# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:

# Copyright 2014-2021 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
#
# This file is part of qutebrowser.
#
# qutebrowser is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# qutebrowser is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.

"""Utilities to show various version information."""

import re
import sys
import glob
import os.path
import platform
import subprocess
import importlib
import collections
import pathlib
import configparser
import enum
import datetime
import getpass
import functools
import dataclasses
from typing import (Mapping, Optional, Sequence, Tuple, ClassVar, Dict, cast,
                    TYPE_CHECKING)


from PyQt5.QtCore import PYQT_VERSION_STR, QLibraryInfo, qVersion
from PyQt5.QtNetwork import QSslSocket
from PyQt5.QtGui import (QOpenGLContext, QOpenGLVersionProfile,
                         QOffscreenSurface)
from PyQt5.QtWidgets import QApplication

try:
    from PyQt5.QtWebKit import qWebKitVersion
except ImportError:  # pragma: no cover
    qWebKitVersion = None  # type: ignore[assignment]  # noqa: N816
try:
    from PyQt5.QtWebEngine import PYQT_WEBENGINE_VERSION_STR
except ImportError:  # pragma: no cover
    # Added in PyQt 5.13
    PYQT_WEBENGINE_VERSION_STR = None  # type: ignore[assignment]


import qutebrowser
from qutebrowser.utils import log, utils, standarddir, usertypes, message, resources
from qutebrowser.misc import objects, earlyinit, sql, httpclient, pastebin, elf
from qutebrowser.browser import pdfjs
from qutebrowser.config import config
if TYPE_CHECKING:
    from qutebrowser.config import websettings

_LOGO = r'''
         ______     ,,
    ,.-"`      | ,-` |
  .^           ||    |
 /    ,-*^|    ||    |
;    /    |    ||    ;-*```^*.
;   ;     |    |;,-*`         \
|   |     |  ,-*`    ,-"""\    \
|    \   ,-"`    ,-^`|     \    |
 \    `^^    ,-;|    |     ;    |
  *;     ,-*`  ||    |     /   ;;
    `^^`` |    ||    |   ,^    /
          |    ||    `^^`    ,^
          |  _,"|        _,-"
          -*`   ****"""``

'''


@dataclasses.dataclass
class DistributionInfo:

    """Information about the running distribution."""

    id: Optional[str]
    parsed: 'Distribution'
    pretty: str


pastebin_url = None


class Distribution(enum.Enum):

    """A known Linux distribution.

    Usually lines up with ID=... in /etc/os-release.
    """

    unknown = enum.auto()
    ubuntu = enum.auto()
    debian = enum.auto()
    void = enum.auto()
    arch = enum.auto()  # includes rolling-release derivatives
    gentoo = enum.auto()  # includes funtoo
    fedora = enum.auto()
    opensuse = enum.auto()
    linuxmint = enum.auto()
    manjaro = enum.auto()
    kde_flatpak = enum.auto()  # org.kde.Platform
    neon = enum.auto()
    nixos = enum.auto()
    alpine = enum.auto()
    solus = enum.auto()


def _parse_os_release() -> Optional[Dict[str, str]]:
    """Parse an /etc/os-release file."""
    filename = os.environ.get('QUTE_FAKE_OS_RELEASE', '/etc/os-release')
    info = {}
    try:
        with open(filename, 'r', encoding='utf-8') as f:
            for line in f:
                line = line.strip()
                if (not line) or line.startswith('#') or '=' not in line:
                    continue
                k, v = line.split("=", maxsplit=1)
                info[k] = v.strip('"')
    except (OSError, UnicodeDecodeError):
        return None

    return info


def distribution() -> Optional[DistributionInfo]:
    """Get some information about the running Linux distribution.

    Returns:
        A DistributionInfo object, or None if no info could be determined.
            parsed: A Distribution enum member
            pretty: Always a string (might be "Unknown")
    """
    info = _parse_os_release()
    if info is None:
        return None

    pretty = info.get('PRETTY_NAME', None)
    if pretty in ['Linux', None]:  # Funtoo has PRETTY_NAME=Linux
        pretty = info.get('NAME', 'Unknown')
    assert pretty is not None

    dist_id = info.get('ID', None)
    id_mappings = {
        'funtoo': 'gentoo',  # does not have ID_LIKE=gentoo
        'artix': 'arch',
        'org.kde.Platform': 'kde_flatpak',
    }

    ids = []
    if dist_id is not None:
        ids.append(id_mappings.get(dist_id, dist_id))
    if 'ID_LIKE' in info:
        ids.extend(info['ID_LIKE'].split())

    parsed = Distribution.unknown
    for cur_id in ids:
        try:
            parsed = Distribution[cur_id]
        except KeyError:
            pass
        else:
            break

    return DistributionInfo(parsed=parsed, pretty=pretty, id=dist_id)


def is_flatpak() -> bool:
    """Whether qutebrowser is running via Flatpak.

