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

# Copyright 2014-2018 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 <http://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 enum
import datetime
import getpass

import attr
import pkg_resources
from PyQt5.QtCore import PYQT_VERSION_STR, QLibraryInfo
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

try:
    from PyQt5.QtWebEngineWidgets import QWebEngineProfile
except ImportError:  # pragma: no cover
    QWebEngineProfile = None

import qutebrowser
from qutebrowser.utils import log, utils, standarddir, usertypes, message
from qutebrowser.misc import objects, earlyinit, sql, httpclient, pastebin
from qutebrowser.browser import pdfjs


@attr.s
class DistributionInfo:

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

    id = attr.ib()
    parsed = attr.ib()
    version = attr.ib()
    pretty = attr.ib()


pastebin_url = None
Distribution = enum.Enum(
    'Distribution', ['unknown', 'ubuntu', 'debian', 'void', 'arch',
                     'gentoo', 'fedora', 'opensuse', 'linuxmint', 'manjaro'])


def distribution():
    """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
            version: A Version object, or None
            pretty: Always a string (might be "Unknown")
    """
    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('#'):
                    continue
                k, v = line.split("=", maxsplit=1)
                info[k] = v.strip('"')
    except (OSError, UnicodeDecodeError):
        return None

    pretty = info.get('PRETTY_NAME', 'Unknown')
    if pretty == 'Linux':  # Thanks, Funtoo
        pretty = info.get('NAME', pretty)

    if 'VERSION_ID' in info:
        dist_version = pkg_resources.parse_version(info['VERSION_ID'])
    else:
        dist_version = None

    dist_id = info.get('ID', None)
    id_mappings = {
        'funtoo': 'gentoo',  # does not have ID_LIKE=gentoo
    }
    try:
        parsed = Distribution[id_mappings.get(dist_id, dist_id)]
    except KeyError:
        parsed = Distribution.unknown

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


def _git_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 utils.read_file('git-commit-id')
    except (OSError, ImportError):
        return None


def _git_str_subprocess(gitpath):
    """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 = subprocess.run(
            ['git', 'describe', '--match=NeVeRmAtCh', '--always', '--dirty'],
            cwd=gitpath, check=True,
            stdout=subprocess.PIPE).stdout.decode('UTF-8').strip()
        date = subprocess.run(
            ['git', 'show', '-s', '--format=%ci', 'HEAD'],
            cwd=gitpath, check=True,
            stdout=subprocess.PIPE).stdout.decode('UTF-8').strip()
        return '{} ({})'.format(commit_hash, date)
    except (subprocess.CalledProcessError, OSError):
        return None


def _release_info():
    """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


def _module_versions():
    """Get versions of optional modules.

    Return:
        A list of lines with version info.
    """
    lines = []
    modules = collections.OrderedDict([
        ('sip', ['SIP_VERSION_STR']),
        ('colorama', ['VERSION', '__version__']),
        ('pypeg2', ['__version__']),
        ('jinja2', ['__version__']),
        ('pygments', ['__version__']),
        ('yaml', ['__version__']),
        ('cssutils', ['__version__']),
        ('attr', ['__version__']),
        ('PyQt5.QtWebEngineWidgets', []),
        ('PyQt5.QtWebKitWidgets', []),
    ])
    for modname, attributes in modules.items():
        try:
            module = importlib.import_module(modname)
        except ImportError:
            text = '{}: no'.format(modname)
        else:
            for name in attributes:
                try:
                    text = '{}: {}'.format(modname, getattr(module, name))
                except AttributeError:
                    pass
                else:
                    break
            else:
                text = '{}: yes'.format(modname)
        lines.append(text)
    return lines


def _path_info():
    """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():
    """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, versioninfo, machine = platform.mac_ver()
        if all(not e for e in versioninfo):
            versioninfo = ''
        else:
            versioninfo = '.'.join(versioninfo)
        osver = ', '.join([e for e in [release, versioninfo, machine] if e])
    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():
    """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 pdfjsVersion) = '([^']+)';$",
            re.MULTILINE)

        match = version_re.search(pdfjs_file)
        if not match:
            pdfjs_version = 'unknown'
        else:
            pdfjs_version = match.group(2)
        if file_path is None:
            file_path = 'bundled'
        return '{} ({})'.format(pdfjs_version, file_path)


def _chromium_version():
    """Get the Chromium version for QtWebEngine.

    This can also be checked by looking at this file with the right Qt tag:
    https://github.com/qt/qtwebengine/blob/dev/tools/scripts/version_resolver.py#L41

    Quick reference:
    Qt 5.7:  Chromium 49
    Qt 5.8:  Chromium 53
    Qt 5.9:  Chromium 56
    Qt 5.10: Chromium 61
    Qt 5.11: Chromium 63
    Qt 5.12: Chromium 65 (?)
    """
    if QWebEngineProfile is None:
        # This should never happen
        return 'unavailable'
    profile = QWebEngineProfile()
    ua = profile.httpUserAgent()
    match = re.search(r' Chrome/([^ ]*) ', ua)
    if not match:
        log.misc.error("Could not get Chromium version from: {}".format(ua))
        return 'unknown'
    return match.group(1)


def _backend():
    """Get the backend line with relevant information."""
    if objects.backend == usertypes.Backend.QtWebKit:
        return 'new QtWebKit (WebKit {})'.format(qWebKitVersion())
    else:
        webengine = usertypes.Backend.QtWebEngine
        assert objects.backend == webengine, objects.backend
        return 'QtWebEngine (Chromium {})'.format(_chromium_version())


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


def version():
    """Return a string with various version information."""
    lines = ["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 += [
        '',
        '{}: {}'.format(platform.python_implementation(),
                        platform.python_version()),
        'Qt: {}'.format(earlyinit.qt_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'),
    ]

    qapp = QApplication.instance()
    if qapp:
        style = qapp.style()
        lines.append('Style: {}'.format(style.metaObject().className()))

    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),
        "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 += [
        '',
        'Uptime: {}'.format(_uptime()),
    ]

    return '\n'.join(lines)


def opengl_vendor():  # 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()

    old_context = 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("opengl_vendor: Creating context failed!")
        return None

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

    try:
        if ctx.isOpenGLES():
            # Can't use versionFunctions there
            return None

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

        vf = ctx.versionFunctions(vp)
        if vf is None:
            log.init.debug("opengl_vendor: Getting version functions failed!")
            return None

        return vf.glGetString(vf.GL_VENDOR)
    finally:
        ctx.doneCurrent()
        if old_context and old_surface:
            old_context.makeCurrent(old_surface)


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

    def _on_paste_version_success(url):
        global pastebin_url
        _yank_url(url)
        pbclient.deleteLater()
        pastebin_url = url

    def _on_paste_version_err(text):
        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(),
                   private=True)
