# check if Doxygen is installed
find_package(Doxygen)
if (DOXYGEN_FOUND)
    # set input and output files
    set(DOXYGEN_IN ${CMAKE_CURRENT_LIST_DIR}/Doxyfile.in)
    set(DOXYGEN_OUT ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile)
    set(DOXYGEN_SOURCE ${CMAKE_CURRENT_LIST_DIR}/../library/Zippy)
    set(DOXYGEN_QUIET YES)

    # request to configure the file
    configure_file(${DOXYGEN_IN} ${DOXYGEN_OUT})
    message("Building Doxygen documentation...")

    # note the option ALL which allows to build the docs together with the application
    add_custom_target( Documentation ALL
            COMMAND ${DOXYGEN_EXECUTABLE} ${DOXYGEN_OUT}
            WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
            COMMENT "Generating API documentation with Doxygen"
            VERBATIM )
else (DOXYGEN_FOUND)
    message("Doxygen need to be installed to generate the doxygen documentation")
endif (DOXYGEN_FOUND)