    If packaged via Flatpak, the environment is has restricted access to the host
    system.
    """
    return flatpak_id() is not None


_FLATPAK_INFO_PATH = '/.flatpak-info'


def flatpak_id() -> Optional[str]:
    """Get the ID of the currently running Flatpak (or None if outside of Flatpak)."""
    if 'FLATPAK_ID' in os.environ:
        return os.environ['FLATPAK_ID']

    # 'FLATPAK_ID' was only added in Flatpak 1.2.0:
    # https://lists.freedesktop.org/archives/flatpak/2019-January/001464.html
    # but e.g. Ubuntu 18.04 ships 1.0.9.
    info_file = pathlib.Path(_FLATPAK_INFO_PATH)
    if not info_file.exists():
        return None

    parser = configparser.ConfigParser()
    parser.read(info_file)
    return parser['Application']['name']


def _git_str() -> Optional[str]:
    """Try to find out git version.

    Return:
        string containing the git commit ID.
        None if there was an error or we're not in a git repo.
    """
    # First try via subprocess if possible
    commit = None
    if not hasattr(sys, "frozen"):
        try:
            gitpath = os.path.join(os.path.dirname(os.path.realpath(__file__)),
                                   os.path.pardir, os.path.pardir)
        except (NameError, OSError):
            log.misc.exception("Error while getting git path")
        else:
            commit = _git_str_subprocess(gitpath)
    if commit is not None:
        return commit
    # If that fails, check the git-commit-id file.
    try:
        return resources.read_file('git-commit-id')
    except (OSError, ImportError):
        return None


def _call_git(gitpath: str, *args: str) -> str:
    """Call a git subprocess."""
    return subprocess.run(
        ['git'] + list(args),
        cwd=gitpath, check=True,
        stdout=subprocess.PIPE).stdout.decode('UTF-8').strip()


def _git_str_subprocess(gitpath: str) -> Optional[str]:
    """Try to get the git commit ID and timestamp by calling git.

    Args:
        gitpath: The path where the .git folder is.

    Return:
        The ID/timestamp on success, None on failure.
    """
    if not os.path.isdir(os.path.join(gitpath, ".git")):
        return None
    try:
        # https://stackoverflow.com/questions/21017300/21017394#21017394
        commit_hash = _call_git(gitpath, 'describe', '--match=NeVeRmAtCh',
                                '--always', '--dirty')
        date = _call_git(gitpath, 'show', '-s', '--format=%ci', 'HEAD')
        branch = _call_git(gitpath, 'rev-parse', '--abbrev-ref', 'HEAD')
        return '{} on {} ({})'.format(commit_hash, branch, date)
    except (subprocess.CalledProcessError, OSError):
        return None


def _release_info() -> Sequence[Tuple[str, str]]:
    """Try to gather distribution release information.

    Return:
        list of (filename, content) tuples.
    """
    blacklisted = ['ANSI_COLOR=', 'HOME_URL=', 'SUPPORT_URL=',
                   'BUG_REPORT_URL=']
    data = []
    for fn in glob.glob("/etc/*-release"):
        lines = []
        try:
            with open(fn, 'r', encoding='utf-8') as f:
                for line in f.read().strip().splitlines():
                    if not any(line.startswith(bl) for bl in blacklisted):
                        lines.append(line)

                if lines:
                    data.append((fn, '\n'.join(lines)))
        except OSError:
            log.misc.exception("Error while reading {}.".format(fn))
    return data


class ModuleInfo:

    """Class to query version information of qutebrowser dependencies.

