#include <iostream>
#include <fstream>
#include <vector>
#include <cstdlib>
#include <stdexcept>
using namespace std;

struct Instance
{
  string name;
  bool selected;

  Instance(const string &name)
  {
    selected=false;
    this->name=name;
  }
};

int main(int argc, char **argv)
{
  if (argc!=2)
  {
    cout << "syntax: selection <file containing the list>\n";
    exit(1);
  }

  ifstream in(argv[1]);
  vector<Instance> list;
  string tmp,mode;
  int nb,total=0;

  srandom(2017);

#define SQL
#ifdef SQL
    ofstream sql("list.sql");
    int idevent=88;
#endif


  while(in.good())
  {
    list.clear();

    while(in.peek()=='#' || in.peek()=='\n')
      getline(in,tmp);
    
    in >> nb; // number of instances to select;
    in >> mode; // first or rand
    getline(in,tmp);

    if(mode!="first" && mode!="rand")
      throw runtime_error(string("unexpected mode: ")+mode);

    if (!in.good())
      break;

    while(in.good())
    {
      getline(in,tmp);
      if (tmp.length()==0)
	break;

      if(tmp[0]=='#')
	continue;

      list.push_back(Instance(tmp));
    }

    if(nb>=list.size())
    {
      // select every instance
      for(size_t i=0;i<list.size();++i)
	list[i].selected=true;
    }
    else
    {
      if(mode=="rand")
      {
	// random selection
	int i,n=0;
	while(n<nb)
	{
	  i=random()%list.size();
	  
	  if (!list[i].selected)
	  {
	    list[i].selected=true;
	    ++n;
	  }
	}
      }
      else
      {
	// select the first
	for(int i=0;i<nb;++i)
	  list[i].selected=true;
      }
    }

    if(nb>list.size())
      cout << "## WARNING: not enough instances!\n";

    cout << "## " << nb <<  " " << mode << " instances are selected out of " 
	 << list.size() << ":\n";
    for(int i=0;i<list.size();++i)
      if (list[i].selected)
      {
	++total;
	cout << list[i].name << endl;

#ifdef SQL
	int start=0;
	for(int j=0;j<list[i].name.length();++j)
	  if(list[i].name[j]=='@')
	    start=j+1;

	if(!sql.good())
	  throw runtime_error("can't write to sql file");

	sql << "insert into selectedbenchs (idevent,idbench) select "
	    << idevent << ",idbench from benchs where filename='" 
	    << list[i].name.substr(start) 
	    << "' except select idevent,idbench from selectedbenchs;" << endl;
#endif
      }

    cout << "# done (" << total << " instances selected)\n\n";
  }
}