#.rst:
# FindPAPI
# -------
#
# Find PAPI, the Performance Application Programming Interface.
#
# This module only supports finding the PAPI C library and headers.
# This module optionally supports searching for PAPI components by
# using the standard PAPI functions. To find which components are
# activated on your system use the command `papi_component_avail`.
#
# Imported targets
# ^^^^^^^^^^^^^^^^
#
# This module defines the following :prop_tgt:`IMPORTED` target:
#
# ``PAPI::PAPI``
#   The PAPI library, if found.
#
# Result variables
# ^^^^^^^^^^^^^^^^
#
# This module will set the following variables in your project:
#
# ``PAPI_INCLUDE_DIRS``
#   where to find papi.h
#
# ``PAPI_LIBRARIES``
#   the libraries to link against in order to use PAPI.
#
# ``PAPI_FOUND``
#   If false, do not try to use PAPI.
#
# ``PAPI_VERSION_STRING``
#   the version of the PAPI library found
#
# ``PAPI_<COMPONENT>_FOUND``
#   If false, the specified PAPI component was not found

find_path(PAPI_INCLUDE_DIR NAMES papi.h)
mark_as_advanced(PAPI_INCLUDE_DIR)

if(NOT PAPI_LIBRARY)
    find_library(PAPI_LIBRARY_RELEASE NAMES papi papi64)
    mark_as_advanced(PAPI_LIBRARY_RELEASE)

    find_library(PAPI_LIBRARY_DEBUG NAMES papid papi-d)
    mark_as_advanced(PAPI_LIBRARY_DEBUG)

    include(SelectLibraryConfigurations)
    select_library_configurations(PAPI)
endif()

set(WORK_DIR "${PROJECT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/FindPAPI")
if(PAPI_INCLUDE_DIR)
    if(EXISTS "${PAPI_INCLUDE_DIR}/papi.h")
        file(
            STRINGS
            "${PAPI_INCLUDE_DIR}/papi.h"
            papi_version_str
            REGEX "^#define[\t ]+PAPI_VERSION[\t ]+.*"
        )

        string(
            REGEX REPLACE
            "^#define[\t ]+PAPI_VERSION[\t ]+PAPI_VERSION_NUMBER[(]+([0-9,]*)[)]+"
            "\\1"
            PAPI_VERSION_STRING
            "${papi_version_str}"
        )
        string(REPLACE "," "." PAPI_VERSION_STRING "${PAPI_VERSION_STRING}")
        unset(papi_version_str)
    endif()

    if(PAPI_LIBRARY)
        # find the components
        enable_language(C)
        foreach(component IN LISTS PAPI_FIND_COMPONENTS)
            set(SRC_FILE "${WORK_DIR}/papi_${component}_detect.c")
            set(BIN_FILE "${WORK_DIR}/papi_${component}_detect.bin")
            file(
                WRITE
                "${SRC_FILE}"
                "
                #include <papi.h>
                int main() {
                 int retval;
                 retval = PAPI_library_init(PAPI_VER_CURRENT);
                   if (retval != PAPI_VER_CURRENT && retval > 0)
                    return -1;
                   if (PAPI_get_component_index(\"${component}\") == PAPI_ENOCMP)
                    return 0;
                   return 1;
                }"
            )
            try_run(
                PAPI_${component}_FOUND
                gko_result_unused
                "${WORK_DIR}"
                "${SRC_FILE}"
                CMAKE_FLAGS -DINCLUDE_DIRECTORIES=${PAPI_INCLUDE_DIR}
                LINK_LIBRARIES ${PAPI_LIBRARY}
                COPY_FILE ${BIN_FILE}
            )

            if(NOT PAPI_${component}_FOUND EQUAL 1)
                unset(PAPI_${component}_FOUND)
            endif()
        endforeach()
    endif()
endif()

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(
    PAPI
    REQUIRED_VARS PAPI_LIBRARY PAPI_INCLUDE_DIR
    VERSION_VAR PAPI_VERSION_STRING
    HANDLE_COMPONENTS
)

if(PAPI_sde_FOUND)
    # PAPI SDE is another library and header, let's try to find them
    find_path(PAPI_SDE_INCLUDE_DIR NAMES sde_lib.h)
    mark_as_advanced(PAPI_SDE_INCLUDE_DIR)

    if(NOT PAPI_SDE_LIBRARY)
        find_library(PAPI_SDE_LIBRARY_RELEASE NAMES sde)
        mark_as_advanced(PAPI_SDE_LIBRARY_RELEASE)

        find_library(PAPI_SDE_LIBRARY_DEBUG NAMES sded sde-d)
        mark_as_advanced(PAPI_SDE_LIBRARY_DEBUG)

        include(SelectLibraryConfigurations)
        select_library_configurations(PAPI_SDE)
    endif()

