import { NextRequest, NextResponse } from "next/server";
import { getPocketBaseConfig, getPaymentConfig, SITE_ID } from "@/config/services.config";
import { getAdminToken } from "@/app/lib/pocketbase/admin";

const DEFAULT_PASSWORD = "12345678";

function parseOrderId(orderId: string): { userId: string; payType: string } {
  if (!orderId.includes("_order_")) return { userId: "", payType: "unknown" };
  const prefix = orderId.split("_order_")[0];
  if (prefix.includes("_")) {
    const lastUnderscore = prefix.lastIndexOf("_");
    return {
      userId: prefix.slice(0, lastUnderscore),
      payType: prefix.slice(lastUnderscore + 1).toLowerCase(),
    };
  }
  return { userId: prefix, payType: "unknown" };
}

function decodePendingEmail(userId: string): string | null {
  if (!userId.startsWith("pending_")) return null;
  try {
    return Buffer.from(userId.slice(8), "hex").toString("utf-8");
  } catch {
    return null;
  }
}

async function queryZpayPaid(orderId: string): Promise<boolean> {
  const config = getPaymentConfig();
  if (!config.apiUrl) {
    console.error("queryZpayPaid: PAYMENT_API_URL not configured");
    return false;
  }
  try {
    const controller = new AbortController();
    const timeout = setTimeout(() => controller.abort(), 10000);
    const url = `${config.apiUrl}/cnomadcna/zpay_order_status?out_trade_no=${encodeURIComponent(orderId)}`;
    const res = await fetch(url, { cache: "no-store", signal: controller.signal })
      .finally(() => clearTimeout(timeout));
    const data = await res.json().catch(() => ({}));
    if (!data?.paid) {
      console.warn(`queryZpayPaid: not paid yet, order_id=${orderId}, response=`, JSON.stringify(data));
    }
    return !!data?.paid;
  } catch (e) {
    console.error(`queryZpayPaid: fetch error, order_id=${orderId}`, e);
    return false;
  }
}

async function ensureSiteVip(
  base: string,
  adminToken: string,
  userId: string,
  orderId: string,
): Promise<boolean> {
  try {
    const filter = `user_id = "${userId}" && site_id = "${SITE_ID}"`;
    const checkRes = await fetch(
      `${base}/api/collections/site_vip/records?filter=${encodeURIComponent(filter)}&perPage=1`,
      { headers: { Authorization: `Bearer ${adminToken}` }, cache: "no-store" }
    );
    if (checkRes.ok) {
      const checkData = await checkRes.json();
      const existing = (checkData?.items ?? [])[0];
      if (existing) {
        await fetch(`${base}/api/collections/site_vip/records/${existing.id}`, {
          method: "PATCH",
          headers: { "Content-Type": "application/json", Authorization: `Bearer ${adminToken}` },
          body: JSON.stringify({ order_id: orderId, expires_at: "" }),
        });
        return true;
      }
    }
    const createRes = await fetch(`${base}/api/collections/site_vip/records`, {
      method: "POST",
      headers: { "Content-Type": "application/json", Authorization: `Bearer ${adminToken}` },
      body: JSON.stringify({ user_id: userId, site_id: SITE_ID, order_id: orderId, expires_at: "" }),
    });
    return createRes.ok;
  } catch (e) {
    console.error("ensureSiteVip error:", e);
    return false;
  }
}

async function createUserByEmail(base: string, adminToken: string, email: string): Promise<string | null> {
  const createRes = await fetch(`${base}/api/collections/users/records`, {
    method: "POST",
    headers: { "Content-Type": "application/json", Authorization: `Bearer ${adminToken}` },
    body: JSON.stringify({ email, password: DEFAULT_PASSWORD, passwordConfirm: DEFAULT_PASSWORD }),
  });
  if (createRes.ok) {
    const data = await createRes.json();
    return data?.id ?? null;
  }
  if (createRes.status === 400) {
    const filter = `email="${email}"`;
    const getRes = await fetch(
      `${base}/api/collections/users/records?filter=${encodeURIComponent(filter)}&perPage=1`,
      { headers: { Authorization: `Bearer ${adminToken}` }, cache: "no-store" }
    );
    if (getRes.ok) {
      const getData = await getRes.json();
      return (getData?.items ?? [])[0]?.id ?? null;
    }
  }
  return null;
}

