/*!
   \file utils.hpp
   \author Ha NGUYEN
   \since 06 Oct 2014
   \date 10 Feb 2015


   \brief Some utils for Xios
 */

#ifndef __XIOS_UTILS_HPP__
#define __XIOS_UTILS_HPP__

#include <vector>
#include <limits>
#include "array_new.hpp"
#include "exception.hpp"

namespace xios
{
  template<typename K>
  struct CArrayTraits {
    typedef K ArrayType;
  };

  template<typename K>
  struct CArrayBoolTraits : public CArrayTraits<K> {
    typedef bool Type;
  };

  template<>
  struct CArrayBoolTraits<CArray<bool,1> >
  {
    static inline void resizeArray(CArray<bool,1>& boolArray, const std::vector<int>& dimensionSize)
    {
      if (1 != dimensionSize.size())
        ERROR("utils::CArrayBoolTraits",
                <<"Dimension of resized array mismatch"<<endl
                <<"Dimension of resized is 1 "<<endl
                <<"Dimension of vetor resizing is "<< dimensionSize.size());
      boolArray.resize(dimensionSize[0]);
    }
  };

  template<>
  struct CArrayBoolTraits<CArray<bool,2> >
  {
    static inline void resizeArray(CArray<bool,2>& boolArray, const std::vector<int>& dimensionSize)
    {
      if (2 != dimensionSize.size())
        ERROR("utils::CArrayBoolTraits",
                <<"Dimension of resized array mismatch"<<endl
                <<"Dimension of resized is 2 "<<endl
                <<"Dimension of vetor resizing is "<< dimensionSize.size());
      boolArray.resize(dimensionSize[0], dimensionSize[1]);
    }
  };

  template<>
  struct CArrayBoolTraits<CArray<bool,3> >
  {
    static inline void resizeArray(CArray<bool,3>& boolArray, const std::vector<int>& dimensionSize)
    {
      if (3 != dimensionSize.size())
        ERROR("utils::CArrayBoolTraits",
                <<"Dimension of resized array mismatch"<<endl
                <<"Dimension of resized is 3 "<<endl
                <<"Dimension of vetor resizing is "<< dimensionSize.size());
      boolArray.resize(dimensionSize[0], dimensionSize[1], dimensionSize[2]);
    }
  };

  template<>
  struct CArrayBoolTraits<CArray<bool,4> >
  {
    static inline void resizeArray(CArray<bool,4>& boolArray, const std::vector<int>& dimensionSize)
    {
      if (4 != dimensionSize.size())
        ERROR("utils::CArrayBoolTraits",
                <<"Dimension of resized array mismatch"<<endl
                <<"Dimension of resized is 4 "<<endl
                <<"Dimension of vetor resizing is "<< dimensionSize.size());
      boolArray.resize(dimensionSize[0], dimensionSize[1], dimensionSize[2], dimensionSize[3]);
    }
  };

  template<>
  struct CArrayBoolTraits<CArray<bool,5> >
  {
    static inline void resizeArray(CArray<bool,5>& boolArray, const std::vector<int>& dimensionSize)
    {
      if (5 != dimensionSize.size())
        ERROR("utils::CArrayBoolTraits",
                <<"Dimension of resized array mismatch"<<endl
                <<"Dimension of resized is 5 "<<endl
                <<"Dimension of vetor resizing is "<< dimensionSize.size());
      boolArray.resize(dimensionSize[0], dimensionSize[1],
                       dimensionSize[2], dimensionSize[3], dimensionSize[4]);
    }
  };

  template<>
  struct CArrayBoolTraits<CArray<bool,6> >
  {
    static inline void resizeArray(CArray<bool,6>& boolArray, const std::vector<int>& dimensionSize)
    {
      if (6 != dimensionSize.size())
        ERROR("utils::CArrayBoolTraits",
                <<"Dimension of resized array mismatch"<<endl
                <<"Dimension of resized is 6 "<<endl
                <<"Dimension of vetor resizing is "<< dimensionSize.size());
      boolArray.resize(dimensionSize[0], dimensionSize[1],
                       dimensionSize[2], dimensionSize[3],
                       dimensionSize[4], dimensionSize[5]);
    }
  };

  template<>
  struct CArrayBoolTraits<CArray<bool,7> >
  {
    static inline void resizeArray(CArray<bool,7>& boolArray, const std::vector<int>& dimensionSize)
    {
      if (7 != dimensionSize.size())
        ERROR("utils::CArrayBoolTraits",
                <<"Dimension of resized array mismatch"<<endl
                <<"Dimension of resized is 7 "<<endl
                <<"Dimension of vetor resizing is "<< dimensionSize.size());
      boolArray.resize(dimensionSize[0], dimensionSize[1],
                       dimensionSize[2], dimensionSize[3],
                       dimensionSize[4], dimensionSize[5], dimensionSize[6]);
    }
  };

  template <int v>
  struct Int2Type
  {
  enum { value = v };
  };

  template<typename T>
  union TypeToBytes {
    T value;
    unsigned char bytes[sizeof(T)];
  };

  template<typename T>
  struct HashAlgorithm
  {
    /*!
      Adapted version of one-at-a-time hash by Bob Jenkins,
      which is an expanded version of his Dr. Dobbs article.
    */
    static inline size_t jenkins_hash(const T& value)
    {
      TypeToBytes<T> u;
      (u.value) = value;

      size_t hash = 0;
      size_t length = sizeof(value);

