# Copyright 2016 gRPC authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from distutils import cygwinccompiler
from distutils import extension
from distutils import util
import errno
import os
import os.path
import pkg_resources
import platform
import re
import shlex
import shutil
import sys
import sysconfig

import setuptools
from setuptools.command import build_ext

import subprocess
from subprocess import PIPE

# TODO(atash) add flag to disable Cython use

_PACKAGE_PATH = os.path.realpath(os.path.dirname(__file__))
_README_PATH = os.path.join(_PACKAGE_PATH, 'README.rst')

os.chdir(os.path.dirname(os.path.abspath(__file__)))
sys.path.insert(0, os.path.abspath('.'))

import _parallel_compile_patch
import protoc_lib_deps
import grpc_version

_EXT_INIT_SYMBOL = None
if sys.version_info[0] == 2:
    _EXT_INIT_SYMBOL = "init_protoc_compiler"
else:
    _EXT_INIT_SYMBOL = "PyInit__protoc_compiler"

_parallel_compile_patch.monkeypatch_compile_maybe()

CLASSIFIERS = [
    'Development Status :: 5 - Production/Stable',
    'Programming Language :: Python',
    'Programming Language :: Python :: 2',
    'Programming Language :: Python :: 2.7',
    'Programming Language :: Python :: 3',
    'Programming Language :: Python :: 3.4',
    'Programming Language :: Python :: 3.5',
    'Programming Language :: Python :: 3.6',
    'License :: OSI Approved :: Apache Software License',
]

PY3 = sys.version_info.major == 3


def _env_bool_value(env_name, default):
    """Parses a bool option from an environment variable"""
    return os.environ.get(env_name, default).upper() not in ['FALSE', '0', '']


# Environment variable to determine whether or not the Cython extension should
# *use* Cython or use the generated C files. Note that this requires the C files
# to have been generated by building first *with* Cython support.
BUILD_WITH_CYTHON = _env_bool_value('GRPC_PYTHON_BUILD_WITH_CYTHON', 'False')

# Export this variable to force building the python extension with a statically linked libstdc++.
# At least on linux, this is normally not needed as we can build manylinux-compatible wheels on linux just fine
# without statically linking libstdc++ (which leads to a slight increase in the wheel size).
# This option is useful when crosscompiling wheels for aarch64 where
# it's difficult to ensure that the crosscompilation toolchain has a high-enough version
# of GCC (we require >4.9) but still uses old-enough libstdc++ symbols.
# TODO(jtattermusch): remove this workaround once issues with crosscompiler version are resolved.
BUILD_WITH_STATIC_LIBSTDCXX = _env_bool_value(
    'GRPC_PYTHON_BUILD_WITH_STATIC_LIBSTDCXX', 'False')


def check_linker_need_libatomic():
    """Test if linker on system needs libatomic."""
    code_test = (b'#include <atomic>\n' +
                 b'int main() { return std::atomic<int64_t>{}; }')
    cxx = os.environ.get('CXX', 'c++')
    cpp_test = subprocess.Popen([cxx, '-x', 'c++', '-std=c++11', '-'],
                                stdin=PIPE,
                                stdout=PIPE,
                                stderr=PIPE)
    cpp_test.communicate(input=code_test)
    if cpp_test.returncode == 0:
        return False
    # Double-check to see if -latomic actually can solve the problem.
    # https://github.com/grpc/grpc/issues/22491
    cpp_test = subprocess.Popen(
        [cxx, '-x', 'c++', '-std=c++11', '-latomic', '-'],
        stdin=PIPE,
        stdout=PIPE,
        stderr=PIPE)
    cpp_test.communicate(input=code_test)
    return cpp_test.returncode == 0


class BuildExt(build_ext.build_ext):
    """Custom build_ext command."""

    def get_ext_filename(self, ext_name):
        # since python3.5, python extensions' shared libraries use a suffix that corresponds to the value
        # of sysconfig.get_config_var('EXT_SUFFIX') and contains info about the architecture the library targets.
        # E.g. on x64 linux the suffix is ".cpython-XYZ-x86_64-linux-gnu.so"
        # When crosscompiling python wheels, we need to be able to override this suffix
        # so that the resulting file name matches the target architecture and we end up with a well-formed
        # wheel.
        filename = build_ext.build_ext.get_ext_filename(self, ext_name)
        orig_ext_suffix = sysconfig.get_config_var('EXT_SUFFIX')
        new_ext_suffix = os.getenv('GRPC_PYTHON_OVERRIDE_EXT_SUFFIX')
        if new_ext_suffix and filename.endswith(orig_ext_suffix):
            filename = filename[:-len(orig_ext_suffix)] + new_ext_suffix
        return filename


