# -*- coding: utf-8 -*-
"""
    jinja2.filters
    ~~~~~~~~~~~~~~

    Bundled jinja filters.

    :copyright: (c) 2010 by the Jinja Team.
    :license: BSD, see LICENSE for more details.
"""
import re
import math

from random import choice
from operator import itemgetter
from itertools import groupby
from jinja2.utils import Markup, 
escape, pformat, urlize, soft_unicode, \
     unicode_ur
lencode
from jinja2.runtime import Undefined
from jinja2.exceptions import FilterArgumentError
from jinja2._compat import imap, string_types, text_type, iteritems


_word_re = re.compile(r'\w+(?u)')


def contextfilter(f):
    """Decorator for marking context dependent filters. The current
    :class:`Context` will be passed as first argument.
    """
    f.contextfilter = True
    return f


def evalcontextfilter(f):
    """Decorator for marking eval-context dependent filters.  An eval
    context object is passed as first argument.  For more information
    about the eval context, see :ref:`eval-context`.

    .. versionadded:: 2.4
    """
    f.evalcontextfilter = True
    return f


def environmentfilter(f):
    """Decorator for marking evironment dependent filters.  The current
    :class:`Environment` is passed to the filter as first argument.
    """
    f.environmentfilter = True
    return f


def make_attrgetter(environment, attribute):
    """Returns a callable that looks up the given attribute from a
    passed object with the rules of the environment.  Dots are allowed
    to access attributes of attributes.  Integer parts in paths are
    looked up as integers.
    """
    if not isinstance(attribute, string_types) \
       or ('.' not in attribute and not attribute.isdigit()):
        return lambda x: environment.getitem(x, attribute)
    attribute = attribute.split('.')
    def attrgetter(item):
        for part in attribute:
            if part.isdigit():
                part = int(part)
            item = environment.getitem(item, part)
        return item
    return attrgetter


def do_forceescape(value):
    """Enforce HTML escaping.  This will probably double escape variables."""
    if hasattr(value, '__html__'):
        value = value.__html__()
    return escape(text_type(value))


def do_urlencode(value):
    """Escape strings for use in URLs (uses UTF-8 encoding).  It accepts both
    dictionaries and regular strings as well as pairwise iterables.

    .. versionadded:: 2.7
    """
    itemiter = None
    if isinstance(value, dict):
        itemiter = iteritems(value)
    elif not isinstance(value, string_types):
        try:
            itemiter = iter(value)
        except TypeError:
            pass
    if itemiter is None:
        return unicode_urlencode(value)
    return u'&'.join(unicode_urlencode(k) + '=' +
                     unicode_urlencode(v) for k, v in itemiter)


@evalcontextfilter
def do_replace(eval_ctx, s, old, new, count=None):
    """Return a copy of the value with all occurrences of a substring
    replaced with a new one. The first argument is the substring
    that should be replaced, the second is the replacement string.
    If the optional third argument ``count`` is given, only the first
    ``count`` occurrences are replaced:

    .. sourcecode:: jinja

        {{ "Hello World"|replace("Hello", "Goodbye") }}
            -> Goodbye World

        {{ "aaaaargh"|replace("a", "d'oh, ", 2) }}
            -> d'oh, d'oh, aaargh
    """
    if count is None:
        count = -1
    if not eval_ctx.autoescape:
        return text_type(s).replace(text_type(old), text_type(new), count)
    if hasattr(old, '__html__') or hasattr(new, '__html__') and \
       not hasattr(s, '__html__'):
        s = escape(s)
    else:
        s = soft_unicode(s)
    return s.replace(soft_unicode(old), soft_unicode(new), count)


def do_upper(s):
    """Convert a value to uppercase."""
    return soft_unicode(s).upper()


def do_lower(s):
    """Convert a value to lowercase."""
    return soft_unicode(s).lower()


@evalcontextfilter
def do_xmlattr(_eval_ctx, d, autospace=True):
    """Create an SGML/XML attribute string based on the items in a dict.
    All values that are neither `none` nor `undefined` are automatically
    escaped:

    .. sourcecode:: html+jinja

        <ul{{ {'class': 'my_list', 'missing': none,
                'id': 'list-%d'|format(variable)}|xmlattr }}>
        ...
        </ul>

    Results in something like this:

    .. sourcecode:: html

        <ul class="my_list" id="list-42">
        ...
        </ul>

    As you can see it automatically prepends a space in front of the item
    if the filter returned something unless the second parameter is false.
    """
    rv = u' '.join(
        u'%s="%s"' % (escape(key), escape(value))
        for key, value in iteritems(d)
        if value is not None and not isinstance(value, Undefined)
    )
    if autospace and rv:
        rv = u' ' + rv
    if _eval_ctx.autoescape:
        rv = Markup(rv)
    return rv


def do_capitalize(s):
    """Capitalize a value. The first character will be uppercase, all others
    lowercase.
    """
    return soft_unicode(s).capitalize()


def do_title(s):
    """Return a titlecased version of the value. I.e. words will start with
    uppercase letters, all remaining characters are lowercase.
    """
    rv = []
    for item in re.compile(r'([-\s]+)(?u)').split(soft_unicode(s)):
        if not item:
            continue
        rv.append(item[0].upper() + item[1:].lower())
    return ''.join(rv)


def do_dictsort(value, case_sensitive=False, by='key'):
    """Sort a dict and yield (key, value) pairs. Because python dicts are
    unsorted you may want to use this function to order them by either
    key or value:

    .. sourcecode:: jinja

        {% for item in mydict|dictsort %}
            sort the dict by key, case insensitive

        {% for item in mydict|dictsort(true) %}
            sort the dict by key, case sensitive

        {% for item in mydict|dictsort(false, 'value') %}
            sort the dict by value, case insensitive
    """
    if by == 'key':
        pos = 0
    elif by == 'value':
        pos = 1
    else:
        raise FilterArgumentError('You can only sort by either '
                                  '"key" or "value"')
    def sort_func(item):
        value = item[pos]
        if isinstance(value, string_types) and not case_sensitive:
            value = value.lower()
        return value

    return sorted(value.items(), key=sort_func)


@environmentfilter
def do_sort(environment, value, reverse=False, case_sensitive=False,
            attribute=None):
    """Sort an iterable.  Per default it sorts ascending, if you pass it
    true as first argument it will reverse the sorting.

    If the iterable is made of strings the third parameter can be used to
    control the case sensitiveness of the comparison which is disabled by
    default.

    .. sourcecode:: jinja

        {% for item in iterable|sort %}
            ...
        {% endfor %}

    It is also possible to sort by an attribute (for example to sort
    by the date of an object) by specifying the `attribute` parameter:

    .. sourcecode:: jinja

        {% for item in iterable|sort(attribute='date') %}
            ...
        {% endfor %}

    .. versionchanged:: 2.6
       The `attribute` parameter was added.
    """
    if not case_sensitive:
        def sort_func(item):
            if isinstance(item, string_types):
                item = item.lower()
            return item
    else:
        sort_func = None
    if attribute is not None:
        getter = make_attrgetter(environment, attribute)
        def sort_func(item, processor=sort_func or (lambda x: x)):
            return processor(getter(item))
    return sorted(value, key=sort_func, reverse=reverse)


def do_default(value, default_value=u'', boolean=False):
    """If the value is undefined it will return the passed default value,
    otherwise the value of the variable:

    .. sourcecode:: jinja

        {{ my_variable|default('my_variable is not defined') }}

    This will output the value of ``my_variable`` if the variable was
    defined, otherwise ``'my_variable 