import functools
from typing import Any, Dict
from django.conf import settings
from django.contrib.auth import get_user
from django.contrib.auth.mixins import PermissionRequiredMixin
from django.db.models import Q
from django.http import Http404, HttpResponseRedirect
from django.http.request import QueryDict
from django.shortcuts import get_object_or_404
from django.views.generic.base import TemplateView
from django.views.generic import detail, edit, list
from django.urls import reverse, reverse_lazy
from django.utils import timezone

from guardian.shortcuts import get_objects_for_user

from board.forms import *
from board.models import Ban, BanTemplate, Board, NewsPost, Post, Report
from board.utils import *

__all__ = (
    "ActionSuccessView",
    "BanCreateView",
    "BanSuccessView",
    "BannedView",
    "BoardView",
    "NewsListView",
    "PostCreateView",
    "PostModifyView",
    "PostModifySuccessView",
    "PostView",
    "PostSuccessView",
    "PostDeleteView",
    "PostWipeView",
    "ReplyCreateView",
    "ReportView",
)


def can_modify(user):
    if not user:
        return False
    # TODO add more permissions as required
    return (
        user.has_perm("board.set_sticky")
        or user.has_perm("board.set_bump")
        or user.has_perm("board.set_lock")
    )


class ActionSuccessView(TemplateView):
    template_name = "board/action_success.html"
    message = "Action completed."
    window_timeout = 0

    def get_context_data(self, **kwargs: Any) -> Dict[str, Any]:
        context = super().get_context_data(**kwargs)
        context["message"] = self.message
        context["window_timeout"] = self.window_timeout
        return context


class BannedView(TemplateView):
    template_name = "board/banned.html"

    def get_context_data(self, **kwargs):
        context = super(TemplateView, self).get_context_data(**kwargs)
        ip = get_client_ip(self.request)
        bans = get_ip_bans(ip)

        now = timezone.now()
        active_bans = [ban for ban in bans if not ban.expires or ban.expires > now]
        context["bans"] = bans
        context["active_bans"] = active_bans
        context["ip"] = ip

        return context


class BoardMixin:
    @functools.cached_property
    def board(self) -> Board:
        return get_object_or_404(Board, url=self.kwargs["url"])  # type: ignore


class NewsSnippetMixin:
    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["news"] = NewsPost.objects.order_by("-id")[:3]
        return context


class CreateView(BoardMixin, edit.CreateView):
    """
    Helper class that sets a few variables for posts and check against bans.
    This should not be used by itself.

    This class sets the following variables on GET and POST:
    * self.board
    """

    def get_form_kwargs(self):
        kwargs = super(CreateView, self).get_form_kwargs()
        kwargs["board"] = self.board
        kwargs["ip"] = get_client_ip(self.request)
        return kwargs

    def dispatch(self, request, *args, **kwargs):
        # Check for bans
        ip = get_client_ip(request)
        if request.method == "POST" and is_banned(ip, self.board):
            return HttpResponseRedirect(reverse("board:banned"))
        else:
            return super(CreateView, self).dispatch(request, *args, **kwargs)


class BoardView(NewsSnippetMixin, BoardMixin, TemplateView):
    template_name = "board/board_detail.html"

    def get(self, request, *args, **kwargs):
        # If the page isn't set, then redirect to the /page/1 url
        if "page" not in kwargs:
            return HttpResponseRedirect(
                reverse("board:board_detail", kwargs={"url": kwargs["url"], "page": 1})
            )
        return super(BoardView, self).get(request, *args, **kwargs)

    def get_context_data(self, **kwargs):
        page = self.kwargs["page"]

        if page not in range(1, self.board.max_pages + 1):
            raise Http404()

        threads_per_page = self.board.threads_per_page
        start = (page - 1) * threads_per_page
        end = start + threads_per_page
        thread_count = self.board.threads.count()
        last_page = (thread_count // threads_per_page) + 1

        kwargs["board"] = self.board
        kwargs["threads"] = self.board.threads.order_by("-sticky", "-last_bump")[
            start:end
        ]
        kwargs["current_page"] = page
        kwargs["pages"] = range(1, last_page + 1)
        kwargs["last_page"] = last_page
        kwargs["max_upload_size"] = settings.MAX_UPLOAD_SIZE
        return super(BoardView, self).get_context_data(**kwargs)


class PostCreateView(CreateView):
    model = Post
    form_class = PostForm
    template_name = "board/post_create.html"

