option(GCOV_ENABLE "Enable/use GCOV code coverage for tests" ON)

if(GCOV_ENABLE)
  find_program(GCOV_BINARY NAMES gcov gcov-7)
  find_program(LCOV_BINARY NAMES lcov)
  message(STATUS "Using gcov ${GCOV_BINARY} and LCOV ${LCOV_BINARY}")
  add_compile_options(-g -O0 -fprofile-arcs -ftest-coverage)
  link_libraries(-coverage -lgcov)
  set(CMAKE_CXX_OUTPUT_EXTENSION_REPLACE ON)
  add_custom_target(
    tests_clean
    WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
    COMMAND ${CMAKE_COMMAND} -E remove_directory ${PROJECT_BINARY_DIR}/Coverage
    COMMAND ${LCOV_BINARY} -b ${PROJECT_BINARY_DIR} -d ${PROJECT_BINARY_DIR} --zerocounters
    COMMAND ${CMAKE_COMMAND} -E remove ${PROJECT_BINARY_DIR}/.ctest-finished
    )

  set(ctest_test_args --timeout 30 --output-on-failure)

  include(ProcessorCount)
  ProcessorCount(N)
  if(N EQUAL 0)
    message(
      WARNING "CTest: There was an issue reading the core count, tests won't be run in parallel"
      )
  else()
    message(STATUS "CTest: Detected ${N} CPU threads")
    set(ctest_test_args -j${N} ${ctest_test_args})
  endif()

  # This step needs to always return OK but log whether it was successful or not. The thought here
  # is that if the tests all pass, .ctest-finished is created and we can check for its existance
  # after generating the report to determine if the overall build result is a pass or fail.
  add_custom_target(
    test_run_all
    COMMAND ${CMAKE_CTEST_COMMAND} ${ctest_test_args}
    COMMAND ${CMAKE_COMMAND} -E touch .ctest-finished || exit 0
    BYPRODUCTS ${PROJECT_BINARY_DIR}/.ctest-finished
    WORKING_DIRECTORY "${PROJECT_BINARY_DIR}"
    DEPENDS tests_clean tests
    )

  add_custom_target(
    test_coverage_report
    WORKING_DIRECTORY "${PROJECT_BINARY_DIR}"
    COMMAND
      ${LCOV_BINARY} --capture --gcov-tool="${GCOV_BINARY}" --directory ${PROJECT_BINARY_DIR}
      --output-file ${PROJECT_BINARY_DIR}/coverage.info
      # Strip system headers and other uninteresting stuff.
    COMMAND
      ${LCOV_BINARY} --remove coverage.info '/usr/*' '${PROJECT_SOURCE_DIR}/tests/*'
      '${PROJECT_SOURCE_DIR}/lib/Catch2/*' -o coverage.info
      # Package it up.
    COMMAND genhtml coverage.info --output-directory Coverage
    COMMAND tar -zcvf Coverage.tar.gz Coverage
            # Cheat and compare a file to itself to check for existence. File-Not-Found is a failure
            # code.
    COMMAND ../../utils/gcovr.py -r . -e '../../tests' -e '../../lib/Catch2' | tee Summary.txt
    COMMAND ${CMAKE_COMMAND} -E compare_files ${PROJECT_BINARY_DIR}/.ctest-finished
            ${PROJECT_BINARY_DIR}/.ctest-finished
    BYPRODUCTS ${PROJECT_BINARY_DIR}/Summary.txt ${PROJECT_BINARY_DIR}/Coverage.tar.gz
               ${PROJECT_BINARY_DIR}Coverage ${PROJECT_BINARY_DIR}/coverage.info
    DEPENDS test_run_all
    )
else()
  set(CMAKE_CXX_OUTPUT_EXTENSION_REPLACE OFF)
endif()

add_subdirectory(unit)