    Attributes:
        name: Name of the module as it is imported.
        _version_attributes:
            Sequence of attribute names belonging to the module which may hold
            version information.
        min_version: Minimum version of this module which qutebrowser can use.
        _installed: Is the module installed? Determined at runtime.
        _version: Version of the module. Determined at runtime.
        _initialized:
            Set to `True` if the `self._installed` and `self._version`
            attributes have been set.
    """

    def __init__(
        self,
        name: str,
        version_attributes: Sequence[str],
        min_version: Optional[str] = None
    ):
        self.name = name
        self._version_attributes = version_attributes
        self.min_version = min_version
        self._installed = False
        self._version: Optional[str] = None
        self._initialized = False

    def _reset_cache(self) -> None:
        """Reset the version cache.

        It is necessary to call this method in unit tests that mock a module's
        version number.
        """
        self._installed = False
        self._version = None
        self._initialized = False

    def _initialize_info(self) -> None:
        """Import module and set `self.installed` and `self.version`."""
        try:
            module = importlib.import_module(self.name)
        except (ImportError, ValueError):
            self._installed = False
            return
        else:
            self._installed = True

        for attribute_name in self._version_attributes:
            if hasattr(module, attribute_name):
                version = getattr(module, attribute_name)
                assert isinstance(version, (str, float))
                self._version = str(version)
                break

        self._initialized = True

    def get_version(self) -> Optional[str]:
        """Finds the module version if it exists."""
        if not self._initialized:
            self._initialize_info()
        return self._version

    def is_installed(self) -> bool:
        """Checks whether the module is installed."""
        if not self._initialized:
            self._initialize_info()
        return self._installed

    def is_outdated(self) -> Optional[bool]:
        """Checks whether the module is outdated.

        Return:
            A boolean when the version and minimum version are both defined.
            Otherwise `None`.
        """
        version = self.get_version()
        if (
            not self.is_installed()
            or version is None
            or self.min_version is None
        ):
            return None
        return version < self.min_version

    def is_usable(self) -> bool:
        """Whether the module is both installed and not outdated."""
        return self.is_installed() and not self.is_outdated()

    def __str__(self) -> str:
        if not self.is_installed():
            return f'{self.name}: no'

        version = self.get_version()
        if version is None:
            return f'{self.name}: yes'

        text = f'{self.name}: {version}'
        if self.is_outdated():
            text += f" (< {self.min_version}, outdated)"
        return text


MODULE_INFO: Mapping[str, ModuleInfo] = collections.OrderedDict([
    # FIXME: Mypy doesn't understand this. See https://github.com/python/mypy/issues/9706
    (name, ModuleInfo(name, *args))  # type: ignore[arg-type, misc]
    for (name, *args) in
    [
        ('sip', ['SIP_VERSION_STR']),
        ('colorama', ['VERSION', '__version__']),
        ('jinja2', ['__version__']),
        ('pygments', ['__version__']),
        ('yaml', ['__version__']),
        ('adblock', ['__version__'], "0.3.2"),
        ('PyQt5.QtWebEngineWidgets', []),
        ('PyQt5.QtWebEngine', ['PYQT_WEBENGINE_VERSION_STR']),
        ('PyQt5.QtWebKitWidgets', []),
    ]
])


def _module_versions() -> Sequence[str]:
    """Get versions of optional modules.

    Return:
        A list of lines with version info.
    """
    return [str(mod_info) for mod_info in MODULE_INFO.values()]


def _path_info() -> Mapping[str, str]:
    """Get info about important path names.

    Return:
        A dictionary of descriptive to actual path names.
    """
    info = {
        'config': standarddir.config(),
        'data': standarddir.data(),
        'cache': standarddir.cache(),
        'runtime': standarddir.runtime(),
    }
    if standarddir.config() != standarddir.config(auto=True):
        info['auto config'] = standarddir.config(auto=True)
    if standarddir.data() != standarddir.data(system=True):
        info['system data'] = standarddir.data(system=True)
    return info


def _os_info() -> Sequence[str]:
    """Get operating system info.

    Return:
        A list of lines with version info.
    """
    lines = []
    releaseinfo = None
    if utils.is_linux:
        osver = ''
        releaseinfo = _release_info()
    elif utils.is_windows:
        osver = ', '.join(platform.win32_ver())
    elif utils.is_mac:
        release, info_tpl, machine = platform.mac_ver()
        if all(not e for e in info_tpl):
            versioninfo = ''
        else:
            versioninfo = '.'.join(info_tpl)
        osver = ', '.join(e for e in [release, versioninfo, machine] if e)
    elif utils.is_posix:
        osver = ' '.join(platform.uname())
    else:
        osver = '?'
    lines.append('OS Version: {}'.format(osver))
    if releaseinfo is not None:
        for (fn, data) in releaseinfo:
            lines += ['', '--- {} ---'.format(fn), data]
    return lines


def _pdfjs_version() -> str:
    """Get the pdf.js version.

