// -*- c++ -*- (enables emacs c++ mode)
//===========================================================================
//
// Copyright (C) 2003-2008 Yves Renard
//
// This file is a part of GETFEM++
//
// Getfem++  is  free software;  you  can  redistribute  it  and/or modify it
// under  the  terms  of the  GNU  Lesser General Public License as published
// by  the  Free Software Foundation;  either version 2.1 of the License,  or
// (at your option) any later version.
// This program  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 Lesser General Public
// License for more details.
// You  should  have received a copy of the GNU Lesser General Public License
// along  with  this program;  if not, write to the Free Software Foundation,
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//
// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
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//===========================================================================

/**@file gmm_conjugated.h
   @author  Yves Renard <Yves.Renard@insa-lyon.fr>
   @date September 18, 2003.
   @brief handle conjugation of complex matrices/vectors.
*/
#ifndef GMM_CONJUGATED_H__
#define GMM_CONJUGATED_H__

#include "gmm_def.h"

namespace gmm {
  ///@cond DOXY_SHOW_ALL_FUNCTIONS

  /* ********************************************************************* */
  /*		Conjugated references on vectors            		   */
  /* ********************************************************************* */

  template <typename IT> struct conjugated_const_iterator {
    typedef typename std::iterator_traits<IT>::value_type      value_type;
    typedef typename std::iterator_traits<IT>::pointer         pointer;
    typedef typename std::iterator_traits<IT>::reference       reference;
    typedef typename std::iterator_traits<IT>::difference_type difference_type;
    typedef typename std::iterator_traits<IT>::iterator_category
    iterator_category;

    IT it;
    
    conjugated_const_iterator(void) {}
    conjugated_const_iterator(const IT &i) : it(i) {}
    
    inline size_type index(void) const { return it.index(); }
    conjugated_const_iterator operator ++(int)
    { conjugated_const_iterator tmp = *this; ++it; return tmp; }
    conjugated_const_iterator operator --(int) 
    { conjugated_const_iterator tmp = *this; --it; return tmp; }
    conjugated_const_iterator &operator ++() { ++it; return *this; }
    conjugated_const_iterator &operator --() { --it; return *this; }
    conjugated_const_iterator &operator +=(difference_type i)
      { it += i; return *this; }
    conjugated_const_iterator &operator -=(difference_type i)
      { it -= i; return *this; }
    conjugated_const_iterator operator +(difference_type i) const
      { conjugated_const_iterator itb = *this; return (itb += i); }
    conjugated_const_iterator operator -(difference_type i) const
      { conjugated_const_iterator itb = *this; return (itb -= i); }
    difference_type operator -(const conjugated_const_iterator &i) const
      { return difference_type(it - i.it); }
    
    value_type operator  *() const { return gmm::conj(*it); }
    value_type operator [](size_type ii) const { return gmm::conj(it[ii]); }
    
    bool operator ==(const conjugated_const_iterator &i) const
      { return (i.it == it); }
    bool operator !=(const conjugated_const_iterator &i) const
      { return (i.it != it); }
    bool operator < (const conjugated_const_iterator &i) const
      { return (it < i.it); }
  };

  template <typename V> struct conjugated_vector_const_ref {
    typedef conjugated_vector_const_ref<V> this_type;
    typedef typename linalg_traits<V>::value_type value_type;
    typedef typename linalg_traits<V>::const_iterator iterator;
    typedef typename linalg_traits<this_type>::reference reference;
    typedef typename linalg_traits<this_type>::origin_type origin_type;

    iterator begin_, end_;
    const origin_type *origin;
    size_type size_;

    conjugated_vector_const_ref(const V &v)
      : begin_(vect_const_begin(v)), end_(vect_const_end(v)),
	origin(linalg_origin(v)),
	size_(vect_size(v)) {}

    reference operator[](size_type i) const
    { return gmm::conj(linalg_traits<V>::access(origin, begin_, end_, i)); }
  };

