'''
Utility functions used by the cibuildwheel tests.

This file is added to the PYTHONPATH in the test runner at bin/run_test.py.
'''

import os
import platform as pm
import shutil
import subprocess
import sys
from contextlib import contextmanager
from tempfile import mkdtemp

IS_WINDOWS_RUNNING_ON_AZURE = os.path.exists('C:\\hostedtoolcache')
IS_WINDOWS_RUNNING_ON_TRAVIS = os.environ.get('TRAVIS_OS_NAME') == 'windows'


# Python 2 does not have a tempfile.TemporaryDirectory context manager
@contextmanager
def TemporaryDirectoryIfNone(path):
    _path = path or mkdtemp()
    try:
        yield _path
    finally:
        if path is None:
            shutil.rmtree(_path)


def cibuildwheel_get_build_identifiers(project_path, env=None):
    '''
    Returns the list of build identifiers that cibuildwheel will try to build
    for the current platform.
    '''
    cmd_output = subprocess.check_output(
        [sys.executable, '-m', 'cibuildwheel', '--print-build-identifiers', project_path],
        universal_newlines=True,
        env=env,
    )

    return cmd_output.strip().split('\n')


def cibuildwheel_run(project_path, env=None, add_env=None, output_dir=None):
    '''
    Runs cibuildwheel as a subprocess, building the project at project_path.

    Uses the current Python interpreter.

    :param project_path: path of the project to be built.
    :param env: full environment to be used, os.environ if None
    :param add_env: environment used to update env
    :param output_dir: directory where wheels are saved. If None, a temporary
    directory will be used for the duration of the command.
    :return: list of built wheels (file names).
    '''
    if env is None:
        env = os.environ.copy()
        # If present in the host environment, remove the MACOSX_DEPLOYMENT_TARGET for consistency
        env.pop('MACOSX_DEPLOYMENT_TARGET', None)

    if add_env is not None:
        env.update(add_env)

    with TemporaryDirectoryIfNone(output_dir) as _output_dir:
        subprocess.check_call(
            [sys.executable, '-m', 'cibuildwheel', '--output-dir', str(_output_dir), project_path],
            env=env,
        )
        wheels = os.listdir(_output_dir)
    return wheels


def expected_wheels(package_name, package_version, manylinux_versions=None,
                    macosx_deployment_target=None):
    '''
    Returns a list of expected wheels from a run of cibuildwheel.
    '''
    # per PEP 425 (https://www.python.org/dev/peps/pep-0425/), wheel files shall have name of the form
    # {distribution}-{version}(-{build tag})?-{python tag}-{abi tag}-{platform tag}.whl
    # {python tag} and {abi tag} are closely related to the python interpreter used to build the wheel
    # so we'll merge them below as python_abi_tag

    python_abi_tags = ['cp35-cp35m', 'cp36-cp36m', 'cp37-cp37m', 'cp38-cp38']
    extra_python_abi_tags = ['cp27-cp27m', 'pp27-pypy_73', 'pp36-pypy36_pp73']

    if platform == 'linux':
        if pm.machine() not in ['x86_64', 'i686']:
            if manylinux_versions is None:
                manylinux_versions = ['manylinux2014']
            architectures = {'cp': [pm.machine()]}
        else:
            if manylinux_versions is None:
                manylinux_versions = ['manylinux1', 'manylinux2010']
            python_abi_tags += extra_python_abi_tags
            python_abi_tags.append('cp27-cp27mu')  # python 2.7 has 2 different ABI on manylinux
            architectures = {'cp': ['x86_64', 'i686'], 'pp': ['x86_64']}
        platform_tags = {}
        for python_implemention in architectures:
            platform_tags[python_implemention] = [
                '{manylinux_version}_{architecture}'.format(
                    manylinux_version=manylinux_version, architecture=architecture)
                for architecture in architectures[python_implemention]
                for manylinux_version in manylinux_versions
            ]

        def get_platform_tags(python_abi_tag):
            return platform_tags[python_abi_tag[:2]]
    elif platform == 'windows':
        python_abi_tags += extra_python_abi_tags
        platform_tags = {'cp': ['win32', 'win_amd64'], 'pp': ['win32']}

        def get_platform_tags(python_abi_tag):
            return platform_tags[python_abi_tag[:2]]

    elif platform == 'macos':
        python_abi_tags += extra_python_abi_tags

        def get_platform_tags(python_abi_tag):
            default_version = '10.7' if python_abi_tag.startswith('pp') else '10.9'
            return ['macosx_{}_x86_64'.format((macosx_deployment_target or default_version).replace('.', '_'))]
    else:
        raise Exception('unsupported platform')

    templates = []
    for python_abi_tag in python_abi_tags:
        for platform_tag in get_platform_tags(python_abi_tag):
            templates.append('{package_name}-{package_version}-{python_abi_tag}-{platform_tag}.whl'.format(
                package_name=package_name, package_version=package_version,
                python_abi_tag=python_abi_tag, platform_tag=platform_tag
            ))

    if IS_WINDOWS_RUNNING_ON_TRAVIS:
        # Python 2.7 isn't supported on Travis.
        templates = [t for t in templates if '-cp27-' not in t and '-pp2' not in t]

    return templates


platform = None

if 'CIBW_PLATFORM' in os.environ:
    platform = os.environ['CIBW_PLATFORM']
elif sys.platform.startswith('linux'):
    platform = 'linux'
elif sys.platform.startswith('darwin'):
    platform = 'macos'
elif sys.platform in ['win32', 'cygwin']:
    platform = 'windows'
else:
    raise Exception('Unsupported platform')