# Copyright 2019-2020 VyOS maintainers and contributors <maintainers@vyos.io>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library.  If not, see <http://www.gnu.org/licenses/>.

import sys
from datetime import datetime

from vyos import debug
from vyos.config import Config
from vyos.logger import syslog
from vyos.version import get_version
from vyos.version import get_full_version_data

# we allow to disable the extra logging
DISABLE = False


_noteworthy = []

def noteworthy(msg):
    """
    noteworthy can be use to take note things which we may not want to
    report to the user may but be worth including in bug report
    if something goes wrong later on
    """
    _noteworthy.append(msg)


# emulate a file object
class _IO(object):
    def __init__(self, std, log):
        self.std = std
        self.log = log

    def write(self, message):
        self.std.write(message)
        if DISABLE:
            return
        for line in message.split('\n'):
            s = line.rstrip()
            if s:
                self.log(s)

    def flush(self):
        self.std.flush()

    def close(self):
        pass


# The function which will be used to report information
# to users when an exception is unhandled
def bug_report(dtype, value, trace):
    from traceback import format_exception

    sys.stdout.flush()
    sys.stderr.flush()

    information = get_full_version_data()
    trace = '\n'.join(format_exception(dtype, value, trace)).replace('\n\n','\n')
    note = ''
    if _noteworthy:
        note = 'noteworthy:\n'
        note += '\n'.join(_noteworthy)

    information.update({
        'date': datetime.now().strftime('%Y-%m-%d %H:%M:%S'),
        'trace': trace,
        'instructions': COMMUNITY if 'rolling' in get_version() else SUPPORTED,
        'note': note,
    })

    sys.stdout.write(INTRO.format(**information))
    sys.stdout.flush()

    sys.stderr.write(FAULT.format(**information))
    sys.stderr.flush()


# define an exception handler to be run when an exception
# reach the end of __main__ and was not intercepted
def intercepter(dtype, value, trace):
    bug_report(dtype, value, trace)
    if debug.enabled('developer'):
        import pdb
        pdb.pm()


def InterceptingLogger(_singleton=[False]):
    skip = _singleton.pop()
    _singleton.append(True)
    if skip:
        return

    # log to syslog any message sent to stderr
    sys.stderr = _IO(sys.stderr, syslog.critical)


# lists as default arguments in function is normally dangerous
# as they will keep any modification performed, unless this is
# what you want to do (in that case to only run the code once)
def InterceptingException(excepthook,_singleton=[False]):
    skip = _singleton.pop()
    _singleton.append(True)
    if skip:
        return

    # install the handler to replace the default behaviour
    # which just prints the exception trace on screen
    sys.excepthook = excepthook


# Do not attempt the extra logging for operational commands
try:
    # This fails during boot
    insession = Config().in_session()
except:
    # we save info on boot to help debugging
    insession = True


# Installing the interception, it currently does not work when
# running testing so we are checking that we are on the router
# as otherwise it prevents dpkg-buildpackage to work
if get_version() and insession:
    InterceptingLogger()
    InterceptingException(intercepter)


# Messages to print
# if the key before the value has not time, syslog takes that as the source of the message

FAULT = """\
Report Time:      {date}
Image Version:    VyOS {version}
Release Train:    {release_train}

Built by:         {built_by}
Built on:         {built_on}
Build UUID:       {build_uuid}
Build Commit ID:  {build_git}

Architecture:     {system_arch}
Boot via:         {boot_via}
System type:      {system_type}

Hardware vendor:  {hardware_vendor}
Hardware model:   {hardware_model}
Hardware S/N:     {hardware_serial}
Hardware UUID:    {hardware_uuid}

{trace}
{note}
"""

INTRO = """\
VyOS had an issue completing a command.

We are sorry that you encountered a problem while using VyOS.
There are a few things you can do to help us (and yourself):
{instructions}

When reporting problems, please include as much information as possible:
- do not obfuscate any data (feel free to contact us privately if your 
  business policy requires it)
- and include all the information presented below

"""

COMMUNITY = """\
- Make sure you are running the latest version of the code available at
  https://downloads.vyos.io/rolling/current/amd64/vyos-rolling-latest.iso
- Consult the forum to see how to handle this issue
  https://forum.vyos.io
- Join our community on slack where our users exchange help and advice
  https://vyos.slack.com
""".strip()

SUPPORTED = """\
- Make sure you are running the latest stable version of VyOS
  the code is available at https://downloads.vyos.io/?dir=release/current
- Contact us using the online help desk
  https://support.vyos.io/
- Join our community on slack where our users exchange help and advice
  https://vyos.slack.com
""".strip()