    Return:
        A string with the version number.
    """
    try:
        pdfjs_file, file_path = pdfjs.get_pdfjs_res_and_path('build/pdf.js')
    except pdfjs.PDFJSNotFound:
        return 'no'
    else:
        pdfjs_file = pdfjs_file.decode('utf-8')
        version_re = re.compile(
            r"^ *(PDFJS\.version|(var|const) pdfjsVersion) = '(?P<version>[^']+)';$",
            re.MULTILINE)

        match = version_re.search(pdfjs_file)
        pdfjs_version = 'unknown' if not match else match.group('version')
        if file_path is None:
            file_path = 'bundled'

        return '{} ({})'.format(pdfjs_version, file_path)


def _get_pyqt_webengine_qt_version() -> Optional[str]:
    """Get the version of the PyQtWebEngine-Qt package.

    With PyQtWebEngine 5.15.3, the QtWebEngine binary got split into its own
    PyQtWebEngine-Qt PyPI package:

    https://www.riverbankcomputing.com/pipermail/pyqt/2021-February/043591.html
    https://www.riverbankcomputing.com/pipermail/pyqt/2021-February/043638.html

    PyQtWebEngine 5.15.4 renamed it to PyQtWebEngine-Qt5...:
    https://www.riverbankcomputing.com/pipermail/pyqt/2021-March/043699.html

    Here, we try to use importlib.metadata or its backport (optional dependency) to
    figure out that version number. If PyQtWebEngine is installed via pip, this will
    give us an accurate answer.
    """
    try:
        import importlib_metadata
    except ImportError:
        try:
            # pylint: disable=line-too-long
            import importlib.metadata as importlib_metadata  # type: ignore[import, no-redef]
        except ImportError:
            log.misc.debug("Neither importlib.metadata nor backport available")
            return None

    for suffix in ['Qt5', 'Qt']:
        try:
            return importlib_metadata.version(f'PyQtWebEngine-{suffix}')
        except importlib_metadata.PackageNotFoundError:
            log.misc.debug(f"PyQtWebEngine-{suffix} not found")

    return None


@dataclasses.dataclass
class WebEngineVersions:

    """Version numbers for QtWebEngine and the underlying Chromium."""

    webengine: utils.VersionNumber
    chromium: Optional[str]
    source: str
    chromium_major: Optional[int] = dataclasses.field(init=False)

    _CHROMIUM_VERSIONS: ClassVar[Dict[utils.VersionNumber, str]] = {
        # Qt 5.12: Chromium 69
        # (LTS)    69.0.3497.128 (~2018-09-11)
        #          5.12.0: Security fixes up to 70.0.3538.102 (~2018-10-24)
        #          5.12.1: Security fixes up to 71.0.3578.94  (2018-12-12)
        #          5.12.2: Security fixes up to 72.0.3626.121 (2019-03-01)
        #          5.12.3: Security fixes up to 73.0.3683.75  (2019-03-12)
        #          5.12.4: Security fixes up to 74.0.3729.157 (2019-05-14)
        #          5.12.5: Security fixes up to 76.0.3809.87  (2019-07-30)
        #          5.12.6: Security fixes up to 77.0.3865.120 (~2019-09-10)
        #          5.12.7: Security fixes up to 79.0.3945.130 (2020-01-16)
        #          5.12.8: Security fixes up to 80.0.3987.149 (2020-03-18)
        #          5.12.9: Security fixes up to 83.0.4103.97  (2020-06-03)
        #          5.12.10: Security fixes up to 86.0.4240.75 (2020-10-06)
        utils.VersionNumber(5, 12): '69.0.3497.128',

        # Qt 5.13: Chromium 73
        #          73.0.3683.105 (~2019-02-28)
        #          5.13.0: Security fixes up to 74.0.3729.157 (2019-05-14)
        #          5.13.1: Security fixes up to 76.0.3809.87  (2019-07-30)
        #          5.13.2: Security fixes up to 77.0.3865.120 (2019-10-10)
        utils.VersionNumber(5, 13): '73.0.3683.105',

