/*! \file */
/* ************************************************************************
 * Copyright (c) 2020-2021 Advanced Micro Devices, Inc.
 *
 * 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 <hip/hip_runtime_api.h>
#include <iostream>
#include <rocsparse.h>

#define HIP_CHECK(stat)                                                        \
    {                                                                          \
        if(stat != hipSuccess)                                                 \
        {                                                                      \
            std::cerr << "Error: hip error in line " << __LINE__ << std::endl; \
            return -1;                                                         \
        }                                                                      \
    }

#define ROCSPARSE_CHECK(stat)                                                        \
    {                                                                                \
        if(stat != rocsparse_status_success)                                         \
        {                                                                            \
            std::cerr << "Error: rocsparse error in line " << __LINE__ << std::endl; \
            return -1;                                                               \
        }                                                                            \
    }

int main(int argc, char* argv[])
{
    // Query device
    int ndev;
    HIP_CHECK(hipGetDeviceCount(&ndev));

    if(ndev < 1)
    {
        std::cerr << "No HIP device found" << std::endl;
        return -1;
    }

    // Query device properties
    hipDeviceProp_t prop;
    HIP_CHECK(hipGetDeviceProperties(&prop, 0));

    std::cout << "Device: " << prop.name << std::endl;

    // rocSPARSE handle
    rocsparse_handle handle;
    ROCSPARSE_CHECK(rocsparse_create_handle(&handle));

    // Print rocSPARSE version and revision
    int  ver;
    char rev[64];

    ROCSPARSE_CHECK(rocsparse_get_version(handle, &ver));
    ROCSPARSE_CHECK(rocsparse_get_git_rev(handle, rev));

    std::cout << "rocSPARSE version: " << ver / 100000 << "." << ver / 100 % 1000 << "."
              << ver % 100 << "-" << rev << std::endl;

    // Input data

    // A = ( 1.0  0.0  0.0 )
    //     ( 2.0  3.0  0.0 )
    //     ( 4.0  5.0  6.0 )

    // Number of rows and columns
    rocsparse_int m = 3;

    // Number of right-hand-sides
    rocsparse_int nrhs = 4;

    // Number of non-zero entries
    rocsparse_int nnz = 6;

    // CSR row pointers
    rocsparse_int hcsr_row_ptr[4] = {0, 1, 3, 6};

    // CSR column indices
    rocsparse_int hcsr_col_ind[6] = {0, 0, 1, 0, 1, 2};

    // CSR values
    double hcsr_val[6] = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0};

    // Transposition of the matrix and rhs matrix
    rocsparse_operation transA = rocsparse_operation_none;
    rocsparse_operation transB = rocsparse_operation_none;

    // Analysis policy
    rocsparse_analysis_policy analysis_policy = rocsparse_analysis_policy_reuse;

    // Solve policy
    rocsparse_solve_policy solve_policy = rocsparse_solve_policy_auto;

    // Scalar alpha and beta
    double alpha = 1.0;

    // B
    rocsparse_int ldb    = m;
    double        hB[12] = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0};

    // Offload data to device
    rocsparse_int* dcsr_row_ptr;
    rocsparse_int* dcsr_col_ind;
    double*        dcsr_val;
    double*        dB;

    HIP_CHECK(hipMalloc((void**)&dcsr_row_ptr, sizeof(rocsparse_int) * (m + 1)));
    HIP_CHECK(hipMalloc((void**)&dcsr_col_ind, sizeof(rocsparse_int) * nnz));
    HIP_CHECK(hipMalloc((void**)&dcsr_val, sizeof(double) * nnz));
    HIP_CHECK(hipMalloc((void**)&dB, sizeof(double) * m * nrhs));

    HIP_CHECK(hipMemcpy(
        dcsr_row_ptr, hcsr_row_ptr, sizeof(rocsparse_int) * (m + 1), hipMemcpyHostToDevice));
    HIP_CHECK(
        hipMemcpy(dcsr_col_ind, hcsr_col_ind, sizeof(rocsparse_int) * nnz, hipMemcpyHostToDevice));
    HIP_CHECK(hipMemcpy(dcsr_val, hcsr_val, sizeof(double) * nnz, hipMemcpyHostToDevice));
    HIP_CHECK(hipMemcpy(dB, hB, sizeof(double) * m * nrhs, hipMemcpyHostToDevice));

