import { and, asc, eq, isNull, lte, notExists } from "drizzle-orm";
import { getDb } from "@/db/client";
import { commissionCheckouts, commissionTickets } from "@/db/schema";
import { CHECKOUT_DURATION_MS } from "@/lib/commission/checkout-expiration";
import { commissionSlipLockKey } from "@/lib/commission/slip-lock";
import { getRedisClient } from "@/lib/redis/client";

const BATCH_SIZE = 100;

export async function removeExpiredUnpaidCheckouts(): Promise<number> {
  const db = getDb();
  const redis = await getRedisClient();
  const cutoff = new Date(Date.now() - CHECKOUT_DURATION_MS);
  const candidates = await db.select({ id: commissionCheckouts.id })
    .from(commissionCheckouts)
    .leftJoin(commissionTickets, eq(commissionTickets.checkoutId, commissionCheckouts.id))
    .where(and(lte(commissionCheckouts.createdAt, cutoff), isNull(commissionTickets.id)))
    .orderBy(asc(commissionCheckouts.createdAt))
    .limit(BATCH_SIZE);

  let removed = 0;
  for (const { id } of candidates) {
    const lockKey = commissionSlipLockKey(id);
    const lockId = crypto.randomUUID();
    if (await redis.set(lockKey, lockId, "EX", 60, "NX") !== "OK") continue;
    try {
      const deleted = await db.delete(commissionCheckouts).where(and(
        eq(commissionCheckouts.id, id),
        lte(commissionCheckouts.createdAt, cutoff),
        notExists(db.select({ id: commissionTickets.id }).from(commissionTickets)
          .where(eq(commissionTickets.checkoutId, id))),
      )).returning({ id: commissionCheckouts.id });
      removed += deleted.length;
    } finally {
      await redis.eval("if redis.call('GET', KEYS[1]) == ARGV[1] then return redis.call('DEL', KEYS[1]) end return 0", 1,
        lockKey, lockId).catch(() => undefined);
    }
  }
  return removed;
}