/*
 * Copyright 2025-2026 NVIDIA CORPORATION & AFFILIATES.  All rights reserved.
 *
 * NOTICE TO LICENSEE:
 *
 * This source code and/or documentation ("Licensed Deliverables") are
 * subject to NVIDIA intellectual property rights under U.S. and
 * international Copyright laws.
 *
 * These Licensed Deliverables contained herein is PROPRIETARY and
 * CONFIDENTIAL to NVIDIA and is being provided under the terms and
 * conditions of a form of NVIDIA software license agreement by and
 * between NVIDIA and Licensee ("License Agreement") or electronically
 * accepted by Licensee.  Notwithstanding any terms or conditions to
 * the contrary in the License Agreement, reproduction or disclosure
 * of the Licensed Deliverables to any third party without the express
 * written consent of NVIDIA is prohibited.
 *
 * NOTWITHSTANDING ANY TERMS OR CONDITIONS TO THE CONTRARY IN THE
 * LICENSE AGREEMENT, NVIDIA MAKES NO REPRESENTATION ABOUT THE
 * SUITABILITY OF THESE LICENSED DELIVERABLES FOR ANY PURPOSE.  IT IS
 * PROVIDED "AS IS" WITHOUT EXPRESS OR IMPLIED WARRANTY OF ANY KIND.
 * NVIDIA DISCLAIMS ALL WARRANTIES WITH REGARD TO THESE LICENSED
 * DELIVERABLES, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY,
 * NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE.
 * NOTWITHSTANDING ANY TERMS OR CONDITIONS TO THE CONTRARY IN THE
 * LICENSE AGREEMENT, IN NO EVENT SHALL NVIDIA BE LIABLE FOR ANY
 * SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, OR ANY
 * DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THESE LICENSED DELIVERABLES.
 *
 * U.S. Government End Users.  These Licensed Deliverables are a
 * "commercial item" as that term is defined at 48 C.F.R. 2.101 (OCT
 * 1995), consisting of "commercial computer software" and "commercial
 * computer software documentation" as such terms are used in 48
 * C.F.R. 12.212 (SEPT 1995) and is provided to the U.S. Government
 * only as a commercial end item.  Consistent with 48 C.F.R.12.212 and
 * 48 C.F.R. 227.7202-1 through 227.7202-4 (JUNE 1995), all
 * U.S. Government End Users acquire the Licensed Deliverables with
 * only those rights set forth herein.
 *
 * Any use of the Licensed Deliverables in individual and commercial
 * software must include, in the user documentation and internal
 * comments to the code, the above Disclaimer and U.S. Government End
 * Users Notice.
 */

#ifndef XC_INTEGRATION_GRID_COMPUTE_API_H
#define XC_INTEGRATION_GRID_COMPUTE_API_H

#include <stddef.h>

#include "../macros.h"
#include "../types/cuest_types.h"
#include "../types/cuest_parameter_types.h"
#include "../types/workspace_api.h"

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @brief Compute molecular integration grid point coordinates.
 * @ingroup ExchangeCorrelationAdvanced
 *
 * This routine retrieves the Cartesian coordinates of each molecular grid point 
 * used for exchange–correlation (XC) integration. These are the grid points used 
 * by the corresponding XC integral plan.
 * 
 * The resulting coordinates are written to a user-provided output buffer 
 * of shape (\c npoint × 3), containing the x, y, z coordinates of each grid point.
 *
 * Temporary device workspace must be preallocated based on the size returned by
 * \c cuestXCIntegrationGridComputeWorkspaceQuery.
 *
 * @param[in]  handle             cuEST handle. Must not be NULL.
 * @param[in]  plan               XC integral plan (opaque handle) constructed with \c cuestXCIntPlanCreate. Must not be NULL.
 * @param[in]  parameters         Compute parameters (\c cuestXCIntegrationGridComputeParameters_t) Must not be NULL
 * @param[in]  temporaryWorkspace Preallocated GPU workspace buffer. Must not be NULL.
 * @param[out] outGridPoints      Output buffer for computed grid point coordinates (size: \c npoint × 3) on GPU. Must not be NULL.
 *                                    Elements of this array are overwritten by the calculation results.
 *
 * @return
 *   - \c CUEST_STATUS_SUCCESS on success;
 *   - \c CUEST_STATUS_INVALID_HANDLE if the cuEST handle is NULL;
 *   - \c CUEST_STATUS_NULL_POINTER if any required pointer is NULL;
 *   - \c CUEST_STATUS_INVALID_TYPE if the handle or plan type is incorrect;
 *   - \c CUEST_STATUS_EXCEPTION on device or internal error;
 *   - \c CUEST_STATUS_UNKNOWN_ERROR otherwise.
 */
CUEST_API
cuestStatus_t cuestXCIntegrationGridCompute(
    cuestHandle_t handle,
    const cuestXCIntPlan_t plan,
    const cuestXCIntegrationGridComputeParameters_t parameters,
    cuestWorkspace_t* temporaryWorkspace,
    double* outGridPoints);

