// Copyright (C) 2022 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only

/*!
\page qt-add-grpc.html
\ingroup cmake-commands-qtgrpc

\title qt_add_grpc
\target qt_add_grpc
\summary {Generates Qt-based C++ services using a protobuf schema}
\cmakecommandsince 6.5

Usually \c qtgrpcgen is invoked through the \c qt_add_grpc CMake macro.

\badcode
    qt_add_grpc(<target> <CLIENT|SERVER>
        PROTO_FILES <file> ...
        [PROTO_INCLUDES <path> ...]
        [QML]
        [OUTPUT_DIRECTORY <dir>]
        [GENERATE_PACKAGE_SUBFOLDERS]
        [COPY_COMMENTS]
        [EXPORT_MACRO <infix>]
        [OUTPUT_HEADERS <var>]
        [OUTPUT_TARGETS <var>]
        [HEADER_GUARD <pragma|filename>]
    )
\endcode

\note Only \c {CLIENT} code generation is currently supported.

The source files are created by \c qtgrpcgen and added to the target.
If the target already exists, the files are \e added to the target source
list. If the target doesn't exist, it is created as a library which you must
link to.

The \gRPC library that is generated using the \c qt_add_grpc command refers to
the protobuf symbols that are used in service calls. This means you either need
to use a common target in both \l qt_add_protobuf and \l qt_add_grpc calls or
link the generated protobuf library to the \gRPC one.

Considering the above statement you may reuse the target for both protobuf and
\gRPC client code:
\badcode
    # Generate the protobuf types first
    qt_add_protobuf(test_service_client
        PROTO_FILES
            test_service.protobuf
    )
    ...
    # Reuse the protobuf target and extend it with \gRPC client
    # functionality
    qt_add_grpc(test_service_client CLIENT
        PROTO_FILES
            test_service.protobuf
    )
\endcode

If you want to have separate targets then you need to link the \gRPC client
target to the protobuf one:
\badcode
    # Generate the protobuf types first
    qt_add_protobuf(test_service_protobuf
        PROTO_FILES
            test_service.protobuf
    )
    ...
    # Add separate target with the generated code of the \gRPC client.
    qt_add_grpc(test_service_client CLIENT
        PROTO_FILES
            test_service.protobuf
    )
    target_link_libraries(test_service_client PRIVATE test_service_protobuf)
\endcode

\section1 Arguments
\list
    \include qtprotoccommon.qdocinc proto_files-li
    \include qtprotoccommon.qdocinc proto_includes-li
    \li \c {QML} generates the QML client API for the \gRPC service.
        The argument requires the \c GrpcQuick Qt component.
        \badcode
            find_package(Qt6 6.8 REQUIRED COMPONENTS Quick Protobuf ProtobufQuick Grpc GrpcQuick)
            ...
            # Generate the protobuf types
            qt_add_protobuf(test_service_client
                PROTO_FILES
                    test_service.protobuf
                QML
            )
            ...
            # Generate \gRPC client functionality
            qt_add_grpc(test_service_client CLIENT
                PROTO_FILES
                    test_service.protobuf
                QML
            )
        \endcode
    \include qtprotoccommon.qdocinc output_directory-li
    \include qtprotoccommon.qdocinc generate_package_subfolders-li
    \include qtprotoccommon.qdocinc copy_comments-li
    \include qtprotoccommon.qdocinc export_macro-cmake-li
    \include qtprotoccommon.qdocinc output_headers-li
    \include qtprotoccommon.qdocinc output_targets-li
    \include qtprotoccommon.qdocinc header_guard-li
\endlist

\sa{The qtgrpcgen Tool}
*/
