/* Copyright 2015-2017 Philippe Tillet
* 
* Permission is hereby granted, free of charge, to any person obtaining 
* a copy of this software and associated documentation files 
* (the "Software"), to deal in the Software without restriction, 
* including without limitation the rights to use, copy, modify, merge, 
* publish, distribute, sublicense, and/or sell copies of the Software, 
* and to permit persons to whom the Software is furnished to do so, 
* subject to the following conditions:
* 
* The above copyright notice and this permission notice shall be 
* included in all copies or substantial portions of the Software.
* 
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#include <iostream>
#include <cstring>
#include <algorithm>
#include "isaac/jit/syntax/engine/process.h"
#include "isaac/jit/generation/elementwise_1d.h"
#include "isaac/driver/backend.h"
#include "tools/loop.hpp"
#include "tools/vector_types.hpp"
#include "tools/arguments.hpp"

#include <string>

namespace isaac
{
namespace templates
{

expression_type elementwise_1d::type() const
{ return ELEMENTWISE_1D; }

std::string elementwise_1d::generate_impl(std::string const & suffix, expression_tree const & tree, driver::Device const & device, symbolic::symbols_table const & symbols) const
{
  driver::backend_type backend = device.backend();
  kernel_generation_stream stream(backend);

  std::vector<std::size_t> assignments = symbolic::assignments(tree);
  std::vector<std::size_t> assignments_lhs = symbolic::lhs_of(tree, assignments);
  std::vector<std::size_t> assignments_rhs = symbolic::rhs_of(tree, assignments);

  switch(backend)
  {
    case driver::CUDA:
      stream << "#include  \"vector.h\"" << std::endl; break;
    case driver::OPENCL:
      stream << " __attribute__((reqd_work_group_size(" << ls0_ << "," << ls1_ << ",1)))" << std::endl; break;
  }

  stream << "$KERNEL void elementwise_1d" << suffix << "($SIZE_T N, " << tools::join(kernel_arguments(device, symbols, tree), ", ") << ")";

  stream << "{" << std::endl;
  stream.inc_tab();

  //Open user-provided for-loops
  std::vector<symbolic::sfor*> sfors = symbolic::extract<symbolic::sfor>(tree, symbols);
  for(symbolic::sfor* sym: sfors)
    stream << sym->process("for(int #init ; #end ; #inc)") << std::endl;
  if(sfors.size())
  {
    stream << "{" << std::endl;
    stream.inc_tab();
  }

  element_wise_loop_1D(stream, vwidth_, "i", "N", "$GLOBAL_IDX_0", "$GLOBAL_SIZE_0", [&](unsigned int vwidth)
  {
    std::string dtype = append_width("#scalartype",vwidth);

    //Declares register to store results
    for(symbolic::leaf* sym: symbolic::extract<symbolic::leaf>(tree, symbols, assignments_lhs, false))
      stream << sym->process(dtype + " #name;") << std::endl;

    //Load to registers
    for(symbolic::leaf* sym: symbolic::extract<symbolic::leaf>(tree, symbols, assignments_rhs, false))
      stream << sym->process(dtype + " #name = " + append_width("loadv", vwidth) + "(i);") << std::endl;

    //Compute
    for(size_t idx: assignments)
      for(unsigned int s = 0 ; s < vwidth ; ++s)
         stream << symbols.at(idx)->evaluate({{"leaf", access_vector_type("#name", s, vwidth)}}) << ";" << std::endl;

    //Writes back
    for(symbolic::leaf* sym: symbolic::extract<symbolic::leaf>(tree, symbols, assignments_lhs, false))
      for(unsigned int s = 0 ; s < vwidth ; ++s)
          stream << sym->process("at(i+" + tools::to_string(s)+") = " + access_vector_type("#name", s, vwidth) + ";") << std::endl;
  });
  //Close user-provided for-loops
  if(sfors.size()){
    stream.dec_tab();
    stream << "}" << std::endl;
  }

  stream.dec_tab();
  stream << "}" << std::endl;

//  std::cout << stream.str() << std::endl;
  return stream.str();
}

elementwise_1d::elementwise_1d(unsigned int vwidth, unsigned int ls, unsigned int ng):
    parameterized_base(vwidth,ls,1), ng_(ng)
{}


std::vector<int_t> elementwise_1d::input_sizes(expression_tree const & expressions) const
{
  return {max(expressions.shape())};
}

void elementwise_1d::enqueue(driver::CommandQueue &, driver::Program const & program, std::string const & suffix, runtime::execution_handler const & control)
{
  expression_tree const & expressions = control.x();
  //Size
  int_t size = input_sizes(expressions)[0];
  //Kernel
  std::string name = "elementwise_1d";
  name += suffix;
//  std::cout << name << std::endl;
  driver::Kernel kernel(program, name.c_str());
  //NDRange
  driver::NDRange global(ls0_*ng_);
  driver::NDRange local(ls0_);
  //Arguments
  unsigned int current_arg = 0;
  kernel.setSizeArg(current_arg++, size);
  symbolic::set_arguments(expressions, kernel, current_arg);
  control.execution_options().enqueue(program.context(), kernel, global, local);
}


}
}