    // Matrix descriptor
    rocsparse_mat_descr descr;
    ROCSPARSE_CHECK(rocsparse_create_mat_descr(&descr));

    // Matrix fill mode
    ROCSPARSE_CHECK(rocsparse_set_mat_fill_mode(descr, rocsparse_fill_mode_lower));

    // Matrix diagonal type
    ROCSPARSE_CHECK(rocsparse_set_mat_diag_type(descr, rocsparse_diag_type_non_unit));

    // Matrix info structure
    rocsparse_mat_info info;
    ROCSPARSE_CHECK(rocsparse_create_mat_info(&info));

    // Obtain required buffer size
    size_t buffer_size;
    ROCSPARSE_CHECK(rocsparse_dcsrsm_buffer_size(handle,
                                                 transA,
                                                 transB,
                                                 m,
                                                 nrhs,
                                                 nnz,
                                                 &alpha,
                                                 descr,
                                                 dcsr_val,
                                                 dcsr_row_ptr,
                                                 dcsr_col_ind,
                                                 dB,
                                                 ldb,
                                                 info,
                                                 solve_policy,
                                                 &buffer_size));

    // Allocate temporary buffer
    std::cout << "Allocating " << (buffer_size >> 10) << "kB temporary storage buffer" << std::endl;

    void* temp_buffer;
    HIP_CHECK(hipMalloc(&temp_buffer, buffer_size));

    // Perform analysis step
    ROCSPARSE_CHECK(rocsparse_dcsrsm_analysis(handle,
                                              transA,
                                              transB,
                                              m,
                                              nrhs,
                                              nnz,
                                              &alpha,
                                              descr,
                                              dcsr_val,
                                              dcsr_row_ptr,
                                              dcsr_col_ind,
                                              dB,
                                              ldb,
                                              info,
                                              analysis_policy,
                                              solve_policy,
                                              temp_buffer));

    // Call dcsrsv to perform lower triangular solve LX = B
    ROCSPARSE_CHECK(rocsparse_dcsrsm_solve(handle,
                                           transA,
                                           transB,
                                           m,
                                           nrhs,
                                           nnz,
                                           &alpha,
                                           descr,
                                           dcsr_val,
                                           dcsr_row_ptr,
                                           dcsr_col_ind,
                                           dB,
                                           ldb,
                                           info,
                                           solve_policy,
                                           temp_buffer));

    // Check for zero pivots
    rocsparse_int    pivot;
    rocsparse_status status = rocsparse_csrsm_zero_pivot(handle, info, &pivot);

    if(status == rocsparse_status_zero_pivot)
    {
        std::cout << "Found zero pivot in matrix row " << pivot << std::endl;
    }

    // Print result
    HIP_CHECK(hipMemcpy(hB, dB, sizeof(double) * m * nrhs, hipMemcpyDeviceToHost));

    for(int i = 0; i < nrhs; ++i)
    {
        std::cout << "B[" << i << "]:";

        for(int j = 0; j < m; ++j)
        {
            std::cout << " " << hB[i * ldb + j];
        }

        std::cout << std::endl;
    }

    // Clear rocSPARSE
    ROCSPARSE_CHECK(rocsparse_destroy_mat_info(info));
    ROCSPARSE_CHECK(rocsparse_destroy_mat_descr(descr));
    ROCSPARSE_CHECK(rocsparse_destroy_handle(handle));

    // Clear device memory
    HIP_CHECK(hipFree(dcsr_row_ptr));
    HIP_CHECK(hipFree(dcsr_col_ind));
    HIP_CHECK(hipFree(dcsr_val));
    HIP_CHECK(hipFree(dB));
    HIP_CHECK(hipFree(temp_buffer));

    return 0;
}