      for (size_t i = 0; i < length; ++i)
      {
          hash += u.bytes[i];
          hash += (hash << 10);
          hash ^= (hash >> 6);
      }
      hash += (hash << 3);
      hash ^= (hash >> 11);
      hash += (hash << 15);

      return hash;
    }

    /*!
      Adatped version of (stupid) boost hash (but working)
    */
    static inline size_t boost_hash(const std::vector<T>& vec)
    {
      size_t hash = 0;
      int sizeVec = vec.size();
      for(int i = 0; i < sizeVec; ++i)
      {
        hash ^= i + 0x9e3779b9 + (hash << 6) + (hash >> 2);
      }
      return hash;
    }
  };

  template<typename T, typename Algo = Int2Type<0> >
  struct HashXIOS
  {
    std::size_t operator()(const T& val)
    {
      Algo al;
      return hash_value(val, al);
    }

    std::size_t hashVec(const std::vector<T>& vec)
    {
      return HashAlgorithm<T>::boost_hash(vec);
    }

  private:
    size_t hash_value(const T& val, Int2Type<0>)
    {
      return HashAlgorithm<T>::jenkins_hash(val);
    }
  };

template<typename K>
struct NumTraits {
    typedef K Type;
};

template<>
struct NumTraits<unsigned long>
{
  typedef unsigned long Scalar;
  typedef Scalar magnitudeType;

  static inline Scalar sfmin() {
    return std::numeric_limits<Scalar>::min();
  }
  static inline Scalar sfmax() {
    return std::numeric_limits<Scalar>::max();
  }
  static inline Scalar sflowest() {
    return -(std::numeric_limits<Scalar>::max());
  }
  static inline Scalar epsilon() {
    return std::numeric_limits<Scalar>::epsilon();
  }
  static inline Scalar dummy_precision() {
    return 0;
  }
};

template<>
struct NumTraits<double>
{
  typedef double Scalar;
  typedef Scalar magnitudeType;

  static inline Scalar sfmin() {
    return std::numeric_limits<Scalar>::min();
  }
  static inline Scalar sfmax() {
    return std::numeric_limits<Scalar>::max();
  }
  static inline Scalar sflowest() {
    return -(std::numeric_limits<Scalar>::max());
  }
  static inline Scalar epsilon() {
    return std::numeric_limits<Scalar>::epsilon();
  }
  static inline Scalar dummy_precision() {
    return 1e-12;
  }
  static inline bool isNan(const Scalar& v) {
    return (v != v);
  }
};

template<typename T>
class CArrayStorage
{
public:
  typedef CArray<T,1> StorageType;

public:
  CArrayStorage(const CArray<T,1>& arr) : values(arr) {}

protected:
  const T& atIndex(int idx) const { return values(idx); }
  const StorageType& values;
};

template<typename T>
class CVectorStorage
{
public:
  typedef std::vector<T> StorageType;

public:
  CVectorStorage(const std::vector<T>& vec) : values(vec) {}

protected:
  const T& atIndex(int idx) const { return values[idx]; }
  const StorageType& values;
};


template<
  typename T,
  template <class> class StoragePolicy = CVectorStorage
  >
class XIOSComparatorWithIndex :
  public StoragePolicy<T>
{
public:
  typedef typename  StoragePolicy<T>::StorageType StorageType;

public:
  XIOSComparatorWithIndex(const StorageType& v) : StoragePolicy<T>(v) {}
  bool operator()(int a, int b) { return this->atIndex(a) < this->atIndex(b); }
};

template<
  typename T,
  template <class> class StoragePolicy = CVectorStorage
  >
class XIOSLowerBoundWithIndex :
  public StoragePolicy<T>
{
public:
  typedef typename  StoragePolicy<T>::StorageType StorageType;

public:
  XIOSLowerBoundWithIndex(const StorageType &v) : StoragePolicy<T>(v) {}
  bool operator()(const int a, const T& b) { return this->atIndex(a) < b; }
};

template<
  typename T,
  template <class> class StoragePolicy = CVectorStorage
  >
class XIOSBinarySearchWithIndex :
  public StoragePolicy<T>
{
public:
  typedef typename  StoragePolicy<T>::StorageType StorageType;

public:
  XIOSBinarySearchWithIndex(const StorageType& v) : StoragePolicy<T>(v) {}

  template<typename ForwardIterator>
  bool search(ForwardIterator first, ForwardIterator last, const T& val, ForwardIterator& position)
  {
    first = std::lower_bound(first, last, val, XIOSLowerBoundWithIndex<T, StoragePolicy>(this->values));
    position = first;
    return (first!=last && !(val<this->atIndex(*first)));
  }
};


struct XIOSAlgorithms
{
public:
  template<typename T, template <class> class StoragePolicy>
  static void sortWithIndex(const typename StoragePolicy<T>::StorageType& values, std::vector<int>& rv)
  {
    std::sort(rv.begin(), rv.end(), XIOSComparatorWithIndex<T, StoragePolicy>(values));
  }

  //! Fill in an vector with index begin at 0
  static void fillInIndex(int nbIndex, std::vector<int>& rvIndex)
  {
    if ((0 < nbIndex) && (nbIndex != rvIndex.size())) rvIndex.resize(nbIndex);
    for (int idx = 0; idx < nbIndex; ++idx) rvIndex[idx] = idx;
  }
};

}

#endif // __UTILS_HPP__