    # FIXME: with CMake>=3.17, use NAME_MISMATCHED to get rid of the warning
    find_package_handle_standard_args(
        PAPI_SDE
        REQUIRED_VARS PAPI_SDE_LIBRARY PAPI_SDE_INCLUDE_DIR
        VERSION_VAR PAPI_VERSION_STRING
    )
endif()

if(PAPI_FOUND)
    set(PAPI_LIBRARIES ${PAPI_LIBRARY})
    set(PAPI_INCLUDE_DIRS ${PAPI_INCLUDE_DIR})
    unset(PAPI_LIBRARY)
    unset(PAPI_INCLUDE_DIR)

    if(NOT TARGET PAPI::PAPI)
        add_library(PAPI::PAPI UNKNOWN IMPORTED)
        set_target_properties(
            PAPI::PAPI
            PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${PAPI_INCLUDE_DIRS}"
        )

        if(EXISTS "${PAPI_LIBRARIES}")
            set_target_properties(
                PAPI::PAPI
                PROPERTIES
                    IMPORTED_LINK_INTERFACE_LANGUAGES "C"
                    INTERFACE_LINK_LIBRARIES "${PAPI_LIBRARIES}"
                    IMPORTED_LOCATION "${PAPI_LIBRARIES}"
            )
        endif()
        if(PAPI_LIBRARY_RELEASE)
            set_property(
                TARGET PAPI::PAPI
                APPEND
                PROPERTY IMPORTED_CONFIGURATIONS RELEASE
            )
            set_target_properties(
                PAPI::PAPI
                PROPERTIES
                    IMPORTED_LINK_INTERFACE_LANGUAGES "C"
                    INTERFACE_LINK_LIBRARIES_RELEASE "${PAPI_LIBRARY_RELEASE}"
                    IMPORTED_LOCATION_RELEASE "${PAPI_LIBRARY_RELEASE}"
            )
            unset(PAPI_LIBRARY_RELEASE)
        endif()
        if(PAPI_LIBRARY_DEBUG)
            set_property(
                TARGET PAPI::PAPI
                APPEND
                PROPERTY IMPORTED_CONFIGURATIONS DEBUG
            )
            set_target_properties(
                PAPI::PAPI
                PROPERTIES
                    IMPORTED_LINK_INTERFACE_LANGUAGES "C"
                    INTERFACE_LINK_LIBRARIES_DEBUG "${PAPI_LIBRARY_DEBUG}"
                    IMPORTED_LOCATION_DEBUG "${PAPI_LIBRARY_DEBUG}"
            )
            unset(PAPI_LIBRARY_DEBUG)
        endif()
    endif()
endif()

if(PAPI_SDE_FOUND AND NOT TARGET PAPI::PAPI_SDE)
    set(PAPI_SDE_LIBRARIES ${PAPI_SDE_LIBRARY})
    set(PAPI_SDE_INCLUDE_DIRS ${PAPI_SDE_INCLUDE_DIR})
    unset(PAPI_SDE_LIBRARY)
    unset(PAPI_SDE_INCLUDE_DIR)

    if(NOT TARGET PAPI::PAPI_SDE)
        add_library(PAPI::PAPI_SDE UNKNOWN IMPORTED)
        set_target_properties(
            PAPI::PAPI_SDE
            PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${PAPI_SDE_INCLUDE_DIRS}"
        )

        if(EXISTS "${PAPI_SDE_LIBRARIES}")
            set_target_properties(
                PAPI::PAPI_SDE
                PROPERTIES
                    IMPORTED_LINK_INTERFACE_LANGUAGES "C"
                    INTERFACE_LINK_LIBRARIES "${PAPI_SDE_LIBRARIES}"
                    IMPORTED_LOCATION "${PAPI_SDE_LIBRARIES}"
            )
        endif()
        if(PAPI_SDE_LIBRARY_RELEASE)
            set_property(
                TARGET PAPI::PAPI_SDE
                APPEND
                PROPERTY IMPORTED_CONFIGURATIONS RELEASE
            )
            set_target_properties(
                PAPI::PAPI_SDE
                PROPERTIES
                    IMPORTED_LINK_INTERFACE_LANGUAGES "C"
                    INTERFACE_LINK_LIBRARIES_RELEASE
                        "${PAPI_SDE_LIBRARY_RELEASE}"
                    IMPORTED_LOCATION_RELEASE "${PAPI_SDE_LIBRARY_RELEASE}"
            )
            unset(PAPI_SDE_LIBRARY_RELEASE)
        endif()
        if(PAPI_SDE_LIBRARY_DEBUG)
            set_property(
                TARGET PAPI::PAPI_SDE
                APPEND
                PROPERTY IMPORTED_CONFIGURATIONS DEBUG
            )
            set_target_properties(
                PAPI::PAPI_SDE
                PROPERTIES
                    IMPORTED_LINK_INTERFACE_LANGUAGES "C"
                    INTERFACE_LINK_LIBRARIES_DEBUG "${PAPI_SDE_LIBRARY_DEBUG}"
                    IMPORTED_LOCATION_DEBUG "${PAPI_SDE_LIBRARY_DEBUG}"
            )
            unset(PAPI_SDE_LIBRARY_DEBUG)
        endif()
    endif()
endif()