// =================================================================================================
// This file is part of the CLBlast project. The project is licensed under Apache Version 2.0. This
// project loosely follows the Google C++ styleguide and uses a tab-size of two spaces and a max-
// width of 100 characters per line.
//
// Author(s):
//   Cedric Nugteren <www.cedricnugteren.nl>
//
// This file implements the Xsymm class (see the header for information about the class).
//
// =================================================================================================

#include "routines/level3/xsymm.hpp"

#include <string>
#include <vector>

namespace clblast {
// =================================================================================================

// Constructor: forwards to base class constructor
template <typename T>
Xsymm<T>::Xsymm(Queue &queue, EventPointer event, const std::string &name):
    Xgemm<T>(queue, event, name) {
}

// =================================================================================================

// The main routine
template <typename T>
StatusCode Xsymm<T>::DoSymm(const Layout layout, const Side side, const Triangle triangle,
                            const size_t m, const size_t n,
                            const T alpha,
                            const Buffer<T> &a_buffer, const size_t a_offset, const size_t a_ld,
                            const Buffer<T> &b_buffer, const size_t b_offset, const size_t b_ld,
                            const T beta,
                            const Buffer<T> &c_buffer, const size_t c_offset, const size_t c_ld) {

  // Makes sure all dimensions are larger than zero
  if ((m == 0) || (n == 0) ) { return StatusCode::kInvalidDimension; }

  // Computes the k dimension. This is based on whether or not the symmetric matrix is A (on the
  // left) or B (on the right) in the Xgemm routine.
  auto k = (side == Side::kLeft) ? m : n;

  // Checks for validity of the squared A matrix
  auto status = TestMatrixA(k, k, a_buffer, a_offset, a_ld);
  if (ErrorIn(status)) { return status; }

  // Determines which kernel to run based on the layout (the Xgemm kernel assumes column-major as
  // default) and on whether we are dealing with an upper or lower triangle of the symmetric matrix
  bool is_upper = ((triangle == Triangle::kUpper && layout != Layout::kRowMajor) ||
                   (triangle == Triangle::kLower && layout == Layout::kRowMajor));
  auto kernel_name = (is_upper) ? "SymmUpperToSquared" : "SymmLowerToSquared";

  // Temporary buffer for a copy of the symmetric matrix
  try {
    auto temp_symm = Buffer<T>(context_, k*k);

    // Creates a general matrix from the symmetric matrix to be able to run the regular Xgemm
    // routine afterwards
    try {
      const auto program = GetProgramFromCache(context_, PrecisionValue<T>(), routine_name_);
      auto kernel = Kernel(program, kernel_name);

      // Sets the arguments for the symmetric-to-squared kernel
      kernel.SetArgument(0, static_cast<int>(k));
      kernel.SetArgument(1, static_cast<int>(a_ld));
      kernel.SetArgument(2, static_cast<int>(a_offset));
      kernel.SetArgument(3, a_buffer());
      kernel.SetArgument(4, static_cast<int>(k));
      kernel.SetArgument(5, static_cast<int>(k));
      kernel.SetArgument(6, static_cast<int>(0));
      kernel.SetArgument(7, temp_symm());

      // Uses the common padding kernel's thread configuration. This is allowed, since the
      // symmetric-to-squared kernel uses the same parameters.
      auto global = std::vector<size_t>{Ceil(CeilDiv(k, db_["PAD_WPTX"]), db_["PAD_DIMX"]),
                                        Ceil(CeilDiv(k, db_["PAD_WPTY"]), db_["PAD_DIMY"])};
      auto local = std::vector<size_t>{db_["PAD_DIMX"], db_["PAD_DIMY"]};
      auto kernelEvent = Event();
      status = RunKernel(kernel, queue_, device_, global, local, kernelEvent.pointer());
      if (ErrorIn(status)) { return status; }

      // Synchronize now: 'DoGemm' does not accept a list of events to wait for
      kernelEvent.WaitForCompletion();

      // Runs the regular Xgemm code with either "C := AB+C" or ...
      if (side == Side::kLeft) {
        status = DoGemm(layout, Transpose::kNo, Transpose::kNo,
                        m, n, k,
                        alpha,
                        temp_symm, 0, k,
                        b_buffer, b_offset, b_ld,
                        beta,
                        c_buffer, c_offset, c_ld);
      }

      // ... with "C := BA+C". Note that A and B are now reversed.
      else {
        status = DoGemm(layout, Transpose::kNo, Transpose::kNo,
                        m, n, k,
                        alpha,
                        b_buffer, b_offset, b_ld,
                        temp_symm, 0, k,
                        beta,
                        c_buffer, c_offset, c_ld);

        // A and B are now reversed, so also reverse the error codes returned from the Xgemm routine
        switch(status) {
          case StatusCode::kInvalidMatrixA:      status = StatusCode::kInvalidMatrixB; break;
          case StatusCode::kInvalidMatrixB:      status = StatusCode::kInvalidMatrixA; break;
          case StatusCode::kInvalidLeadDimA:     status = StatusCode::kInvalidLeadDimB; break;
          case StatusCode::kInvalidLeadDimB:     status = StatusCode::kInvalidLeadDimA; break;
          case StatusCode::kInsufficientMemoryA: status = StatusCode::kInsufficientMemoryB; break;
          case StatusCode::kInsufficientMemoryB: status = StatusCode::kInsufficientMemoryA; break;
        }
      }

      // Return the status of the Xgemm routine
      return status;
    } catch (...) { return StatusCode::kInvalidKernel; }
  } catch (...) { return StatusCode::kTempBufferAllocFailure; }
}

// =================================================================================================

// Compiles the templated class
template class Xsymm<half>;
template class Xsymm<float>;
template class Xsymm<double>;
template class Xsymm<float2>;
template class Xsymm<double2>;

// =================================================================================================
} // namespace clblast