#!/usr/bin/env python3

#              Copyright Catch2 Authors
# Distributed under the Boost Software License, Version 1.0.
#   (See accompanying file LICENSE.txt or copy at
#        https://www.boost.org/LICENSE_1_0.txt)

# SPDX-License-Identifier: BSL-1.0

import glob
import os
import subprocess
import sys
import re
import json
import tempfile
from collections import namedtuple
from typing import List

TestInfo = namedtuple('TestInfo', ['name', 'tags'])

cmake_version_regex = re.compile(r'cmake version (\d+)\.(\d+)\.(\d+)')

def get_cmake_version():
    result = subprocess.run(['cmake', '--version'],
                            capture_output = True,
                            check = True,
                            text = True)
    version_match = cmake_version_regex.match(result.stdout)
    if not version_match:
        print('Could not find cmake version in output')
        print(f"output: '{result.stdout}'")
        exit(4)
    return (int(version_match.group(1)),
            int(version_match.group(2)),
            int(version_match.group(3)))

def build_project(sources_dir, output_base_path, catch2_path):
    build_dir = os.path.join(output_base_path, 'ctest-registration-test')
    config_cmd = ['cmake',
                  '-B', build_dir,
                  '-S', sources_dir,
                  f'-DCATCH2_PATH={catch2_path}',
                  '-DCMAKE_BUILD_TYPE=Debug']

    build_cmd = ['cmake',
                 '--build', build_dir,
                 '--config', 'Debug']

    try:
        subprocess.run(config_cmd,
                       capture_output = True,
                       check = True,
                       text = True)
        subprocess.run(build_cmd,
                       capture_output = True,
                       check = True,
                       text = True)
    except subprocess.CalledProcessError as err:
        print('Error when building the test project')
        print(f'cmd: {err.cmd}')
        print(f'stderr: {err.stderr}')
        print(f'stdout: {err.stdout}')
        exit(3)

    return build_dir


def get_test_names(build_path: str) -> List[TestInfo]:
    # For now we assume that Windows builds are done using MSBuild under
    # Debug configuration. This means that we need to add "Debug" folder
    # to the path when constructing it. On Linux, we don't add anything.
    config_path = "Debug" if os.name == 'nt' else ""
    full_path = os.path.join(build_path, config_path, 'tests')

    with tempfile.TemporaryDirectory() as tmpdir:
        fname = f'{tmpdir}/listing-output.json'
        cmd = [full_path,
          '--list-tests',
          '--reporter', 'json',
          '--out', fname
        ]
        result = subprocess.run(cmd,
                                capture_output = False,
                                check = True,
                                text = True)
        with open(fname, mode='r', encoding='utf-8') as file:
            test_listing = json.load(file)

    assert test_listing['version'] == 2

    tests = []
    for test in test_listing['listings']['tests']:
        test_name = test['name']
        tags = test['tags']
        tests.append(TestInfo(test_name, tags))

    return tests


def get_ctest_listing(build_path):
    old_path = os.getcwd()
    os.chdir(build_path)

    cmd = ['ctest', '-C', 'debug', '--show-only=json-v1']
    try:
        result = subprocess.run(cmd,
                                capture_output = True,
                                check = True,
                                text = True)
    except subprocess.CalledProcessError as err:
        print('Error when getting output from CTest')
        print(f'cmd: {err.cmd}')
        print(f'stderr: {err.stderr}')
        print(f'stdout: {err.stdout}')
        exit(4)

    os.chdir(old_path)
    return result.stdout

def extract_tests_from_ctest(ctest_output) -> List[TestInfo]:
    ctest_response = json.loads(ctest_output)
    tests = ctest_response['tests']
    test_infos = []
    for test in tests:
        test_command = test['command']
        # First part of the command is the binary, second is the filter.
        # If there are less, registration has failed. If there are more,
        # registration has changed and the script needs updating.
        assert len(test_command) == 2
        test_name = test_command[1]
        labels = []
        for prop in test['properties']:
            if prop['name'] == 'LABELS':
                labels = prop['value']

        test_infos.append(TestInfo(test_name, labels))

    return test_infos


def check_DL_PATHS(ctest_output):
    ctest_response = json.loads(ctest_output)
    tests = ctest_response['tests']
    for test in tests:
        properties = test['properties']
        for property in properties:
            if property['name'] == 'ENVIRONMENT_MODIFICATION':
                assert len(property['value']) == 2, f"The test provides 2 arguments to DL_PATHS, but instead found {len(property['value'])}"


def add_test_list_extractor(build_path: str) -> str:
    # The actual CTest script file has one of two names:
    #   * `<target>-<short-hash>_tests.cmake` on single-config generators
    #   * `<target>-<short-hash>_tests-<Config>.cmake` on multi-config generators
    #
    # We know the target name (`tests`), so we glob for the hash part
    patterns = [
        os.path.join(build_path, 'tests-*_tests.cmake'),
        os.path.join(build_path, 'tests-*_tests-Debug.cmake'),
    ]
    matches = []
    for pattern in patterns:
        matches.extend(glob.glob(pattern))
    if len(matches) != 1:
        print(f"Found {len(matches)} CTest files in '{build_path}'. Expected only 1.")
        exit(5)
    test_script_file = matches[0]
    basename = os.path.basename(test_script_file)
    extractor_fname = os.path.join(build_path, 'extractor.cmake')
    with open(extractor_fname, 'w') as f:
        f.write(fr"""
cmake_minimum_required(VERSION 3.19)

cmake_policy(VERSION 3.19...4.4)

