// =================================================================================================
// 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 Xtbmv class (see the header for information about the class).
//
// =================================================================================================

#include "routines/level2/xtbmv.hpp"

#include <string>
#include <vector>

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

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

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

// The main routine
template <typename T>
StatusCode Xtbmv<T>::DoTbmv(const Layout layout, const Triangle triangle,
                            const Transpose a_transpose, const Diagonal diagonal,
                            const size_t n, const size_t k,
                            const Buffer<T> &a_buffer, const size_t a_offset, const size_t a_ld,
                            const Buffer<T> &x_buffer, const size_t x_offset, const size_t x_inc) {

  // Creates a copy of X: a temporary scratch buffer
  auto scratch_buffer = Buffer<T>(context_, n*x_inc + x_offset);
  try {
    x_buffer.CopyTo(queue_, n*x_inc + x_offset, scratch_buffer);
  } catch (...) { } // Continues: error-code is returned in MatVec

  // The data is either in the upper or lower triangle
  size_t is_upper = ((triangle == Triangle::kUpper && layout != Layout::kRowMajor) ||
                     (triangle == Triangle::kLower && layout == Layout::kRowMajor));

  // Adds '2' to the parameter if the diagonal is unit
  auto parameter = (diagonal == Diagonal::kUnit) ? is_upper + 2 : is_upper;

  // Runs the generic matrix-vector multiplication, disabling the use of fast vectorized kernels.
  // The specific triangular banded matrix-accesses are implemented in the kernel guarded by the
  // ROUTINE_TBMV define.
  auto fast_kernels = false;
  auto status = MatVec(layout, a_transpose,
                       n, n, static_cast<T>(1),
                       a_buffer, a_offset, a_ld,
                       scratch_buffer, x_offset, x_inc, static_cast<T>(0),
                       x_buffer, x_offset, x_inc,
                       fast_kernels, fast_kernels,
                       parameter, false, k, 0);

  // Returns the proper error code (renames vector Y to X)
  switch(status) {
    case StatusCode::kInvalidVectorY:      return StatusCode::kInvalidVectorX;
    case StatusCode::kInvalidIncrementY:   return StatusCode::kInvalidIncrementX;
    case StatusCode::kInsufficientMemoryY: return StatusCode::kInsufficientMemoryX;
    default: return status;
  }
}

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

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

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