#!/usr/bin/env python3

# Buildtools and buildtools extended installer helper script
#
# Copyright (C) 2017-2020 Intel Corporation
#
# SPDX-License-Identifier: GPL-2.0-only
#
#  NOTE: --with-extended-buildtools is on by default
#
#  Example usage (extended buildtools from milestone):
#    (1) using --url and --filename
#        $ install-buildtools \
#          --url http://downloads.yoctoproject.org/releases/yocto/milestones/yocto-3.1_M3/buildtools \
#          --filename x86_64-buildtools-extended-nativesdk-standalone-3.0+snapshot-20200315.sh
#    (2) using --base-url, --release, --installer-version and --build-date
#        $ install-buildtools \
#          --base-url http://downloads.yoctoproject.org/releases/yocto \
#          --release yocto-3.1_M3 \
#          --installer-version 3.0+snapshot
#          --build-date 202000315
#
#  Example usage (standard buildtools from release):
#    (3) using --url and --filename
#        $ install-buildtools --without-extended-buildtools \
#          --url http://downloads.yoctoproject.org/releases/yocto/yocto-3.0.2/buildtools \
#          --filename x86_64-buildtools-nativesdk-standalone-3.0.2.sh
#    (4) using --base-url, --release and --installer-version
#        $ install-buildtools --without-extended-buildtools \
#          --base-url http://downloads.yoctoproject.org/releases/yocto \
#          --release yocto-3.0.2 \
#          --installer-version 3.0.2
#

import argparse
import logging
import os
import platform
import re
import shutil
import shlex
import stat
import subprocess
import sys
import tempfile
from urllib.parse import quote

scripts_path = os.path.dirname(os.path.realpath(__file__))
lib_path = scripts_path + '/lib'
sys.path = sys.path + [lib_path]
import scriptutils
import scriptpath


PROGNAME = 'install-buildtools'
logger = scriptutils.logger_create(PROGNAME, stream=sys.stdout)

DEFAULT_INSTALL_DIR = os.path.join(os.path.split(scripts_path)[0],'buildtools')
DEFAULT_BASE_URL = 'http://downloads.yoctoproject.org/releases/yocto'
DEFAULT_RELEASE = 'yocto-3.2_M3'
DEFAULT_INSTALLER_VERSION = '3.1+snapshot'
DEFAULT_BUILDDATE = '20200923'

# Python version sanity check
if not (sys.version_info.major == 3 and sys.version_info.minor >= 4):
    logger.error("This script requires Python 3.4 or greater")
    logger.error("You have Python %s.%s" %
	  (sys.version_info.major, sys.version_info.minor))
    sys.exit(1)

# The following three functions are copied directly from
# bitbake/lib/bb/utils.py, in order to allow this script
# to run on versions of python earlier than what bitbake
# supports (e.g. less than Python 3.5 for YP 3.1 release)

def _hasher(method, filename):
    import mmap

    with open(filename, "rb") as f:
        try:
            with mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ) as mm:
                for chunk in iter(lambda: mm.read(8192), b''):
                    method.update(chunk)
        except ValueError:
            # You can't mmap() an empty file so silence this exception
            pass
    return method.hexdigest()


def md5_file(filename):
    """
    Return the hex string representation of the MD5 checksum of filename.
    """
    import hashlib
    return _hasher(hashlib.md5(), filename)

def sha256_file(filename):
    """
    Return the hex string representation of the 256-bit SHA checksum of
    filename.
    """
    import hashlib
    return _hasher(hashlib.sha256(), filename)


def main():
    global DEFAULT_INSTALL_DIR
    global DEFAULT_BASE_URL
    global DEFAULT_RELEASE
    global DEFAULT_INSTALLER_VERSION
    global DEFAULT_BUILDDATE
    filename = ""
    release = ""
    buildtools_url = ""
    install_dir = ""
    arch = platform.machine()