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["board"] = self.board
        context["max_upload_size"] = settings.MAX_UPLOAD_SIZE
        context["capcodes"] = get_objects_for_user(
            get_user(self.request), "board.use_capcode"
        )
        return context

    def get_form_kwargs(self):
        kwargs = super(PostCreateView, self).get_form_kwargs()
        kwargs["user"] = self.request.user
        if "user_token" not in self.request.session:
            # Generate a user token
            self.request.session["user_token"] = generate_user_token()
        kwargs["user_token"] = self.request.session["user_token"]
        return kwargs

    def get_success_url(self) -> str:
        query = QueryDict(mutable=True)
        query["next"] = self.get_form().instance.get_absolute_url().split("#")[0]
        return reverse("board:post_success") + "?" + query.urlencode()


class PostModifyView(PermissionRequiredMixin, edit.UpdateView):
    model = Post
    form_class = PostModifyForm
    template_name = "board/post_modify.html"
    success_url = reverse_lazy("board:post_modify_success")
    raise_exception = True

    def has_permission(self) -> bool:
        return can_modify(self.request.user)

    def dispatch(self, request, *args, **kwargs):
        self.post_obj = get_object_or_404(Post, id=kwargs["pk"])
        self.board = self.post_obj.board
        return super(PostModifyView, self).dispatch(request, *args, **kwargs)

    def get_form_kwargs(self) -> Dict[str, Any]:
        kwargs = super(PostModifyView, self).get_form_kwargs()
        kwargs["user"] = self.request.user
        return kwargs


class PostModifySuccessView(PermissionRequiredMixin, ActionSuccessView):
    raise_exception = True

    def has_permission(self) -> bool:
        return can_modify(self.request.user)


class ReplyCreateView(CreateView):
    model = Post
    form_class = ReplyForm
    template_name = "board/reply_create.html"
    success_url = reverse_lazy("board:post_success")

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["board"] = self.board
        post_id = self.kwargs["id"]
        context["post"] = get_object_or_404(Post, id=post_id)
        context["max_upload_size"] = settings.MAX_UPLOAD_SIZE
        context["capcodes"] = get_objects_for_user(
            get_user(self.request), "board.use_capcode"
        )
        return context

    def get_form_kwargs(self):
        kwargs = super(ReplyCreateView, self).get_form_kwargs()
        post_id = self.kwargs["id"]
        post = get_object_or_404(Post, id=post_id)
        kwargs["op"] = post
        kwargs["user"] = self.request.user
        if "user_token" not in self.request.session:
            # Generate a user token
            self.request.session["user_token"] = generate_user_token()
        kwargs["user_token"] = self.request.session["user_token"]
        return kwargs

    def get_success_url(self) -> str:
        query = QueryDict(mutable=True)
        query["next"] = self.get_form().instance.get_absolute_url()
        return reverse("board:post_success") + "?" + query.urlencode()


class PostView(NewsSnippetMixin, TemplateView):
    template_name = "board/post_detail.html"

    def get_context_data(self, **kwargs):
        kwargs["board"] = self.board
        post_id = self.kwargs["id"]
        post = get_object_or_404(Post, id=post_id)
        kwargs["post"] = post
        kwargs["replies"] = post.replies.all().order_by("id")
        kwargs["max_upload_size"] = settings.MAX_UPLOAD_SIZE
        return super(PostView, self).get_context_data(**kwargs)

    def dispatch(self, request, *args, **kwargs):
        # Set the board on this object
        self.board = get_object_or_404(Board, url=kwargs["url"])
        return super(PostView, self).dispatch(request, *args, **kwargs)


class PostSuccessView(ActionSuccessView):
    template_name = "board/post_success.html"
    window_timeout = settings.POST_WINDOW_CLOSE_TIMEOUT


