/*******************************************************************************
 *
 * TRIQS: a Toolbox for Research in Interacting Quantum Systems
 *
 * Copyright (C) 2011 by O. Parcollet
 *
 * TRIQS 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 3 of the License, or (at your option) any later
 * version.
 *
 * TRIQS 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
 * TRIQS. If not, see <http://www.gnu.org/licenses/>.
 *
 ******************************************************************************/
#ifndef TRIQS_ARRAY_VECTOR_H
#define TRIQS_ARRAY_VECTOR_H
#include "indexmaps/cuboid/map.hpp"
#include "indexmaps/cuboid/slice.hpp"
#include "impl/indexmap_storage_pair.hpp"
#include "impl/assignment.hpp"
#include "impl/flags.hpp"
#include <algorithm>

namespace triqs { namespace arrays {

 template <typename ValueType, ull_t Opt=0, bool Borrowed =false, bool IsConst=false> class vector_view;
 template <typename ValueType, ull_t Opt=0> class vector;

 // ---------------------- vector_view --------------------------------

#define IMPL_TYPE indexmap_storage_pair< indexmaps::cuboid::map<1,Opt,0> , storages::shared_block<ValueType,Borrowed>, Opt, 0, IsConst, Tag::vector_view >

 /** */
 template <typename ValueType, ull_t Opt, bool Borrowed, bool IsConst>
  class vector_view : Tag::vector_view, TRIQS_CONCEPT_TAG_NAME(MutableVector), public  IMPL_TYPE {
  public :
   typedef vector     <ValueType,Opt>       regular_type;
   typedef vector_view<ValueType,Opt,false> view_type;
   typedef vector_view<ValueType, Opt, false, true> const_view_type;
   typedef vector_view<ValueType,Opt,true>  weak_view_type;

   typedef typename IMPL_TYPE::indexmap_type indexmap_type;
   typedef typename IMPL_TYPE::storage_type storage_type;

   /// Build from an IndexMap and a storage
   template<typename S, ull_t Opt2, ull_t To2> vector_view (indexmaps::cuboid::map<1, Opt2,To2> const & Ind,S const & Mem): IMPL_TYPE(Ind, Mem) {}

   /// Build from anything that has an indexmap and a storage compatible with this class
   template<typename ISP>
    vector_view(const ISP & X): IMPL_TYPE(X.indexmap(),X.storage()) {}

#ifdef TRIQS_WITH_PYTHON_SUPPORT
   /// Build from a numpy.array : throws if X is not a numpy.array
   explicit vector_view (PyObject * X): IMPL_TYPE(X, false, "vector_view "){}
#endif

   /// Copy construction
   vector_view(vector_view const & X): IMPL_TYPE(X.indexmap(),X.storage()) {}

   vector_view () = delete;

   // Move
    vector_view(vector_view && X) { this->swap_me(X);}

   /// Swap
   friend void swap( vector_view & A, vector_view & B) { A.swap_me(B);}

   /// Rebind the view
   void rebind(vector_view const& X) {
    this->indexmap_ = X.indexmap_;
    this->storage_ = X.storage_;
   }

   // rebind the other view, iif this is const, and the other is not.
   template <bool C = IsConst> ENABLE_IFC(C) rebind(vector_view<ValueType, Opt, Borrowed, !IsConst> const& X) {
    this->indexmap_ = X.indexmap_;
    this->storage_ = X.storage_;
   }

   /** Assignment.  The size of the array MUST match exactly.  */
   template<typename RHS> vector_view & operator=(const RHS & X) { triqs_arrays_assign_delegation(*this,X); return *this; }

   vector_view & operator=(vector_view const & X) {triqs_arrays_assign_delegation(*this,X); return *this; }//cf array_view class comment

   // Move assignment not defined : will use the copy = since view must copy data

   size_t size() const { return this->shape()[0];}

   std::ptrdiff_t stride() const { return this->indexmap().strides()[0];}

   TRIQS_DEFINE_COMPOUND_OPERATORS(vector_view);

