# Distributed under the MIT License.
# See LICENSE.txt for details.
#
# This file contains functions used by CMake to add Catch tests to CTest.
#
# Catch is a testing framework available on Github:
# https://github.com/philsquared/Catch
# It supports a variety of different styles of tests including BDD and fixture
# tests.
#
# Usage
# =====
# To run the tests, type 'ctest' in the build directory. You can specify
# a regex to match the test name using 'ctest -R Unit.Blah', or run all
# tests with a certain tag using 'ctest -L tag'
#
# Attributes
# ==========
# Attributes allow you to modify properties of the test. Attributes are
# specified as follows:
# // [[TimeOut, 10]]
# // [[OutputRegex, A regular expression that is expected to match the output
# //   from the test]]
# SPECTRE_TEST_CASE("Unit.Blah", "[Unit]") {
#
# Note the space after the comma!
#
# Available attributes are:
# TimeOut - override the default timeout and set the timeout to N seconds. This
#           should be set very sparingly since unit tests are designed to be
#           short. If your test is too long you should consider testing smaller
#           portions of the code if possible, or writing an integration test
#           instead.
# OutputRegex - When testing failure modes the exact error message must be
#               tested, not just that the test failed. Since the string passed
#               is a regular expression you must escape any regex tokens. For
#               example, to match "some (word) and" you must specify the
#               string "some \(word\) and".

add_custom_target(unit-tests)

spectre_define_test_timeout_factor_option(UNIT "unit")

# Environment variables for test
set(_CATCH_TEST_ENV_VARS "")
# - Disable ASAN's leak sanitizer because Charm++ has false positives
list(APPEND _CATCH_TEST_ENV_VARS "ASAN_OPTIONS=detect_leaks=0")
# - Set PYTHONPATH to find Python modules
list(APPEND _CATCH_TEST_ENV_VARS "PYTHONPATH=${PYTHONPATH}")

# Main function - the only one designed to be called from outside this module.
function(spectre_add_catch_tests TEST_TARGET)
  get_target_property(SOURCE_FILES ${TEST_TARGET} SOURCES)
  list(FILTER SOURCE_FILES EXCLUDE REGEX "TestMain.*$")
  # For each of the source files, we use spectre_parse_file to find all the
  # Catch tests inside the source file and add them to CTest.
  # We ignore the Charm++ generated header files.

  file(MAKE_DIRECTORY "${CMAKE_BINARY_DIR}/tmp")

  unset(ABSOLUTE_SOURCE_FILES)
  foreach (SOURCE_FILE ${SOURCE_FILES})
    string(REGEX MATCH ".*(decl.h|def.h)" CHARM_INTERFACE_FILE
      "${SOURCE_FILE}")
    if (NOT CHARM_INTERFACE_FILE)
      if (NOT IS_ABSOLUTE ${SOURCE_FILE})
        set(SOURCE_FILE ${CMAKE_CURRENT_LIST_DIR}/${SOURCE_FILE})
      endif()
      set(ABSOLUTE_SOURCE_FILES "${ABSOLUTE_SOURCE_FILES};${SOURCE_FILE}")
    endif()
  endforeach()

  execute_process(
    COMMAND
    ${Python_EXECUTABLE}
    ${CMAKE_SOURCE_DIR}/cmake/SpectreParseTests.py
    ${ABSOLUTE_SOURCE_FILES}
    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/tmp
    RESULT_VARIABLE PARSED_TESTS_SUCCESSFULLY)
  if (${PARSED_TESTS_SUCCESSFULLY} GREATER 0)
    message(FATAL_ERROR "Failed to parse test files")
  endif()

  set_property(GLOBAL PROPERTY SPECTRE_FAILURE_TESTS_PROPERTY "")

  foreach (SOURCE_FILE ${ABSOLUTE_SOURCE_FILES})
    spectre_parse_file(${SOURCE_FILE} ${TEST_TARGET})
  endforeach ()

  get_property(
    SPECTRE_FAILURE_TESTS
    GLOBAL
    PROPERTY
    SPECTRE_FAILURE_TESTS_PROPERTY)
  set_property(GLOBAL PROPERTY SPECTRE_FAILURE_TESTS_PROPERTY "")

