from django.core.paginator import Paginator
from django.shortcuts import get_object_or_404, redirect
from django.template.defaultfilters import linebreaks_filter
from django.utils.decorators import method_decorator
from django.views.generic import FormView, ListView

from activities.models import Hashtag, Post, PostInteraction, TimelineEvent
from core.decorators import cache_page
from users.decorators import identity_required
from users.models import Identity

from .compose import Compose


@method_decorator(identity_required, name="dispatch")
class Home(FormView):

    template_name = "activities/home.html"

    form_class = Compose.form_class

    def get_form(self, form_class=None):
        return self.form_class(request=self.request, **self.get_form_kwargs())

    def get_context_data(self):
        context = super().get_context_data()
        events = (
            TimelineEvent.objects.filter(
                identity=self.request.identity,
                type__in=[TimelineEvent.Types.post, TimelineEvent.Types.boost],
            )
            .select_related("subject_post", "subject_post__author")
            .prefetch_related("subject_post__attachments", "subject_post__mentions")
            .order_by("-created")
        )
        context["interactions"] = PostInteraction.get_event_interactions(
            events, self.request.identity
        )
        context["current_page"] = "home"
        context["allows_refresh"] = True
        paginator = Paginator(events, 50)
        page_number = self.request.GET.get("page")
        context["page_obj"] = paginator.get_page(page_number)
        return context

    def form_valid(self, form):
        Post.create_local(
            author=self.request.identity,
            content=linebreaks_filter(form.cleaned_data["text"]),
            summary=form.cleaned_data.get("content_warning"),
            visibility=self.request.identity.config_identity.default_post_visibility,
        )
        return redirect(".")


@method_decorator(
    cache_page("cache_timeout_page_timeline", public_only=True), name="dispatch"
)
class Tag(ListView):

    template_name = "activities/tag.html"
    extra_context = {
        "current_page": "tag",
        "allows_refresh": True,
    }
    paginate_by = 50

    def get(self, request, hashtag, *args, **kwargs):
        tag = hashtag.lower().lstrip("#")
        if hashtag != tag:
            # SEO sanitize
            return redirect(f"/tags/{tag}/", permanent=True)
        self.hashtag = get_object_or_404(Hashtag.objects.public(), hashtag=tag)
        return super().get(request, *args, **kwargs)

    def get_queryset(self):
        return (
            Post.objects.public()
            .filter(author__restriction=Identity.Restriction.none)
            .tagged_with(self.hashtag)
            .select_related("author")
            .prefetch_related("attachments", "mentions")
            .order_by("-created")
        )

    def get_context_data(self):
        context = super().get_context_data()
        context["hashtag"] = self.hashtag
        context["interactions"] = PostInteraction.get_post_interactions(
            context["page_obj"], self.request.identity
        )
        return context


@method_decorator(
    cache_page("cache_timeout_page_timeline", public_only=True), name="dispatch"
)
class Local(ListView):

    template_name = "activities/local.html"
    extra_context = {
        "current_page": "local",
        "allows_refresh": True,
    }
    paginate_by = 50

    def get_queryset(self):
        return (
            Post.objects.local_public()
            .filter(author__restriction=Identity.Restriction.none)
            .select_related("author", "author__domain")
            .prefetch_related("attachments", "mentions", "emojis")
            .order_by("-created")
        )

    def get_context_data(self):
        context = super().get_context_data()
        context["interactions"] = PostInteraction.get_post_interactions(
            context["page_obj"], self.request.identity
        )
        return context


@method_decorator(identity_required, name="dispatch")
class Federated(ListView):

    template_name = "activities/federated.html"
    extra_context = {
        "current_page": "federated",
        "allows_refresh": True,
    }
    paginate_by = 50

    def get_queryset(self):
        return (
            Post.objects.filter(
                visibility=Post.Visibilities.public, in_reply_to__isnull=True
            )
            .filter(author__restriction=Identity.Restriction.none)
            .select_related("author", "author__domain")
            .prefetch_related("attachments", "mentions", "emojis")
            .order_by("-created")
        )

    def get_context_data(self):
        context = super().get_context_data()
        context["interactions"] = PostInteraction.get_post_interactions(
            context["page_obj"], self.request.identity
        )
        return context


@method_decorator(identity_required, name="dispatch")
class Notifications(ListView):

    template_name = "activities/notifications.html"
    extra_context = {
        "current_page": "notifications",
        "allows_refresh": True,
    }
    paginate_by = 50
    notification_types = {
        "followed": TimelineEvent.Types.followed,
        "boosted": TimelineEvent.Types.boosted,
        "mentioned": TimelineEvent.Types.mentioned,
        "liked": TimelineEvent.Types.liked,
    }

    def get_queryset(self):
        # Did they ask to change options?
        notification_options = self.request.session.get("notification_options", {})
        for type_name in self.notification_types:
            notification_options.setdefault(type_name, True)
            if self.request.GET.get(type_name) == "true":
                notification_options[type_name] = True
            elif self.request.GET.get(type_name) == "false":
                notification_options[type_name] = False
        self.request.session["notification_options"] = notification_options
        # Return appropriate events
        types = []
        for type_name, type in self.notification_types.items():
            if notification_options.get(type_name, True):
                types.append(type)
        return (
            TimelineEvent.objects.filter(identity=self.request.identity, type__in=types)
            .order_by("-created")
            .select_related(
                "subject_post",
                "subject_post__author",
                "subject_post__author__domain",
                "subject_identity",
            )
            .prefetch_related("subject_post__emojis")
        )

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        # Collapse similar notifications into one
        events = []
        for event in context["page_obj"]:
            if (
                events
                and event.type
                in [
                    TimelineEvent.Types.liked,
                    TimelineEvent.Types.boosted,
                    TimelineEvent.Types.mentioned,
                ]
                and event.subject_post_id == events[-1].subject_post_id
            ):
                events[-1].collapsed = True
            events.append(event)
        # Retrieve what kinds of things to show
        context["events"] = events
        context["notification_options"] = self.request.session["notification_options"]
        context["interactions"] = PostInteraction.get_event_interactions(
            context["page_obj"],
            self.request.identity,
        )
        return context