import { NextRequest, NextResponse } from "next/server";
import { db, users, userFollows, eq, and } from "@epicure/db";
import { requireSession } from "@/lib/api-auth";
import { applyRateLimit } from "@/lib/rate-limit";
import { createNotification } from "@/lib/notifications";

type Params = { params: Promise<{ username: string }> };

export async function POST(_req: NextRequest, { params }: Params) {
  const { session, response } = await requireSession();
  if (response) return response;

  const limited = await applyRateLimit(`rl:follow:${session!.user.id}`, 30, 60);
  if (limited) return limited;

  const { username } = await params;

  const target = await db.query.users.findFirst({ where: eq(users.username, username) });
  if (!target) return NextResponse.json({ error: "Not found" }, { status: 404 });
  if (target.id === session!.user.id) return NextResponse.json({ error: "Cannot follow yourself" }, { status: 400 });

  await db.insert(userFollows)
    .values({ followerId: session!.user.id, followingId: target.id })
    .onConflictDoNothing();

  void createNotification({ userId: target.id, type: "follow", actorId: session!.user.id });

  return NextResponse.json({ following: true });
}

export async function DELETE(_req: NextRequest, { params }: Params) {
  const { session, response } = await requireSession();
  if (response) return response;
  const { username } = await params;

  const target = await db.query.users.findFirst({ where: eq(users.username, username) });
  if (!target) return NextResponse.json({ error: "Not found" }, { status: 404 });

  await db.delete(userFollows).where(
    and(eq(userFollows.followerId, session!.user.id), eq(userFollows.followingId, target.id))
  );

  return NextResponse.json({ following: false });
}