/**
 * 共享支付触发逻辑 - 与首页「立即加入」效果一致
 * 供首页、课程页、云手机页等所有「立即报名」按钮使用，直接发起支付，不跳转首页
 *
 * 校验逻辑：
 * - 页面有本地存储（登录资料 + paidType=vip）时，优先使用本地存储并立即展示；后台悄悄校验，若 user 被删或 VIP 被撤则更新本地状态
 * - 无身份标识和 VIP 权限等存储时，点击按钮直接进入支付流程，不校验本地 userId
 */
import { getPayEnv, getDeviceFromEnv } from "@/app/lib/payEnv";
import { getPaymentConfig } from "@/config/services.config";

const ANONYMOUS_USER_COOKIE = "nomadvip_anon_uid";
const ANONYMOUS_USER_COOKIE_MAX_AGE = 60 * 60 * 24 * 30;
const PAY_ORDER_COOKIE = "nomadvip_pay_order";
const PAY_ORDER_MAX_AGE = 60 * 15;
const VIP_PAY_TEST_MODE_KEY = "vipPayTestMode";
const PAY_LAUNCH_OVERLAY_ID = "nomadvip-pay-launch-overlay";

function getStorage(key: string): string | null {
  if (typeof window === "undefined") return null;
  return localStorage.getItem(key);
}

function setStorage(key: string, value: string): void {
  if (typeof window === "undefined") return;
  localStorage.setItem(key, value);
}

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 setAnonymousUserCookie(userId: string): void {
  if (typeof document === "undefined") return;
  if (!/^user\d+$/.test(userId)) return;
  const secure = window.location.protocol === "https:" ? "; Secure" : "";
  document.cookie = `${ANONYMOUS_USER_COOKIE}=${encodeURIComponent(
    userId
  )}; Path=/; Max-Age=${ANONYMOUS_USER_COOKIE_MAX_AGE}; SameSite=Lax${secure}`;
}

function setPayOrderCookie(orderId: string): void {
  if (typeof document === "undefined") return;
  const normalizedOrderId = orderId.trim();
  if (!normalizedOrderId) return;
  const secure = window.location.protocol === "https:" ? "; Secure" : "";
  document.cookie = `${PAY_ORDER_COOKIE}=${encodeURIComponent(
    `${normalizedOrderId}|${Date.now()}`
  )}; Path=/; Max-Age=${PAY_ORDER_MAX_AGE}; SameSite=Lax${secure}`;
}

function getDisplayProfile() {
  const wechatNick = (getStorage("wechatNick") || "").trim();
  const userName = (getStorage("userName") || "").trim();
  const userEmail = (getStorage("userEmail") || "").trim();
  const wechatAvatar = (getStorage("wechatAvatar") || "").trim();
  const displayName = wechatNick || userName || userEmail || "当前用户";
  return { displayName, avatar: wechatAvatar || "" };
}

function showPayLaunchOverlay(displayName: string, avatar?: string): void {
  if (typeof document === "undefined") return;
  if (!(avatar || "").trim()) return;
  const prev = document.getElementById(PAY_LAUNCH_OVERLAY_ID);
  if (prev) prev.remove();
  const safeName = displayName.replace(/[&<>"']/g, (c) => ({ "&": "&amp;", "<": "&lt;", ">": "&gt;", '"': "&quot;", "'": "&#39;" })[c] || c);
  const safeAvatar = (avatar || "").replace(/[&<>"']/g, (c) => ({ "&": "&amp;", "<": "&lt;", ">": "&gt;", '"': "&quot;", "'": "&#39;" })[c] || c);
  const node = document.createElement("div");
  node.id = PAY_LAUNCH_OVERLAY_ID;
  node.style.cssText = "position:fixed;inset:0;z-index:9999;display:flex;align-items:center;justify-content:center;background:rgba(15,23,42,.28);pointer-events:none;";
  node.innerHTML = `
    <div style="display:flex;align-items:center;gap:10px;padding:12px 14px;border-radius:12px;background:#0f172a;color:#e2e8f0;box-shadow:0 10px 30px rgba(2,6,23,.35);max-width:90vw;">
      <img src="${safeAvatar}" alt="${safeName}" style="width:30px;height:30px;border-radius:9999px;object-fit:cover;border:1px solid rgba(148,163,184,.5);" />
      <div style="font-size:13px;line-height:1.35;">
        <div style="font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:56vw;">开通对象：${safeName}</div>
        <div style="opacity:.88;">正在为你升级 VIP，马上进入支付...</div>
      </div>
    </div>
  `;
  document.body.appendChild(node);
  window.setTimeout(() => {
    const current = document.getElementById(PAY_LAUNCH_OVERLAY_ID);
    if (current) current.remove();
  }, 2400);
}

