// 主世界钩子(document_start):被动观察页面自己发出的请求,把命中的响应体副本
// postMessage 给 content.js。参照 FetchV / 猫抓一类捕获扩展的通行模式。
//
// 铁律:只观察,不改写请求与响应;任何异常都必须静默,绝不能影响页面本身。

(() => {
  "use strict";

  const MARKER = "__hexi_bf2042_capture__";
  const API_PREFIX =
    "https://api.tracker.gg/api/v2/bf2042/standard/profile/";

  function match(url) {
    return typeof url === "string" && url.startsWith(API_PREFIX);
  }

  function report(url, status, body) {
    try {
      window.postMessage({ [MARKER]: true, url, status, body }, "*");
    } catch (_) {
      /* 忽略:上报失败不能影响页面 */
    }
  }

  // ---- fetch ----
  // 用 Proxy 包一层:Function.prototype.toString.call() 显示为 native
  // (Proxy 的 target 是原生函数),比"改写后补 toString"更难被识破。
  if (typeof window.fetch === "function") {
    const orig = window.fetch;
    window.fetch = new Proxy(orig, {
      apply(target, thisArg, args) {
        const input = args[0];
        const url =
          typeof input === "string" ? input : (input && input.url) || "";
        const result = Reflect.apply(target, thisArg, args);
        if (match(url)) {
          result
            .then((resp) => {
              try {
                const ctype = resp.headers.get("content-type") || "";
                if (!ctype.includes("json")) return;
                // 立刻 clone,免得页面随后消费了原响应体
                resp
                  .clone()
                  .json()
                  .then((body) => report(url, resp.status, body))
                  .catch(() => {});
              } catch (_) {}
            })
            .catch(() => {});
        }
        return result;
      },
    });
  }

  // ---- XMLHttpRequest ----
  const XHR = window.XMLHttpRequest;
  if (XHR && XHR.prototype) {
    const origOpen = XHR.prototype.open;
    const origSend = XHR.prototype.send;
    const urls = new WeakMap(); // 挂在实例上会留可见的自定义属性,用 WeakMap 更干净

    XHR.prototype.open = new Proxy(origOpen, {
      apply(target, thisArg, args) {
        try {
          urls.set(thisArg, String(args[1] ?? ""));
        } catch (_) {}
        return Reflect.apply(target, thisArg, args);
      },
    });

    XHR.prototype.send = new Proxy(origSend, {
      apply(target, thisArg, args) {
        try {
          const url = urls.get(thisArg);
          if (match(url)) {
            thisArg.addEventListener(
              "loadend",
              () => {
                try {
                  const rt = thisArg.responseType;
                  let body = null;
                  if (rt === "" || rt === "text") {
                    body = JSON.parse(thisArg.responseText);
                  } else if (rt === "json") {
                    body = thisArg.response;
                  } else {
                    return; // arraybuffer / blob 等类型不处理
                  }
                  if (body != null) report(url, thisArg.status, body);
                } catch (_) {}
              },
              { once: true }
            );
          }
        } catch (_) {}
        return Reflect.apply(target, thisArg, args);
      },
    });
  }
})();