  template <typename V> struct linalg_traits<conjugated_vector_const_ref<V> > {
    typedef conjugated_vector_const_ref<V> this_type;
    typedef typename linalg_traits<V>::origin_type origin_type;
    typedef linalg_const is_reference;
    typedef abstract_vector linalg_type;
    typedef typename linalg_traits<V>::value_type value_type;
    typedef value_type reference;
    typedef abstract_null_type iterator;
    typedef conjugated_const_iterator<typename
                   linalg_traits<V>::const_iterator> const_iterator;
    typedef typename linalg_traits<V>::storage_type storage_type;
    typedef typename linalg_traits<V>::index_sorted index_sorted;
    static size_type size(const this_type &v) { return v.size_; }
    static iterator begin(this_type &v) { return iterator(v.begin_); }
    static const_iterator begin(const this_type &v)
    { return const_iterator(v.begin_); }
    static iterator end(this_type &v)
    { return iterator(v.end_); }
    static const_iterator end(const this_type &v)
    { return const_iterator(v.end_); }
    static value_type access(const origin_type *o, const const_iterator &it,
			     const const_iterator &ite, size_type i)
    { return gmm::conj(linalg_traits<V>::access(o, it.it, ite.it, i)); }
    static const origin_type* origin(const this_type &v) { return v.origin; }
  };

  template<typename V> std::ostream &operator <<
    (std::ostream &o, const conjugated_vector_const_ref<V>& m)
  { gmm::write(o,m); return o; }

  /* ********************************************************************* */
  /*		Conjugated references on matrices            		   */
  /* ********************************************************************* */

  template <typename M> struct conjugated_row_const_iterator {
    typedef conjugated_row_const_iterator<M> iterator;
    typedef typename linalg_traits<M>::const_row_iterator ITER;
    typedef typename linalg_traits<M>::value_type value_type;
    typedef ptrdiff_t difference_type;
    typedef size_t size_type;

    ITER it;

    iterator operator ++(int) { iterator tmp = *this; it++; return tmp; }
    iterator operator --(int) { iterator tmp = *this; it--; return tmp; }
    iterator &operator ++()   { it++; return *this; }
    iterator &operator --()   { it--; return *this; }
    iterator &operator +=(difference_type i) { it += i; return *this; }
    iterator &operator -=(difference_type i) { it -= i; return *this; }
    iterator operator +(difference_type i) const 
    { iterator itt = *this; return (itt += i); }
    iterator operator -(difference_type i) const
    { iterator itt = *this; return (itt -= i); }
    difference_type operator -(const iterator &i) const
    { return it - i.it; }

    ITER operator *() const { return it; }
    ITER operator [](int i) { return it + i; }

    bool operator ==(const iterator &i) const { return (it == i.it); }
    bool operator !=(const iterator &i) const { return !(i == *this); }
    bool operator < (const iterator &i) const { return (it < i.it); }

    conjugated_row_const_iterator(void) {}
    conjugated_row_const_iterator(const ITER &i) : it(i) { }

  };

  template <typename M> struct  conjugated_row_matrix_const_ref {
    
    typedef conjugated_row_matrix_const_ref<M> this_type;
    typedef typename linalg_traits<M>::const_row_iterator iterator;
    typedef typename linalg_traits<M>::value_type value_type;
    typedef typename linalg_traits<this_type>::origin_type origin_type;

    iterator begin_, end_;
    const origin_type *origin;
    size_type nr, nc;

    conjugated_row_matrix_const_ref(const M &m)
      : begin_(mat_row_begin(m)), end_(mat_row_end(m)),
	origin(linalg_origin(m)), nr(mat_ncols(m)), nc(mat_nrows(m)) {}

    value_type operator()(size_type i, size_type j) const
    { return gmm::conj(linalg_traits<M>::access(begin_+j, i)); }
  };