   // to make interface similar to std::vector : forward [] to ()
   template<typename Arg> typename std::result_of<const IMPL_TYPE(Arg)>::type operator[](Arg && arg) const { return (*this) (std::forward<Arg>(arg));}
   template<typename Arg> typename std::result_of<IMPL_TYPE(Arg)>::type operator[](Arg && arg)       { return (*this) (std::forward<Arg>(arg));}
   // gcc 4.6 does not like this one...
   //template<typename Arg> auto operator[](Arg && arg) const DECL_AND_RETURN((*this)(std::forward<Arg>(arg)));
   //template<typename Arg> auto operator[](Arg && arg)       DECL_AND_RETURN((*this)(std::forward<Arg>(arg)));
  };
#undef IMPL_TYPE

 template < class V, int R,  ull_t OptionFlags, ull_t To, bool Borrowed, bool IsConst> 
  struct ISPViewType< V, R,OptionFlags,To, Tag::vector_view, Borrowed, IsConst> { typedef vector_view<V,OptionFlags,Borrowed,IsConst> type; };

 template <typename ValueType, ull_t Opt = 0, bool Borrowed = false>
 using vector_const_view = vector_view<ValueType, Opt, Borrowed, true>;

 // ---------------------- vector--------------------------------
#define IMPL_TYPE indexmap_storage_pair< indexmaps::cuboid::map<1,Opt,0> , storages::shared_block<ValueType>, Opt, 0, false,Tag::vector_view >

 template <typename ValueType, ull_t Opt>
  class vector: Tag::vector,  TRIQS_CONCEPT_TAG_NAME(MutableVector), public IMPL_TYPE {
   public :
    typedef typename IMPL_TYPE::value_type value_type;
    typedef typename IMPL_TYPE::storage_type storage_type;
    typedef typename IMPL_TYPE::indexmap_type indexmap_type;
    typedef vector<ValueType, Opt> regular_type;
    typedef vector_view<ValueType, Opt> view_type;
    typedef vector_view<ValueType, Opt, false, true> const_view_type;
    typedef vector_view<ValueType, Opt, true> weak_view_type;

    /// Empty vector.
    vector(){}

    // Move
    explicit vector(vector && X) { this->swap_me(X); }

    ///
    vector(size_t dim):IMPL_TYPE(indexmap_type(mini_vector<size_t,1>(dim))) {}

    /// to mimic std vector
    template<typename Arg>
    vector(size_t dim, Arg && arg):IMPL_TYPE(indexmap_type(mini_vector<size_t,1>(dim))) { (*this)() = std::forward<Arg>(arg);}

    /** Makes a true (deep) copy of the data. */
    vector(const vector & X): IMPL_TYPE(X.indexmap(),X.storage().clone()) {}

    /**
     * Build a new vector from X.domain() and fill it with by evaluating X. X can be :
     *  - another type of array, array_view, matrix,.... (any <IndexMap, Storage> pair)
     *  - a expression : e.g. array<int, IndexOrder::C<1> > A( B+ 2*C);
     *  - ml : useless directly, since there only one ml, but used in generic code it maintains the same constructor as array, matrix 
     */
    template <typename T>
     //vector(const T & X, typename boost::enable_if< ImmutableCuboidArray<T> >::type *dummy =0):
     vector(const T & X, TYPE_ENABLE_IF(memory_layout<1>, ImmutableCuboidArray<T>) ml = memory_layout<1>(IMPL_TYPE::indexmap_type::traversal_order)):
      IMPL_TYPE(indexmap_type(X.domain(),ml)) { triqs_arrays_assign_delegation(*this,X); }

#ifdef TRIQS_WITH_PYTHON_SUPPORT
    ///Build from a numpy.array X (or any object from which numpy can make a numpy.array). Makes a copy.
    explicit vector (PyObject * X): IMPL_TYPE(X, true, "vector "){}
#endif

    // build from a init_list
    template<typename T> 
     vector(std::initializer_list<T> const & l): 
      IMPL_TYPE(indexmap_type(mini_vector<size_t,1>(l.size()),memory_layout<1>(IMPL_TYPE::indexmap_type::traversal_order))) {
       size_t i=0;
       for (auto const & x : l) (*this)(i++) = x;
      }

