# Run doxygen with PROJECT_NUMBER supplied from CMake, and fail on any warning.
#
# Driven by the `docs` target in the top-level CMakeLists.txt. It is a separate
# script rather than a COMMAND because it has to do three things in sequence --
# feed the configuration in, then read the log back, then decide -- and a
# custom-target command list cannot branch on the result of an earlier command.
#
# The version comes in from CMake rather than living in the Doxyfile so that
# project() stays the single place a version number is written.

if(NOT AKSL_DOXYGEN OR NOT AKSL_SOURCE_DIR OR NOT AKSL_VERSION)
  message(FATAL_ERROR "RunDoxygen.cmake needs AKSL_DOXYGEN, AKSL_SOURCE_DIR and AKSL_VERSION")
endif()

set(_doxyfile "${AKSL_SOURCE_DIR}/Doxyfile")
set(_logfile  "${AKSL_SOURCE_DIR}/doxygen-warnings.log")
file(READ "${_doxyfile}" _config)
# Later settings win in a Doxyfile, so appending is enough to override.
set(_config "${_config}\nPROJECT_NUMBER = ${AKSL_VERSION}\n")

set(_generated "${AKSL_SOURCE_DIR}/Doxyfile.generated")
file(WRITE "${_generated}" "${_config}")

execute_process(
  COMMAND "${AKSL_DOXYGEN}" "${_generated}"
  WORKING_DIRECTORY "${AKSL_SOURCE_DIR}"
  RESULT_VARIABLE _result
  OUTPUT_QUIET
)
file(REMOVE "${_generated}")

if(NOT _result EQUAL 0)
  message(FATAL_ERROR "doxygen exited ${_result}")
endif()

# WARN_IF_UNDOCUMENTED and WARN_NO_PARAMDOC are on, so anything in the log is a
# public function, parameter or return value nobody has described. Treat it the
# way an uncovered line or a surviving mutant is treated: as work, not as noise.
if(EXISTS "${_logfile}")
  file(READ "${_logfile}" _warnings)
  string(STRIP "${_warnings}" _warnings)
  if(NOT _warnings STREQUAL "")
    message("${_warnings}")
    message(FATAL_ERROR
            "doxygen reported undocumented entities; see doxygen-warnings.log")
  endif()
endif()

message(STATUS "API documentation written to ${AKSL_SOURCE_DIR}/doxygen/html")