"""This file houses various core utility functions for GPP"""
import datetime
import re

import django.core.mail
from django.contrib.sites.models import Site
from django.conf import settings

import mailer


def send_mail(subject, message, from_email, recipient_list, 
        fail_silently = False, auth_user = None, auth_password = None):
    """The main gpp send email function.
    Use this function to send email from the site. It will obey debug settings and
    log all emails.
    """

    if settings.MAILER_ENQUEUE_MAIL:
        mailer.enqueue_mail(subject, message, from_email, recipient_list)
    elif settings.GPP_SEND_EMAIL:
        django.core.mail.send_mail(subject, message, from_email, recipient_list,
                fail_silently, auth_user, auth_password)

    import logging
    logging.debug('EMAIL:\nFrom: %s\nTo: %s\nSubject: %s\nMessage:\n%s' %
            (from_email, str(recipient_list), subject, message))


def email_admins(subject, message):
    """Emails the site admins. Goes through the site send_mail function."""
    site = Site.objects.get_current()
    subject = '[%s] %s' % (site.name, subject)
    send_mail(subject, 
            message, 
            '%s@%s' % (settings.GPP_NO_REPLY_EMAIL, site.domain),
            [mail_tuple[1] for mail_tuple in settings.ADMINS])


def email_managers(subject, message):
    """Emails the site managers. Goes through the site send_mail function."""
    site = Site.objects.get_current()
    subject = '[%s] %s' % (site.name, subject)
    send_mail(subject, 
            msg, 
            '%s@%s' % (settings.GPP_NO_REPLY_EMAIL, site.domain),
            [mail_tuple[1] for mail_tuple in settings.MANAGERS])


def get_full_name(user):
    """Returns the user's full name if available, otherwise falls back
    to the username."""
    full_name = user.get_full_name()
    if full_name:
        return full_name
    return user.username


BASE_YEAR = 2010

def copyright_str():
    curr_year = datetime.datetime.now().year
    if curr_year == BASE_YEAR:
        year_range = str(BASE_YEAR)
    else:
        year_range = "%d - %d" % (BASE_YEAR, curr_year)

    return 'Copyright (C) %s, SurfGuitar101.com' % year_range


IP_PAT = re.compile('(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})')

def get_ip(request):
    """Returns the IP from the request or None if it cannot be retrieved."""
    ip = request.META.get('HTTP_X_FORWARDED_FOR',
            request.META.get('REMOTE_ADDR'))

    if ip:
        match = IP_PAT.match(ip)
        ip = match.group(1) if match else None

    return ip


def get_page(qdict):
    """Attempts to retrieve the value for "page" from the given query dict and
    return it as an integer. If the key cannot be found or converted to an
    integer, 1 is returned.
    """
    n = qdict.get('page', 1)
    try:
        n = int(n)
    except ValueError:
        n = 1
    return n