// Copyright (C) 2010, Guy Barrand. All rights reserved.
// See the file tools.license for terms.

#ifndef tools_rntuple
#define tools_rntuple

// interfaces to read ntuple.

#include "scast"
#include "cids"

#include <string>
#include <vector>

namespace tools {
namespace read {

class icol {
public:
  virtual ~icol(){}
public:
  virtual void* cast(cid) const = 0;
  virtual cid id_cls() const = 0;
public:
  virtual const std::string& name() const = 0;
public:
  virtual void stop() {}
  virtual bool fetch_entry() const {return false;} //for binded column API.
};
  
template <class T>
class icolumn : public virtual icol {
public:
  static cid id_class() {
    static const T s_v = T(); //do that for T = std::string.
    return _cid(s_v);
  }
public: //icol
  virtual void* cast(cid a_class) const {
    if(void* p = cmp_cast<icolumn>(this,a_class)) return p;
    return 0;
  }
  virtual cid id_cls() const {return id_class();}
public:
  virtual ~icolumn(){}
public:
  virtual bool get_entry(T&) const = 0;
};

class intuple {
public:
  virtual ~intuple(){}
public:
  virtual void start() = 0;
  virtual bool next() = 0;
  virtual icol* find_icol(const std::string&) = 0;
  virtual const std::vector<icol*>& columns() const = 0;
public:
  virtual void stop() {}
public:
  template <class T>
  icolumn<T>* find_column(const std::string& a_name){
    read::icol* col = find_icol(a_name);
    if(!col) return 0;
    return id_cast<read::icol, icolumn<T> >(*col);
  }
};

}}

#endif