// 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 "touplow"
#include "forit"
#include "mnmx"

#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:
  typedef T entry_t;
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:
  static const std::string& s_class() {
    static const std::string s_v("tools::read::intuple");
    return s_v;
  }
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;
  virtual const std::string& title() const = 0;
  virtual bool number_of_entries(uint64&) const = 0;
public:
  virtual void stop() {}
public:
  size_t number_of_columns() const {return columns().size();}

  void column_names(std::vector<std::string>& a_names) const {
    a_names.clear();
    const std::vector<icol*>& _cols = columns();
    tools_vforcit(icol*,_cols,it) a_names.push_back((*it)->name());
  }

  icol* find_icol_case_insensitive(const std::string& a_name) { //for gopaw and exlib::evaluator.
    std::string low_a_name = a_name;
    tolowercase(low_a_name);
    std::string low_name;
    const std::vector<icol*>& _cols = columns();
    tools_vforcit(icol*,_cols,it) {
      low_name = (*it)->name();
      tolowercase(low_name);
      if(low_name==low_a_name) return *it;
    }
    return 0;
  }

  template <class T>
  icolumn<T>* find_column(const std::string& a_name){
    icol* col = find_icol(a_name);
    if(!col) return 0;
    return id_cast<icol, icolumn<T> >(*col);
  }

  template <class T>
  bool find_column(const std::string& a_name,icolumn<T>*& a_col,bool a_case_sensitive = true) { //for gopaw and exlib::evaluator.
    icol* col = a_case_sensitive ? find_icol(a_name) : find_icol_case_insensitive(a_name);
    if(!col) {a_col = 0;return false;}
    a_col = id_cast<icol, icolumn<T> >(*col);
    return a_col?true:false;
  }

  template <class T>
  bool column_is_of_type(const std::string& a_name,bool& a_is,bool a_case_sensitive = true) {
    icol* col = a_case_sensitive ? find_icol(a_name) : find_icol_case_insensitive(a_name);
    if(!col) {a_is = false;return false;}
    a_is = id_cast<icol, icolumn<T> >(*col)?true:false;
    return true;
  }

  template <class T>
  bool column_min(unsigned int a_col,T& a_value) {
    a_value = T();
    const std::vector<icol*>& cols = columns();
    if(cols.empty()) return false;
    if(a_col>=cols.size()) return false;
    icol* _base_col = cols[a_col];
    icolumn<T>* _col = id_cast<icol, icolumn<T> >(*_base_col);
    if(!_col) return false;
    uint64 _rows;
    if(!number_of_entries(_rows)) return false;
    start();
    T v;
   {for(uint64 row=0;row<_rows;row++) {
      if(!next()) {a_value = T();return false;}
      if(!_col->get_entry(v)) {}
      if(!row) {
        a_value = v;
      } else {
        a_value = mn<T>(a_value,v);
      }
    }}
    return true;
  }

  template <class T>
  bool column_max(unsigned int a_col,T& a_value) {
    a_value = T();
    const std::vector<icol*>& cols = columns();
    if(cols.empty()) return false;
    if(a_col>=cols.size()) return false;
    icol* _base_col = cols[a_col];
    icolumn<T>* _col = id_cast<icol, icolumn<T> >(*_base_col);
    if(!_col) return false;
    uint64 _rows;
    if(!number_of_entries(_rows)) return false;
    start();
    T v;
   {for(uint64 row=0;row<_rows;row++) {
      if(!next()) {a_value = T();return false;}
      if(!_col->get_entry(v)) {}
      if(!row) {
        a_value = v;
      } else {
        a_value = mx<T>(a_value,v);
      }
    }}
    return true;
  }

};

}}

#endif