// SPDX-License-Identifier: Apache-2.0
// 
// Copyright 2008-2016 Conrad Sanderson (https://conradsanderson.id.au)
// Copyright 2008-2016 National ICT Australia (NICTA)
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// https://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ------------------------------------------------------------------------



#if defined(ARMA_USE_BLAS)


//! \namespace blas namespace for BLAS functions
namespace blas
  {
  
  
  template<typename eT>
  inline
  void
  gemv(const char* transA, const blas_int* m, const blas_int* n, const eT* alpha, const eT* A, const blas_int* ldA, const eT* x, const blas_int* incx, const eT* beta, eT* y, const blas_int* incy)
    {
    arma_type_check((is_blas_type<eT>::value == false));
    
    #if defined(ARMA_USE_FORTRAN_HIDDEN_ARGS)
      {
           if(    is_float<eT>::value)  { typedef    float T; arma_fortran(arma_sgemv)(transA, m, n, (const T*)alpha, (const T*)A, ldA, (const T*)x, incx, (const T*)beta, (T*)y, incy, 1); }
      else if(   is_double<eT>::value)  { typedef   double T; arma_fortran(arma_dgemv)(transA, m, n, (const T*)alpha, (const T*)A, ldA, (const T*)x, incx, (const T*)beta, (T*)y, incy, 1); }
      else if( is_cx_float<eT>::value)  { typedef blas_cxf T; arma_fortran(arma_cgemv)(transA, m, n, (const T*)alpha, (const T*)A, ldA, (const T*)x, incx, (const T*)beta, (T*)y, incy, 1); }
      else if(is_cx_double<eT>::value)  { typedef blas_cxd T; arma_fortran(arma_zgemv)(transA, m, n, (const T*)alpha, (const T*)A, ldA, (const T*)x, incx, (const T*)beta, (T*)y, incy, 1); }
      }
    #else
      {
           if(    is_float<eT>::value)  { typedef    float T; arma_fortran(arma_sgemv)(transA, m, n, (const T*)alpha, (const T*)A, ldA, (const T*)x, incx, (const T*)beta, (T*)y, incy); }
      else if(   is_double<eT>::value)  { typedef   double T; arma_fortran(arma_dgemv)(transA, m, n, (const T*)alpha, (const T*)A, ldA, (const T*)x, incx, (const T*)beta, (T*)y, incy); }
      else if( is_cx_float<eT>::value)  { typedef blas_cxf T; arma_fortran(arma_cgemv)(transA, m, n, (const T*)alpha, (const T*)A, ldA, (const T*)x, incx, (const T*)beta, (T*)y, incy); }
      else if(is_cx_double<eT>::value)  { typedef blas_cxd T; arma_fortran(arma_zgemv)(transA, m, n, (const T*)alpha, (const T*)A, ldA, (const T*)x, incx, (const T*)beta, (T*)y, incy); }
      }
    #endif
    }
  
  
  
  template<typename eT>
  inline
  void
  gemm(const char* transA, const char* transB, const blas_int* m, const blas_int* n, const blas_int* k, const eT* alpha, const eT* A, const blas_int* ldA, const eT* B, const blas_int* ldB, const eT* beta, eT* C, const blas_int* ldC)
    {
    arma_type_check((is_blas_type<eT>::value == false));
    
