"""Views DRF — PostViewSet, CommentViewSet, auth endpoints."""
from __future__ import annotations

from django.contrib.auth import authenticate
from django.contrib.auth.models import User
from django.db.models import Count
from django.utils import timezone
from rest_framework import status, viewsets
from rest_framework.authtoken.models import Token
from rest_framework.decorators import action, api_view, permission_classes
from rest_framework.permissions import AllowAny, IsAuthenticated, IsAuthenticatedOrReadOnly
from rest_framework.request import Request
from rest_framework.response import Response

from .models import Comment, Post
from .serializers import CommentSerializer, PostSerializer


# ── Auth ─────────────────────────────────────────────────────

@api_view(["POST"])
@permission_classes([AllowAny])
def register(request: Request) -> Response:
    username = request.data.get("username", "").strip()
    password = request.data.get("password", "")
    email = request.data.get("email", "")

    if not username or not password:
        return Response({"error": "username et password requis"}, status=400)
    if len(password) < 6:
        return Response({"error": "Mot de passe trop court (min 6 chars)"}, status=400)
    if User.objects.filter(username=username).exists():
        return Response({"error": "Username déjà utilisé"}, status=409)

    user = User.objects.create_user(username=username, password=password, email=email)
    token, _ = Token.objects.get_or_create(user=user)
    return Response({"token": token.key, "user_id": user.id, "username": user.username}, status=201)


@api_view(["POST"])
@permission_classes([AllowAny])
def login_view(request: Request) -> Response:
    user = authenticate(
        username=request.data.get("username", ""),
        password=request.data.get("password", ""),
    )
    if user is None:
        return Response({"error": "Identifiants incorrects"}, status=401)
    token, _ = Token.objects.get_or_create(user=user)
    return Response({"token": token.key, "user_id": user.id})


# ── Posts ─────────────────────────────────────────────────────

class PostViewSet(viewsets.ModelViewSet):
    serializer_class = PostSerializer
    permission_classes = [IsAuthenticatedOrReadOnly]

    def get_queryset(self):
        qs = (
            Post.objects
            .select_related("author")
            .prefetch_related("comments__author")
            .annotate(comment_count=Count("comments"))
        )
        # Filtre par statut (défaut : published pour les non-auth)
        status_param = self.request.query_params.get("status")
        if status_param:
            qs = qs.filter(status=status_param)
        elif not self.request.user.is_authenticated:
            qs = qs.filter(status="published")
        return qs

    @action(detail=True, methods=["post"], permission_classes=[IsAuthenticated])
    def publish(self, request: Request, pk: int = None) -> Response:
        post = self.get_object()
        if post.author != request.user and not request.user.is_staff:
            return Response({"error": "Non autorisé"}, status=403)
        if post.status == "published":
            return Response({"detail": "Déjà publié"}, status=400)
        post.status = "published"
        post.published_at = timezone.now()
        post.save()
        return Response(self.get_serializer(post).data)

    @action(detail=False, methods=["get"], permission_classes=[IsAuthenticated])
    def my_drafts(self, request: Request) -> Response:
        drafts = Post.objects.filter(author=request.user, status="draft")
        serializer = self.get_serializer(drafts, many=True)
        return Response(serializer.data)


# ── Comments ─────────────────────────────────────────────────

class CommentViewSet(viewsets.ModelViewSet):
    serializer_class = CommentSerializer
    permission_classes = [IsAuthenticatedOrReadOnly]
    http_method_names = ["get", "post", "delete"]

    def get_queryset(self):
        return (
            Comment.objects
            .filter(post_id=self.kwargs["post_pk"])
            .select_related("author")
        )

    def perform_create(self, serializer: CommentSerializer) -> None:
        serializer.save(
            author=self.request.user,
            post_id=self.kwargs["post_pk"],
        )