/***************************************************************************
                          Array_impl.h  -  description
                             -------------------
    begin                : Nov 8, 2012
    copyright            : (C) 2012 by Tomas Oberhuber
    email                : tomas.oberhuber@fjfi.cvut.cz
 ***************************************************************************/

/* See Copyright Notice in tnl/Copyright */

#pragma once

#include <iostream>
#include <stdexcept>

#include <TNL/Assert.h>
#include <TNL/Math.h>
#include <TNL/TypeInfo.h>
#include <TNL/Containers/detail/ArrayIO.h>
#include <TNL/Containers/detail/ArrayAssignment.h>

#include "Array.h"

namespace TNL {
namespace Containers {

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >::
Array( Array&& array )
: data( std::move(array.data) ),
  size( std::move(array.size) ),
  allocator( std::move(array.allocator) )
{
   array.data = nullptr;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >::
Array( const Allocator& allocator )
: allocator( allocator )
{
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >::
Array( const IndexType& size, const AllocatorType& allocator )
: allocator( allocator )
{
   this->setSize( size );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >::
Array( const IndexType& size, const Value& value, const AllocatorType& allocator )
: allocator( allocator )
{
   this->setSize( size );
   *this = value;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >::
Array( Value* data,
       const IndexType& size,
       const AllocatorType& allocator )
: allocator( allocator )
{
   this->setSize( size );
   Algorithms::MemoryOperations< Device >::copy( this->getData(), data, size );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >::
Array( const Array< Value, Device, Index, Allocator >& array )
{
   this->setSize( array.getSize() );
   Algorithms::MemoryOperations< Device >::copy( this->getData(), array.getData(), array.getSize() );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >::
Array( const Array< Value, Device, Index, Allocator >& array,
       const AllocatorType& allocator )
: allocator( allocator )
{
   this->setSize( array.getSize() );
   Algorithms::MemoryOperations< Device >::copy( this->getData(), array.getData(), array.getSize() );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >::
Array( const Array< Value, Device, Index, Allocator >& array,
       IndexType begin,
       IndexType size,
       const AllocatorType& allocator )
: allocator( allocator )
{
   if( size == 0 )
      size = array.getSize() - begin;
   TNL_ASSERT_LT( begin, array.getSize(), "Begin of array is out of bounds." );
   TNL_ASSERT_LE( begin + size, array.getSize(), "End of array is out of bounds." );

   this->setSize( size );
   Algorithms::MemoryOperations< Device >::copy( this->getData(), &array.getData()[ begin ], size );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
      template< typename Value_,
                typename Device_,
                typename Index_,
                typename Allocator_ >
Array< Value, Device, Index, Allocator >::
Array( const Array< Value_, Device_, Index_, Allocator_ >& a )
{
   *this = a;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename InValue >
Array< Value, Device, Index, Allocator >::
Array( const std::initializer_list< InValue >& list,
       const AllocatorType& allocator )
: allocator( allocator )
{
   this->setSize( list.size() );
   // Here we assume that the underlying array for std::initializer_list is
   // const T[N] as noted here:
   // https://en.cppreference.com/w/cpp/utility/initializer_list
   Algorithms::MultiDeviceMemoryOperations< Device, Devices::Host >::copy( this->getData(), &( *list.begin() ), list.size() );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename InValue >
Array< Value, Device, Index, Allocator >::
Array( const std::list< InValue >& list,
       const AllocatorType& allocator )
: allocator( allocator )
{
   this->setSize( list.size() );
   Algorithms::MemoryOperations< Device >::copyFromIterator( this->getData(), this->getSize(), list.cbegin(), list.cend() );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename InValue >
Array< Value, Device, Index, Allocator >::
Array( const std::vector< InValue >& vector,
       const AllocatorType& allocator )
: allocator( allocator )
{
   this->setSize( vector.size() );
   Algorithms::MultiDeviceMemoryOperations< Device, Devices::Host >::copy( this->getData(), vector.data(), vector.size() );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Allocator
Array< Value, Device, Index, Allocator >::
getAllocator() const
{
   return allocator;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
String
Array< Value, Device, Index, Allocator >::
getSerializationType()
{
   return detail::ArrayIO< Value, Device, Index >::getSerializationType();
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
String
Array< Value, Device, Index, Allocator >::
getSerializationTypeVirtual() const
{
   return this->getSerializationType();
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
void
Array< Value, Device, Index, Allocator >::
releaseData()
{
   if( this->data ) {
      if( ! std::is_fundamental< ValueType >::value )
         // call the destructor of each element
         Algorithms::MemoryOperations< Device >::destruct( this->data, this->size );
      allocator.deallocate( this->data, this->size );
   }
   this->data = nullptr;
   this->size = 0;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
void
Array< Value, Device, Index, Allocator >::
reallocate( Index size )
{
   TNL_ASSERT_GE( size, (Index) 0, "Array size must be non-negative." );

   if( this->size == size )
      return;

