# coding=utf-8

# python imports
import datetime
import json
import urllib
import re
import sys
from HTMLParser import HTMLParser

# django settings
from django.conf import settings
from django.contrib.auth import SESSION_KEY
from django.contrib.auth import BACKEND_SESSION_KEY
from django.contrib.auth import load_backend
from django.contrib.auth.models import AnonymousUser
from django.core.cache import cache
from django.core.urlresolvers import reverse
from django.http import Http404
from django.http import HttpResponse
from django.http import HttpResponseRedirect
from django.shortcuts import _get_queryset
from django.utils.functional import Promise
from django.utils.encoding import force_unicode
from django.utils import translation

# lfc imports
import lfc.models


def get_cached_object(klass, *args, **kwargs):
    """
    Uses get() to return an object.

    klass may be a Model, Manager, or QuerySet object. All other passed
    arguments and keyword arguments are used in the get() query.

    Note: Like with get(), an MultipleObjectsReturned will be raised if more than one
    object is found.
    """
    # CACHE
    cache_key = "%s-%s" % (klass.__name__.lower(), kwargs.values()[0])
    object = cache.get(cache_key)
    if object is not None:
        return object

    queryset = _get_queryset(klass)
    object = queryset.get(*args, **kwargs)
    cache.set(cache_key, object)
    return object


class HttpJsonResponse(HttpResponse):
    """HttpResponse subclass that renders a json dict.
    The content given is nested inside the 'html' key of the dict,
    any kwargs given are also appended as key-value-pairs to the result.

    TODO: Subclass Djangos JsonResponse when updating to Django 1.7
    """
    def __init__(self, content, status=None, content_type=None, **kwargs):

        if content_type is None:
            content_type = "application/json"

        content = render_to_json(content, **kwargs)

        HttpResponse.__init__(self, content=content, status=status,
            content_type=content_type)


class MessageHttpResponseRedirect(HttpResponseRedirect):
    """Specific HttpResponseRedirect to set a cookie with a message.
    """
    def __init__(self, redirect_to, message):
        HttpResponseRedirect.__init__(self, redirect_to)

        # We just keep the message two seconds.
        max_age = 2
        expires = datetime.datetime.strftime(
            datetime.datetime.utcnow() +
            datetime.timedelta(seconds=max_age), "%a, %d-%b-%Y %H:%M:%S GMT")

        self.set_cookie("message", lfc_quote(message), max_age=max_age, expires=expires)


def set_message_to_reponse(response, msg):
    """Sets message cookie with passed message to passed response.
    """
    # We just keep the message two seconds.
    max_age = 2
    expires = datetime.datetime.strftime(
        datetime.datetime.utcnow() +
        datetime.timedelta(seconds=max_age), "%a, %d-%b-%Y %H:%M:%S GMT")

    response.set_cookie("message", lfc_quote(msg), max_age=max_age, expires=expires)
    return response


def render_to_json(html, **kwargs):
    """Renders given data to jsnon
    """
    data = {"html": html}
    data.update(**kwargs)

    return json.dumps(data, cls=LazyEncoder)


def return_as_json(html, message):
    """
    """
    return HttpResponse(get_json(html, message))


def get_json(html, message):
    """Returns html and message json encoded.
    """
    return json.dumps({"html": html, "message": message}, cls=LazyEncoder)


class LazyEncoder(json.JSONEncoder):
    """JSONEncoder which encodes django's lazy i18n strings.

    This is mainly used to return status messages along with content to ajax
    calls.
    """
    def default(self, obj):
        if isinstance(obj, Promise):
            return force_unicode(obj)
        return obj


def get_content_object(request=None, *args, **kwargs):
    """Returns specific content object based on passed parameters.

    This method should be used if one wants the specific content object
    instead of the BaseContent object.

    You can consider this as the equivalent to Django's get method.
    """
    obj = lfc.models.BaseContent.objects.get(*args, **kwargs)
    return obj.get_content_object()


def get_content_objects(request=None, *args, **kwargs):
    """Returns specific content objects based on passed parameters.

    This method should be used if one wants the specific content object
    instead of the BaseContent object.

    Takes permissions of the current and start_date and end_date of object
    into account.

    You can consider this as the equivalent to Django's filter method.
    """
    objs = lfc.models.BaseContent.objects.filter(*args, **kwargs)
    parent = kwargs.get("parent")

    if parent and parent.order_by:
        objs = objs.order_by(parent.order_by)

    result = []

    if request is None or request.user.is_superuser:
        for obj in objs:
            obj = obj.get_content_object()
            if lfc.utils.registration.get_info(obj):
                result.append(obj)
    else:
        for obj in objs:
            obj = obj.get_content_object()
            if lfc.utils.registration.get_info(obj) and \
                obj.has_permission(request.user, "view") and \
                obj.is_active(request.user):
                obj = obj.get_content_object()
                result.append(obj)

    return result


def get_portal(pk=1):
    """Returns the default portal.
    """
    # CACHE
    cache_key = "%s-portal-%s" % (settings.CACHE_MIDDLEWARE_KEY_PREFIX, pk)
    portal = cache.get(cache_key)
    if portal:
        return portal

    # At the moment the default portal should always exist.
    try:
        portal = lfc.models.Portal.objects.get(pk=pk)
    except lfc.models.Portal.DoesNotExist:
        portal = lfc.models.Portal.objects.filter()[0]

    cache.set(cache_key, portal)
    return portal


def get_user_from_session_key(session_key):
    """Returns the user from the passed session_key.

