import py, os, sys, shutil
import subprocess
from testing.udir import udir

if sys.platform == 'win32':
    py.test.skip('snippets do not run on win32')
if sys.version_info < (2, 7):
    py.test.skip('fails e.g. on a Debian/Ubuntu which patches virtualenv'
                 ' in a non-2.6-friendly way')

def create_venv(name):
    tmpdir = udir.join(name)
    try:
        subprocess.check_call(['virtualenv', 
            #'--never-download', <= could be added, but causes failures
            # in random cases on random machines
                               '-p', os.path.abspath(sys.executable),
                               str(tmpdir)])
    except OSError as e:
        py.test.skip("Cannot execute virtualenv: %s" % (e,))

    site_packages = None
    for dirpath, dirnames, filenames in os.walk(str(tmpdir)):
        if os.path.basename(dirpath) == 'site-packages':
            site_packages = dirpath
            break
    paths = ""
    if site_packages:
        try:
            from cffi import _pycparser
            modules = ('cffi', '_cffi_backend')
        except ImportError:
            modules = ('cffi', '_cffi_backend', 'pycparser')
            try:
                import ply
            except ImportError:
                pass
            else:
                modules += ('ply',)   # needed for older versions of pycparser
        paths = []
        for module in modules:
            target = __import__(module, None, None, [])
            if not hasattr(target, '__file__'):   # for _cffi_backend on pypy
                continue
            src = os.path.abspath(target.__file__)
            for end in ['__init__.pyc', '__init__.pyo', '__init__.py']:
                if src.lower().endswith(end):
                    src = src[:-len(end)-1]
                    break
            paths.append(os.path.dirname(src))
        paths = os.pathsep.join(paths)
    return tmpdir, paths

SNIPPET_DIR = py.path.local(__file__).join('..', 'snippets')

def really_run_setup_and_program(dirname, venv_dir_and_paths, python_snippet):
    venv_dir, paths = venv_dir_and_paths
    def remove(dir):
        dir = str(SNIPPET_DIR.join(dirname, dir))
        shutil.rmtree(dir, ignore_errors=True)
    remove('build')
    remove('__pycache__')
    for basedir in os.listdir(str(SNIPPET_DIR.join(dirname))):
        remove(os.path.join(basedir, '__pycache__'))
    olddir = os.getcwd()
    python_f = udir.join('x.py')
    python_f.write(py.code.Source(python_snippet))
    try:
        os.chdir(str(SNIPPET_DIR.join(dirname)))
        if os.name == 'nt':
            bindir = 'Scripts'
        else:
            bindir = 'bin'
        vp = str(venv_dir.join(bindir).join('python'))
        env = os.environ.copy()
        env['PYTHONPATH'] = paths
        subprocess.check_call((vp, 'setup.py', 'clean'), env=env)
        subprocess.check_call((vp, 'setup.py', 'install'), env=env)
        subprocess.check_call((vp, str(python_f)), env=env)
    finally:
        os.chdir(olddir)

def run_setup_and_program(dirname, python_snippet):
    venv_dir = create_venv(dirname + '-cpy')
    really_run_setup_and_program(dirname, venv_dir, python_snippet)
    #
    sys._force_generic_engine_ = True
    try:
        venv_dir = create_venv(dirname + '-gen')
        really_run_setup_and_program(dirname, venv_dir, python_snippet)
    finally:
        del sys._force_generic_engine_
    # the two files lextab.py and yacctab.py are created by not-correctly-
    # installed versions of pycparser.
    assert not os.path.exists(str(SNIPPET_DIR.join(dirname, 'lextab.py')))
    assert not os.path.exists(str(SNIPPET_DIR.join(dirname, 'yacctab.py')))

class TestZIntegration(object):
    def teardown_class(self):
        if udir.isdir():
            udir.remove(ignore_errors=True)
        udir.ensure(dir=1)

    def test_infrastructure(self):
        run_setup_and_program('infrastructure', '''
        import snip_infrastructure
        assert snip_infrastructure.func() == 42
        ''')

    def test_distutils_module(self):
        run_setup_and_program("distutils_module", '''
        import snip_basic_verify
        p = snip_basic_verify.C.getpwuid(0)
        assert snip_basic_verify.ffi.string(p.pw_name) == b"root"
        ''')

    def test_distutils_package_1(self):
        run_setup_and_program("distutils_package_1", '''
        import snip_basic_verify1
        p = snip_basic_verify1.C.getpwuid(0)
        assert snip_basic_verify1.ffi.string(p.pw_name) == b"root"
        ''')

    def test_distutils_package_2(self):
        run_setup_and_program("distutils_package_2", '''
        import snip_basic_verify2
        p = snip_basic_verify2.C.getpwuid(0)
        assert snip_basic_verify2.ffi.string(p.pw_name) == b"root"
        ''')

    def test_setuptools_module(self):
        run_setup_and_program("setuptools_module", '''
        import snip_setuptools_verify
        p = snip_setuptools_verify.C.getpwuid(0)
        assert snip_setuptools_verify.ffi.string(p.pw_name) == b"root"
        ''')

    def test_setuptools_package_1(self):
        run_setup_and_program("setuptools_package_1", '''
        import snip_setuptools_verify1
        p = snip_setuptools_verify1.C.getpwuid(0)
        assert snip_setuptools_verify1.ffi.string(p.pw_name) == b"root"
        ''')

    def test_setuptools_package_2(self):
        run_setup_and_program("setuptools_package_2", '''
        import snip_setuptools_verify2
        p = snip_setuptools_verify2.C.getpwuid(0)
        assert snip_setuptools_verify2.ffi.string(p.pw_name) == b"root"
        ''')

    def test_set_py_limited_api(self):
        from cffi.setuptools_ext import _set_py_limited_api
        try:
            import setuptools
        except ImportError as e:
            py.test.skip(str(e))
        orig_version = setuptools.__version__
        expecting_limited_api = not hasattr(sys, 'gettotalrefcount')
        try:
            setuptools.__version__ = '26.0.0'
            from setuptools import Extension

            kwds = _set_py_limited_api(Extension, {})
            assert kwds.get('py_limited_api', False) == expecting_limited_api

            setuptools.__version__ = '25.0'
            kwds = _set_py_limited_api(Extension, {})
            assert kwds.get('py_limited_api', False) == False

            setuptools.__version__ = 'development'
            kwds = _set_py_limited_api(Extension, {})
            assert kwds.get('py_limited_api', False) == expecting_limited_api

        finally:
            setuptools.__version__ = orig_version