   // Allocating zero bytes is useless. Moreover, the allocators don't behave the same way:
   // "operator new" returns some non-zero address, the latter returns a null pointer.
   if( size == 0 ) {
      this->releaseData();
      return;
   }

   // handle initial allocations
   if( this->size == 0 ) {
      this->data = allocator.allocate( size );
      if( ! std::is_fundamental< ValueType >::value )
         // call the constructor of each element
         Algorithms::MemoryOperations< Device >::construct( this->data, size );

      this->size = size;
      TNL_ASSERT_TRUE( this->data,
                       "This should never happen - allocator did not throw on an error." );
      return;
   }

   // allocate an array with the correct size
   Array aux( size );

   // copy the old elements into aux
   Algorithms::MemoryOperations< Device >::
         copy( aux.getData(), this->getData(), TNL::min( this->size, size ) );

   // swap *this with aux, old data will be released
   this->swap( aux );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
void
Array< Value, Device, Index, Allocator >::
resize( Index size )
{
   // remember the old size and reallocate the array
   const Index old_size = this->size;
   reallocate( size );

   if( old_size < size )
      if( ! std::is_fundamental< ValueType >::value )
         // initialize the appended elements
         Algorithms::MemoryOperations< Device >::construct( this->data + old_size, size - old_size );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
void
Array< Value, Device, Index, Allocator >::
resize( Index size, const ValueType& value )
{
   // remember the old size and reallocate the array
   const Index old_size = this->size;
   reallocate( size );

   if( old_size < size )
      // copy value into the appended elements
      Algorithms::MemoryOperations< Device >::construct( this->data + old_size, size - old_size, value );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
void
Array< Value, Device, Index, Allocator >::
setSize( Index size )
{
   TNL_ASSERT_GE( size, (Index) 0, "Array size must be non-negative." );

   if( this->size == size )
      return;

   // release data to avoid copying the elements to the new memory location
   this->releaseData();
   // resize from size 0 does not copy anything, initialization is done as intended
   this->resize( size );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
__cuda_callable__
Index
Array< Value, Device, Index, Allocator >::
getSize() const
{
   return this->size;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename ArrayT >
void
Array< Value, Device, Index, Allocator >::
setLike( const ArrayT& array )
{
   setSize( array.getSize() );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
typename Array< Value, Device, Index, Allocator >::ViewType
Array< Value, Device, Index, Allocator >::
getView( IndexType begin, IndexType end )
{
   if( end == 0 )
      end = getSize();
   return ViewType( getData() + begin, end - begin );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
typename Array< Value, Device, Index, Allocator >::ConstViewType
Array< Value, Device, Index, Allocator >::
getConstView( IndexType begin, IndexType end ) const
{
   if( end == 0 )
      end = getSize();
   return ConstViewType( getData() + begin, end - begin );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >::
operator ViewType()
{
   return getView();
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >::
operator ConstViewType() const
{
   return getConstView();
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
void
Array< Value, Device, Index, Allocator >::
swap( Array< Value, Device, Index, Allocator >& array )
{
   TNL::swap( this->size, array.size );
   TNL::swap( this->data, array.data );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
void
Array< Value, Device, Index, Allocator >::
reset()
{
   this->releaseData();
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
bool
__cuda_callable__
Array< Value, Device, Index, Allocator >::
empty() const
{
   return data == nullptr;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
__cuda_callable__
const Value*
Array< Value, Device, Index, Allocator >::
getData() const
{
   return this->data;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
__cuda_callable__
Value*
Array< Value, Device, Index, Allocator >::
getData()
{
   return this->data;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
__cuda_callable__
const Value*
Array< Value, Device, Index, Allocator >::
getArrayData() const
{
   return this->data;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
__cuda_callable__
Value*
Array< Value, Device, Index, Allocator >::
getArrayData()
{
   return this->data;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
__cuda_callable__ void
Array< Value, Device, Index, Allocator >::
setElement( const Index& i, const Value& x )
{
   TNL_ASSERT_GE( i, (Index) 0, "Element index must be non-negative." );
   TNL_ASSERT_LT( i, this->getSize(), "Element index is out of bounds." );
   Algorithms::MemoryOperations< Device >::setElement( &( this->data[ i ] ), x );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
__cuda_callable__ Value
Array< Value, Device, Index, Allocator >::
getElement( const Index& i ) const
{
   TNL_ASSERT_GE( i, (Index) 0, "Element index must be non-negative." );
   TNL_ASSERT_LT( i, this->getSize(), "Element index is out of bounds." );
   return Algorithms::MemoryOperations< Device >::getElement( & ( this->data[ i ] ) );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
__cuda_callable__
Value&
Array< Value, Device, Index, Allocator >::
operator[]( const Index& i )
{
#ifdef __CUDA_ARCH__
   TNL_ASSERT_TRUE( (std::is_same< Device, Devices::Cuda >{}()), "Attempt to access data not allocated on CUDA device from CUDA device." );
#else
   TNL_ASSERT_FALSE( (std::is_same< Device, Devices::Cuda >{}()), "Attempt to access data not allocated on the host from the host." );
#endif
   TNL_ASSERT_GE( i, (Index) 0, "Element index must be non-negative." );
   TNL_ASSERT_LT( i, this->getSize(), "Element index is out of bounds." );
   return this->data[ i ];
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
__cuda_callable__
const Value&
Array< Value, Device, Index, Allocator >::
operator[]( const Index& i ) const
{
#ifdef __CUDA_ARCH__
   TNL_ASSERT_TRUE( (std::is_same< Device, Devices::Cuda >{}()), "Attempt to access data not allocated on CUDA device from CUDA device." );
#else
   TNL_ASSERT_FALSE( (std::is_same< Device, Devices::Cuda >{}()), "Attempt to access data not allocated on the host from the host." );
#endif
   TNL_ASSERT_GE( i, (Index) 0, "Element index must be non-negative." );
   TNL_ASSERT_LT( i, this->getSize(), "Element index is out of bounds." );
   return this->data[ i ];
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >&
Array< Value, Device, Index, Allocator >::
operator=( const Array< Value, Device, Index, Allocator >& array )
{
   //TNL_ASSERT_EQ( array.getSize(), this->getSize(), "Array sizes must be the same." );
   if( this->getSize() != array.getSize() )
      this->setLike( array );
   if( this->getSize() > 0 )
      Algorithms::MemoryOperations< Device >::
         copy( this->getData(),
                     array.getData(),
                     array.getSize() );
   return *this;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >&
Array< Value, Device, Index, Allocator >::
operator=( Array< Value, Device, Index, Allocator >&& array )
{
   reset();

