import logging

from datetime import datetime, timedelta, date
from datetime import time as dtime

from boards.abstracts.exceptions import BannedException, ArchiveException
from django.db import models, transaction
from django.utils import timezone
from django.dispatch import Signal
from django.core.exceptions import PermissionDenied

import boards

from boards.models.user import Ban
from boards.mdx_neboard import Parser
from boards.models import Attachment
from boards import utils

__author__ = 'neko259'

POSTS_PER_DAY_RANGE = 7
NO_IP = '0.0.0.0'


post_import_deps = Signal()


class PostManager(models.Manager):
    @transaction.atomic
    def create_post(self, title: str, text: str, files=[], thread=None,
                    ip=NO_IP, tags: list=None,
                    tripcode='', monochrome=False, images=[],
                    file_urls=[]):
        """
        Creates new post
        """

        if thread is not None and thread.is_archived():
            raise ArchiveException('Cannot post into an archived thread')

        if not utils.is_anonymous_mode():
            is_banned = Ban.objects.filter(ip=ip).exists()
        else:
            is_banned = False

        if is_banned:
            raise PermissionDenied()

        if not tags:
            tags = []

        posting_time = timezone.now()
        new_thread = False
        if not thread:
            thread = boards.models.thread.Thread.objects.create(
                bump_time=posting_time, last_edit_time=posting_time,
                monochrome=monochrome)
            list(map(thread.tags.add, tags))
            new_thread = True

        pre_text = Parser().preparse(text)

        post = self.create(title=title,
                           text=pre_text,
                           pub_time=posting_time,
                           poster_ip=ip,
                           thread=thread,
                           last_edit_time=posting_time,
                           tripcode=tripcode,
                           opening=new_thread)

        logger = logging.getLogger('boards.post.create')

        logger.info('Created post [{}] with text [{}] by {}'.format(post,
            post.get_text(),post.poster_ip))

        for file in files:
            self._add_file_to_post(file, post)
        for image in images:
            post.attachments.add(image)
        for file_url in file_urls:
            post.attachments.add(Attachment.objects.create_from_url(file_url))

        post.set_global_id()

        # Thread needs to be bumped only when the post is already created
        if not new_thread:
            thread.last_edit_time = posting_time
            thread.bump()
            thread.save()

        return post

    def delete_posts_by_ip(self, ip):
        """
        Deletes all posts of the author with same IP
        """

        posts = self.filter(poster_ip=ip)
        for post in posts:
            post.delete()

    @utils.cached_result()
    def get_posts_per_day(self) -> float:
        """
        Gets average count of posts per day for the last 7 days
        """

        day_end = date.today()
        day_start = day_end - timedelta(POSTS_PER_DAY_RANGE)

        day_time_start = timezone.make_aware(datetime.combine(
            day_start, dtime()), timezone.get_current_timezone())
        day_time_end = timezone.make_aware(datetime.combine(
            day_end, dtime()), timezone.get_current_timezone())

        posts_per_period = float(self.filter(
            pub_time__lte=day_time_end,
            pub_time__gte=day_time_start).count())

        ppd = posts_per_period / POSTS_PER_DAY_RANGE

        return ppd

    def get_post_per_days(self, days) -> int:
        day_end = date.today() + timedelta(1)
        day_start = day_end - timedelta(days)

        day_time_start = timezone.make_aware(datetime.combine(
            day_start, dtime()), timezone.get_current_timezone())
        day_time_end = timezone.make_aware(datetime.combine(
            day_end, dtime()), timezone.get_current_timezone())

        return self.filter(
            pub_time__lte=day_time_end,
            pub_time__gte=day_time_start).count()

    @transaction.atomic
    def import_post(self, title: str, text: str, pub_time: str, global_id,
                    opening_post=None, tags=list(), files=list(),
                    file_urls=list(), tripcode=None, last_edit_time=None):
        is_opening = opening_post is None
        if is_opening:
            thread = boards.models.thread.Thread.objects.create(
                bump_time=pub_time, last_edit_time=pub_time)
            list(map(thread.tags.add, tags))
        else:
            thread = opening_post.get_thread()

        post = self.create(title=title,
                           text=text,
                           pub_time=pub_time,
                           poster_ip=NO_IP,
                           last_edit_time=last_edit_time or pub_time,
                           global_id=global_id,
                           opening=is_opening,
                           thread=thread,
                           tripcode=tripcode)

        for file in files:
            self._add_file_to_post(file, post)
        for file_url in file_urls:
            post.attachments.add(Attachment.objects.create_from_url(file_url))

        url_to_post = '[post]{}[/post]'.format(str(global_id))
        replies = self.filter(text__contains=url_to_post)
        for reply in replies:
            post_import_deps.send(reply)

    @transaction.atomic
    def update_post(self, post, title: str, text: str, pub_time: str,
                    tags=list(), files=list(), file_urls=list(), tripcode=None):
        post.title = title
        post.text = text
        post.pub_time = pub_time
        post.tripcode = tripcode
        post.save()

        post.clear_cache()

        post.attachments.clear()
        for file in files:
            self._add_file_to_post(file, post)
        for file_url in file_urls:
            post.attachments.add(Attachment.objects.create_from_url(file_url))

        thread = post.get_thread()
        thread.tags.clear()
        list(map(thread.tags.add, tags))

    def _add_file_to_post(self, file, post):
        post.attachments.add(Attachment.objects.create_with_hash(file))