function savePendingOrder(orderId: string): void {
  const normalizedOrderId = orderId.trim();
  if (!normalizedOrderId) return;
  setPayOrderCookie(normalizedOrderId);
  setStorage(PAY_ORDER_COOKIE, `${normalizedOrderId}|${Date.now()}`);
}

function getStoredAnonymousUserId(): string | null {
  const memosAccount = getStorage("memosAccount");
  if (memosAccount && /^user\d+$/.test(memosAccount)) return memosAccount;
  const userId = getStorage("userId");
  if (userId && /^user\d+$/.test(userId)) return userId;
  const cookieUserId = getCookie(ANONYMOUS_USER_COOKIE);
  if (cookieUserId && /^user\d+$/.test(cookieUserId)) {
    setStorage("memosAccount", cookieUserId);
    return cookieUserId;
  }
  return null;
}

/** 同步获取 userId，用于微信内立即表单提交，避免异步导致手势失效 */
function getOrCreateUserIdSync(): string {
  const anonymousUserId = getStoredAnonymousUserId();
  if (anonymousUserId) {
    setStorage("userId", anonymousUserId);
    setAnonymousUserCookie(anonymousUserId);
    return anonymousUserId;
  }
  let userId = getStorage("userId");
  if (userId?.startsWith("{") && userId.includes("data")) {
    try {
      const parsed = JSON.parse(userId) as { data?: string };
      if (parsed?.data) {
        userId = parsed.data;
        setStorage("userId", userId);
      }
    } catch {
      userId = null;
    }
  }
  if (!userId) {
    userId = `user${Date.now()}`;
    setStorage("userId", userId);
  }
  return userId;
}

async function getOrCreateUserId(): Promise<string> {
  const syncId = getOrCreateUserIdSync();
  if (syncId && !syncId.startsWith("user")) {
    return syncId;
  }
  try {
    const meRes = await fetch("/api/auth/me", { credentials: "include", cache: "no-store" });
    const meData = await meRes.json();
    if (meData?.user?.id) {
      setStorage("userId", meData.user.id);
      return meData.user.id;
    }
  } catch {
    /* ignore */
  }
  return syncId;
}

function redirectToPayZpay(params: {
  user_id: string;
  wechat_userid?: string;
  wechat_nick?: string;
  wechat_avatar?: string;
  return_url: string;
  total_fee: number;
  type: string;
  channel: "alipay" | "wxpay";
  device: "pc" | "h5" | "wechat";
}) {
  const form = document.createElement("form");
  form.method = "POST";
  form.action = "/api/pay";
  form.target = "_self";
  form.style.display = "none";
  const fields: [string, string][] = [
    ["user_id", params.user_id],
    ...(params.wechat_userid ? [["wechat_userid", params.wechat_userid] as [string, string]] : []),
    ...(params.wechat_nick ? [["wechat_nick", params.wechat_nick] as [string, string]] : []),
    ...(params.wechat_avatar ? [["wechat_avatar", params.wechat_avatar] as [string, string]] : []),
    ["return_url", params.return_url],
    ["total_fee", String(params.total_fee)],
    ["type", params.type],
    ["channel", params.channel],
    ["device", params.device],
    ["provider", "zpay"],
    ["html", "1"],
  ];
  fields.forEach(([k, v]) => {
    const input = document.createElement("input");
    input.type = "hidden";
    input.name = k;
    input.value = v;
    form.appendChild(input);
  });
  document.body.appendChild(form);
  form.submit();
}

