# This macro is for internal use only
#
# It is used in the function trailbook_ev_generate_rst_from_manifest().
# It adds an custom command to generate the RST file from the manifest file
macro(_trailbook_ev_generate_rst_from_manifest_generate_command)
    string(REPLACE "/manifest.yaml" ".rst" GENERATED_FILE "${TRAILBOOK_EV_REFERENCE_MODULES_DIRECTORY}/${RELATIVE_PATH_MANIFEST}")

    get_filename_component(RELATIVE_PATH ${RELATIVE_PATH_MANIFEST} DIRECTORY)

    set(GENERATED_FILE "${TRAILBOOK_EV_REFERENCE_MODULES_DIRECTORY}/${RELATIVE_PATH}/autogenerated.rst")
    get_filename_component(GENERATED_PATH ${GENERATED_FILE} DIRECTORY)
    set(TEMPLATES_DIRECTORY "${CMAKE_CURRENT_FUNCTION_LIST_DIR}/templates")
    if(EXISTS "${MODULE_DIR}/docs/")
        set(HANDWRITTEN_MODULE_DOC "--module-handwritten-doc" "index.inc")
    endif()

    add_custom_command(
        OUTPUT
            ${GENERATED_FILE}
        DEPENDS
            ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/process_template.py
            ${args_MANIFEST_FILE}
            ${TEMPLATES_DIRECTORY}/module.rst.jinja
            ${TEMPLATES_DIRECTORY}/macros.jinja
            trailbook_${args_TRAILBOOK_NAME}_stage_prepare_sphinx_source_after
            ${DEPS_STAGE_PREPARE_SPHINX_SOURCE_AFTER}
        COMMENT
            "Generating RST file ${GENERATED_FILE} from manifest ${args_MANIFEST_FILE}"
        COMMAND
            ${CMAKE_COMMAND} -E make_directory "${GENERATED_PATH}"
        COMMAND
            ${Python3_EXECUTABLE}
            ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/process_template.py
            --template-dir "${TEMPLATES_DIRECTORY}"
            --template-file "${TEMPLATES_DIRECTORY}/module.rst.jinja"
            --name "${MODULE_NAME}"
            --data-file "${args_MANIFEST_FILE}"
            --target-file "${GENERATED_FILE}"
            ${HANDWRITTEN_MODULE_DOC}
    )

    set(TOP_LEVEL_MODULE_DIRECTORY "${CMAKE_SOURCE_DIR}")
    get_filename_component(CURRENT_RELATIVE_FOLDER_TMP "${RELATIVE_PATH_MANIFEST}" DIRECTORY)
    get_filename_component(CURRENT_RELATIVE_FOLDER "modules/${CURRENT_RELATIVE_FOLDER_TMP}" DIRECTORY)

    while(NOT CURRENT_RELATIVE_FOLDER STREQUAL "modules")

        set(CURRENT_INDEX_DIRECTORY_CONCAT "${CMAKE_SOURCE_DIR}/${CURRENT_RELATIVE_FOLDER}")
        get_filename_component(CURRENT_INDEX_DIRECTORY "${CURRENT_INDEX_DIRECTORY_CONCAT}" ABSOLUTE)
        set(CURRENT_DEST_DIRECTORY_CONCAT "${TRAILBOOK_EV_REFERENCE_DIRECTORY}/${CURRENT_RELATIVE_FOLDER}")
        get_filename_component(CURRENT_DEST_DIRECTORY "${CURRENT_DEST_DIRECTORY_CONCAT}" ABSOLUTE)

        set(INDEX_FILE "${CURRENT_DEST_DIRECTORY}/autogenerated.rst")
        get_filename_component(CURRENT_FOLDER_NAME "${CURRENT_INDEX_DIRECTORY}" NAME)
        string(REPLACE "/" "_" INDEX_TARGET_SUFFIX "${CURRENT_RELATIVE_FOLDER}")
        get_property(is_create_index_cmd_added DIRECTORY "${CURRENT_INDEX_DIRECTORY}" PROPERTY did_add_create_index_cmd SET)

        if (NOT ${is_create_index_cmd_added})
            message(VERBOSE "ADDING DEFINITION OF add_custom_command FOR THE INDEX FILE OF ${CURRENT_DEST_DIRECTORY} FOR ${INDEX_FILE}")

            set(INDEX_TEMPLATE_FILE "${TEMPLATES_DIRECTORY}/module_ref_index.rst.jinja")

            set(CUSTOM_TEMPLATE_SUBSTITUTION_SCRIPT "${CMAKE_CURRENT_BINARY_DIR}/DOCS_process_index_template_${INDEX_TARGET_SUFFIX}.py")

            configure_file(
                "${CMAKE_CURRENT_FUNCTION_LIST_DIR}/process_index_template.py.in"
                "${CUSTOM_TEMPLATE_SUBSTITUTION_SCRIPT}"
                @ONLY
            )

            add_custom_command(
                OUTPUT
                    "${INDEX_FILE}"
                COMMAND ${CMAKE_COMMAND} -E make_directory "${CURRENT_DEST_DIRECTORY}"
                COMMAND ${Python3_EXECUTABLE} "${CUSTOM_TEMPLATE_SUBSTITUTION_SCRIPT}"
                DEPENDS
                    "${INDEX_TEMPLATE_FILE}"
                    "${CUSTOM_TEMPLATE_SUBSTITUTION_SCRIPT}"
                    trailbook_${args_TRAILBOOK_NAME}_stage_prepare_sphinx_source_after
                    ${DEPS_STAGE_PREPARE_SPHINX_SOURCE_AFTER}
                COMMENT "Rendering Jinja2 template for ${INDEX_TARGET_SUFFIX}"
                VERBATIM
            )

