find_package(Doxygen)

if (DOXYGEN_FOUND)
  set(INPUT_FILE ${CMAKE_CURRENT_SOURCE_DIR}/Doxyfile.in)
  set(INPUT_CSS_FILE ${CMAKE_CURRENT_SOURCE_DIR}/qtify.css)
  set(INPUT_README_FILE ${CMAKE_CURRENT_SOURCE_DIR}/../README.md)
  set(OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR})
  set(OUTPUT_FILE ${OUTPUT_DIR}/Doxyfile)
  set(OUTPUT_CSS_FILE ${OUTPUT_DIR}/qtify.css)
  configure_file(${INPUT_FILE} ${OUTPUT_FILE} @ONLY)
  file(COPY ${INPUT_CSS_FILE} ${INPUT_README_FILE} DESTINATION ${OUTPUT_DIR})
  add_custom_target(doc ${DOXYGEN_EXECUTABLE} ${OUTPUT_FILE} WORKING_DIRECTORY ${OUTPUT_DIR} COMMENT "Generating the API documentation with Doxygen" VERBATIM)
endif()