/**
 * 支付状态轮询：点击支付后轮询，支付成功刷新，超时重置
 * 优先使用 sessionStorage（pay_pending_order），其次 cookie
 */
import { useEffect, useRef, useState } from "react";

const COOKIE_NAME = "nomadvip_pay_order";
const SESSION_KEY_ORDER = "pay_pending_order";
const SESSION_KEY_TS = "pay_pending_ts";
const POLL_INTERVAL = 2000;
const MAX_POLLS = 160; // ~5 分钟
const MAX_AGE_MS = 15 * 60 * 1000;

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`;
}

function getSessionOrder(): [string | null, boolean] {
  if (typeof window === "undefined") return [null, false];
  const orderId = sessionStorage.getItem(SESSION_KEY_ORDER)?.trim() || null;
  const ts = sessionStorage.getItem(SESSION_KEY_TS);
  const timestamp = ts ? parseInt(ts, 10) : NaN;
  if (!orderId) return [null, false];
  if (Number.isNaN(timestamp)) return [orderId, true];
  if (Date.now() - timestamp > MAX_AGE_MS) return [orderId, false];
  return [orderId, true];
}

function setSessionOrder(orderId: string): void {
  if (typeof window === "undefined") return;
  sessionStorage.setItem(SESSION_KEY_ORDER, orderId);
  sessionStorage.setItem(SESSION_KEY_TS, String(Date.now()));
}

function clearSessionOrder(): void {
  if (typeof window === "undefined") return;
  sessionStorage.removeItem(SESSION_KEY_ORDER);
  sessionStorage.removeItem(SESSION_KEY_TS);
}

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];
  if (Date.now() - ts > MAX_AGE_MS) return [orderId, false];
  return [orderId, true];
}

function getOrderIdToPoll(): [string | null, "session" | "cookie" | null] {
  const [sessionOrder, sessionValid] = getSessionOrder();
  if (sessionOrder && sessionValid) return [sessionOrder, "session"];
  const raw = getCookie(COOKIE_NAME);
  const [cookieOrder, cookieValid] = parsePayOrderCookie(raw);
  if (cookieOrder && cookieValid) return [cookieOrder, "cookie"];
  return [null, null];
}

export function setPayPendingOrder(orderId: string): void {
  setSessionOrder(orderId);
}

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

  useEffect(() => {
    const [orderId] = getOrderIdToPoll();
    if (!orderId) {
      const raw = getCookie(COOKIE_NAME);
      if (raw) clearCookie(COOKIE_NAME);
      return;
    }

    setPolling(true);
    let count = 0;
    const timer = setInterval(async () => {
      count++;
      if (count > MAX_POLLS) {
        clearInterval(timer);
        clearSessionOrder();
        clearCookie(COOKIE_NAME);
        setPolling(false);
        onTimeoutRef.current?.();
        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);
          clearSessionOrder();
          clearCookie(COOKIE_NAME);
          setPolling(false);
          onPaidRef.current(orderId);
        }
      } catch {
        // 继续轮询
      }
    }, POLL_INTERVAL);

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

  return polling;
}