    /**
     * Resizes the vector. NB : all references to the storage is invalidated.
     * Does not initialize the vector by default: to resize and init, do resize(IND).init()
     */
    vector & resize (size_t L) { IMPL_TYPE::resize(typename IMPL_TYPE::domain_type(mini_vector<size_t,1>(L))); return *this; }

    /**
     * Resizes the vector. NB : all references to the storage is invalidated.
     * Does not initialize the vector by default: to resize and init, do resize(IND).init()
     */
    vector & resize (const indexmaps::cuboid::domain_t<IMPL_TYPE::rank> & l) { IMPL_TYPE::resize(l); return *this; }

    /// Assignement resizes the vector.  All references to the storage are therefore invalidated.
    vector & operator=(const vector & X) { IMPL_TYPE::resize_and_clone_data(X); return *this; }

    /**
     * Assignement resizes the vector.  All references to the storage are therefore invalidated.
     * NB : to avoid that, do make_view(A) = X instead of A = X
     */
    template<typename RHS>
     vector & operator=(const RHS & X) {
      static_assert(  ImmutableCuboidArray<RHS>::value, "Assignment : RHS not supported");
      IMPL_TYPE::resize(X.domain());
      triqs_arrays_assign_delegation(*this,X);
      return *this;
     }

    /// Move assignment
    vector & operator=(vector && X) { this->swap_me(X); return *this;}

    /// Swap
    friend void swap( vector & A, vector & B) { A.swap_me(B);}

    ///
    size_t size() const { return this->shape()[0];}

    ///
    std::ptrdiff_t stride() const { return this->indexmap().strides()[0];}

    TRIQS_DEFINE_COMPOUND_OPERATORS(vector);

    // to make interface similar to std::vector : forward [] to ()
   template<typename Arg> typename std::result_of<const IMPL_TYPE(Arg)>::type operator[](Arg && arg) const { return (*this) (std::forward<Arg>(arg));}
   template<typename Arg> typename std::result_of<IMPL_TYPE(Arg)>::type operator[](Arg && arg)       { return (*this) (std::forward<Arg>(arg));}
   //template<typename Arg> auto operator[](Arg && arg) const DECL_AND_RETURN((*this)(std::forward<Arg>(arg)));
   //template<typename Arg> auto operator[](Arg && arg)       DECL_AND_RETURN((*this)(std::forward<Arg>(arg)));

  };//vector class
}}//namespace triqs::arrays

#undef IMPL_TYPE

#include "./blas_lapack/scal.hpp"
#include "./blas_lapack/copy.hpp"
#include "./blas_lapack/swap.hpp"
#include "./blas_lapack/axpy.hpp"
namespace triqs { namespace arrays {

 // norm2 squared
 template <typename V> typename std::enable_if<ImmutableVector<V>::value, typename V::value_type>::type norm2_sqr(V const& a) {
  int dim = a.size();
  auto r = typename V::value_type{};
  for (int i = 0; i < dim; ++i) r += a(i) * a(i);
  return r;
 }
 
 // norm2
 template <typename V> typename std::enable_if<ImmutableVector<V>::value, typename V::value_type>::type norm2(V const& a) {
  using std::sqrt;
  return sqrt(norm2(a));
 }

 // lexicographical comparison operators
 template<typename V1, typename V2>
  typename std::enable_if< ImmutableVector<V1>::value &&  ImmutableVector<V2>::value , bool>::type
  operator < (V1 const & a, V2 const & b) { return std::lexicographical_compare(a.begin(), a.end(), b.begin(), b.end());}

 template<typename V1, typename V2>
  typename std::enable_if< ImmutableVector<V1>::value &&  ImmutableVector<V2>::value , bool>::type
  operator > (V1 const & a, V2 const & b) { return (b<a); }

 template<typename RHS, typename T, ull_t Opt>
  typename boost::enable_if< is_vector_or_view <RHS > >::type
  triqs_arrays_assign_delegation (vector<T,Opt> & lhs, RHS const & rhs) { blas::copy(rhs,lhs); }

