export default {
  async fetch(request, env) {
    const url = new URL(request.url);

    // Meta 验证 Webhook
    if (request.method === "GET" && url.pathname === "/webhook") {
      const mode = url.searchParams.get("hub.mode");
      const token = url.searchParams.get("hub.verify_token");
      const challenge = url.searchParams.get("hub.challenge");

      if (
        mode === "subscribe" &&
        token === env.VERIFY_TOKEN &&
        challenge
      ) {
        return new Response(challenge, {
          status: 200,
          headers: {
            "Content-Type": "text/plain; charset=UTF-8"
          }
        });
      }

      return new Response("forbidden", {
        status: 403
      });
    }

    // 接收 WhatsApp 推送消息
    if (request.method === "POST" && url.pathname === "/webhook") {
      try {
        const body = await request.json();

        console.log("收到 WhatsApp Webhook：");
        console.log(JSON.stringify(body));

        return new Response("EVENT_RECEIVED", {
          status: 200
        });
      } catch (error) {
        console.error("Webhook JSON 解析失败：", error);

        return new Response("Bad Request", {
          status: 400
        });
      }
    }

    return new Response("Not Found", {
      status: 404
    });
  }
};