/**
 * @brief Query temporary workspace requirements for grid coordinate computation.
 * @ingroup ExchangeCorrelationAdvanced
 *
 * Determines the GPU memory workspace needed to generate the coordinates
 * of molecular integration grid points defined by the provided XC integral plan.
 * This function must be called before \c cuestXCIntegrationGridCompute to ensure sufficient allocation.
 *
 * Only workspace sizes are computed; input and output pointers may be NULL.
 *
 * @param[in]  handle                       cuEST handle. Must not be NULL.
 * @param[in]  plan                         XC integral plan (opaque handle) constructed with \c cuestXCIntPlanCreate. Must not be NULL.
 * @param[in]  parameters                   Compute parameters (\c cuestXCIntegrationGridComputeParameters_t) Must not be NULL
 * @param[out] temporaryWorkspaceDescriptor Output descriptor for required workspace sizes (in bytes). Must not be NULL.
 * @param      outGridPoints                Output array for grid point coordinates. May be NULL.
 *
 * @return
 *   - \c CUEST_STATUS_SUCCESS on success;
 *   - \c CUEST_STATUS_INVALID_HANDLE if the cuEST handle is NULL;
 *   - \c CUEST_STATUS_NULL_POINTER if any required pointer is NULL;
 *   - \c CUEST_STATUS_INVALID_TYPE if handles are of incorrect type;
 *   - \c CUEST_STATUS_EXCEPTION on device or internal error;
 *   - \c CUEST_STATUS_UNKNOWN_ERROR otherwise.
 */
CUEST_API
cuestStatus_t cuestXCIntegrationGridComputeWorkspaceQuery(
    cuestHandle_t handle,
    const cuestXCIntPlan_t plan,
    const cuestXCIntegrationGridComputeParameters_t parameters,
    cuestWorkspaceDescriptor_t* temporaryWorkspaceDescriptor,
    double* outGridPoints);