  # Generate shell script that runs all non-failure tests manually
  string(REPLACE ";" " " SPECTRE_FAILURE_TESTS "${SPECTRE_FAILURE_TESTS}")
  file(WRITE
    "${CMAKE_BINARY_DIR}/tmp/NonFailureTests${TEST_TARGET}.sh"
    "#!/bin/bash -e\n"
    "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/${TEST_TARGET} ${SPECTRE_FAILURE_TESTS}")
  file(COPY
    "${CMAKE_BINARY_DIR}/tmp/NonFailureTests${TEST_TARGET}.sh"
    DESTINATION "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}"
    FILE_PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE
    )
  file(REMOVE "${CMAKE_BINARY_DIR}/tmp/NonFailureTests${TEST_TARGET}.sh")
endfunction()

# Parses the cpp file and extracts the tests specified in it. Each test is then
# added to CTest, and the run command is adjusted according to timeout,
# willfail, and serialization needs.
function(spectre_parse_file SOURCE_FILE TEST_TARGET)
  if (NOT EXISTS ${SOURCE_FILE})
    message(WARNING "Could not find source file:\n\"${SOURCE_FILE}\"\nfor \
        tests\n.")
    return()
  endif ()

  file(STRINGS ${SOURCE_FILE} CONTENTS NEWLINE_CONSUME)

  # Remove commented out tests so they are not added to ctest
  string(REGEX REPLACE "\n[ \t]*//+[^\n]+" "\n" CONTENTS "${CONTENTS}")

  # The regex searches for SPECTRE_TEST_CASE_METHOD, SCENARIO and SPECTRE_TEST_CASE
  # to find tests that need to be added.  TESTS will be a list of all tests
  # found in the SOURCE_FILE.
  string(REGEX MATCHALL
    "(CATCH_)?(SPECTRE_TEST_CASE_METHOD|SCENARIO|SPECTRE_TEST_CASE)[ \t]*\\([^\)]+\\)[ \t]*{"
    TESTS
    "${CONTENTS}")

  set(FAILURE_TESTS "")
  foreach (TEST_NAME ${TESTS})
    # Get test type and fixture if applicable
    string(REGEX MATCH "(CATCH_)?(SPECTRE_TEST_CASE_METHOD|SCENARIO|SPECTRE_TEST_CASE)"
      TEST_TYPE "${TEST_NAME}")

    # Get string parts of test definition
    string(REGEX MATCHALL "\"[^\"]+\"" TEST_STRINGS "${TEST_NAME}")

    # Strip wrapping quotation marks of each element of the list
    # TEST_STRINGS
    string(REGEX REPLACE "^\"(.*)\"$" "\\1" TEST_STRINGS "${TEST_STRINGS}")
    # If a test name went on multiple lines, there will either be a sequence
    # .";" or ";". from the line break (after replacing all the whitespace with
    # ;) Remove these from the test string
    string(REPLACE ".\";\"" "." TEST_STRINGS "${TEST_STRINGS}")
    string(REPLACE "\";\"." "." TEST_STRINGS "${TEST_STRINGS}")
    # Remove the last set of quotation marks
    string(REPLACE "\";\"" ";" TEST_STRINGS "${TEST_STRINGS}")

    # Validate that a test name and tags have been provided
    list(LENGTH TEST_STRINGS TEST_STRINGS_LENGTH)
    if (NOT TEST_STRINGS_LENGTH EQUAL 2)
      message(FATAL_ERROR
        "You must provide a valid test name and tags "
        "for all tests in ${SOURCE_FILE}. Cannot use the test:\n"
        "\"${TEST_STRINGS}\"\n")
    endif ()

    # Assign name and tags
    list(GET TEST_STRINGS 0 NAME)
    if ("${TEST_TYPE}" STREQUAL "SCENARIO")
      set(NAME "Scenario: ${NAME}")
    endif ()
    set(CTEST_NAME "${NAME}")