        # Qt 5.14: Chromium 77
        #          77.0.3865.129 (~2019-10-10)
        #          5.14.0: Security fixes up to 77.0.3865.129 (~2019-09-10)
        #          5.14.1: Security fixes up to 79.0.3945.117 (2020-01-07)
        #          5.14.2: Security fixes up to 80.0.3987.132 (2020-03-03)
        utils.VersionNumber(5, 14): '77.0.3865.129',

        # Qt 5.15: Chromium 80
        #          80.0.3987.163 (2020-04-02)
        #          5.15.0: Security fixes up to 81.0.4044.138 (2020-05-05)
        #          5.15.1: Security fixes up to 85.0.4183.83  (2020-08-25)
        #          5.15.2: Updated to 83.0.4103.122           (~2020-06-24)
        #                  Security fixes up to 86.0.4240.183 (2020-11-02)
        #          5.15.3: Updated to 87.0.4280.144           (~2020-12-02)
        #                  Security fixes up to 88.0.4324.150 (2021-02-04)
        utils.VersionNumber(5, 15): '80.0.3987.163',
        utils.VersionNumber(5, 15, 2): '83.0.4103.122',
        utils.VersionNumber(5, 15, 3): '87.0.4280.144',
    }

    def __post_init__(self) -> None:
        """Set the major Chromium version."""
        if self.chromium is None:
            self.chromium_major = None
        else:
            self.chromium_major = int(self.chromium.split('.')[0])

    def __str__(self) -> str:
        s = f'QtWebEngine {self.webengine}'
        if self.chromium is not None:
            s += f', based on Chromium {self.chromium}'
        if self.source != 'UA':
            s += f' (from {self.source})'
        return s

    @classmethod
    def from_ua(cls, ua: 'websettings.UserAgent') -> 'WebEngineVersions':
        """Get the versions parsed from a user agent.

        This is the most reliable and "default" way to get this information (at least
        until QtWebEngine adds an API for it). However, it needs a fully initialized
        QtWebEngine, and we sometimes need this information before that is available.
        """
        assert ua.qt_version is not None, ua
        return cls(
            webengine=utils.VersionNumber.parse(ua.qt_version),
            chromium=ua.upstream_browser_version,
            source='UA',
        )

    @classmethod
    def from_elf(cls, versions: elf.Versions) -> 'WebEngineVersions':
        """Get the versions based on an ELF file.

        This only works on Linux, and even there, depends on various assumption on how
        QtWebEngine is built (e.g. that the version string is in the .rodata section).

        On Windows/macOS, we instead rely on from_pyqt, but especially on Linux, people
        sometimes mix and match Qt/QtWebEngine versions, so this is a more reliable
        (though hackish) way to get a more accurate result.
        """
        return cls(
            webengine=utils.VersionNumber.parse(versions.webengine),
            chromium=versions.chromium,
            source='ELF',
        )

    @classmethod
    def _infer_chromium_version(
            cls,
            pyqt_webengine_version: utils.VersionNumber,
    ) -> Optional[str]:
        """Infer the Chromium version based on the PyQtWebEngine version."""
        chromium_version = cls._CHROMIUM_VERSIONS.get(pyqt_webengine_version)
        if chromium_version is not None:
            return chromium_version

        # 5.15 patch versions change their QtWebEngine version, but no changes are
        # expected after 5.15.3.
        v5_15_3 = utils.VersionNumber(5, 15, 3)
        if v5_15_3 <= pyqt_webengine_version < utils.VersionNumber(6):
            minor_version = v5_15_3
        else:
            # e.g. 5.14.2 -> 5.14
            minor_version = pyqt_webengine_version.strip_patch()

        return cls._CHROMIUM_VERSIONS.get(minor_version)

    @classmethod
    def from_importlib(cls, pyqt_webengine_qt_version: str) -> 'WebEngineVersions':
        """Get the versions based on the PyQtWebEngine version.