  template <typename M>
  struct linalg_traits<conjugated_row_matrix_const_ref<M> > {
    typedef conjugated_row_matrix_const_ref<M> this_type;
    typedef typename linalg_traits<M>::origin_type origin_type;
    typedef linalg_const is_reference;
    typedef abstract_matrix linalg_type;
    typedef typename linalg_traits<M>::value_type value_type;
    typedef value_type reference;
    typedef typename linalg_traits<M>::storage_type storage_type;
    typedef typename linalg_traits<M>::const_sub_row_type vector_type;
    typedef conjugated_vector_const_ref<vector_type> sub_col_type;
    typedef conjugated_vector_const_ref<vector_type> const_sub_col_type;
    typedef conjugated_row_const_iterator<M> col_iterator;
    typedef conjugated_row_const_iterator<M> const_col_iterator;
    typedef abstract_null_type const_sub_row_type;
    typedef abstract_null_type sub_row_type;
    typedef abstract_null_type const_row_iterator;
    typedef abstract_null_type row_iterator;
    typedef col_major sub_orientation;
    typedef typename linalg_traits<M>::index_sorted index_sorted;
    static inline size_type ncols(const this_type &m) { return m.nc; }
    static inline size_type nrows(const this_type &m) { return m.nr; }
    static inline const_sub_col_type col(const const_col_iterator &it)
    { return conjugated(linalg_traits<M>::row(it.it)); }
    static inline const_col_iterator col_begin(const this_type &m)
    { return const_col_iterator(m.begin_); }
    static inline const_col_iterator col_end(const this_type &m)
    { return const_col_iterator(m.end_); }
    static inline const origin_type* origin(const this_type &m)
    { return m.origin; }
    static value_type access(const const_col_iterator &it, size_type i)
    { return gmm::conj(linalg_traits<M>::access(it.it, i)); }
  };

  template<typename M> std::ostream &operator <<
  (std::ostream &o, const conjugated_row_matrix_const_ref<M>& m)
  { gmm::write(o,m); return o; }


  template <typename M> struct conjugated_col_const_iterator {
    typedef conjugated_col_const_iterator<M> iterator;
    typedef typename linalg_traits<M>::const_col_iterator ITER;
    typedef typename linalg_traits<M>::value_type value_type;
    typedef ptrdiff_t difference_type;
    typedef size_t size_type;

    ITER it;

    iterator operator ++(int) { iterator tmp = *this; it++; return tmp; }
    iterator operator --(int) { iterator tmp = *this; it--; return tmp; }
    iterator &operator ++()   { it++; return *this; }
    iterator &operator --()   { it--; return *this; }
    iterator &operator +=(difference_type i) { it += i; return *this; }
    iterator &operator -=(difference_type i) { it -= i; return *this; }
    iterator operator +(difference_type i) const 
    { iterator itt = *this; return (itt += i); }
    iterator operator -(difference_type i) const
    { iterator itt = *this; return (itt -= i); }
    difference_type operator -(const iterator &i) const
    { return it - i.it; }

    ITER operator *() const { return it; }
    ITER operator [](int i) { return it + i; }

    bool operator ==(const iterator &i) const { return (it == i.it); }
    bool operator !=(const iterator &i) const { return !(i == *this); }
    bool operator < (const iterator &i) const { return (it < i.it); }

    conjugated_col_const_iterator(void) {}
    conjugated_col_const_iterator(const ITER &i) : it(i) { }

  };

  template <typename M> struct  conjugated_col_matrix_const_ref {
    
    typedef conjugated_col_matrix_const_ref<M> this_type;
    typedef typename linalg_traits<M>::const_col_iterator iterator;
    typedef typename linalg_traits<M>::value_type value_type;
    typedef typename linalg_traits<this_type>::origin_type origin_type;

    iterator begin_, end_;
    const origin_type *origin;
    size_type nr, nc;

    conjugated_col_matrix_const_ref(const M &m)
      : begin_(mat_col_begin(m)), end_(mat_col_end(m)),
	origin(linalg_origin(m)), nr(mat_ncols(m)), nc(mat_nrows(m)) {}

    value_type operator()(size_type i, size_type j) const
    { return gmm::conj(linalg_traits<M>::access(begin_+i, j)); }
  };