   this->size = array.size;
   this->data = array.data;
   array.size = 0;
   array.data = nullptr;
   return *this;
}


template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename T, typename..., typename >
Array< Value, Device, Index, Allocator >&
Array< Value, Device, Index, Allocator >::
operator=( const T& data )
{
   detail::ArrayAssignment< Array, T >::resize( *this, data );
   detail::ArrayAssignment< Array, T >::assign( *this, data );
   return *this;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename InValue >
Array< Value, Device, Index, Allocator >&
Array< Value, Device, Index, Allocator >::
operator=( const std::list< InValue >& list )
{
   this->setSize( list.size() );
   Algorithms::MemoryOperations< Device >::copyFromIterator( this->getData(), this->getSize(), list.cbegin(), list.cend() );
   return *this;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename InValue >
Array< Value, Device, Index, Allocator >&
Array< Value, Device, Index, Allocator >::
operator=( const std::vector< InValue >& vector )
{
   if( (std::size_t) this->getSize() != vector.size() )
      this->setSize( vector.size() );
   Algorithms::MultiDeviceMemoryOperations< Device, Devices::Host >::copy( this->getData(), vector.data(), vector.size() );
   return *this;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename ArrayT >
bool
Array< Value, Device, Index, Allocator >::
operator==( const ArrayT& array ) const
{
   if( array.getSize() != this->getSize() )
      return false;
   if( this->getSize() == 0 )
      return true;
   return Algorithms::MultiDeviceMemoryOperations< Device, typename ArrayT::DeviceType >::
            compare( this->getData(),
                           array.getData(),
                           array.getSize() );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename ArrayT >
bool
Array< Value, Device, Index, Allocator >::
operator!=( const ArrayT& array ) const
{
   return ! ( *this == array );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
void
Array< Value, Device, Index, Allocator >::
setValue( const ValueType& v,
          IndexType begin,
          IndexType end )
{
   TNL_ASSERT_TRUE( this->getData(), "Attempted to set a value of an empty array." );
   if( end == 0 )
      end = this->getSize();
   Algorithms::MemoryOperations< Device >::set( &this->getData()[ begin ], v, end - begin );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename Function >
void
Array< Value, Device, Index, Allocator >::
forElements( IndexType begin,
             IndexType end,
             Function&& f )
{
   this->getView().forElements( begin, end, f );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename Function >
void
Array< Value, Device, Index, Allocator >::
forElements( IndexType begin,
             IndexType end,
             Function&& f ) const
{
   this->getConstView().forElements( begin, end, f );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename Function >
void
Array< Value, Device, Index, Allocator >::
forAllElements( Function&& f )
{
   this->getView().forAllElements( f );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename Function >
void
Array< Value, Device, Index, Allocator >::
forAllElements( Function&& f ) const
{
   const auto view = this->getConstView();
   view.forAllElements( f );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename Fetch,
         typename Reduce,
         typename Result >
Result
Array< Value, Device, Index, Allocator >::
reduceElements( const Index begin, Index end, Fetch&& fetch, Reduce&& reduce, const Result& zero )
{
   return this->getView().reduceElements( begin, end, fetch, reduce, zero );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename Fetch,
         typename Reduce,
         typename Result >
Result
Array< Value, Device, Index, Allocator >::
reduceElements( const Index begin, Index end, Fetch&& fetch, Reduce&& reduce, const Result& zero ) const
{
   return this->getConstView().reduceElements( begin, end, fetch, reduce, zero );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename Fetch,
             typename Reduce,
             typename Result >
Result
Array< Value, Device, Index, Allocator >::
reduceEachElement( Fetch&& fetch, Reduce&& reduce, const Result& zero )
{
   return this->getView().reduceEachElement( fetch, reduce, zero );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
   template< typename Fetch,
         typename Reduce,
         typename Result >
Result
Array< Value, Device, Index, Allocator >::
reduceEachElement( Fetch&& fetch, Reduce&& reduce, const Result& zero ) const
{
   return this->getConstView().reduceEachElement( fetch, reduce, zero );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
bool
Array< Value, Device, Index, Allocator >::
containsValue( const ValueType& v,
               IndexType begin,
               IndexType end ) const
{
   TNL_ASSERT_TRUE( this->getData(), "Attempted to check a value of an empty array." );
   if( end == 0 )
      end = this->getSize();

