old-scribeengine/scribeengine/lib/utils.py

# -*- 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, h

class KeywordProcessor(object):
    """Process user-supplied keywords, tags, or search terms.

    This tries to be as flexible as possible while being efficient.
    The vast majority of the work is done in the regular expression."""

    def __init__(self, separators=' \t', quotes=['"', "'"], groups=[], group=False, normalize=None, sort=False, result=list):
        """Configure the processor.

        separators: A list of acceptable separator characters.  The first will be used for joins.
        quotes: Pass a list or tuple of allowable quotes. E.g. ["\"", "'"] or None to disable.
        groups: Pass a string, list, or tuple of allowable prefixes.  E.g. '+-' or None to disable.
        group: Pass in the type you want to group by, e.g. list, tuple, or dict.
        normalize: Pass a function which will normalize the results.  E.g. lambda s: s.lower().strip(' \"')
        sort: Sort the resulting list (or lists) alphabeticlly.
        result: The return type.  One of set, tuple, list.

        If groups are defined, and group is not, the result will be a list/tuple/set of tuples, e.g. [('+', "foo"), ...]
        """
        separators = list(separators)
        self.pattern = ''.join((
                ('[\s%s]*' % (''.join(separators), )), # Trap possible leading space or separators.
                '(',
                    ('[%s]%s' % (''.join([i for i in list(groups) if i is not None]), '?' if None in groups else '')) if groups else '', # Pass groups=('+','-') to handle optional leading + or -.
                    ''.join([(r'%s[^%s]+%s|' % (i, i, i)) for i in quotes]) if quotes else '', # Match any amount of text (that isn't a quote) inside quotes.
                    ('[^%s]+' % (''.join(separators), )), # Match any amount of text that isn't whitespace.
                ')',
                ('[%s]*' % (''.join(separators), )), # Match possible separator character.
            ))
        self.regex = re.compile(self.pattern)
        self.groups = list(groups)
        self.group = dict if group is True else group
        self.normalize = normalize
        self.sort = sort
        self.result = result

    def split(self, value):
        if not isinstance(value, basestring):
            raise TypeError("Invalid type for argument 'value'.")
        matches = self.regex.findall(value)
        if callable(self.normalize):
            matches = [self.normalize(i) for i in matches]
        if self.sort:
            matches.sort()
        if not self.groups:
            return self.result(matches)
        groups = dict([(i, list()) for i in self.groups])
        if None not in groups.iterkeys():
            groups[None] = list() # To prevent errors.
        for i in matches:
            if i[0] in self.groups:
                groups[i[0]].append(i[1:])
            else:
                groups[None].append(i)
        if self.group is dict:
            return groups
        if self.group is False or self.group is None:
            results = []
            for group in self.groups:
                results.extend([(group, match) for match in groups[group]])
            return self.result(results)
        return self.group([[match for match in groups[group]] for group in self.groups])


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)

def paginate(query, page_size, current_page, base_url=None):
    query_count = query.count()
    page_count = query_count / page_size
    if query_count % page_size > 0:
        page_count += 1
    offset = (current_page - 1) * page_size
    records = query.offset(offset).limit(page_size).all()
    prev_page = current_page - 1 if current_page - 1 >= 1 else 1
    next_page = current_page + 1 if current_page + 1 <= page_count else page_count
    if base_url:
        return {
            u'page': h.url_for(base_url, page=current_page),
            u'first': h.url_for(base_url, page=1),
            u'prev': h.url_for(base_url, page=prev_page),
            u'next': h.url_for(base_url, page=next_page),
            u'last': h.url_for(base_url, page=page_count),
            u'start': offset + 1,
            u'end': offset + len(records),
            u'total': query_count,
            u'records': records
        }
    else:
        return {
            u'page': current_page,
            u'first': 1,
            u'prev': prev_page,
            u'next': next_page,
            u'last': page_count,
            u'start': offset + 1,
            u'end': offset + len(records),
            u'total': query_count,
            u'records': records
        }