async function redirectToPayZpayH5(
  params: {
    user_id: string;
    wechat_userid?: string;
    wechat_nick?: string;
    wechat_avatar?: string;
    return_url: string;
    total_fee: number;
    type: string;
    channel: "alipay" | "wxpay";
  },
  onPendingOrder?: (orderId: string) => void
): Promise<string | null> {
  const res = await fetch("/api/pay", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      ...params,
      device: "h5",
      provider: "zpay",
      html: "0",
    }),
  });
  const data = await res.json().catch(() => ({}));
  if (!data?.ok) {
    alert(data?.error || "支付发起失败");
    return null;
  }
  const hasRedirect = !!data?.redirect_url;
  const hasParams = !!data?.params && !!data?.payUrl;
  if (!hasRedirect && !hasParams) {
    alert(data?.error || "支付发起失败");
    return null;
  }
  const orderId = data?.order_id?.trim() || null;
  if (orderId) {
    savePendingOrder(orderId);
    onPendingOrder?.(orderId);
  }
  if (data?.redirect_url) {
    window.location.href = data.redirect_url;
    return orderId;
  }
  const form = document.createElement("form");
  form.method = "POST";
  form.action = data.payUrl;
  form.target = "_self";
  form.style.display = "none";
  for (const [k, v] of Object.entries(data.params as Record<string, string>)) {
    if (v == null) continue;
    const input = document.createElement("input");
    input.type = "hidden";
    input.name = k;
    input.value = String(v);
    form.appendChild(input);
  }
  document.body.appendChild(form);
  form.submit();
  document.body.removeChild(form);
  return orderId;
}

/** 微信内：同步表单 POST 到 /api/pay，避免异步 fetch 后 form.submit 被微信拦截 */
function payWechatXorpaySync(params: {
  user_id: string;
  wechat_userid?: string;
  wechat_nick?: string;
  wechat_avatar?: string;
  return_url: string;
  total_fee: number;
  type: string;
  channel: "alipay" | "wxpay";
}) {
  const form = document.createElement("form");
  form.method = "POST";
  form.action = "/api/pay";
  form.target = "_self";
  form.style.display = "none";
  const fields: [string, string][] = [
    ["user_id", params.user_id],
    ...(params.wechat_userid ? [["wechat_userid", params.wechat_userid] as [string, string]] : []),
    ...(params.wechat_nick ? [["wechat_nick", params.wechat_nick] as [string, string]] : []),
    ...(params.wechat_avatar ? [["wechat_avatar", params.wechat_avatar] as [string, string]] : []),
    ["return_url", params.return_url],
    ["total_fee", String(params.total_fee)],
    ["type", params.type],
    ["channel", params.channel],
    ["device", "wechat"],
    ["provider", "xorpay"],
    ["html", "1"],
  ];
  fields.forEach(([k, v]) => {
    const input = document.createElement("input");
    input.type = "hidden";
    input.name = k;
    input.value = v;
    form.appendChild(input);
  });
  document.body.appendChild(form);
  form.submit();
}

/**
 * 触发支付 - 与首页「立即加入」效果一致，直接发起支付流程
 * @param onPendingOrder 可选，H5 支付时收到 order_id 的回调（用于轮询）
 */
export async function triggerPay(
  onPendingOrder?: (orderId: string) => void
): Promise<void> {
  const userId =
    typeof navigator !== "undefined" && /MicroMessenger/i.test(navigator.userAgent)
      ? getOrCreateUserIdSync()
      : await getOrCreateUserId();
  if (/^user\d+$/.test(userId)) {
    setStorage("memosAccount", userId);
    setStorage("userId", userId);
    setAnonymousUserCookie(userId);
  }
  const returnUrl = `${window.location.origin}/paid`;
  const env = getPayEnv();
  const device = getDeviceFromEnv(env);
  const wechatUserId =
    (getStorage("wechatUserId") || "").trim() ||
    (getStorage("userid") || "").trim();
  const isPayTestMode = getStorage(VIP_PAY_TEST_MODE_KEY) === "1";
  const totalFee = isPayTestMode ? 100 : getPaymentConfig().defaultAmount ?? 8800;
  const profile = getDisplayProfile();
  const shouldShowLaunchOverlay =
    device !== "wechat" && !!(profile.avatar || "").trim();
  if (shouldShowLaunchOverlay) {
    showPayLaunchOverlay(profile.displayName, profile.avatar);
  }
  const base = {
    user_id: userId,
    wechat_userid: wechatUserId || undefined,
    wechat_nick: profile.displayName,
    wechat_avatar: profile.avatar || undefined,
    return_url: returnUrl,
    total_fee: totalFee,
    type: "vip",
    channel: "wxpay" as const,
  };
  if (device === "wechat") {
    payWechatXorpaySync(base);
  } else if (device === "h5") {
    await redirectToPayZpayH5(base, onPendingOrder);
  } else {
    redirectToPayZpay({ ...base, device });
  }
}