    # Gets the TAGS of the test which is element 1 of TEST_STRINGS,
    # strips the enclosing brackets, and makes a list
    list(GET TEST_STRINGS 1 TAGS)
    string(TOLOWER "${TAGS}" TAGS)
    string(REPLACE "]" ";" TAGS "${TAGS}")
    string(REPLACE "[" "" TAGS "${TAGS}")

    # These files are generated by the SpectreParseTests.py
    if(NOT EXISTS "${CMAKE_BINARY_DIR}/tmp/${CTEST_NAME}.output_regex")
      message(FATAL_ERROR
        "Failed to parse out the test ${TEST_NAME} in the file ${SOURCE_FILE}."
        " This means the python script cmake/SpectreParseTests.py failed to "
        "correctly identify the tests.")
    endif()
    file(READ "${CMAKE_BINARY_DIR}/tmp/${CTEST_NAME}.output_regex" OUTPUT_REGEX)
    file(REMOVE "${CMAKE_BINARY_DIR}/tmp/${CTEST_NAME}.output_regex")
    file(READ "${CMAKE_BINARY_DIR}/tmp/${CTEST_NAME}.timeout" TIMEOUT)
    file(REMOVE "${CMAKE_BINARY_DIR}/tmp/${CTEST_NAME}.timeout")

    # The default TIMEOUT is set to -1, but overwritten by each type
    # of test or a specified TIMEOUT attribute for a given test.
    # Thus we can use it to check if each test has been tagged by an
    # appropriate type.
    if (TIMEOUT EQUAL -1)
      message(FATAL_ERROR
        "You must set at least one tag of value [unit] "
        "for \"${NAME}\" in ${SOURCE_FILE}\n")
    endif ()

    # Triple timeout if address sanitizer is enabled.
    if (ASAN)
      math(EXPR TIMEOUT "3 * ${TIMEOUT}")
    endif()

    spectre_test_timeout(TIMEOUT UNIT ${TIMEOUT})

    # Add the test and set its properties
    # - Skip benchmarks during unit testing
    add_test(NAME ${CTEST_NAME}
      COMMAND ${SPECTRE_TEST_RUNNER} $<TARGET_FILE:${TEST_TARGET}>
      \"${NAME}\" --durations yes
      --warn NoAssertions
      --skip-benchmarks
      --name "\"$<CONFIGURATION>.${CTEST_NAME}\"")

    # Check if the test is supposed to fail. If so then let ctest know
    # that a failed test is actually a pass.
    if (NOT "${OUTPUT_REGEX}" STREQUAL "")
      if (NOT "${CMAKE_BUILD_TYPE}" STREQUAL "Debug")
        set(OUTPUT_REGEX
          "${OUTPUT_REGEX}|### No ASSERT tests in release mode ###")
      endif()
      set_tests_properties(
        ${CTEST_NAME} PROPERTIES
        FAIL_REGULAR_EXPRESSION "No tests ran"
        TIMEOUT ${TIMEOUT}
        PASS_REGULAR_EXPRESSION "${OUTPUT_REGEX}"
        LABELS "${TAGS}"
        ENVIRONMENT "${_CATCH_TEST_ENV_VARS}")
      set(FAILURE_TESTS "\"~${CTEST_NAME}\";${FAILURE_TESTS}")
    else ()
      set_tests_properties(
        ${CTEST_NAME} PROPERTIES
        FAIL_REGULAR_EXPRESSION "No tests ran"
        TIMEOUT ${TIMEOUT}
        LABELS "${TAGS}"
        ENVIRONMENT "${_CATCH_TEST_ENV_VARS}")
    endif ()
  endforeach ()
  set_property(GLOBAL PROPERTY SPECTRE_FAILURE_TESTS ${FAILURE_TESTS})
  get_property(
    SPECTRE_FAILURE_TESTS
    GLOBAL
    PROPERTY
    SPECTRE_FAILURE_TESTS_PROPERTY)
  set(SPECTRE_FAILURE_TESTS
    "${SPECTRE_FAILURE_TESTS};${FAILURE_TESTS}")
  set_property(GLOBAL
    PROPERTY
    SPECTRE_FAILURE_TESTS_PROPERTY
    ${SPECTRE_FAILURE_TESTS})
endfunction()