/**
 * @brief Compute molecular integration weights for XC quadrature.
 * @ingroup ExchangeCorrelationAdvanced
 *
 * This routine computes the integration weights associated with each grid point
 * in the molecular integration grid used for exchange–correlation (XC) integration.
 * The weights returned depend on the selected weight type, specified by \c weightType.
 * 
 * Supported weight types include:
 *   - \c CUEST_XCINTEGRATIONWEIGHT_PARAMETERS_WEIGHTTYPE_TOTAL — total integration weight (angular x radial x Becke);
 *   - \c CUEST_XCINTEGRATIONWEIGHT_PARAMETERS_WEIGHTTYPE_BECKE — Becke atomic partition weights;
 *   - \c CUEST_XCINTEGRATIONWEIGHT_PARAMETERS_WEIGHTTYPE_QUADRATURE — quadrature-only weights (angular x radial).
 *
 * The result is written to \c outGridWeights (size: \c npoint × 1).
 * Temporary workspace must be preallocated based on 
 * \c cuestXCIntegrationWeightComputeWorkspaceQuery.
 *
 * @param[in]  handle             cuEST handle. Must not be NULL.
 * @param[in]  plan               XC integral plan (opaque handle) constructed with \c cuestXCIntPlanCreate. Must not be NULL.
 * @param[in]  weightType         Weight type to return (total, Becke, quadrature).
 * @param[in]  parameters         Compute parameters (\c cuestXCIntegrationWeightComputeParameters_t) Must not be NULL
 * @param[in]  temporaryWorkspace Preallocated GPU workspace buffer for temporary data. Must not be NULL.
 * @param[out] outGridWeights     Output buffer for integration weights (size: \c npoint × 1) on GPU. Must not be NULL.
 *                                    Elements of this array are overwritten by the calculation results.
 *
 * @return
 *   - \c CUEST_STATUS_SUCCESS on success;
 *   - \c CUEST_STATUS_INVALID_HANDLE if the cuEST handle is NULL;
 *   - \c CUEST_STATUS_NULL_POINTER if any required pointer is NULL;
 *   - \c CUEST_STATUS_INVALID_TYPE if the handle or plan type is invalid;
 *   - \c CUEST_STATUS_INVALID_ARGUMENT if \c weightType is unrecognized;
 *   - \c CUEST_STATUS_EXCEPTION on device or internal error;
 *   - \c CUEST_STATUS_UNKNOWN_ERROR otherwise.
 */
CUEST_API
cuestStatus_t cuestXCIntegrationWeightCompute(
    cuestHandle_t handle,
    const cuestXCIntPlan_t plan,
    cuestXCIntegrationWeightComputeParametersWeightType_t weightType,
    const cuestXCIntegrationWeightComputeParameters_t parameters,
    cuestWorkspace_t* temporaryWorkspace,
    double* outGridWeights);

/**
 * @brief Query the temporary workspace required (in bytes) for computing XC integration weights.
 * @ingroup ExchangeCorrelationAdvanced
 *
 * Determines GPU memory workspace requirements to compute integration weights 
 * on the molecular grid as defined by the provided XC integral plan. The required 
 * workspace depends on the grid structure and selected weight type.
 *
 * This query should be executed before calling \c cuestXCIntegrationWeightCompute
 * to ensure that sufficient device memory is available.
 *
 * @param[in]  handle                       cuEST handle. Must not be NULL.
 * @param[in]  plan                         XC integral plan (opaque handle) constructed with \c cuestXCIntPlanCreate. Must not be NULL.
 * @param[in]  weightType                   Weight type to return (total, Becke, quadrature).
 * @param[in]  parameters                   Compute parameters (\c cuestXCIntegrationWeightComputeParameters_t) Must not be NULL
 * @param[out] temporaryWorkspaceDescriptor Output descriptor for required temporary workspace sizes (in bytes). Must not be NULL.
 * @param      outGridWeights               Optional output buffer for computed weights. May be NULL.
 *
 * @return
 *   - \c CUEST_STATUS_SUCCESS on success;
 *   - \c CUEST_STATUS_INVALID_HANDLE if the cuEST handle is NULL;
 *   - \c CUEST_STATUS_NULL_POINTER if any required pointer is NULL;
 *   - \c CUEST_STATUS_INVALID_TYPE if the handle or plan type is incorrect;
 *   - \c CUEST_STATUS_INVALID_ARGUMENT if \c weightType is unsupported;
 *   - \c CUEST_STATUS_EXCEPTION on device or internal error;
 *   - \c CUEST_STATUS_UNKNOWN_ERROR otherwise.
 */
CUEST_API
cuestStatus_t cuestXCIntegrationWeightComputeWorkspaceQuery(
    cuestHandle_t handle,
    const cuestXCIntPlan_t plan,
    cuestXCIntegrationWeightComputeParametersWeightType_t weightType,
    const cuestXCIntegrationWeightComputeParameters_t parameters,
    cuestWorkspaceDescriptor_t* temporaryWorkspaceDescriptor,
    double* outGridWeights);

#ifdef __cplusplus
}
#endif

#endif /* XC_INTEGRATION_GRID_COMPUTE_API_H */