   return Algorithms::MemoryOperations< Device >::containsValue( &this->getData()[ begin ], end - begin, v );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
bool
Array< Value, Device, Index, Allocator >::
containsOnlyValue( const ValueType& v,
                   IndexType begin,
                   IndexType end ) const
{
   TNL_ASSERT_TRUE( this->getData(), "Attempted to check a value of an empty array." );
   if( end == 0 )
      end = this->getSize();

   return Algorithms::MemoryOperations< Device >::containsOnlyValue( &this->getData()[ begin ], end - begin, v );
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
void
Array< Value, Device, Index, Allocator >::
save( const String& fileName ) const
{
   File( fileName, std::ios_base::out ) << *this;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
void
Array< Value, Device, Index, Allocator >::
load( const String& fileName )
{
   File( fileName, std::ios_base::in ) >> *this;
}

template< typename Value,
          typename Device,
          typename Index,
          typename Allocator >
Array< Value, Device, Index, Allocator >::
~Array()
{
   this->releaseData();
}

template< typename Value, typename Device, typename Index, typename Allocator >
std::ostream& operator<<( std::ostream& str, const Array< Value, Device, Index, Allocator >& array )
{
   str << "[ ";
   if( array.getSize() > 0 )
   {
      str << array.getElement( 0 );
      for( Index i = 1; i < array.getSize(); i++ )
         str << ", " << array.getElement( i );
   }
   str << " ]";
   return str;
}

// Serialization of arrays into binary files.
template< typename Value, typename Device, typename Index, typename Allocator >
File& operator<<( File& file, const Array< Value, Device, Index, Allocator >& array )
{
   using IO = detail::ArrayIO< Value, Index, Allocator >;
   saveObjectType( file, IO::getSerializationType() );
   const Index size = array.getSize();
   file.save( &size );
   IO::save( file, array.getData(), array.getSize() );
   return file;
}

template< typename Value, typename Device, typename Index, typename Allocator >
File& operator<<( File&& file, const Array< Value, Device, Index, Allocator >& array )
{
   File& f = file;
   return f << array;
}

// Deserialization of arrays from binary files.
template< typename Value, typename Device, typename Index, typename Allocator >
File& operator>>( File& file, Array< Value, Device, Index, Allocator >& array )
{
   using IO = detail::ArrayIO< Value, Index, Allocator >;
   const String type = getObjectType( file );
   if( type != IO::getSerializationType() )
      throw Exceptions::FileDeserializationError( file.getFileName(), "object type does not match (expected " + IO::getSerializationType() + ", found " + type + ")." );
   Index _size;
   file.load( &_size );
   if( _size < 0 )
      throw Exceptions::FileDeserializationError( file.getFileName(), "invalid array size: " + std::to_string(_size) );
   array.setSize( _size );
   IO::load( file, array.getData(), array.getSize() );
   return file;
}

template< typename Value, typename Device, typename Index, typename Allocator >
File& operator>>( File&& file, Array< Value, Device, Index, Allocator >& array )
{
   File& f = file;
   return f >> array;
}

} // namespace Containers
} // namespace TNL