    parser = argparse.ArgumentParser(
        description="Buildtools installation helper",
        add_help=False)
    parser.add_argument('-u', '--url',
                        help='URL from where to fetch buildtools SDK installer, not '
                             'including filename (optional)\n'
                             'Requires --filename.',
                        action='store')
    parser.add_argument('-f', '--filename',
                        help='filename for the buildtools SDK installer to be installed '
                             '(optional)\nRequires --url',
                        action='store')
    parser.add_argument('-d', '--directory',
                        default=DEFAULT_INSTALL_DIR,
                        help='directory where buildtools SDK will be installed (optional)',
                        action='store')
    parser.add_argument('-r', '--release',
                        default=DEFAULT_RELEASE,
                        help='Yocto Project release string for SDK which will be '
                             'installed (optional)',
                        action='store')
    parser.add_argument('-V', '--installer-version',
                        default=DEFAULT_INSTALLER_VERSION,
                        help='version string for the SDK to be installed (optional)',
                        action='store')
    parser.add_argument('-b', '--base-url',
                        default=DEFAULT_BASE_URL,
                        help='base URL from which to fetch SDK (optional)', action='store')
    parser.add_argument('-t', '--build-date',
                        default=DEFAULT_BUILDDATE,
                        help='Build date of pre-release SDK (optional)', action='store')
    group = parser.add_mutually_exclusive_group()
    group.add_argument('--with-extended-buildtools', action='store_true',
                       dest='with_extended_buildtools',
                       default=True,
                       help='enable extended buildtools tarball (on by default)')
    group.add_argument('--without-extended-buildtools', action='store_false',
                       dest='with_extended_buildtools',
                       help='disable extended buildtools (traditional buildtools tarball)')
    group = parser.add_mutually_exclusive_group()
    group.add_argument('-c', '--check', help='enable checksum validation',
                        default=True, action='store_true')
    group.add_argument('-n', '--no-check', help='disable checksum validation',
                        dest="check", action='store_false')
    parser.add_argument('-D', '--debug', help='enable debug output',
                        action='store_true')
    parser.add_argument('-q', '--quiet', help='print only errors',
                        action='store_true')

    parser.add_argument('-h', '--help', action='help',
                        default=argparse.SUPPRESS,
                        help='show this help message and exit')

    args = parser.parse_args()

    if args.debug:
        logger.setLevel(logging.DEBUG)
    elif args.quiet:
        logger.setLevel(logging.ERROR)

    if args.url and args.filename:
        logger.debug("--url and --filename detected. Ignoring --base-url "
                     "--release --installer-version  arguments.")
        filename = args.filename
        buildtools_url = "%s/%s" % (args.url, filename)
    else:
        if args.base_url:
            base_url = args.base_url
        else:
            base_url = DEFAULT_BASE_URL
        if args.release:
            # check if this is a pre-release "milestone" SDK
            m = re.search(r"^(?P<distro>[a-zA-Z\-]+)(?P<version>[0-9.]+)(?P<milestone>_M[1-9])$",
                          args.release)
            logger.debug("milestone regex: %s" % m)
            if m and m.group('milestone'):
                logger.debug("release[distro]: %s" % m.group('distro'))
                logger.debug("release[version]: %s" % m.group('version'))
                logger.debug("release[milestone]: %s" % m.group('milestone'))
                if not args.build_date:
                    logger.error("Milestone installers require --build-date")
                else:
                    if args.with_extended_buildtools:
                        filename = "%s-buildtools-extended-nativesdk-standalone-%s-%s.sh" % (
                            arch, args.installer_version, args.build_date)
                    else:
                        filename = "%s-buildtools-nativesdk-standalone-%s-%s.sh" % (
                            arch, args.installer_version, args.build_date)
                    safe_filename = quote(filename)
                    buildtools_url = "%s/milestones/%s/buildtools/%s" % (base_url, args.release, safe_filename)
            # regular release SDK
            else:
                if args.with_extended_buildtools:
                    filename = "%s-buildtools-extended-nativesdk-standalone-%s.sh" % (arch, args.installer_version)
                else:
                    filename = "%s-buildtools-nativesdk-standalone-%s.sh" % (arch, args.installer_version)
                safe_filename = quote(filename)
                buildtools_url = "%s/%s/buildtools/%s" % (base_url, args.release, safe_filename)

    tmpsdk_dir = tempfile.mkdtemp()
    try:
        # Fetch installer
        logger.info("Fetching buildtools installer")
        tmpbuildtools = os.path.join(tmpsdk_dir, filename)
        ret = subprocess.call("wget -q -O %s %s" %
                              (tmpbuildtools, buildtools_url), shell=True)
        if ret != 0:
            logger.error("Could not download file from %s" % buildtools_url)
            return ret