# There are some situations (like on Windows) where CC, CFLAGS, and LDFLAGS are
# entirely ignored/dropped/forgotten by distutils and its Cygwin/MinGW support.
# We use these environment variables to thus get around that without locking
# ourselves in w.r.t. the multitude of operating systems this ought to build on.
# We can also use these variables as a way to inject environment-specific
# compiler/linker flags. We assume GCC-like compilers and/or MinGW as a
# reasonable default.
EXTRA_ENV_COMPILE_ARGS = os.environ.get('GRPC_PYTHON_CFLAGS', None)
EXTRA_ENV_LINK_ARGS = os.environ.get('GRPC_PYTHON_LDFLAGS', None)
if EXTRA_ENV_COMPILE_ARGS is None:
    EXTRA_ENV_COMPILE_ARGS = '-std=c++11'
    if 'win32' in sys.platform:
        if sys.version_info < (3, 5):
            # We use define flags here and don't directly add to DEFINE_MACROS below to
            # ensure that the expert user/builder has a way of turning it off (via the
            # envvars) without adding yet more GRPC-specific envvars.
            # See https://sourceforge.net/p/mingw-w64/bugs/363/
            if '32' in platform.architecture()[0]:
                EXTRA_ENV_COMPILE_ARGS += ' -D_ftime=_ftime32 -D_timeb=__timeb32 -D_ftime_s=_ftime32_s -D_hypot=hypot'
            else:
                EXTRA_ENV_COMPILE_ARGS += ' -D_ftime=_ftime64 -D_timeb=__timeb64 -D_hypot=hypot'
        else:
            # We need to statically link the C++ Runtime, only the C runtime is
            # available dynamically
            EXTRA_ENV_COMPILE_ARGS += ' /MT'
    elif "linux" in sys.platform or "darwin" in sys.platform:
        EXTRA_ENV_COMPILE_ARGS += ' -fno-wrapv -frtti'
if EXTRA_ENV_LINK_ARGS is None:
    EXTRA_ENV_LINK_ARGS = ''
    # NOTE(rbellevi): Clang on Mac OS will make all static symbols (both
    # variables and objects) global weak symbols. When a process loads the
    # protobuf wheel's shared object library before loading *this* C extension,
    # the runtime linker will prefer the protobuf module's version of symbols.
    # This results in the process using a mixture of symbols from the protobuf
    # wheel and this wheel, which may be using different versions of
    # libprotobuf. In the case that they *are* using different versions of
    # libprotobuf *and* there has been a change in data layout (or in other
    # invariants) segfaults, data corruption, or "bad things" may happen.
    #
    # This flag ensures that on Mac, the only global symbol is the one loaded by
    # the Python interpreter. The problematic global weak symbols become local
    # weak symbols.  This is not required on Linux since the compiler does not
    # produce global weak symbols. This is not required on Windows as our ".pyd"
    # file does not contain any symbols.
    #
    # Finally, the leading underscore here is part of the Mach-O ABI. Unlike
    # more modern ABIs (ELF et al.), Mach-O prepends an underscore to the names
    # of C functions.
    if "darwin" in sys.platform:
        EXTRA_ENV_LINK_ARGS += ' -Wl,-exported_symbol,_{}'.format(
            _EXT_INIT_SYMBOL)
    if "linux" in sys.platform or "darwin" in sys.platform:
        EXTRA_ENV_LINK_ARGS += ' -lpthread'
        if check_linker_need_libatomic():
            EXTRA_ENV_LINK_ARGS += ' -latomic'
    elif "win32" in sys.platform and sys.version_info < (3, 5):
        msvcr = cygwinccompiler.get_msvcr()[0]
        EXTRA_ENV_LINK_ARGS += (
            ' -static-libgcc -static-libstdc++ -mcrtdll={msvcr}'
            ' -static -lshlwapi'.format(msvcr=msvcr))

EXTRA_COMPILE_ARGS = shlex.split(EXTRA_ENV_COMPILE_ARGS)
EXTRA_LINK_ARGS = shlex.split(EXTRA_ENV_LINK_ARGS)

if BUILD_WITH_STATIC_LIBSTDCXX:
    EXTRA_LINK_ARGS.append('-static-libstdc++')