        This is called if we don't want to fully initialize QtWebEngine (so
        from_ua isn't possible), we're not on Linux (or ELF parsing failed), but we have
        a PyQtWebEngine-Qt{,5} package from PyPI, so we could query its exact version.
        """
        parsed = utils.VersionNumber.parse(pyqt_webengine_qt_version)
        return cls(
            webengine=parsed,
            chromium=cls._infer_chromium_version(parsed),
            source='importlib',
        )

    @classmethod
    def from_pyqt(cls, pyqt_webengine_version: str) -> 'WebEngineVersions':
        """Get the versions based on the PyQtWebEngine version.

        This is the "last resort" if we don't want to fully initialize QtWebEngine (so
        from_ua isn't possible), we're not on Linux (or ELF parsing failed), and
        PyQtWebEngine-Qt{5,} isn't available from PyPI.

        Here, we assume that the PyQtWebEngine version is the same as the QtWebEngine
        version, and infer the Chromium version from that. This assumption isn't
        generally true, but good enough for some scenarios, especially the prebuilt
        Windows/macOS releases.
        """
        parsed = utils.VersionNumber.parse(pyqt_webengine_version)
        if utils.VersionNumber(5, 15, 3) <= parsed < utils.VersionNumber(6):
            # If we land here, we're in a tricky situation where we are forced to guess:
            #
            # PyQt 5.15.3 and 5.15.4 from PyPI come with QtWebEngine 5.15.2 (Chromium
            # 83), not 5.15.3 (Chromium 87). Given that there was no binary release of
            # QtWebEngine 5.15.3, this is unlikely to change before Qt 6.
            #
            # However, at this point:
            #
            # - ELF parsing failed
            #   (so we're likely on macOS or Windows, but not definitely)
            #
            # - Getting infos from a PyPI-installed PyQtWebEngine failed
            #   (so we're either in a PyInstaller-deployed qutebrowser, or a self-built
            #   or distribution-installed Qt)
            #
            # PyQt 5.15.3 and 5.15.4 come with QtWebEngine 5.15.2 (83-based), but if
            # someone lands here with the last Qt/PyQt installed from source, they might
            # be using QtWebEngine 5.15.3 (87-based). For now, we play it safe, and only
            # do this kind of "downgrade" when we know we're using PyInstaller.
            frozen = hasattr(sys, 'frozen')
            log.misc.debug(f"PyQt5 >= 5.15.3, frozen {frozen}")
            if frozen:
                parsed = utils.VersionNumber(5, 15, 2)

        return cls(
            webengine=parsed,
            chromium=cls._infer_chromium_version(parsed),
            source='PyQt',
        )

    @classmethod
    def from_qt(cls, qt_version: str, *, source: str = 'Qt') -> 'WebEngineVersions':
        """Get the versions based on the Qt version.

        This is called if we don't have PYQT_WEBENGINE_VERSION, i.e. with PyQt 5.12.
        """
        parsed = utils.VersionNumber.parse(qt_version)
        return cls(
            webengine=parsed,
            chromium=cls._infer_chromium_version(parsed),
            source=source,
        )


def qtwebengine_versions(avoid_init: bool = False) -> WebEngineVersions:
    """Get the QtWebEngine and Chromium version numbers.

    If we have a parsed user agent, we use it here. If not, we avoid initializing
    things at all costs (because this gets called early to find out about commandline
    arguments). Instead, we fall back on looking at the ELF file (on Linux), or, if that
    fails, use the PyQtWebEngine version.

    This can also be checked by looking at this file with the right Qt tag:
    https://code.qt.io/cgit/qt/qtwebengine.git/tree/tools/scripts/version_resolver.py#n41

    See WebEngineVersions above for a quick reference.

    Also see:

    - https://chromiumdash.appspot.com/schedule
    - https://www.chromium.org/developers/calendar
    - https://chromereleases.googleblog.com/
    """
    from qutebrowser.browser.webengine import webenginesettings

    if webenginesettings.parsed_user_agent is None and not avoid_init:
        webenginesettings.init_user_agent()

    if webenginesettings.parsed_user_agent is not None:
        return WebEngineVersions.from_ua(webenginesettings.parsed_user_agent)

    override = os.environ.get('QUTE_QTWEBENGINE_VERSION_OVERRIDE')
    if override is not None:
        return WebEngineVersions.from_qt(override, source='override')

    versions = elf.parse_webenginecore()
    if versions is not None:
        return WebEngineVersions.from_elf(versions)