        # Verify checksum
        if args.check:
            logger.info("Fetching buildtools installer checksum")
            checksum_type = ""
            for checksum_type in ["md5sum", "sha256sum"]:
                check_url = "{}.{}".format(buildtools_url, checksum_type)
                checksum_filename = "{}.{}".format(filename, checksum_type)
                tmpbuildtools_checksum = os.path.join(tmpsdk_dir, checksum_filename)
                ret = subprocess.call("wget -q -O %s %s" %
                                      (tmpbuildtools_checksum, check_url), shell=True)
                if ret == 0:
                    break
            else:
                if ret != 0:
                    logger.error("Could not download file from %s" % check_url)
                    return ret
            regex = re.compile(r"^(?P<checksum>[0-9a-f]+)\s+(?P<path>.*/)?(?P<filename>.*)$")
            with open(tmpbuildtools_checksum, 'rb') as f:
                original = f.read()
                m = re.search(regex, original.decode("utf-8"))
                logger.debug("checksum regex match: %s" % m)
                logger.debug("checksum: %s" % m.group('checksum'))
                logger.debug("path: %s" % m.group('path'))
                logger.debug("filename: %s" % m.group('filename'))
                if filename != m.group('filename'):
                    logger.error("Filename does not match name in checksum")
                    return 1
                checksum = m.group('checksum')
            if checksum_type == "md5sum":
                checksum_value = md5_file(tmpbuildtools)
            else:
                checksum_value = sha256_file(tmpbuildtools)
            if checksum == checksum_value:
                    logger.info("Checksum success")
            else:
                logger.error("Checksum %s expected. Actual checksum is %s." %
                             (checksum, checksum_value))
                return 1

        # Make installer executable
        logger.info("Making installer executable")
        st = os.stat(tmpbuildtools)
        os.chmod(tmpbuildtools, st.st_mode | stat.S_IEXEC)
        logger.debug(os.stat(tmpbuildtools))
        if args.directory:
            install_dir = args.directory
            ret = subprocess.call("%s -d %s -y" %
                                  (tmpbuildtools, install_dir), shell=True)
        else:
            install_dir = "/opt/poky/%s" % args.installer_version
            ret = subprocess.call("%s -y" % tmpbuildtools, shell=True)
        if ret != 0:
            logger.error("Could not run buildtools installer")
            return ret

        # Setup the environment
        logger.info("Setting up the environment")
        regex = re.compile(r'^(?P<export>export )?(?P<env_var>[A-Z_]+)=(?P<env_val>.+)$')
        with open("%s/environment-setup-%s-pokysdk-linux" %
                  (install_dir, arch), 'rb') as f:
            for line in f:
                match = regex.search(line.decode('utf-8'))
                logger.debug("export regex: %s" % match)
                if match:
                    env_var = match.group('env_var')
                    logger.debug("env_var: %s" % env_var)
                    env_val = match.group('env_val')
                    logger.debug("env_val: %s" % env_val)
                    os.environ[env_var] = env_val

        # Test installation
        logger.info("Testing installation")
        tool = ""
        m = re.search("extended", tmpbuildtools)
        logger.debug("extended regex: %s" % m)
        if args.with_extended_buildtools and not m:
            logger.info("Ignoring --with-extended-buildtools as filename "
                        "does not contain 'extended'")
        if args.with_extended_buildtools and m:
            tool = 'gcc'
        else:
            tool = 'tar'
        logger.debug("install_dir: %s" % install_dir)
        cmd = shlex.split("/usr/bin/which %s" % tool)
        logger.debug("cmd: %s" % cmd)
        logger.debug("tool: %s" % tool)
        proc = subprocess.Popen(cmd, stdout=subprocess.PIPE)
        output, errors = proc.communicate()
        logger.debug("proc.args: %s" % proc.args)
        logger.debug("proc.communicate(): output %s" % output)
        logger.debug("proc.communicate(): errors %s" % errors)
        which_tool = output.decode('utf-8')
        logger.debug("which %s: %s" % (tool, which_tool))
        ret = proc.returncode
        if not which_tool.startswith(install_dir):
            logger.error("Something went wrong: %s not found in %s" %
                         (tool, install_dir))
        if ret != 0:
            logger.error("Something went wrong: installation failed")
        else:
            logger.info("Installation successful. Remember to source the "
                        "environment setup script now and in any new session.")
        return ret

    finally:
        # cleanup tmp directory
        shutil.rmtree(tmpsdk_dir)


if __name__ == '__main__':
    try:
        ret = main()
    except Exception:
        ret = 1
        import traceback

        traceback.print_exc()
    sys.exit(ret)