/**
 * 微信 H5 支付完成后可能不跳转，通过 cookie 中的订单号轮询检测支付状态
 * cookie 格式：order_id|timestamp，仅对 15 分钟内设置的 cookie 轮询，避免陈旧 cookie 误触发
 */
import { useEffect, useRef, useState } from "react";

const COOKIE_NAME = "join_pay_order";
const POLL_INTERVAL = 2000;
const MAX_POLLS = 150; // 约 5 分钟
const MAX_AGE_MS = 15 * 60 * 1000; // 15 分钟

function getCookie(name: string): string | null {
  if (typeof document === "undefined") return null;
  const match = document.cookie.match(new RegExp(`(?:^|; )${name}=([^;]*)`));
  return match ? decodeURIComponent(match[1]) : null;
}

function clearCookie(name: string): void {
  if (typeof document === "undefined") return;
  document.cookie = `${name}=; path=/; max-age=0`;
}

/** 解析 cookie：order_id|timestamp，返回 [orderId, isValid]。无时间戳视为过期并清除 */
function parsePayOrderCookie(raw: string | null): [string | null, boolean] {
  if (!raw?.trim()) return [null, false];
  const parts = raw.split("|");
  const orderId = parts[0]?.trim() || raw.trim();
  const ts = parts[1] ? parseInt(parts[1], 10) : NaN;
  if (!orderId) return [null, false];
  if (Number.isNaN(ts)) return [orderId, false]; // 旧格式无时间戳，视为过期
  if (Date.now() - ts > MAX_AGE_MS) return [orderId, false]; // 超过 15 分钟
  return [orderId, true];
}

export function usePayStatusPoll(onPaid: () => void): boolean {
  const [polling, setPolling] = useState(false);
  const onPaidRef = useRef(onPaid);
  onPaidRef.current = onPaid;

  useEffect(() => {
    const raw = getCookie(COOKIE_NAME);
    const [orderId, isValid] = parsePayOrderCookie(raw);
    if (!orderId || !isValid) {
      if (raw) clearCookie(COOKIE_NAME);
      return;
    }

    setPolling(true);
    let count = 0;
    const timer = setInterval(async () => {
      count++;
      if (count > MAX_POLLS) {
        clearInterval(timer);
        clearCookie(COOKIE_NAME);
        setPolling(false);
        return;
      }
      try {
        const res = await fetch(`/api/pay/status?order_id=${encodeURIComponent(orderId)}`);
        const data = await res.json();
        if (data?.ok && data?.paid) {
          clearInterval(timer);
          clearCookie(COOKIE_NAME);
          setPolling(false);
          onPaidRef.current();
        }
      } catch {
        // 继续轮询
      }
    }, POLL_INTERVAL);

    return () => clearInterval(timer);
  }, []);

  return polling;
}