# -*- coding: utf-8 -*-
# vim: autoindent shiftwidth=4 expandtab textwidth=80 tabstop=4 softtabstop=4

###############################################################################
# ScribeEngine - Open Source Blog Software                                    #
# --------------------------------------------------------------------------- #
# Copyright (c) 2010 Raoul Snyman                                             #
# --------------------------------------------------------------------------- #
# 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; version 2 of the License.                              #
#                                                                             #
# 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., 59  #
# Temple Place, Suite 330, Boston, MA 02111-1307 USA                          #
###############################################################################

import re
import hashlib
import hmac
import string
from random import choice
from datetime import datetime

from pylons import config, c
from turbomail import Message

from scribeengine.lib.base import render

def send_mail(template, mail_to, mail_from, subject, variables={}, attachments=[]):
    """
    Sends an e-mail using the template ``template``.

    ``template``
        The template to use.

    ``mail_to``
        One or more addresses to send the e-mail to.

    ``mail_from``
        The address to send e-mail from.

    ``subject``
        The subject of the e-mail.

    ``variables``
        Variables to be used in the template.

    ``attachments``
        If you want to attach files to the e-mail, use this list.
    """
    for name, value in variables.iteritems():
        setattr(c, name, value)
    message = Message(mail_from, mail_to, subject)
    message.plain = render(template)
    message.send()

def generate_url(title):
    """
    Generate a friendly URL from a blog post title.

    ``title``
        The title of the blog post.
    """
    return re.sub(r'[^a-zA-Z0-9]+', u'-', title.lower()).strip('-')

def hash_password(password):
    """
    Return an HMAC SHA256 hash of a password.

    ``password``
        The password to hash.
    """
    return unicode(hmac.new(config[u'security.salt'], password,
        hashlib.sha256).hexdigest(), 'utf-8')

def generate_key(length):
    """
    Generate a random set of letters and numbers of length ``length``. Usually
    used to generate activation keys.

    ``length``
        The length of the key.
    """
    return ''.join([choice(string.letters + string.digits) for i in range(length)])

def month_first_day(datetime):
    """
    Returns a modified datetime with the day being midnight of the first day of
    the month, given a datetime object.
    """
    return datetime.replace(day=1, hour=0, minute=0, second=0, microsecond=0)

def month_last_day(datetime):
    """
    Returns a modified datetime with the day being the last day of the month,
    given a datetime object.
    """
    if datetime.month in [1, 3, 5, 7, 8, 10, 12]:
        day = 31
    elif datetime.month in [4, 6, 9, 11]:
        day = 30
    else:
        if datetime.year % 4 == 0 and datetime.year % 100 != 0 or datetime.year % 400 == 0:
            day = 29
        else:
            day = 28
    return datetime.replace(day=day, hour=23, minute=59, second=59, microsecond=99999)