/*
Copyright (C) 2001  Erik Fears        

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software

      Foundation, Inc.
      59 Temple Place - Suite 330 
      Boston, MA  02111-1307, USA.  

*/

#include "h.h"

Question::Question()
{
  m_question.answer  = 0;
  m_history = 0;
  m_lastaccess = 0;
}

Question::~Question()
{
}


int Question::load_question()
{

   srand(( unsigned)time(NULL));
 
   ifstream in;

   char out[1024];
   int rand_line = 0;

   questions();       //Recount questions if needed
   resize_history();  //Resize history if needed (to avoid infinite loop below)
   
   while(!rand_line)
   {
      rand_line =  1 + (int) ((double)rand() * (m_lines - 1 + 1.0) / (RAND_MAX+1.0));

      if(in_history(rand_line))
         rand_line = 0;
      else
         add_history(rand_line);

   }

   in.open(config->GAME_DB, ios::in); 

   if(in.fail())
     return 0;
      

   for(int i=0;i<rand_line;i++)
     in.getline(m_question.raw,QUESTIONMAX,'\n');
  
   m_question.answers = 0;

   for(int i=0;i < (int) strlen(m_question.raw);i++)
      if(m_question.raw[i] == ';')
        m_question.answers++;
    
   m_question.answers -= 3;


   m_question.nick = strtok(m_question.raw, ";");
   m_question.type = atoi(strtok(NULL, ";"));
   m_question.question = strtok(NULL, ";");
  
   if(m_question.answer)
     delete m_question.answer;

   m_question.answer = new char*[m_question.answers]; 
   
   if(!m_question.question || !m_question.nick)
       return 0;
   
   for(int i=0;i<m_question.answers;i++)
   {
      m_question.answer[i] = strtok(NULL,";");

      if(m_question.answer[i] == 0)
         break;

      if(i == 0)
         strcpy(m_question.mainanswer,m_question.answer[0]);
      if(i == 1)
	 strcpy(m_question.hintanswer,m_question.answer[1]);
   }
  
   if(m_question.answers < 1)
       return 0;
    
              //Clean answers (strip non alphanumerics)
   for(int i=0;i < m_question.answers;i++) 
      parse->clean(m_question.answer[i]);

   in.close();
   return 1;        //No errors
}


int Question::questions()
{
   ifstream in;
   struct stat filestats;
   
   int num_lines = 0;
   char temp[1024];

   //Check to see if we already have current information on the DB
   stat(config->GAME_DB, &filestats);

   if(!(filestats.st_mtime > m_lastaccess)) //If so, return
    {
      return m_lines;
    }
   //Else count the lines again 
   m_lines = 0;

   in.open(config->GAME_DB, ios::in);

   if(in.fail())
       return 0;
    
   while(in.getline(temp,1024,'\n') && !in.eof())
       m_lines++;

   in.close();
   
   time(&m_lastaccess);   //Update last access
      
   return m_lines;
}

/*
 * Keep history size within 50%
 */



void Question::resize_history()
{
   history_struct *p;
   int diff;
   
   diff = m_historysize - (m_lines / 2); //Find how much over 50% we are
                                        
   for(int i=0; i < diff;i++)            //Delete that much
    {
       p = m_history->next;               
       delete m_history;
       m_historysize--;
       m_history = p;
    }


}


/*
 *  Check if value is contained in the list
 */

int Question::in_history(int value)
{

  for(history_struct *p = m_history; p ;p = p->next)  //Traverse history sequentially
     if(value == p->value)      //Return 1 if found
       return 1;
  return 0;
}

/*
 *  Add to list
 * List is not sorted for efficiency because we want to know what
 * questions were asked in what order!
 */

void Question::add_history(int value)
{
   history_struct *newlink;
   history_struct *p1, *p2;
   
   newlink = new history_struct;

   if(!m_history)                              //Add it as first element
     {
        m_history = newlink;
	newlink->value = value;
	newlink->next = 0;
	m_historysize++;
     }
   else                                        //Else add to tail
     {
        for(p1 = m_history;p1->next;p1 = p1->next);    //Find tail
           
        p1->next = newlink;
	newlink->value = value;
        newlink->next = 0;
        m_historysize++;
     }	 

   //Once it is added, remove head if we're at the history limit (50%)
   if((m_lines / 2) < m_historysize)
     {
        p2 = m_history->next;   //Keep temp pointer to the second element
	
        m_historysize--;        //Delete head     
        delete m_history;
	
	m_history = p2;         //Make second element, the new head
     }
     
}


void Question::savestate(ofstream &out)
{

   //Write out history size
   out.write((char *) &m_historysize, sizeof(int));
   //Write out history
   for(history_struct *h = m_history; h; h = h->next)
     out.write((char *) &(h->value), sizeof(int));

}

void Question::loadstate(ifstream &in)
{
    
    int length;
    history_struct *th; // tmp ptr

   //Clear history
   for(history_struct *h = m_history; h ;)
    {
       if(!h->next)
         {
             delete h;
             break;
         }
       th = h->next;
       delete h;
       h = th;
    }
  
    m_history = 0;  

    in.read((char *) &length, sizeof(int));

    for(int i = 0; i < length; i++)
     {
         th = new history_struct;
         in.read((char *) &(th->value), sizeof(int));
         
          if(!m_history)
            {
               m_history = th;
               th->next = 0;
            }
          else
            {

                 for(history_struct *h = m_history;h;h = h->next)
                   {
                      if(!h->next)
                       {
                          h->next = th;
                          th->next = 0;
                          break;
                       }
 
                   }
         

             }

     }
}