#
# Locate and configure the gRPC library
#
# Adds the following targets:
#
#  gRPC::grpc - gRPC library
#  gRPC::grpc++ - gRPC C++ library
#  gRPC::grpc++_reflection - gRPC C++ reflection library
#  gRPC::grpc_cpp_plugin - C++ generator plugin for Protocol Buffers
#
# Generates C++ sources from the .proto files
#
# grpc_generate_cpp (<SLIB> <HDRS> <DEST> [<ARGN>...])
#  PLIB - Proto Static Library generated by .proto file
#  HDRS - variable to define with autogenerated source files and header files
#  DEST - directory where the source files will be created
#  ARGN - .proto files
function(GRPC_GENERATE_CPP PLIB HDRS DEST)
    add_custom_command(
            OUTPUT  ${DEST}/${HDRS}.pb.cc
            ${DEST}/${HDRS}.pb.h
            ${DEST}/${HDRS}.grpc.pb.cc
            ${DEST}/${HDRS}.grpc.pb.h
            COMMAND ${GRPC_BINARY_DIR}/protoc
            ARGS --grpc_out "${DEST}"
            --cpp_out "${DEST}"
            -I "${DEST}"
            --plugin=protoc-gen-grpc=${GRPC_BINARY_DIR}/grpc_cpp_plugin
            ${ARGN})

    add_library(${PLIB}
            ${DEST}/${HDRS}.pb.cc
            ${DEST}/${HDRS}.pb.h
            ${DEST}/${HDRS}.grpc.pb.cc
            ${DEST}/${HDRS}.grpc.pb.h)
    set_target_properties(${PLIB} PROPERTIES
            ARCHIVE_OUTPUT_DIRECTORY ${DEST})
    target_link_libraries(${PLIB}
            ${GRPC_CLIENT_LIBS})
    if (EXISTS ${DEST}/${PLIB})
        message("${BoldGreen} Added ${PLIB} files at ${DEST} successfully!${ColourReset}")
    else ()
        message(FATAL_ERROR "Add ${PLIB} code failed!")
    endif ()
endfunction()

if(NOT DEFINED GRPC_ROOT)
    message(FATAL_ERROR "GRPC_ROOT not set in FindgRPC.cmake")
else()
    set(CMAKE_CXX_STANDARD 14)
    set(protobuf_MODULE_COMPATIBLE TRUE)
    list(APPEND CMAKE_PREFIX_PATH "${GRPC_ROOT}/lib/cmake/protobuf/")
    find_package(Protobuf CONFIG REQUIRED)
    message("${BoldGreen}Using protobuf ${Protobuf_VERSION}${ColourReset}")
    list(APPEND CMAKE_PREFIX_PATH "${GRPC_ROOT}/lib/cmake/absl/")
    find_package(absl CONFIG REQUIRED)
    message("${BoldGreen}Using absl-cpp ${absl_VERSION}${ColourReset}")
    list(APPEND CMAKE_PREFIX_PATH "${GRPC_ROOT}/lib/cmake/grpc/")
    find_package(gRPC CONFIG REQUIRED)
    message("${BoldGreen}Using gRPC-cpp ${gRPC_VERSION}${ColourReset}")
    find_path(GRPC_BINARY_DIR grpc_cpp_plugin ${GRPC_ROOT}/bin)
    find_path(GRPC_LIBRARY_DIR cmake/grpc/gRPCConfig.cmake ${GRPC_ROOT}/lib)
    find_path(GRPC_INCLUDE_DIR grpc/grpc.h PATHS ${_GRPC_INCLUDE_DIR} )
    mark_as_advanced(
            GRPC_BINARY_DIR
            GRPC_LIBRARY_DIR
            GRPC_INCLUDE_DIR
    )
    message("${BoldGreen}GRPC_INCLUDE_DIR is ${GRPC_INCLUDE_DIR}${ColourReset}")
endif ()
find_program(PROTOBUF_PROTOC protoc)
find_program(GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin)
set(REFLECTION gRPC::grpc++_reflection)
set(GRPC_GRPCPP gRPC::grpc++)
include(${CMAKE_ROOT}/Modules/FindPackageHandleStandardArgs.cmake)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(gRPC DEFAULT_MSG
        PROTOBUF_PROTOC REFLECTION GRPC_GRPCPP GRPC_CPP_PLUGIN_EXECUTABLE)