import { timingSafeEqual } from "node:crypto";
import { NextResponse } from "next/server";
import { runEventReminders } from "@/lib/meeting/reminders";

export const dynamic = "force-dynamic";

function safeEqual(a: string, b: string): boolean {
  const bufA = Buffer.from(a);
  const bufB = Buffer.from(b);
  if (bufA.length !== bufB.length) return false;
  return timingSafeEqual(bufA, bufB);
}

/**
 * Intended to be called by an external cron job every few minutes, e.g.:
 *   curl -H "Authorization: Bearer $CRON_SECRET" https://anouma.org/api/cron/event-reminders
 */
export async function GET(request: Request) {
  const secret = process.env.CRON_SECRET;
  if (!secret) {
    return NextResponse.json({ error: "CRON_SECRET is not configured" }, { status: 500 });
  }

  const authHeader = request.headers.get("authorization");
  if (!authHeader || !safeEqual(authHeader, `Bearer ${secret}`)) {
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
  }

  try {
    const result = await runEventReminders();
    return NextResponse.json({ ok: true, ...result });
  } catch (error) {
    console.error("event-reminders cron failed", error);
    return NextResponse.json({ error: "Internal error" }, { status: 500 });
  }
}