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

from django.core.exceptions import PermissionDenied
from django.db import models, transaction
from django.dispatch import Signal
from django.shortcuts import redirect
from django.utils import timezone

import boards
from boards import utils
from boards.abstracts.exceptions import ArchiveException
from boards.abstracts.constants import REGEX_TAGS, REGEX_REPLY
from boards.mdx_neboard import Parser
from boards.models import Attachment
from boards.models.attachment import StickerPack, AttachmentSticker
from boards.models.user import Ban

__author__ = 'neko259'

POSTS_PER_DAY_RANGE = 7
NO_IP = '0.0.0.0'


post_import_deps = Signal()

FORM_TEXT = 'text'
FORM_TAGS = 'tags'

REFLINK_PREFIX = '>>'


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=[], stickerpack=False):
        """
        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, stickerpack=stickerpack)
            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_raw_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()

        self._create_stickers(post)

        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 create_from_form(self, request, form, opening_post, html_response=True):
        ip = utils.get_client_ip(request)

        data = form.cleaned_data

        title = form.get_title()
        text = data[FORM_TEXT]
        files = form.get_files()
        file_urls = form.get_file_urls()
        images = form.get_images()

        text = self._remove_invalid_links(text)

        if opening_post:
            post_thread = opening_post.get_thread()
            monochrome = False
            stickerpack = False
            tags = []
        else:
            tags = data[FORM_TAGS]
            monochrome = form.is_monochrome()
            stickerpack = form.is_stickerpack()
            post_thread = None

        post = self.create_post(title=title, text=text, files=files,
                                thread=post_thread, ip=ip,
                                tripcode=form.get_tripcode(),
                                images=images, file_urls=file_urls,
                                monochrome=monochrome,
                                stickerpack=stickerpack, tags=tags)

        if form.is_subscribe():
            from boards.abstracts.settingsmanager import get_settings_manager
            settings_manager = get_settings_manager(request)
            settings_manager.add_or_read_fav_thread(
                post.get_thread().get_opening_post())

        if html_response:
            return redirect(post.get_absolute_url())
        else:
            return post

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

    def _create_stickers(self, post):
        thread = post.get_thread()
        stickerpack_thread = thread.is_stickerpack()
        if stickerpack_thread:
            logger = logging.getLogger('boards.stickers')
            if not post.is_opening():
                has_title = len(post.title) > 0
                has_one_attachment = post.attachments.count() == 1
                opening_post = thread.get_opening_post()
                valid_name = REGEX_TAGS.match(post.title)
                if has_title and has_one_attachment and valid_name:
                    existing_sticker = AttachmentSticker.objects.filter(
                        name=post.get_title()).first()
                    attachment = post.attachments.first()
                    if existing_sticker:
                        existing_sticker.attachment = attachment
                        existing_sticker.save()
                        logger.info('Updated sticker {} with new attachment'.format(existing_sticker))
                    else:
                        try:
                            stickerpack = StickerPack.objects.get(
                                name=opening_post.get_title(), tripcode=post.tripcode)
                            sticker = AttachmentSticker.objects.create(
                                stickerpack=stickerpack, name=post.get_title(),
                                attachment=attachment)
                            logger.info('Created sticker {}'.format(sticker))
                        except StickerPack.DoesNotExist:
                            pass
            else:
                stickerpack, created = StickerPack.objects.get_or_create(
                    name=post.get_title(), tripcode=post.tripcode)
                if created:
                    logger.info('Created stickerpack {}'.format(stickerpack))

    def _remove_invalid_links(self, text):
        """
        Replace invalid links in posts so that they won't be parsed.
        Invalid links are links to non-existent posts
        """

        for reply_number in re.finditer(REGEX_REPLY, text):
            post_id = reply_number.group(1)
            post = self.filter(id=post_id)
            if not post.exists():
                text = text.replace(REFLINK_PREFIX + post_id, post_id)

        return text