export async function POST(request: NextRequest) {
  try {
    const body = await request.json().catch(() => ({}));
    const orderId = String(body?.order_id || "").trim();
    if (!orderId) {
      return NextResponse.json({ ok: false, error: "Missing order_id" }, { status: 400 });
    }

    let { userId, payType } = parseOrderId(orderId);
    if (!userId || payType !== "meetup") {
      return NextResponse.json({ ok: false, error: "订单格式无效" }, { status: 400 });
    }

    const adminToken = await getAdminToken();
    if (!adminToken) {
      console.error("complete-order: getAdminToken failed, check POCKETBASE_EMAIL/PASSWORD");
      return NextResponse.json({ ok: false, error: "服务配置错误" }, { status: 500 });
    }

    const pb = getPocketBaseConfig();
    const base = pb.url.replace(/\/$/, "");

    // 1. 先查 site_vip 是否已由异步通知创建
    const filter = `order_id = "${orderId}"`;
    const vipRes = await fetch(
      `${base}/api/collections/site_vip/records?filter=${encodeURIComponent(filter)}&perPage=1`,
      { headers: { Authorization: `Bearer ${adminToken}` }, cache: "no-store" }
    );
    let found = false;
    if (vipRes.ok) {
      const vipData = await vipRes.json();
      found = (vipData?.items ?? []).length > 0;
    }

    // 2. 没找到 → 查 ZPAY 确认是否已支付，已支付则直接创建 site_vip
    if (!found) {
      const zpayPaid = await queryZpayPaid(orderId);
      if (!zpayPaid) {
        console.error(`complete-order: ZPAY 未确认支付 order_id=${orderId}`);
        return NextResponse.json({ ok: false, error: "订单不存在或未支付成功" }, { status: 400 });
      }
      console.log(`complete-order: ZPAY 已确认支付，主动创建 site_vip order_id=${orderId}`);

      // pending_ 新用户：先创建用户
      let realUserId = userId;
      if (userId.startsWith("pending_")) {
        const email = decodePendingEmail(userId);
        if (!email) {
          return NextResponse.json({ ok: false, error: "订单格式无效" }, { status: 400 });
        }
        const newId = await createUserByEmail(base, adminToken, email);
        if (!newId) {
          return NextResponse.json({ ok: false, error: "创建用户失败" }, { status: 500 });
        }
        realUserId = newId;
      }

      const created = await ensureSiteVip(base, adminToken, realUserId, orderId);
      if (!created) {
        return NextResponse.json({ ok: false, error: "VIP 开通失败" }, { status: 500 });
      }
    }

    // 3. pending_ 新用户：登录并返回 token
    if (userId.startsWith("pending_")) {
      const email = decodePendingEmail(userId);
      if (!email) {
        return NextResponse.json({ ok: false, error: "订单格式无效" }, { status: 400 });
      }
      const loginRes = await fetch(`${base}/api/collections/users/auth-with-password`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ identity: email, password: DEFAULT_PASSWORD }),
      });
      if (!loginRes.ok) {
        return NextResponse.json({ ok: false, error: "登录失败，请稍后重试" }, { status: 500 });
      }
      const authData = await loginRes.json();
      return NextResponse.json({
        ok: true,
        token: authData.token,
        record: authData.record,
        is_new: true,
      });
    }

    return NextResponse.json({ ok: true, token: null, record: null, is_new: false });
  } catch (error) {
    console.error("complete-order error:", error);
    return NextResponse.json({ ok: false, error: "Operation failed" }, { status: 500 });
  }
}