    #if defined(ARMA_USE_FORTRAN_HIDDEN_ARGS)
      {
           if(    is_float<eT>::value)  { typedef    float T; arma_fortran(arma_sgemm)(transA, transB, m, n, k, (const T*)alpha, (const T*)A, ldA, (const T*)B, ldB, (const T*)beta, (T*)C, ldC, 1, 1); }
      else if(   is_double<eT>::value)  { typedef   double T; arma_fortran(arma_dgemm)(transA, transB, m, n, k, (const T*)alpha, (const T*)A, ldA, (const T*)B, ldB, (const T*)beta, (T*)C, ldC, 1, 1); }
      else if( is_cx_float<eT>::value)  { typedef blas_cxf T; arma_fortran(arma_cgemm)(transA, transB, m, n, k, (const T*)alpha, (const T*)A, ldA, (const T*)B, ldB, (const T*)beta, (T*)C, ldC, 1, 1); }
      else if(is_cx_double<eT>::value)  { typedef blas_cxd T; arma_fortran(arma_zgemm)(transA, transB, m, n, k, (const T*)alpha, (const T*)A, ldA, (const T*)B, ldB, (const T*)beta, (T*)C, ldC, 1, 1); }
      }
    #else
      {
           if(    is_float<eT>::value)  { typedef    float T; arma_fortran(arma_sgemm)(transA, transB, m, n, k, (const T*)alpha, (const T*)A, ldA, (const T*)B, ldB, (const T*)beta, (T*)C, ldC); }
      else if(   is_double<eT>::value)  { typedef   double T; arma_fortran(arma_dgemm)(transA, transB, m, n, k, (const T*)alpha, (const T*)A, ldA, (const T*)B, ldB, (const T*)beta, (T*)C, ldC); }
      else if( is_cx_float<eT>::value)  { typedef blas_cxf T; arma_fortran(arma_cgemm)(transA, transB, m, n, k, (const T*)alpha, (const T*)A, ldA, (const T*)B, ldB, (const T*)beta, (T*)C, ldC); }
      else if(is_cx_double<eT>::value)  { typedef blas_cxd T; arma_fortran(arma_zgemm)(transA, transB, m, n, k, (const T*)alpha, (const T*)A, ldA, (const T*)B, ldB, (const T*)beta, (T*)C, ldC); }
      }
    #endif
    }
  
  
  
  template<typename eT>
  inline
  void
  syrk(const char* uplo, const char* transA, const blas_int* n, const blas_int* k, const eT* alpha, const eT* A, const blas_int* ldA, const eT* beta, eT* C, const blas_int* ldC)
    {
    arma_type_check((is_blas_type<eT>::value == false));
    
    #if defined(ARMA_USE_FORTRAN_HIDDEN_ARGS)
      {
           if( is_float<eT>::value)  { typedef  float T; arma_fortran(arma_ssyrk)(uplo, transA, n, k, (const T*)alpha, (const T*)A, ldA, (const T*)beta, (T*)C, ldC, 1, 1); }
      else if(is_double<eT>::value)  { typedef double T; arma_fortran(arma_dsyrk)(uplo, transA, n, k, (const T*)alpha, (const T*)A, ldA, (const T*)beta, (T*)C, ldC, 1, 1); }
      }
    #else
      {
           if( is_float<eT>::value)  { typedef  float T; arma_fortran(arma_ssyrk)(uplo, transA, n, k, (const T*)alpha, (const T*)A, ldA, (const T*)beta, (T*)C, ldC); }
      else if(is_double<eT>::value)  { typedef double T; arma_fortran(arma_dsyrk)(uplo, transA, n, k, (const T*)alpha, (const T*)A, ldA, (const T*)beta, (T*)C, ldC); }
      }
    #endif
    }
  
  
  
  template<typename T>
  inline
  void
  herk(const char* uplo, const char* transA, const blas_int* n, const blas_int* k, const T* alpha, const std::complex<T>* A, const blas_int* ldA, const T* beta, std::complex<T>* C, const blas_int* ldC)
    {
    arma_type_check((is_blas_type<T>::value == false));
    
    #if defined(ARMA_USE_FORTRAN_HIDDEN_ARGS)
      {
           if( is_float<T>::value)  { typedef float  TT; typedef blas_cxf cx_TT; arma_fortran(arma_cherk)(uplo, transA, n, k, (const TT*)alpha, (const cx_TT*)A, ldA, (const TT*)beta, (cx_TT*)C, ldC, 1, 1); }
      else if(is_double<T>::value)  { typedef double TT; typedef blas_cxd cx_TT; arma_fortran(arma_zherk)(uplo, transA, n, k, (const TT*)alpha, (const cx_TT*)A, ldA, (const TT*)beta, (cx_TT*)C, ldC, 1, 1); }
      }
    #else
      {
           if( is_float<T>::value)  { typedef float  TT; typedef blas_cxf cx_TT; arma_fortran(arma_cherk)(uplo, transA, n, k, (const TT*)alpha, (const cx_TT*)A, ldA, (const TT*)beta, (cx_TT*)C, ldC); }
      else if(is_double<T>::value)  { typedef double TT; typedef blas_cxd cx_TT; arma_fortran(arma_zherk)(uplo, transA, n, k, (const TT*)alpha, (const cx_TT*)A, ldA, (const TT*)beta, (cx_TT*)C, ldC); }
      }
    #endif
    }
  
