import json

from django.conf import settings
from django.contrib import messages
from django.contrib.humanize.templatetags.humanize import naturaltime
from django.core.exceptions import PermissionDenied
from django.http import HttpResponse
from django.shortcuts import redirect
from django.utils.translation import gettext as _
from django.views.generic import View as BaseView

from moku.constants import EMOJI_CATEGORIES, Verbs
from moku.forms.post import PostForm
from moku.images import process_post_image
from moku.models.post import Post
from moku.models.recipe import Recipe
from moku.views.base import FormView


class FeedView(FormView):
    """Allows users to see recent posts and create a new post."""

    template_name = "moku/feed.jinja"
    form_class = PostForm

    def form_valid(self, form):
        if not self.request.user.is_authenticated:
            raise PermissionDenied
        if (
            form.instance.recipe
            and form.instance.recipe.created_by.id != self.request.user.id
        ):
            messages.error(
                self.request, _("you can't add someone else's recipe to your post!")
            )
            return redirect("feed")
        form.instance.created_by = self.request.user
        if "image" in form.changed_data and form.instance.image is not None:
            form.instance.image = process_post_image(form.instance.image)
        form.save()
        messages.success(self.request, _("your post was made!"))
        return redirect("feed")

    def get_context_data(self, **kwargs):
        context = {
            **super().get_context_data(**kwargs),
            "posts": Post.objects.all()[:128],
        }
        if self.request.user.is_authenticated:
            return self.get_authenticated_context_data(context)
        return context

    def get_authenticated_context_data(self, context):
        return {
            **context,
            "emoji": EMOJI_CATEGORIES,
            "verbs": (
                (
                    verb[0],
                    verb[1] % {"user": f"@{self.request.user.username}", "food": "..."},
                )
                for verb in Verbs.CHOICES
            ),
        }

    def get_form(self, form_class=None):
        form = super().get_form(form_class)
        if self.request.user.is_authenticated:
            form.fields["recipe"].queryset = Recipe.objects.filter(
                created_by=self.request.user
            )
        return form


class LatestPostJSONView(BaseView):
    """Renders the latest post from a specific user as JSON."""

    def get(self, request, *args, **kwargs):
        post = (
            Post.objects.prefetch_related("recipe__steps")
            .filter(created_by__username=kwargs.get("username"))
            .order_by("-created_at")
            .first()
        )
        if not post:
            return HttpResponse(
                json.dumps({"post": None}), content_type="application/json"
            )
        post_data = {
            "date": {
                "iso": str(post.created_at),
                "natural": naturaltime(post.created_at),
            },
            "text": post.get_verb_display()
            % {"user": f"@{post.created_by.username}", "food": post.food},
            "food": post.food,
            "verb": {
                "id": post.verb,
                "pattern": post.get_verb_display() % {"user": "$1", "food": "$2"},
            },
            "image": f"{settings.SITE_ROOT_URL}{post.image.url}"
            if post.image
            else None,
            "user": {
                "username": post.created_by.username,
                "url": f"{settings.SITE_ROOT_URL}{post.created_by.get_absolute_url()}",
            },
        }
        if post.recipe:
            post_data["recipe"] = [
                step.instructions for step in post.recipe.steps.all()
            ]
        return HttpResponse(json.dumps(post_data), content_type="application/json")