import logging

import xml.etree.ElementTree as et

from django.http import HttpResponse, Http404

from boards.abstracts.sync_filters import ThreadFilter, TagsFilter,\
        TimestampFromFilter,\
        TAG_THREAD, TAG_TAGS, TAG_TIME_FROM
from boards.models import GlobalId, Post
from boards.models.post.sync import SyncManager


logger = logging.getLogger('boards.sync')


FILTERS = {
        TAG_THREAD: ThreadFilter,
        TAG_TAGS: TagsFilter,
        TAG_TIME_FROM: TimestampFromFilter,
}


def response_list(request):
    request_xml = request.body

    filters = []

    if request_xml is None or len(request_xml) == 0:
        return HttpResponse(content='Use the API')
    else:
        root_tag = et.fromstring(request_xml)
        model_tag = root_tag[0]

        for tag_filter in model_tag:
            filter_name = tag_filter.tag
            model_filter = FILTERS.get(filter_name)
            if not model_filter:
                logger.warning('Unavailable filter: {}'.format(filter_name))
            filters.append(model_filter(tag_filter))

    response_xml = SyncManager.generate_response_list(filters)

    return HttpResponse(content=response_xml)


def response_get(request):
    """
    Processes a GET request with post ID list and returns the posts XML list.
    Request should contain an 'xml' post attribute with the actual request XML.
    """

    request_xml = request.body

    if request_xml is None or len(request_xml) == 0:
        return HttpResponse(content='Use the API')

    posts = []

    root_tag = et.fromstring(request_xml)
    model_tag = root_tag[0]
    for id_tag in model_tag:
        global_id, exists = GlobalId.from_xml_element(id_tag)
        if exists:
            posts.append(Post.objects.get(global_id=global_id))

    response_xml = SyncManager.generate_response_get(posts)

    return HttpResponse(content=response_xml)


def get_post_sync_data(request, post_id):
    try:
        post = Post.objects.get(id=post_id)
    except Post.DoesNotExist:
        raise Http404()

    xml_str = SyncManager.generate_response_get([post])

    return HttpResponse(
        content_type='text/xml; charset=utf-8',
        content=xml_str,
    )