#!/usr/bin/env python3
# Copyright 2020 The Emscripten Authors. All rights reserved.
# Emscripten is available under two separate licenses, the MIT license and the
# University of Illinois/NCSA Open Source License. Both these licenses can be
# found in the LICENSE file.

"""Updates the python binaries that we cache store at
http://storage.google.com/webassembly.

We only supply binaries for windows and macOS, but we do it very different ways for those two OSes.

Windows recipe:
 1. Download the "embeddable zip file" version of python from python.org
 2. Remove .pth file to work around https://bugs.python.org/issue34841
 3. Download and install pywin32 in the `site-packages` directory
 4. Re-zip and upload to storage.google.com

macOS recipe:
 1. Clone cpython
 2. Use homebrew to install and configure openssl (for static linking!)
 3. Build cpython from source and use `make install` to create archive.
"""

import glob
import multiprocessing
import os
import platform
import urllib.request
import shutil
import subprocess
import sys
from subprocess import check_call

version = '3.9.2'
major_minor_version = '.'.join(version.split('.')[:2]) # e.g. '3.9.2' -> '3.9'
base = 'https://www.python.org/ftp/python/%s/' % version
revision = '1'

pywin32_version = '227'
pywin32_base = 'https://github.com/mhammond/pywin32/releases/download/b%s/' % pywin32_version

upload_base = 'gs://webassembly/emscripten-releases-builds/deps/'


def unzip_cmd():
 # Use 7-Zip if available (https://www.7-zip.org/)
 sevenzip = os.path.join(os.getenv('ProgramFiles'), '7-Zip', '7z.exe')
 if os.path.isfile(sevenzip):
 return [sevenzip, 'x']
 # Fall back to 'unzip' tool
 return ['unzip', '-q']


def zip_cmd():
 # Use 7-Zip if available (https://www.7-zip.org/)
 sevenzip = os.path.join(os.getenv('ProgramFiles'), '7-Zip', '7z.exe')
 if os.path.isfile(sevenzip):
 return [sevenzip, 'a', '-mx9']
 # Fall back to 'zip' tool
 return ['zip', '-rq']


def make_python_patch(arch):
 if arch == 'amd64':
 pywin32_filename = 'pywin32-%s.win-%s-py%s.exe' % (pywin32_version, arch, major_minor_version)
 else:
 pywin32_filename = 'pywin32-%s.%s-py%s.exe' % (pywin32_version, arch, major_minor_version)
 filename = 'python-%s-embed-%s.zip' % (version, arch)
 out_filename = 'python-%s-%s-embed-%s+pywin32.zip' % (version, revision, arch)
 if not os.path.exists(pywin32_filename):
 download_url = pywin32_base + pywin32_filename
 print('Downloading pywin32: ' + download_url)
 urllib.request.urlretrieve(download_url, pywin32_filename)

 if not os.path.exists(filename):
 download_url = base + filename
 print('Downloading python: ' + download_url)
 urllib.request.urlretrieve(download_url, filename)

 os.mkdir('python-embed')
 check_call(unzip_cmd() + [os.path.abspath(filename)], cwd='python-embed')
 os.remove(os.path.join('python-embed', 'python%s._pth' % major_minor_version.replace('.', '')))

 os.mkdir('pywin32')
 rtn = subprocess.call(unzip_cmd() + [os.path.abspath(pywin32_filename)], cwd='pywin32')
 assert rtn in [0, 1]

 os.mkdir(os.path.join('python-embed', 'lib'))
 shutil.move(os.path.join('pywin32', 'PLATLIB'), os.path.join('python-embed', 'lib', 'site-packages'))

 check_call(zip_cmd() + [os.path.join('..', out_filename), '.'], cwd='python-embed')

 # cleanup if everything went fine
 shutil.rmtree('python-embed')
 shutil.rmtree('pywin32')

 upload_url = upload_base + out_filename
 print('Uploading: ' + upload_url)
 cmd = ['gsutil', 'cp', '-n', out_filename, upload_url]
 print(' '.join(cmd))
 check_call(cmd)


def build_python():
 if sys.platform.startswith('darwin'):
 osname = 'macos'
 # Take some rather drastic steps to link openssl statically
 check_call(['brew', 'install', 'openssl', 'pkg-config'])
 if platform.machine() == 'x86_64':
 prefix = '/usr/local'
 min_macos_version = '10.13'
 elif platform.machine() == 'arm64':
 prefix = '/opt/homebrew'
 min_macos_version = '11.0'

 osname += '-' + platform.machine() # Append '-x86_64' or '-arm64' depending on current arch. (TODO: Do this for Linux too, move this below?)

 try:
 os.remove(os.path.join(prefix, 'opt', 'openssl', 'lib', 'libssl.dylib'))
 os.remove(os.path.join(prefix, 'opt', 'openssl', 'lib', 'libcrypto.dylib'))
 except Exception:
 pass
 os.environ['PKG_CONFIG_PATH'] = os.path.join(prefix, 'opt', 'openssl', 'lib', 'pkgconfig')
 else:
 osname = 'linux'

 src_dir = 'cpython'
 if not os.path.exists(src_dir):
 check_call(['git', 'clone', 'https://github.com/python/cpython'])
 check_call(['git', 'checkout', 'v' + version], cwd=src_dir)

 min_macos_version_line = '-mmacosx-version-min=' + min_macos_version # Specify the min OS version we want the build to work on
 build_flags = min_macos_version_line + ' -Werror=partial-availability' # Build against latest SDK, but issue an error if using any API that would not work on the min OS version
 env = os.environ.copy()
 env['MACOSX_DEPLOYMENT_TARGET'] = min_macos_version
 check_call(['./configure', 'CFLAGS=' + build_flags, 'CXXFLAGS=' + build_flags, 'LDFLAGS=' + min_macos_version_line], cwd=src_dir, env=env)
 check_call(['make', '-j', str(multiprocessing.cpu_count())], cwd=src_dir, env=env)
 check_call(['make', 'install', 'DESTDIR=install'], cwd=src_dir, env=env)

 install_dir = os.path.join(src_dir, 'install')

 # Install requests module. This is needed in particualr on macOS to ensure
 # SSL certificates are available (certifi in installed and used by requests).
 pybin = os.path.join(src_dir, 'install', 'usr', 'local', 'bin', 'python3')
 pip = os.path.join(src_dir, 'install', 'usr', 'local', 'bin', 'pip3')
 check_call([pybin, pip, 'install', 'requests'])

 dirname = 'python-%s-%s' % (version, revision)
 if os.path.isdir(dirname):
 print('Erasing old build directory ' + dirname)
 shutil.rmtree(dirname)
 os.rename(os.path.join(install_dir, 'usr', 'local'), dirname)
 tarball = 'python-%s-%s-%s.tar.gz' % (version, revision, osname)
 shutil.rmtree(os.path.join(dirname, 'lib', 'python' + major_minor_version, 'test'))
 shutil.rmtree(os.path.join(dirname, 'include'))
 for lib in glob.glob(os.path.join(dirname, 'lib', 'lib*.a')):
 os.remove(lib)
 check_call(['tar', 'zcvf', tarball, dirname])
 print('Uploading: ' + upload_base + tarball)
 check_call(['gsutil', 'cp', '-n', tarball, upload_base + tarball])


def main():
 if sys.platform.startswith('win'):
 for arch in ('amd64', 'win32'):
 make_python_patch(arch)
 else:
 build_python()
 return 0


if __name__ == '__main__':
 sys.exit(main())