# Create your views here.
from django.core.exceptions import ValidationError
from django.http import HttpResponseRedirect
from django.shortcuts import get_object_or_404
from django.utils.decorators import method_decorator
from django.views.decorators.csrf import csrf_protect
from django.views.generic.edit import FormView

from accounts.models import BlogUser
from blog.models import Article
from .forms import CommentForm
from .models import Comment


class CommentPostView(FormView):
    """
    处理文章评论提交的视图
    使用 FormView 来处理表单提交
    """
    form_class = CommentForm                             # 使用的表单类
    template_name = 'blog/article_detail.html'           # 表单出错时重新渲染的模板

    @method_decorator(csrf_protect)
    def dispatch(self, *args, **kwargs):
        # 强制开启 CSRF 防护
        return super(CommentPostView, self).dispatch(*args, **kwargs)

    def get(self, request, *args, **kwargs):
        """
        GET 请求时直接跳回文章详情页（因为评论应为 POST 行为）
        """
        article_id = self.kwargs['article_id']
        article = get_object_or_404(Article, pk=article_id)
        url = article.get_absolute_url()
        return HttpResponseRedirect(url + "#comments")   # 跳转到评论区域

    def form_invalid(self, form):
        """
        表单校验失败时重新渲染页面并显示错误信息
        """
        article_id = self.kwargs['article_id']
        article = get_object_or_404(Article, pk=article_id)

        return self.render_to_response({
            'form': form,
            'article': article
        })

    def form_valid(self, form):
        """
        表单提交且内容合法时执行写入数据库逻辑
        """
        user = self.request.user
        author = BlogUser.objects.get(pk=user.pk)       # 获取当前评论的用户对象
        article_id = self.kwargs['article_id']
        article = get_object_or_404(Article, pk=article_id)

        # 判断文章是否允许评论 (‘c’ 表示关闭评论状态)
        if article.comment_status == 'c' or article.status == 'c':
            raise ValidationError("该文章评论已关闭.")

        # 创建一个未保存的 comment 对象
        comment = form.save(False)
        comment.article = article

        # 获取博客配置：是否需要审核评论
        from djangoblog.utils import get_blog_setting
        settings = get_blog_setting()
        if not settings.comment_need_review:
            comment.is_enable = True   # 如果无需审核，直接设为可显示

        comment.author = author

        # 处理父评论（即：回复某条评论）
        if form.cleaned_data['parent_comment_id']:
            parent_comment = Comment.objects.get(
                pk=form.cleaned_data['parent_comment_id'])
            comment.parent_comment = parent_comment

        comment.save(True)   # 保存评论

        # 评论成功后跳回评论处
        return HttpResponseRedirect(
            "%s#div-comment-%d" %
            (article.get_absolute_url(), comment.pk))