#!/usr/bin/env python
#
# A library that provides a Python interface to the Telegram Bot API
# Copyright (C) 2015-2017
# Leandro Toledo de Souza <devs@python-telegram-bot.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser Public License as published by
# the Free Software Foundation, either version 3 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 Lesser Public License for more details.
#
# You should have received a copy of the GNU Lesser Public License
# along with this program.  If not, see [http://www.gnu.org/licenses/].
# TODO: Remove allow_edited
"""This module contains the RegexHandler class."""

import re
import warnings

from future.utils import string_types

from telegram import Update
from .handler import Handler


class RegexHandler(Handler):
    """Handler class to handle Telegram updates based on a regex.

    It uses a regular expression to check text messages. Read the documentation of the ``re``
    module for more information. The ``re.match`` function is used to determine if an update should
    be handled by this handler.

    Attributes:
        pattern (:obj:`str` | :obj:`Pattern`): The regex pattern.
        callback (:obj:`callable`): The callback function for this handler.
        pass_groups (:obj:`bool`): Optional. Determines whether ``groups`` will be passed to the
            callback function.
        pass_groupdict (:obj:`bool`): Optional. Determines whether ``groupdict``. will be passed to
            the callback function.
        pass_update_queue (:obj:`bool`): Optional. Determines whether ``update_queue`` will be
            passed to the callback function.
        pass_job_queue (:obj:`bool`): Optional. Determines whether ``job_queue`` will be passed to
            the callback function.
        pass_user_data (:obj:`bool`): Optional. Determines whether ``user_data`` will be passed to
            the callback function.
        pass_chat_data (:obj:`bool`): Optional. Determines whether ``chat_data`` will be passed to
            the callback function.

    Note:
        :attr:`pass_user_data` and :attr:`pass_chat_data` determine whether a ``dict`` you
        can use to keep any data in will be sent to the :attr:`callback` function.. Related to
        either the user or the chat that the update was sent in. For each update from the same user
        or in the same chat, it will be the same ``dict``.

    Args:
        pattern (:obj:`str` | :obj:`Pattern`): The regex pattern.
        callback (:obj:`callable`): A function that takes ``bot, update`` as positional arguments.
            It will be called when the :attr:`check_update` has determined that an update should be
            processed by this handler.
        pass_groups (:obj:`bool`, optional): If the callback should be passed the result of
            ``re.match(pattern, data).groups()`` as a keyword argument called ``groups``.
            Default is ``False``
        pass_groupdict (:obj:`bool`, optional): If the callback should be passed the result of
            ``re.match(pattern, data).groupdict()`` as a keyword argument called ``groupdict``.
            Default is ``False``
        pass_update_queue (:obj:`bool`, optional): If set to ``True``, a keyword argument called
            ``update_queue`` will be passed to the callback function. It will be the ``Queue``
            instance used by the :class:`telegram.ext.Updater` and :class:`telegram.ext.Dispatcher`
            that contains new updates which can be used to insert updates. Default is ``False``.
        pass_job_queue (:obj:`bool`, optional): If set to ``True``, a keyword argument called
            ``job_queue`` will be passed to the callback function. It will be a
            :class:`telegram.ext.JobQueue` instance created by the :class:`telegram.ext.Updater`
            which can be used to schedule new jobs. Default is ``False``.
        pass_user_data (:obj:`bool`, optional): If set to ``True``, a keyword argument called
            ``user_data`` will be passed to the callback function. Default is ``False``.
        pass_chat_data (:obj:`bool`, optional): If set to ``True``, a keyword argument called
            ``chat_data`` will be passed to the callback function. Default is ``False``.
        message_updates (:obj:`bool`, optional): Should "normal" message updates be handled?
            Default is ``True``.
        channel_post_updates (:obj:`bool`, optional): Should channel posts updates be handled?
            Default is ``True``.
        edited_updates (:obj:`bool`, optional): Should "edited" message updates be handled? Default
            is ``False``.
        allow_edited (:obj:`bool`, optional): If the handler should also accept edited messages.
            Default is ``False`` - Deprecated. use edited_updates instead.

    Raises:
        ValueError

    """

    def __init__(self,
                 pattern,
                 callback,
                 pass_groups=False,
                 pass_groupdict=False,
                 pass_update_queue=False,
                 pass_job_queue=False,
                 pass_user_data=False,
                 pass_chat_data=False,
                 allow_edited=False,
                 message_updates=True,
                 channel_post_updates=False,
                 edited_updates=False
                 ):
        if not message_updates and not channel_post_updates and not edited_updates:
            raise ValueError(
                'message_updates, channel_post_updates and edited_updates are all False')
        if allow_edited:
            warnings.warn('allow_edited is getting deprecated, please use edited_updates instead')
            edited_updates = allow_edited

        super(RegexHandler, self).__init__(
            callback,
            pass_update_queue=pass_update_queue,
            pass_job_queue=pass_job_queue,
            pass_user_data=pass_user_data,
            pass_chat_data=pass_chat_data)

        if isinstance(pattern, string_types):
            pattern = re.compile(pattern)

        self.pattern = pattern
        self.pass_groups = pass_groups
        self.pass_groupdict = pass_groupdict
        self.allow_edited = allow_edited
        self.message_updates = message_updates
        self.channel_post_updates = channel_post_updates
        self.edited_updates = edited_updates

    def check_update(self, update):
        """Determines whether an update should be passed to this handlers :attr:`callback`.

        Args:
            update (:class:`telegram.Update`): Incoming telegram update.

        Returns:
            :obj:`bool`

        """
        if not isinstance(update, Update) and not update.effective_message:
            return False
        if any([self.message_updates and update.message,
                self.edited_updates and (update.edited_message or update.edited_channel_post),
                self.channel_post_updates and update.channel_post]) and \
                update.effective_message.text:
            match = re.match(self.pattern, update.effective_message.text)
            return bool(match)
        return False

    def handle_update(self, update, dispatcher):
        """Send the update to the :attr:`callback`.

        Args:
            update (:class:`telegram.Update`): Incoming telegram update.
            dispatcher (:class:`telegram.ext.Dispatcher`): Dispatcher that originated the Update.

        """

        optional_args = self.collect_optional_args(dispatcher, update)
        match = re.match(self.pattern, update.effective_message.text)

        if self.pass_groups:
            optional_args['groups'] = match.groups()
        if self.pass_groupdict:
            optional_args['groupdict'] = match.groupdict()

        return self.callback(dispatcher.bot, update, **optional_args)