    pyqt_webengine_qt_version = _get_pyqt_webengine_qt_version()
    if pyqt_webengine_qt_version is not None:
        return WebEngineVersions.from_importlib(pyqt_webengine_qt_version)

    if PYQT_WEBENGINE_VERSION_STR is not None:
        return WebEngineVersions.from_pyqt(PYQT_WEBENGINE_VERSION_STR)

    return WebEngineVersions.from_qt(qVersion())  # type: ignore[unreachable]


def _backend() -> str:
    """Get the backend line with relevant information."""
    if objects.backend == usertypes.Backend.QtWebKit:
        return 'new QtWebKit (WebKit {})'.format(qWebKitVersion())
    elif objects.backend == usertypes.Backend.QtWebEngine:
        return str(qtwebengine_versions(
            avoid_init='avoid-chromium-init' in objects.debug_flags))
    raise utils.Unreachable(objects.backend)


def _uptime() -> datetime.timedelta:
    time_delta = datetime.datetime.now() - objects.qapp.launch_time
    # Round off microseconds
    time_delta -= datetime.timedelta(microseconds=time_delta.microseconds)
    return time_delta


def _autoconfig_loaded() -> str:
    return "yes" if config.instance.yaml_loaded else "no"


def _config_py_loaded() -> str:
    if config.instance.config_py_loaded:
        return "{} has been loaded".format(standarddir.config_py())
    else:
        return "no config.py was loaded"


def version_info() -> str:
    """Return a string with various version information."""
    lines = _LOGO.lstrip('\n').splitlines()

    lines.append("qutebrowser v{}".format(qutebrowser.__version__))
    gitver = _git_str()
    if gitver is not None:
        lines.append("Git commit: {}".format(gitver))

    lines.append('Backend: {}'.format(_backend()))
    lines.append('Qt: {}'.format(earlyinit.qt_version()))

    lines += [
        '',
        '{}: {}'.format(platform.python_implementation(),
                        platform.python_version()),
        'PyQt: {}'.format(PYQT_VERSION_STR),
        '',
    ]

    lines += _module_versions()

    lines += [
        'pdf.js: {}'.format(_pdfjs_version()),
        'sqlite: {}'.format(sql.version()),
        'QtNetwork SSL: {}\n'.format(QSslSocket.sslLibraryVersionString()
                                     if QSslSocket.supportsSsl() else 'no'),
    ]

    if objects.qapp:
        style = objects.qapp.style()
        lines.append('Style: {}'.format(style.metaObject().className()))
        lines.append('Platform plugin: {}'.format(objects.qapp.platformName()))
        lines.append('OpenGL: {}'.format(opengl_info()))

    importpath = os.path.dirname(os.path.abspath(qutebrowser.__file__))

    lines += [
        'Platform: {}, {}'.format(platform.platform(),
                                  platform.architecture()[0]),
    ]
    dist = distribution()
    if dist is not None:
        lines += [
            'Linux distribution: {} ({})'.format(dist.pretty, dist.parsed.name)
        ]

    lines += [
        'Frozen: {}'.format(hasattr(sys, 'frozen')),
        "Imported from {}".format(importpath),
        "Using Python from {}".format(sys.executable),
        "Qt library executable path: {}, data path: {}".format(
            QLibraryInfo.location(QLibraryInfo.LibraryExecutablesPath),
            QLibraryInfo.location(QLibraryInfo.DataPath)
        )
    ]

    if not dist or dist.parsed == Distribution.unknown:
        lines += _os_info()

    lines += [
        '',
        'Paths:',
    ]
    for name, path in sorted(_path_info().items()):
        lines += ['{}: {}'.format(name, path)]

    lines += [
        '',
        'Autoconfig loaded: {}'.format(_autoconfig_loaded()),
        'Config.py: {}'.format(_config_py_loaded()),
        'Uptime: {}'.format(_uptime())
    ]

    return '\n'.join(lines)


@dataclasses.dataclass
class OpenGLInfo:

    """Information about the OpenGL setup in use."""