  
  
  template<typename eT>
  inline
  eT
  dot(const uword n_elem, const eT* x, const eT* y)
    {
    arma_type_check((is_blas_type<eT>::value == false));
    
    if(is_float<eT>::value)
      {
      #if defined(ARMA_BLAS_FLOAT_BUG)
        {
        if(n_elem == 0)  { return eT(0); }
        
        const char trans   = 'T';
        
        const blas_int m   = blas_int(n_elem);
        const blas_int n   = 1;
        const blas_int inc = 1;
        
        const eT alpha     = eT(1);
        const eT beta      = eT(0);
        
        eT result[2];  // paranoia: using two elements instead of one
        
        result[0] = eT(0);
        result[1] = eT(0);
        
        blas::gemv(&trans, &m, &n, &alpha, x, &m, y, &inc, &beta, &result[0], &inc);
        
        return result[0];
        }
      #else
        {
        blas_int n   = blas_int(n_elem);
        blas_int inc = 1;
        
        typedef float T;
        return eT( arma_fortran(arma_sdot)(&n, (const T*)x, &inc, (const T*)y, &inc) );
        }
      #endif
      }
    else
    if(is_double<eT>::value)
      {
      blas_int n   = blas_int(n_elem);
      blas_int inc = 1;
      
      typedef double T;
      return eT( arma_fortran(arma_ddot)(&n, (const T*)x, &inc, (const T*)y, &inc) );
      }
    else
    if( (is_cx_float<eT>::value) || (is_cx_double<eT>::value) )
      {
      if(n_elem == 0)  { return eT(0); }
      
      // using gemv() workaround due to compatibility issues with cdotu() and zdotu()
      
      const char trans   = 'T';
      
      const blas_int m   = blas_int(n_elem);
      const blas_int n   = 1;
      const blas_int inc = 1;
      
      const eT alpha     = eT(1);
      const eT beta      = eT(0);
      
      eT result[2];  // paranoia: using two elements instead of one
      
      result[0] = eT(0);
      result[1] = eT(0);
      
      blas::gemv(&trans, &m, &n, &alpha, x, &m, y, &inc, &beta, &result[0], &inc);
      
      return result[0];
      }
    
    return eT(0);
    }
  
  
  
  template<typename eT>
  arma_inline
  eT
  asum(const uword n_elem, const eT* x)
    {
    arma_type_check((is_blas_type<eT>::value == false));
    
    if(is_float<eT>::value)
      {
      // WARNING: sasum() from Accelerate framework (macOS) may return 'double' instead of 'float'
      
      blas_int n   = blas_int(n_elem);
      blas_int inc = 1;
      
      typedef float T;
      return arma_fortran(arma_sasum)(&n, (const T*)x, &inc);
      }
    else
    if(is_double<eT>::value)
      {
      blas_int n   = blas_int(n_elem);
      blas_int inc = 1;
      
      typedef double T;
      return arma_fortran(arma_dasum)(&n, (const T*)x, &inc);
      }
    
    return eT(0);
    }
  
  
  
  template<typename eT>
  arma_inline
  eT
  nrm2(const uword n_elem, const eT* x)
    {
    arma_type_check((is_blas_type<eT>::value == false));
    
    if(is_float<eT>::value)
      {
      // WARNING: snrm2() from Accelerate framework (macOS) may return 'double' instead of 'float'
      
      blas_int n   = blas_int(n_elem);
      blas_int inc = 1;
      
      typedef float T;
      return arma_fortran(arma_snrm2)(&n, (const T*)x, &inc);
      }
    else
    if(is_double<eT>::value)
      {
      blas_int n   = blas_int(n_elem);
      blas_int inc = 1;
      
      typedef double T;
      return arma_fortran(arma_dnrm2)(&n, (const T*)x, &inc);
      }
    
    return eT(0);
    }
  
  
  }   // namespace blas


#endif