 template<typename RHS, typename T, ull_t Opt>
  typename boost::enable_if< is_vector_or_view <RHS > >::type
  triqs_arrays_compound_assign_delegation (vector<T,Opt> & lhs, RHS const & rhs, mpl::char_<'A'>) {
   T a =  1.0; blas::axpy(a,rhs,lhs);
  }

 template<typename RHS, typename T, ull_t Opt>
  typename boost::enable_if< is_vector_or_view <RHS > >::type
  triqs_arrays_compound_assign_delegation (vector<T,Opt> & lhs, RHS const & rhs, mpl::char_<'S'>) {
   T a = -1.0; blas::axpy(a,rhs,lhs);
  }

 template<typename RHS, typename T, ull_t Opt>
  typename boost::enable_if< is_scalar_for<RHS,vector<T,Opt> > >::type
  triqs_arrays_compound_assign_delegation (vector<T,Opt> & lhs, RHS const & rhs, mpl::char_<'M'>) {
   T a = rhs; blas::scal(a,lhs);
  }

 template<typename RHS, typename T, ull_t Opt>
  typename boost::enable_if< is_scalar_for<RHS,vector<T,Opt> > >::type
  triqs_arrays_compound_assign_delegation (vector<T,Opt> & lhs, RHS const & rhs, mpl::char_<'D'>) {
   T a = 1/rhs; blas::scal(a,lhs);
  }

 template<typename RHS, typename T, ull_t Opt>
  typename boost::enable_if< is_vector_or_view <RHS > >::type
  triqs_arrays_assign_delegation (vector_view<T,Opt> & lhs, RHS const & rhs) { blas::copy(rhs,lhs); }

 template<typename RHS, typename T, ull_t Opt>
  typename boost::enable_if< is_vector_or_view <RHS > >::type
  triqs_arrays_compound_assign_delegation (vector_view<T,Opt> & lhs, RHS const & rhs, mpl::char_<'A'>) {
   T a =  1.0; blas::axpy(a,rhs,lhs);
  }

 template<typename RHS, typename T, ull_t Opt>
  typename boost::enable_if< is_vector_or_view <RHS > >::type
  triqs_arrays_compound_assign_delegation (vector_view<T,Opt> & lhs, RHS const & rhs, mpl::char_<'S'>) {
   T a = -1.0; blas::axpy(a,rhs,lhs);
  }

 template<typename RHS, typename T, ull_t Opt>
  typename boost::enable_if< is_scalar_for<RHS,vector_view<T,Opt> > >::type
  triqs_arrays_compound_assign_delegation (vector_view<T,Opt> & lhs, RHS const & rhs, mpl::char_<'M'>) {
   T a = rhs; blas::scal(a,lhs);
  }

 template<typename RHS, typename T, ull_t Opt>
  typename boost::enable_if< is_scalar_for<RHS,vector_view<T,Opt> > >::type
  triqs_arrays_compound_assign_delegation (vector_view<T,Opt> & lhs, RHS const & rhs, mpl::char_<'D'>) {
   T a = 1/rhs; blas::scal(a,lhs);
  }

 template<typename T, ull_t Opt, bool Borrowed>
  void triqs_arrays_assign_delegation(vector_view<T,Opt,Borrowed> & av, std::vector<T> const& vec) {
   std::size_t size = vec.size();
   for(std::size_t n = 0; n < size; ++n) av(n) = vec[n];
  }

 // swapping 2 vector
 template <typename V, ull_t S1, ull_t S2, bool B1, bool B2>
  void deep_swap(vector_view <V,S1,B1> x, vector_view<V,S2,B2> y) {
   blas::swap(x,y);
  }

 template <typename V, ull_t S1, ull_t S2>
  void deep_swap(vector <V,S1> & x, vector<V,S2>  & y) { blas::swap(x,y);}

}}

// The std::swap is WRONG for a view because of the copy/move semantics of view.
// Use swap instead (the correct one, found by ADL).
namespace std {
template <typename V, triqs::ull_t S, bool B1, bool B2, bool C1, bool C2>
void swap(triqs::arrays::vector_view<V, S, B1, C1>& a, triqs::arrays::vector_view<V, S, B2,C2>& b) = delete;
}

#include "./expression_template/vector_algebra.hpp"

#endif