#include <stdio.h>
#include <stdlib.h>

#include <magma.h>
#include <magma_lapack.h>


// ------------------------------------------------------------
// global variable indicating whether a CUDA GPU is available or not

bool g_have_cuda = false;


// ------------------------------------------------------------
void my_dpotrf(
    magma_uplo_t uplo, magma_int_t n,
    double* A, magma_int_t lda,
    magma_int_t* info )
{
    if ( g_have_cuda ) {
        printf( "magma_dpotrf\n" );
        magma_dpotrf( uplo, n, A, lda, info );
    }
    else {
        printf( "lapackf77_dpotrf\n" );
        lapackf77_dpotrf( lapack_uplo_const(uplo), &n, A, &lda, info );
    }
}


// ------------------------------------------------------------
int main( int argc, char** argv )
{
    // check for CUDA GPU
    int cnt;
    cudaError_t err = cudaGetDeviceCount( &cnt );
    g_have_cuda = (err == 0 && cnt > 0);
    
    // magma_init, magma_finalize don't currently work without a CUDA GPU
    if ( g_have_cuda ) {
        printf( "init\n" );
        magma_init();
    }
    
    // factor simple A matrix
    int n, info, lda;
    double *A;
    n = 100;
    lda = n;
    A = (double*) malloc( lda*n*sizeof(double) );
    for( int j=0; j < n; ++j ) {
        for( int i=0; i < n; ++i ) {
            A[i + j*lda] = rand() / double(RAND_MAX);
        }
        A[ j + j*lda ] += n;  // diagonally dominant
    }
    my_dpotrf( MagmaUpper, n, A, n, &info );
    printf( "info %d\n", info );
    free( A );
    
    if ( g_have_cuda ) {
        printf( "finalize\n" );
        magma_finalize();
    }
    
    printf( "done\n" );
    return 0;
}