/**
 * Article comments API.
 *
 *   GET  /api/comments?article_slug=<slug>   → list, threaded by parent
 *   POST /api/comments                       → create (auth required)
 *
 * Reads: public — anyone can fetch.
 * Writes: signed-in users only. We assert via supabase auth and use the
 *   user's forum_user_profile for the denormalized display fields so the
 *   client can render avatar/name without an extra join per comment.
 */
import { NextRequest, NextResponse } from "next/server";
import { createClient } from "@/lib/supabase/server";

export const dynamic = "force-dynamic";

interface Row {
  id: string;
  article_slug: string;
  parent_comment_id: string | null;
  user_id: string | null;
  content: string;
  author_username: string | null;
  author_display_name: string | null;
  author_avatar_url: string | null;
  is_ai_seeded: boolean;
  upvotes: number;
  downvotes: number;
  vote_score: number;
  status: string;
  created_at: string;
  updated_at: string;
}

export async function GET(req: NextRequest) {
  const slug = new URL(req.url).searchParams.get("article_slug");
  if (!slug) return NextResponse.json({ error: "article_slug required" }, { status: 400 });

  const sb = await createClient();
  const { data, error } = await sb
    .from("article_comments")
    .select("*")
    .eq("article_slug", slug)
    .eq("status", "published")
    .order("vote_score", { ascending: false })
    .order("created_at", { ascending: true })
    .limit(500);

  if (error) return NextResponse.json({ error: error.message }, { status: 500 });
  return NextResponse.json({ comments: data || [] });
}

export async function POST(req: NextRequest) {
  const sb = await createClient();
  const { data: { user } } = await sb.auth.getUser();
  if (!user) {
    return NextResponse.json(
      { error: "Sign in to comment", redirectTo: "/forum/login" },
      { status: 401 },
    );
  }
  let body: { article_slug?: string; content?: string; parent_comment_id?: string | null };
  try { body = await req.json(); }
  catch { return NextResponse.json({ error: "Invalid JSON" }, { status: 400 }); }

  const slug = (body.article_slug || "").trim();
  const content = (body.content || "").trim();
  if (!slug || !content) {
    return NextResponse.json({ error: "article_slug and content required" }, { status: 400 });
  }
  if (content.length > 5000) {
    return NextResponse.json({ error: "Comment too long (5000 char max)" }, { status: 400 });
  }

  // Pull the user's forum profile so we have display name + avatar for
  // denormalized rendering (saves a per-comment join later).
  const { data: prof } = await sb
    .from("forum_user_profiles")
    .select("username, display_name, avatar_url")
    .eq("user_id", user.id)
    .maybeSingle();

  const ins = {
    article_slug: slug,
    user_id: user.id,
    content,
    parent_comment_id: body.parent_comment_id || null,
    is_ai_seeded: false,
    author_username: prof?.username || null,
    author_display_name: prof?.display_name || user.email?.split("@")[0] || "Member",
    author_avatar_url: prof?.avatar_url || null,
  };
  const { data, error } = await sb
    .from("article_comments")
    .insert(ins)
    .select()
    .single();
  if (error) return NextResponse.json({ error: error.message }, { status: 500 });
  return NextResponse.json({ comment: data });
}