#!/usr/bin/env python3
# -*- coding: utf-8  -*-
#
#  jogobot.py
#
#  Copyright 2015 GOLDERWEB – Jonathan Golder <jonathan@golderweb.de>
#
#  This program 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 2 of the License, or
#  (at your option) any later version.
#
#  This program 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 this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA 02110-1301, USA.
#
#

import os
from datetime import datetime
from email.mime.text import MIMEText
from subprocess import Popen, PIPE, TimeoutExpired

import pywikibot

from pywikibot.bot import(
    DEBUG, INFO, WARNING, ERROR, CRITICAL, STDOUT, VERBOSE, logoutput )


def output( text, level="INFO", decoder=None, newline=True,
            layer=None, **kwargs ):
    """
    Wrapper for pywikibot output functions
    """

    text = datetime.utcnow().strftime( "%Y-%m-%d %H:%M:%S (UTC) " ) + text

    if ( level.upper() == "STDOUT" ):
        _level = STDOUT
    elif( level.upper() == "INFO" ):
        _level = INFO
    elif( level.upper() == "WARNING" ):
        _level = WARNING
    elif( level.upper() == "ERROR" ):
        _level = ERROR
    elif( level.upper() == "LOG" or level.upper() == "VERBOSE" ):
        _level = VERBOSE
    elif( level.upper() == "CRITICAL" ):
        _level = CRITICAL
    elif( level.upper() == "DEBUG" ):
        _level = DEBUG
    else:
        pass

    if ( level == DEBUG ):
        logoutput(text, decoder, newline, _level, layer, **kwargs)
    else:
        logoutput(text, decoder, newline, _level, **kwargs)


# Since we like to have timestamps in Output for logging, we replace
# pywikibot.output with jogobot.output via monkey patching
def pywikibot_output( text, decoder=None, newline=True,
                      toStdout=False, **kwargs ):
    r"""Output a message to the user via the userinterface.

    Works like print, but uses the encoding used by the user's console
    (console_encoding in the configuration file) instead of ASCII.

    If decoder is None, text should be a unicode string. Otherwise it
    should be encoded in the given encoding.

    If newline is True, a line feed will be added after printing the text.

    If toStdout is True, the text will be sent to standard output,
    so that it can be piped to another process. All other text will
    be sent to stderr. See: https://en.wikipedia.org/wiki/Pipeline_%28Unix%29

    text can contain special sequences to create colored output. These
    consist of the escape character \03 and the color name in curly braces,
    e. g. \03{lightpurple}. \03{default} resets the color.

    Other keyword arguments are passed unchanged to the logger; so far, the
    only argument that is useful is "exc_info=True", which causes the
    log message to include an exception traceback.

    """
    if toStdout:  # maintained for backwards-compatibity only
        output(text, "STDOUT", decoder, newline, **kwargs)
    else:
        output(text, "INFO", decoder, newline, **kwargs)

pywikibot.output = pywikibot_output


class JogoBot:
    """
    Basic bot framework
    """

    def __init__( self ):
        """
        Initialise our class
        """

        # We need a pywikibot site object
        self.site = pywikibot.Site()

        # We need the shell working directory
        self.cwd = os.getcwd()

    def is_active( self ):
        """
        Checks if whole bot or task specified by task_slug is:
        * not blocked
        * not disabled by file
        * not disabled on wiki
        """
        pass

    def is_active_on_wiki( self, task_slug=None ):
        """
        Checks if whole bot or task specified by task_slug is disabled
        on wiki

        @param task_slug    Slug of task to check, None for whole Bot
        @type str
        """

        # Define page for look up
        if task_slug:
            page_title = "Benutzer:JogoBot/" + task_slug + "/active.js"
        else:
            page_title = "Benutzer:JogoBot/active"

        # Get pywikibot page object
        page = pywikibot.Page( self.site, page_title )

        # Get page text
        page_text = page.get()

        if "true" not in page_text.lower():
            pass
            # Disabled

            # Return False
            # Send E-Mail
            # Create disable-file

    def is_blocked_on_wiki( self ):
        """
        Checks if bot user is blocked on wiki
        """
        if self.site.is_blocked():
            pass
            # Blocked

            # Return False
            # Send E-Mail
            # Create disable-file

    def is_active_by_file(self, task_slug=None):
        """
        Checks if whole bot or task specified by task_slug is disabled
        by file

        @param task_slug    Slug of task to check, None for whole Bot
        @type str
        """

        # Define filepath
        if task_slug:
            disable_file = self.cwd + "/" + task_slug + "/disabled"
        else:
            disable_file = self.cwd + "/disabled"

        if os.path.isfile( disable_file ):
            pass
            # Disabled

            # Return False
            # Send E-Mail

    def create_disable_file( self, task_slug=None ):
        """
        Creates disable file for whole bot or task specified by task_slug

        @param task_slug    Slug of task to check, None for whole Bot
        @type str
        """

        # Define filepath
        if task_slug:
            disable_file = self.cwd + "/" + task_slug + "/disabled"
        else:
            disable_file = self.cwd + "/disabled"

        # Try to create file
        with open(disable_file, 'a'):
            pass

    @staticmethod
    def sendmail( Subject, Body, To=None, CC=None, BCC=None,
                  From="JogoBot <tools.jogobot@tools.wmflabs.org>" ):
        """
        Provides a simple wrapper for exim (MTA) on tool labs
        Params should be formated according related fields in RFC 5322

        @param subject  Mail subject
        @type subject str
        @param body    Mail body as (formated) string
        @type body  unicode-str
        @param to   Mail-Recipiends (comma-separeded)
        @type str
        @param from Mail-Sender
        @type str
        """

        # Create mail body as MIME-Object
        msg = MIMEText(Body)

        # Set up mail header
        msg['Subject'] = Subject

        msg['From'] = From

        if To:
            msg['To'] = To

        if CC:
            msg['CC'] = CC

        if BCC:
            msg['BCC'] = BCC

        msg['Content-Type'] = 'text/plain; charset=utf-8'

        # Make sure we have a recipient
        if not( To or CC or BCC):
            raise JogoBotMailError( "No recipient was provided!" )

        # Send the message via exim
        with Popen( ["/usr/sbin/exim", "-odf", "-i", "-t"],
                    stdin=PIPE, universal_newlines=True) as MTA:
            MTA.communicate(msg.as_string())

            # Try to get returncode of MTA
            # Process is not terminated until timeout, set returncode to None
            try:
                returncode = MTA.wait(timeout=30)
            except TimeoutExpired:
                returncode = None

        # Catch MTA errors
        if returncode:
            raise JogoBotMailError( "/usr/sbin/exim terminated with " +
                                    "returncode != 0. Returncode was " +
                                    str( returncode ) )


class JogoBotMailError( Exception ):
    """
    Handles errors occuring in class JogoBot related to mail actions
    """
    pass