"use server";

import { revalidatePath } from "next/cache";
import { auth } from "@/lib/auth";
import { prisma } from "@/lib/prisma";
import { isAllowed } from "@/lib/services/moderation";

// website_article_comments.comment is VARCHAR(255); keep the write within bounds.
const COMMENT_MAX = 255;

/**
 * Post a comment on a news article as the SIGNED-IN user. The author id is read
 * from the session (re-fetched via auth()), never from the submitted FormData,
 * so a crafted form cannot post as another account. The articleId comes from the
 * form and is validated as a BigInt (website_articles.id is UNSIGNED BIGINT).
 */
export async function postComment(formData: FormData): Promise<void> {
  const session = await auth();
  if (!session?.user?.id) return;

  const userId = Number(session.user.id);
  if (!Number.isFinite(userId)) return;

  const comment = String(formData.get("comment") ?? "").trim().slice(0, COMMENT_MAX);
  if (!comment) return;

  // Block filtered/AI-flagged content before it touches the DB (fail-open).
  if (!(await isAllowed(comment)).ok) return;

  const articleIdRaw = String(formData.get("articleId") ?? "").trim();
  if (!/^\d+$/.test(articleIdRaw)) return;

  let articleId: bigint;
  try {
    articleId = BigInt(articleIdRaw);
  } catch {
    return;
  }

  let slug: string | null;
  try {
    // Confirm the article exists (and grab its slug for revalidation).
    const article = await prisma.websiteArticles.findUnique({
      where: { id: articleId },
      select: { slug: true },
    });
    if (!article) return;
    slug = article.slug;

    const now = new Date();
    await prisma.websiteArticleComments.create({
      data: {
        articleId,
        userId,
        comment,
        createdAt: now,
        updatedAt: now,
      },
    });
  } catch {
    // DB unavailable — fail soft; nothing to persist.
    return;
  }

  if (slug) revalidatePath(`/news/${slug}`);
}