# This dummies out the `add_test` and `set_tests_properties` commands
# inside the CTest script, so we can include it during CMake script call.
macro(add_test)
endmacro()
macro(set_tests_properties)
endmacro()

include(${{CMAKE_CURRENT_LIST_DIR}}/{basename})

list(LENGTH tests_TESTS num_tests)
message(STATUS "NUM TESTS: ${{num_tests}}")

# '[' and ']' were escaped into ASCII 2 and 3 respectively, we have to
# unescape them back here. Note that this has to be done per-element,
# or CMake's list parsing breaks (which is why they were escaped).
string(ASCII 2 _LeftBracketListingEscape)
string(ASCII 3 _RightBracketListingEscape)

foreach(test IN LISTS tests_TESTS)
  string(REPLACE "${{_LeftBracketListingEscape}}" "[" test "${{test}}")
  string(REPLACE "${{_RightBracketListingEscape}}" "]" test "${{test}}")
  string(REPLACE "\\" "\\\\" test "${{test}}")
  string(REPLACE "\r" "\\r" test "${{test}}")
  string(REPLACE "\n" "\\n" test "${{test}}")
  message(STATUS "TEST_NAME: ${{test}}")
endforeach()
""")
    return extractor_fname


def extract_tests_list_from_ctest_script(build_path: str) -> List[str]:
    extractor = add_test_list_extractor(build_path)

    cmd = ['cmake', '-P', extractor]

    try:
        result = subprocess.run(cmd,
                                capture_output = True,
                                check = True,
                                text = True)
    except subprocess.CalledProcessError as err:
        print('Error when calling CTest test extractor')
        print(f'cmd: {err.cmd}')
        print(f'stderr: {err.stderr}')
        print(f'stdout: {err.stdout}')
        exit(4)

    lines = result.stdout.strip().split('\n')
    test_num_line = lines[0]
    test_lines = lines[1:]

    test_num_prefix = '-- NUM TESTS: '
    assert test_num_prefix in test_num_line, test_num_line
    test_num_line = test_num_line[len(test_num_prefix):]
    num_tests = int(test_num_line)

    assert num_tests == len(test_lines), len(test_lines)
    test_name_prefix = '-- TEST_NAME: '
    assert all(test_name_prefix in x for x in test_lines)
    test_names = [x[len(test_name_prefix):] for x in test_lines]

    # Unescape the names, so that names with literal newlines have newlines in them again
    test_names = [x.encode('utf-8').decode('unicode-escape') for x in test_names]
    return test_names


def escape_catch2_test_names(infos: List[TestInfo]):
    escaped = []
    for info in infos:
      name = info.name
      for char in ('\\', ',', '[', ']'):
          name = name.replace(char, f"\\{char}")
      escaped.append(TestInfo(name, info.tags))
    return escaped


if __name__ == '__main__':
    if len(sys.argv) != 3:
        print(f'Usage: {sys.argv[0]} path-to-catch2-cml output-path')
        exit(2)
    catch2_path = sys.argv[1]
    output_base_path = sys.argv[2]
    sources_dir = os.path.dirname(os.path.abspath(sys.argv[0]))

    build_path = build_project(sources_dir, output_base_path, catch2_path)

    raw_catch_test_names = get_test_names(build_path)
    catch_test_names = escape_catch2_test_names(raw_catch_test_names)
    ctest_output = get_ctest_listing(build_path)
    ctest_test_names = extract_tests_from_ctest(ctest_output)

    mismatched = 0
    for catch_test in catch_test_names:
        if catch_test not in ctest_test_names:
            print(f"Catch2 test '{catch_test}' not found in CTest")
            mismatched += 1
    for ctest_test in ctest_test_names:
        if ctest_test not in catch_test_names:
            print(f"CTest test '{ctest_test}' not found in Catch2")
            mismatched += 1

    if mismatched:
        print(f"Found {mismatched} mismatched tests catch test names and ctest test commands!")
        exit(1)
    print(f"{len(catch_test_names)} tests matched in CTest listing")

    test_list_names = sorted(extract_tests_list_from_ctest_script(build_path))
    expected_names = sorted(info.name for info in raw_catch_test_names)
    if test_list_names != expected_names:
        print("TEST_LIST variable (tests_TESTS) does not match Catch2 test listing!")
        for name in test_list_names:
            if name not in expected_names:
                print(f"  TEST_LIST name '{name}' not in Catch2 listing")
        for name in expected_names:
            if name not in test_list_names:
                print(f"  Catch2 name '{name}' not in TEST_LIST")
        exit(1)
    print(f"{len(test_list_names)} tests matched in TEST_LIST variable")

    cmake_version = get_cmake_version()
    if cmake_version >= (3, 27):
        check_DL_PATHS(ctest_output)