  template <typename M>
  struct linalg_traits<conjugated_col_matrix_const_ref<M> > {
    typedef conjugated_col_matrix_const_ref<M> this_type;
    typedef typename linalg_traits<M>::origin_type origin_type;
    typedef linalg_const is_reference;
    typedef abstract_matrix linalg_type;
    typedef typename linalg_traits<M>::value_type value_type;
    typedef value_type reference;
    typedef typename linalg_traits<M>::storage_type storage_type;
    typedef typename linalg_traits<M>::const_sub_col_type vector_type;
    typedef conjugated_vector_const_ref<vector_type> sub_row_type;
    typedef conjugated_vector_const_ref<vector_type> const_sub_row_type;
    typedef conjugated_col_const_iterator<M> row_iterator;
    typedef conjugated_col_const_iterator<M> const_row_iterator;
    typedef abstract_null_type const_sub_col_type;
    typedef abstract_null_type sub_col_type;
    typedef abstract_null_type const_col_iterator;
    typedef abstract_null_type col_iterator;
    typedef row_major sub_orientation;
    typedef typename linalg_traits<M>::index_sorted index_sorted;
    static inline size_type nrows(const this_type &m) { return m.nr; }
    static inline size_type ncols(const this_type &m) { return m.nc; }
    static inline const_sub_row_type row(const const_row_iterator &it)
    { return conjugated(linalg_traits<M>::col(it.it)); }
    static inline const_row_iterator row_begin(const this_type &m)
    { return const_row_iterator(m.begin_); }
    static inline const_row_iterator row_end(const this_type &m)
    { return const_row_iterator(m.end_); }
    static inline const origin_type* origin(const this_type &m)
    { return m.origin; }
    static value_type access(const const_row_iterator &it, size_type i)
    { return gmm::conj(linalg_traits<M>::access(it.it, i)); }
  };

  template<typename M> std::ostream &operator <<
  (std::ostream &o, const conjugated_col_matrix_const_ref<M>& m)
  { gmm::write(o,m); return o; }


  template <typename L, typename SO> struct conjugated_return__ {
    typedef conjugated_row_matrix_const_ref<L> return_type;
  };
  template <typename L> struct conjugated_return__<L, col_major> {
    typedef conjugated_col_matrix_const_ref<L> return_type;
  };
  template <typename L, typename T, typename LT> struct conjugated_return_ {
    typedef const L & return_type;
  };
  template <typename L, typename T>
  struct conjugated_return_<L, std::complex<T>, abstract_vector> {
    typedef conjugated_vector_const_ref<L> return_type;
  };
  template <typename L, typename T>
  struct conjugated_return_<L, T, abstract_matrix> {
    typedef typename conjugated_return__<L,
    typename principal_orientation_type<typename
    linalg_traits<L>::sub_orientation>::potype
    >::return_type return_type;
  };
  template <typename L> struct conjugated_return {
    typedef typename
    conjugated_return_<L, typename linalg_traits<L>::value_type,
		       typename linalg_traits<L>::linalg_type		       
		       >::return_type return_type;
  };

  ///@endcond
  /** return a conjugated view of the input matrix or vector. */
  template <typename L> inline
  typename conjugated_return<L>::return_type
  conjugated(const L &v) {
    return conjugated(v, typename linalg_traits<L>::value_type(),
		      typename linalg_traits<L>::linalg_type());
  }
  ///@cond DOXY_SHOW_ALL_FUNCTIONS

  template <typename L, typename T, typename LT> inline
  const L & conjugated(const L &v, T, LT) { return v; }

  template <typename L, typename T> inline
  conjugated_vector_const_ref<L> conjugated(const L &v, std::complex<T>,
					    abstract_vector)
  { return conjugated_vector_const_ref<L>(v); }

  template <typename L, typename T> inline
  typename conjugated_return__<L,
    typename principal_orientation_type<typename
    linalg_traits<L>::sub_orientation>::potype>::return_type
  conjugated(const L &v, T, abstract_matrix) {
    return conjugated(v, typename principal_orientation_type<typename
		      linalg_traits<L>::sub_orientation>::potype());
  }

  template <typename L> inline
  conjugated_row_matrix_const_ref<L> conjugated(const L &v, row_major)
  { return conjugated_row_matrix_const_ref<L>(v); }

  template <typename L> inline
  conjugated_col_matrix_const_ref<L> conjugated(const L &v, col_major)
  { return conjugated_col_matrix_const_ref<L>(v); }
  
  ///@endcond
  

}

#endif //  GMM_CONJUGATED_H__
