from django.utils.translation import ungettext, ugettext as _

from django.utils.encoding import force_unicode

from django import template

from django.template import defaultfilters

from datetime import date

import re

register = template.Library()

def ordinal(value):

    """

    Converts an integer to its ordinal as a string. 1 is '1st', 2 is '2nd',

    3 is '3rd', etc. Works for any integer.

    """

    try:

        value = int(value)

    except ValueError:

        return value

    t = (_('th'), _('st'), _('nd'), _('rd'), _('th'), _('th'), _('th'), _('th'), _('th'), _('th'))

    if value % 100 in (11, 12, 13): # special case

        return u"%d%s" % (value, t[0])

    return u'%d%s' % (value, t[value % 10])

ordinal.is_safe = True

register.filter(ordinal)

def intcomma(value):

    """

    Converts an integer to a string containing commas every three digits.

    For example, 3000 becomes '3,000' and 45000 becomes '45,000'.

    """

    orig = force_unicode(value)

    new = re.sub("^(-?\d+)(\d{3})", '\g<1>,\g<2>', orig)

    if orig == new:

        return new

    else:

        return intcomma(new)

intcomma.is_safe = True

register.filter(intcomma)

def intword(value):

    """

    Converts a large integer to a friendly text representation. Works best for

    numbers over 1 million. For example, 1000000 becomes '1.0 million', 1200000

    becomes '1.2 million' and '1200000000' becomes '1.2 billion'.

    """

    value = int(value)

    if value < 1000000:

        return value

    if value < 1000000000:

        new_value = value / 1000000.0

        return ungettext('%(value).1f million', '%(value).1f million', new_value) % {'value': new_value}

    if value < 1000000000000:

        new_value = value / 1000000000.0

        return ungettext('%(value).1f billion', '%(value).1f billion', new_value) % {'value': new_value}

    if value < 1000000000000000:

        new_value = value / 1000000000000.0

        return ungettext('%(value).1f trillion', '%(value).1f trillion', new_value) % {'value': new_value}

    return value

intword.is_safe = False

register.filter(intword)

def apnumber(value):

    """

    For numbers 1-9, returns the number spelled out. Otherwise, returns the

    number. This follows Associated Press style.

    """

    try:

        value = int(value)

    except ValueError:

        return value

    if not 0 < value < 10:

        return value

    return (_('one'), _('two'), _('three'), _('four'), _('five'), _('six'), _('seven'), _('eight'), _('nine'))[value-1]

apnumber.is_safe = True

register.filter(apnumber)

def naturalday(value, arg=None):

    """

    For date values that are tomorrow, today or yesterday compared to

    present day returns representing string. Otherwise, returns a string

    formatted according to settings.DATE_FORMAT.

    """

    try: 

        value = date(value.year, value.month, value.day)

    except AttributeError:

        # Passed value wasn't a date object

        return value

    except ValueError:

        # Date arguments out of range

        return value

    delta = value - date.today()

    if delta.days == 0:

        return _(u'today')

    elif delta.days == 1:

        return _(u'tomorrow')

    elif delta.days == -1:

        return _(u'yesterday')

    return defaultfilters.date(value, arg)

register.filter(naturalday)