class PostDeleteView(PermissionRequiredMixin, edit.DeleteView):
    model = Post
    form_class = PostDeleteForm
    permission_required = ("board.delete_post",)
    template_name = "board/post_confirm_delete.html"
    success_url = reverse_lazy("board:post_delete_success")
    raise_exception = True

    def has_permission(self) -> bool:
        object = self.get_object()
        user_token = self.request.session.get("user_token", None)
        return self.request.user.has_perm("board.delete_post") or (
            user_token and object.user_token == user_token
        )

    def form_valid(self, form):
        success_url = self.get_success_url()
        if form["image_only"].value() != "0":
            self.object.image.delete()
            self.object.thumbnail.delete()
        else:
            self.object.delete()
        return HttpResponseRedirect(success_url)


class PostWipeView(PermissionRequiredMixin, detail.SingleObjectMixin, TemplateView):
    model = Post
    permission_required = ("wipe_user",)
    template_name = "board/post_wipe.html"
    success_url = reverse_lazy("board:post_wipe_success")

    @property
    def all_posts(self):
        return Post.objects.filter(
            Q(ip=self.object.ip) | Q(user_token=self.object.user_token)
        )

    def dispatch(self, request, *args, **kwargs):
        self.object = self.get_object()
        return super(PostWipeView, self).dispatch(request, *args, **kwargs)

    def post(self, request, *args, **kwargs):
        # Wipe user's posts
        self.all_posts.delete()
        # Success redirect
        success_url = self.get_success_url()
        return HttpResponseRedirect(success_url)

    def get_context_data(self, **kwargs):
        context = super(PostWipeView, self).get_context_data(**kwargs)
        # context["all_posts"] = self.all_posts
        # for some reason, {{all_posts.count}} does not seem to work in the template.
        context["all_posts_count"] = self.all_posts.count()
        return context

    def get_success_url(self):
        return self.success_url


class ReportView(CreateView):
    model = Report
    form_class = ReportForm
    success_url = reverse_lazy("board:report_success")

    @property
    def board_url(self) -> str:
        return self.kwargs["url"]

    @property
    def post_id(self) -> int:
        return self.kwargs["id"]

    def get_form_kwargs(self):
        kwargs = super(ReportView, self).get_form_kwargs()
        post_id = self.kwargs["id"]
        post = get_object_or_404(Post, id=post_id)
        kwargs["op"] = post
        return kwargs


class BanCreateView(PermissionRequiredMixin, edit.CreateView):
    model = Ban
    form_class = BanForm
    permission_required = "board.add_ban"
    success_url = reverse_lazy("board:ban_success")
    raise_exception = True

    def get_context_data(self, **kwargs: Any) -> Dict[str, Any]:
        context = super().get_context_data(**kwargs)
        context["board"] = self.board
        context["post"] = self.post_obj
        ip = self.post_obj.ip
        now = timezone.now()
        bans = [
            ban
            for ban in get_ip_bans(ip)
            if ban.board == self.board or ban.board is None
        ]
        context["previous_bans"] = [
            ban for ban in bans if ban.expires and ban.expires < now
        ]
        context["current_bans"] = [
            ban for ban in bans if not ban.expires or ban.expires > now
        ]
        context["templates"] = BanTemplate.objects.filter(
            Q(board=self.board) | Q(board=None)
        )

        return context

    def get_form_kwargs(self) -> Dict[str, Any]:
        kwargs = super(edit.CreateView, self).get_form_kwargs()
        post_id = self.kwargs["id"]
        post = get_object_or_404(Post, id=post_id)
        kwargs["op"] = post
        return kwargs

    def dispatch(self, request, *args, **kwargs):
        self.board = get_object_or_404(Board, url=kwargs["url"])
        self.post_obj = get_object_or_404(Post, pk=kwargs["id"])
        return super().dispatch(request, *args, **kwargs)


class BanSuccessView(PermissionRequiredMixin, ActionSuccessView):
    permission_required = "ban.create"
    raise_exception = True


class NewsListView(list.ListView):
    model = NewsPost
    template_name = "board/news_list.html"
    ordering = ("-created",)