    # If we're using OpenGL ES. If so, no further information is available.
    gles: bool = False

    # The name of the vendor. Examples:
    # - nouveau
    # - "Intel Open Source Technology Center", "Intel", "Intel Inc."
    vendor: Optional[str] = None

    # The OpenGL version as a string. See tests for examples.
    version_str: Optional[str] = None

    # The parsed version as a (major, minor) tuple of ints
    version: Optional[Tuple[int, ...]] = None

    # The vendor specific information following the version number
    vendor_specific: Optional[str] = None

    def __str__(self) -> str:
        if self.gles:
            return 'OpenGL ES'
        return '{}, {}'.format(self.vendor, self.version_str)

    @classmethod
    def parse(cls, *, vendor: str, version: str) -> 'OpenGLInfo':
        """Parse OpenGL version info from a string.

        The arguments should be the strings returned by OpenGL for GL_VENDOR
        and GL_VERSION, respectively.

        According to the OpenGL reference, the version string should have the
        following format:

        <major>.<minor>[.<release>] <vendor-specific info>
        """
        if ' ' not in version:
            log.misc.warning("Failed to parse OpenGL version (missing space): "
                             "{}".format(version))
            return cls(vendor=vendor, version_str=version)

        num_str, vendor_specific = version.split(' ', maxsplit=1)

        try:
            parsed_version = tuple(int(i) for i in num_str.split('.'))
        except ValueError:
            log.misc.warning("Failed to parse OpenGL version (parsing int): "
                             "{}".format(version))
            return cls(vendor=vendor, version_str=version)

        return cls(vendor=vendor, version_str=version,
                   version=parsed_version, vendor_specific=vendor_specific)


@functools.lru_cache(maxsize=1)
def opengl_info() -> Optional[OpenGLInfo]:  # pragma: no cover
    """Get the OpenGL vendor used.

    This returns a string such as 'nouveau' or
    'Intel Open Source Technology Center'; or None if the vendor can't be
    determined.
    """
    assert QApplication.instance()

    override = os.environ.get('QUTE_FAKE_OPENGL')
    if override is not None:
        log.init.debug("Using override {}".format(override))
        vendor, version = override.split(', ', maxsplit=1)
        return OpenGLInfo.parse(vendor=vendor, version=version)

    old_context = cast(Optional[QOpenGLContext], QOpenGLContext.currentContext())
    old_surface = None if old_context is None else old_context.surface()

    surface = QOffscreenSurface()
    surface.create()

    ctx = QOpenGLContext()
    ok = ctx.create()
    if not ok:
        log.init.debug("Creating context failed!")
        return None

    ok = ctx.makeCurrent(surface)
    if not ok:
        log.init.debug("Making context current failed!")
        return None

    try:
        if ctx.isOpenGLES():
            # Can't use versionFunctions there
            return OpenGLInfo(gles=True)

        vp = QOpenGLVersionProfile()
        vp.setVersion(2, 0)

        try:
            vf = ctx.versionFunctions(vp)
        except ImportError as e:
            log.init.debug("Importing version functions failed: {}".format(e))
            return None

        if vf is None:
            log.init.debug("Getting version functions failed!")
            return None

        vendor = vf.glGetString(vf.GL_VENDOR)
        version = vf.glGetString(vf.GL_VERSION)

        return OpenGLInfo.parse(vendor=vendor, version=version)
    finally:
        ctx.doneCurrent()
        if old_context and old_surface:
            old_context.makeCurrent(old_surface)


def pastebin_version(pbclient: pastebin.PastebinClient = None) -> None:
    """Pastebin the version and log the url to messages."""
    def _yank_url(url: str) -> None:
        utils.set_clipboard(url)
        message.info("Version url {} yanked to clipboard.".format(url))

    def _on_paste_version_success(url: str) -> None:
        assert pbclient is not None
        global pastebin_url
        url = url.strip()
        _yank_url(url)
        pbclient.deleteLater()
        pastebin_url = url

    def _on_paste_version_err(text: str) -> None:
        assert pbclient is not None
        message.error("Failed to pastebin version"
                      " info: {}".format(text))
        pbclient.deleteLater()

    if pastebin_url:
        _yank_url(pastebin_url)
        return

    app = QApplication.instance()
    http_client = httpclient.HTTPClient()

    misc_api = pastebin.PastebinClient.MISC_API_URL
    pbclient = pbclient or pastebin.PastebinClient(http_client, parent=app,
                                                   api_url=misc_api)

    pbclient.success.connect(_on_paste_version_success)
    pbclient.error.connect(_on_paste_version_err)

    pbclient.paste(getpass.getuser(),
                   "qute version info {}".format(qutebrowser.__version__),
                   version_info(),
                   private=True)