return NULL;
 char *p = s;
 while(*p == ' ')
   p++;
 strcpy(s,p);
 p = s + strlen(s)-1;
 while(p >= s && *p == ' ')
   *p-- = '\0';
 return s;
}