            set_property(
                DIRECTORY "${CURRENT_INDEX_DIRECTORY}"
                PROPERTY did_add_create_index_cmd
                "TRUE"
            )
            add_custom_target(
                trailbook_${args_TRAILBOOK_NAME}_generate_reference_index_for_module_${INDEX_TARGET_SUFFIX}
                DEPENDS
                    "${INDEX_FILE}"
                    trailbook_${args_TRAILBOOK_NAME}_stage_prepare_sphinx_source_after
                    ${DEPS_STAGE_PREPARE_SPHINX_SOURCE_AFTER}
                COMMENT
                    "Target to generate RST file ${INDEX_FILE}"
            )
            set_property(
                TARGET
                    trailbook_${args_TRAILBOOK_NAME}
                APPEND
                PROPERTY
                    ADDITIONAL_DEPS_STAGE_BUILD_SPHINX_BEFORE
                        "${INDEX_FILE}"
                        trailbook_${args_TRAILBOOK_NAME}_generate_reference_index_for_module_${INDEX_TARGET_SUFFIX}
            )
        else()
            message(VERBOSE "SKIPPING DEFINITION OF add_custom_command FOR THE INDEX FILE OF ${CURRENT_FOLDER_NAME}")
        endif()

        # go up one level
        get_filename_component(CURRENT_RELATIVE_FOLDER "${CURRENT_RELATIVE_FOLDER}" DIRECTORY)
    endwhile()
endmacro()


# This function generates an RST file from a manifest definition file.
# It takes the following arguments:
# TRAILBOOK_NAME (required):    The name of the trailbook.
# MANIFEST_FILE (required):     The absolute path to the manifest 
#                               definition file.
# Usage:
# trailbook_ev_generate_rst_from_manifest(
#     TRAILBOOK_NAME <trailbook_name>
#     MANIFEST_FILE <path_to_manifest_definition_file>
# )
function(trailbook_ev_generate_rst_from_manifest)
    set(options)
    set(one_value_args
        TRAILBOOK_NAME
        MANIFEST_FILE
    )
    set(multi_value_args)
    cmake_parse_arguments(
        "args"
        "${options}"
        "${one_value_args}"
        "${multi_value_args}"
        ${ARGN}
    )

    # Parameter TRAILBOOK_NAME
    #   - is required
    #   - there should be a target named trailbook_<TRAILBOOK_NAME>
    if(NOT args_TRAILBOOK_NAME)
        message(FATAL_ERROR "trailbook_ext_ev_generate_rst_from_manifest: TRAILBOOK_NAME argument is required")
    endif()
    if(NOT TARGET trailbook_${args_TRAILBOOK_NAME})
        message(
            FATAL_ERROR
            "trailbook_ext_ev_generate_rst_from_manifest: No target named trailbook_${args_TRAILBOOK_NAME} found."
            " Did you forget to call add_trailbook() first?"
        )
    endif()

    # Parameter MANIFEST_FILE
    #   - is required
    #   - must be a absolute path
    #   - must exist
    if(NOT args_MANIFEST_FILE)
        message(FATAL_ERROR "trailbook_ext_ev_generate_rst_from_manifest: MANIFEST_FILE argument is required")
    endif()
    if(NOT IS_ABSOLUTE "${args_MANIFEST_FILE}")
        message(FATAL_ERROR "trailbook_ext_ev_generate_rst_from_manifest: MANIFEST_FILE must be an absolute path")
    endif()
    if(NOT EXISTS "${args_MANIFEST_FILE}")
        message(FATAL_ERROR "trailbook_ext_ev_generate_rst_from_manifest: MANIFEST_FILE must exist")
    endif()

    get_target_property(
        TRAILBOOK_INSTANCE_SOURCE_DIRECTORY
        trailbook_${args_TRAILBOOK_NAME}
        TRAILBOOK_INSTANCE_SOURCE_DIRECTORY
    )
    get_target_property(
        DEPS_STAGE_PREPARE_SPHINX_SOURCE_AFTER
        trailbook_${args_TRAILBOOK_NAME}
        DEPS_STAGE_PREPARE_SPHINX_SOURCE_AFTER
    )

    set(TRAILBOOK_EV_REFERENCE_DIRECTORY "${TRAILBOOK_INSTANCE_SOURCE_DIRECTORY}/reference")
    set(TRAILBOOK_EV_REFERENCE_MODULES_DIRECTORY "${TRAILBOOK_EV_REFERENCE_DIRECTORY}/modules")
    get_filename_component(MODULE_DIR ${args_MANIFEST_FILE} DIRECTORY)
    get_filename_component(MODULE_NAME ${MODULE_DIR} NAME_WE)

    file(RELATIVE_PATH RELATIVE_PATH_MANIFEST
         "${CMAKE_SOURCE_DIR}/modules"
         "${args_MANIFEST_FILE}"
    )

    _trailbook_ev_generate_rst_from_manifest_generate_command()

    add_custom_target(
        trailbook_${args_TRAILBOOK_NAME}_generate_rst_from_manifest_${MODULE_NAME}
        DEPENDS
            ${GENERATED_FILE}
            trailbook_${args_TRAILBOOK_NAME}_stage_prepare_sphinx_source_after
            ${DEPS_STAGE_PREPARE_SPHINX_SOURCE_AFTER}
        COMMENT
            "Target to generate RST file ${GENERATED_FILE} from manifest definition ${args_MANIFEST_FILE}"
    )
    set_property(
        TARGET
            trailbook_${args_TRAILBOOK_NAME}
        APPEND
        PROPERTY
            ADDITIONAL_DEPS_STAGE_BUILD_SPHINX_BEFORE
                ${GENERATED_FILE}
                trailbook_${args_TRAILBOOK_NAME}_generate_rst_from_manifest_${MODULE_NAME}
    )
endfunction()