CC_FILES = [os.path.normpath(cc_file) for cc_file in protoc_lib_deps.CC_FILES]
PROTO_FILES = [
    os.path.normpath(proto_file) for proto_file in protoc_lib_deps.PROTO_FILES
]
CC_INCLUDE = os.path.normpath(protoc_lib_deps.CC_INCLUDE)
PROTO_INCLUDE = os.path.normpath(protoc_lib_deps.PROTO_INCLUDE)

GRPC_PYTHON_TOOLS_PACKAGE = 'grpc_tools'
GRPC_PYTHON_PROTO_RESOURCES_NAME = '_proto'

DEFINE_MACROS = ()
if "win32" in sys.platform:
    DEFINE_MACROS += (('WIN32_LEAN_AND_MEAN', 1),)
    if '64bit' in platform.architecture()[0]:
        DEFINE_MACROS += (('MS_WIN64', 1),)
elif "linux" in sys.platform or "darwin" in sys.platform:
    DEFINE_MACROS += (('HAVE_PTHREAD', 1),)

# By default, Python3 distutils enforces compatibility of
# c plugins (.so files) with the OSX version Python was built with.
# We need OSX 10.10, the oldest which supports C++ thread_local.
if 'darwin' in sys.platform:
    mac_target = sysconfig.get_config_var('MACOSX_DEPLOYMENT_TARGET')
    if mac_target and (pkg_resources.parse_version(mac_target) <
                       pkg_resources.parse_version('10.10.0')):
        os.environ['MACOSX_DEPLOYMENT_TARGET'] = '10.10'
        os.environ['_PYTHON_HOST_PLATFORM'] = re.sub(
            r'macosx-[0-9]+\.[0-9]+-(.+)', r'macosx-10.10-\1',
            util.get_platform())


def package_data():
    tools_path = GRPC_PYTHON_TOOLS_PACKAGE.replace('.', os.path.sep)
    proto_resources_path = os.path.join(tools_path,
                                        GRPC_PYTHON_PROTO_RESOURCES_NAME)
    proto_files = []
    for proto_file in PROTO_FILES:
        source = os.path.join(PROTO_INCLUDE, proto_file)
        target = os.path.join(proto_resources_path, proto_file)
        relative_target = os.path.join(GRPC_PYTHON_PROTO_RESOURCES_NAME,
                                       proto_file)
        try:
            os.makedirs(os.path.dirname(target))
        except OSError as error:
            if error.errno == errno.EEXIST:
                pass
            else:
                raise
        shutil.copy(source, target)
        proto_files.append(relative_target)
    return {GRPC_PYTHON_TOOLS_PACKAGE: proto_files}


def extension_modules():
    if BUILD_WITH_CYTHON:
        plugin_sources = [os.path.join('grpc_tools', '_protoc_compiler.pyx')]
    else:
        plugin_sources = [os.path.join('grpc_tools', '_protoc_compiler.cpp')]

    plugin_sources += [
        os.path.join('grpc_tools', 'main.cc'),
        os.path.join('grpc_root', 'src', 'compiler', 'python_generator.cc')
    ] + [os.path.join(CC_INCLUDE, cc_file) for cc_file in CC_FILES]

    plugin_ext = extension.Extension(
        name='grpc_tools._protoc_compiler',
        sources=plugin_sources,
        include_dirs=[
            '.',
            'grpc_root',
            os.path.join('grpc_root', 'include'),
            CC_INCLUDE,
        ],
        language='c++',
        define_macros=list(DEFINE_MACROS),
        extra_compile_args=list(EXTRA_COMPILE_ARGS),
        extra_link_args=list(EXTRA_LINK_ARGS),
    )
    extensions = [plugin_ext]
    if BUILD_WITH_CYTHON:
        from Cython import Build
        return Build.cythonize(extensions)
    else:
        return extensions


setuptools.setup(name='grpcio-tools',
                 version=grpc_version.VERSION,
                 description='Protobuf code generator for gRPC',
                 long_description=open(_README_PATH, 'r').read(),
                 author='The gRPC Authors',
                 author_email='grpc-io@googlegroups.com',
                 url='https://grpc.io',
                 license='Apache License 2.0',
                 classifiers=CLASSIFIERS,
                 ext_modules=extension_modules(),
                 packages=setuptools.find_packages('.'),
                 install_requires=[
                     'protobuf>=3.5.0.post1, < 4.0dev',
                     'grpcio>={version}'.format(version=grpc_version.VERSION),
                     'setuptools',
                 ],
                 package_data=package_data(),
                 cmdclass={
                     'build_ext': BuildExt,
                 })