    This is a workaround for jquery.upload, which is used to mass upload images
    and files.
    """
    try:
        session_engine = __import__(settings.SESSION_ENGINE, {}, {}, [''])
        session_wrapper = session_engine.SessionStore(session_key)
        user_id = session_wrapper.get(SESSION_KEY)
        auth_backend = load_backend(session_wrapper.get(BACKEND_SESSION_KEY))
        if user_id and auth_backend:
            return auth_backend.get_user(user_id)
        else:
            return AnonymousUser()
    except AttributeError:
        return AnonymousUser()


def login_form(next=None):
    """Returns the lfc login form.
    """
    if next:
        url = "%s?next=%s" % (reverse("lfc_login"), next)
    else:
        url = reverse("lfc_login")

    return HttpResponseRedirect(url)


def traverse_object(request, path):
    """Returns the the object with the given path.
    """
    language = translation.get_language()

    # CACHE
    cache_key_1 = "%s-obj-%s" % (settings.CACHE_MIDDLEWARE_KEY_PREFIX, path)
    cache_key_2 = "%s-%s" % (request.user.id, language)

    obj = get_cache([cache_key_1, cache_key_2])
    if obj:
        return obj
    paths = path.split("/")
    language = translation.get_language()

    try:
        obj = lfc.utils.get_content_object(request, slug=paths[0],
            parent=None, language__in=("0", language))
    except lfc.models.BaseContent.DoesNotExist:
        raise Http404

    for path in paths[1:]:
        try:
            obj = obj.children.get(slug=path, language__in=("0", obj.language)).get_content_object()
        except lfc.models.BaseContent.DoesNotExist:
            raise Http404

    set_cache([cache_key_1, cache_key_2], obj)
    return obj


def delete_cache(keys):
    """Deletes cache based on keys
    """
    if len(keys) == 1:
        cache.delete(keys[0])
    else:
        start = cache.get(keys[0])
        d = start
        for key in keys[1:-1]:
            d = d[key]

        del d[keys[-1]]
        cache.set(keys[0], start)


def set_cache(keys, value):
    """Caches value in a dict which is based on keys.
    """
    assert(isinstance(keys, (tuple, list)))
    assert(len(keys) > 1)

    start = cache.get(keys[0])
    if start is None:
        start = {}
    d = start
    for key in keys[1:-1]:
        if key not in d.keys():
            d[key] = {}
        d = d[key]

    d[keys[-1]] = value

    cache.set(keys[0], start)


def get_cache(keys):
    """Returns cached value based on keys.
    """
    assert(isinstance(keys, (tuple, list)))
    assert(len(keys) > 1)

    d = cache.get(keys[0])
    if d is None:
        return None
    else:
        for key in keys[1:]:
            try:
                d = d[key]
            except KeyError:
                return None
        return d


def clear_cache():
    """Clears the complete cache.
    """
    # memcached
    try:
        cache._cache.flush_all()
    except AttributeError:
        pass

    try:
        cache._cache.clear()
    except AttributeError:
        pass

    try:
        cache._expire_info.clear()
    except AttributeError:
        pass


def import_module(module):
    """Imports module with given dotted name.
    """
    try:
        module = sys.modules[module]
    except KeyError:
        __import__(module)
        module = sys.modules[module]
    return module


def get_lol(objects, objects_per_row=3):
    """Returns a list of list of given objects.
    """
    result = []
    row = []
    for i, object in enumerate(objects):
        row.append(object)
        if (i + 1) % objects_per_row == 0:
            result.append(row)
            row = []

    if len(row) > 0:
        result.append(row)

    return result


def lfc_quote(string, encoding="utf-8"):
    """Encodes string to encoding before quoting.
    """
    return urllib.quote(string.encode(encoding))


class HTML2TextParser(HTMLParser):
    """HTMLParser to strip all HTML.
    """
    def __init__(self):
        HTMLParser.__init__(self)
        self.__text = ""

    def handle_entityref(self, name):
        name = name.replace(u"uuml", u"ü")
        name = name.replace(u"auml", u"ä")
        name = name.replace(u"ouml", u"o")
        name = name.replace(u"Uuml", u"Ü")
        name = name.replace(u"Auml", u"Ä")
        name = name.replace(u"Ouml", u"Ö")
        name = name.replace(u"szlig", u"ß")
        name = name.replace(u"ndash", u"-")
        self.__text += name

    def handle_data(self, data):
        if len(data) > 0:
            data = re.sub('[ \t\r\n]+', ' ', data)
            self.__text += data

    def handle_starttag(self, tag, attrs):
        self.__text += " "

    def handle_endtag(self, tag):
        self.__text += " "

    def text(self):
        return ''.join(self.__text).strip()


def html2text(html):
    """Removes HTML from given html
    """
    parser = HTML2TextParser()
    parser.feed(html)
    parser.close()
    return parser.text()
