/**
 * Cloudflare API 抓包桩(仅测试用):
 * 拦截 globalThis.fetch,对 dash.cloudflare.com / api.cloudflare.com 返回固定响应,
 * 并记录真实发出的 HTTP 调用。生产代码里没有任何模拟实现——接入链路跑的始终是
 * RealCFApi,测试只是在传输层把它要访问的 Cloudflare 换成本地桩。
 */

/** # 成员变量: 记录到的 Cloudflare API 调用 **/
export interface CfCall {
  /** 请求方法 **/
  method: string;
  /** 完整 URL **/
  url: string;
  /** 路径(去掉 base) **/
  path: string;
  /** Authorization 头(Cloudflare API 是 OAuth Bearer token;token 端点是 Basic) **/
  authorization: string | null;
  /** 请求体文本(URL 编码或 JSON);multipart 上传记 null **/
  body: string | null;
}

/** # 成员变量: 桩的返回数据配置 **/
export interface CfMockOptions {
  /** /zones 返回的域名列表;每个 zone 自带 account(与真实 Cloudflare 响应一致) **/
  zones?: { id: string; name: string; account_id: string; status: string; account?: { id: string; name: string } }[];
  /** OAuth token 端点签发的 access token **/
  accessToken?: string;
  /** token 端点 HTTP 状态(测失败分支用) **/
  tokenStatus?: number;
  /** 授权端点(dash.cloudflare.com/oauth2/auth)的固定 Location 跳转目标;不传则按 scopesAllowed 判定 **/
  authorizeRedirect?: string;
  /** 授权端点允许的 scope 集合;其余一律 invalid_scope 并点名第一个被拒的(不传 = 全拒) **/
  scopesAllowed?: string[];
  /** 授权端点固定错误(走 Cloudflare 自己的 /oauth/error 页,不弹回回调地址) **/
  authorizeError?: string;
}

/** # 成员变量: Cloudflare API 桩句柄 **/
export interface CfMock {
  /** 已记录的调用 **/
  calls: CfCall[];
  /** 恢复原始 fetch **/
  restore(): void;
  /** 是否发生过指定 method + 路径子串的调用 **/
  hit(method: string, pathPart: string): boolean;
  /** 取出第一条匹配调用的 body **/
  bodyOf(method: string, pathPart: string): string | null;
}

const TOKEN_URL = "https://dash.cloudflare.com/oauth2/token";
const CF_AUTHORIZE_URL = "https://dash.cloudflare.com/oauth2/auth";
const REDIRECT_URI = "http://localhost/api/oauth/cloudflare/callback";
const API_BASE = "https://api.cloudflare.com/client/v4";

/** # 函数
 * 安装 Cloudflare API 桩:接管 globalThis.fetch,返回记录与恢复句柄
 * 参数: opts.zones 决定发现到的资源,tokenStatus 可模拟 token 兑换失败
 */
export function installCloudflareMock(opts: CfMockOptions = {}): CfMock {
  const account = { id: "cf-acct-real-1", name: "Real Cloudflare Account" };
  // zone 自带 account(真实 Cloudflare 就在 zone 上附带),账号名因此无需账号级读权限
  const zones = opts.zones ?? [
    { id: "zone-example", name: "example.com", account_id: account.id, status: "active", account },
    { id: "zone-demo", name: "demo.com", account_id: account.id, status: "active", account },
  ];
  const accessToken = opts.accessToken ?? "cf-oauth-access-token-xyz";
  const calls: CfCall[] = [];
  const original = globalThis.fetch;

  globalThis.fetch = (async (input: RequestInfo | URL, init?: RequestInit): Promise<Response> => {
    const url = typeof input === "string" ? input : input instanceof URL ? input.toString() : input.url;
    const method = (init?.method ?? (input instanceof Request ? input.method : "GET")).toUpperCase();
    const headers = new Headers(
      init?.headers ?? (input instanceof Request ? input.headers : undefined),
    );
    const rawBody = init?.body;
    const body =
      typeof rawBody === "string"
        ? rawBody
        : rawBody instanceof URLSearchParams
          ? rawBody.toString()
          : null;

    calls.push({
      method,
      url,
      path: url.startsWith(API_BASE) ? url.slice(API_BASE.length) : url,
      authorization: headers.get("authorization"),
      // multipart 上传(Email Worker 脚本)读不出文本,只记方法与路径
      body: rawBody instanceof FormData ? null : body,
    });

    const json = (result: unknown, status = 200) =>
      new Response(JSON.stringify({ success: true, errors: [], messages: [], result }), {
        status,
        headers: { "Content-Type": "application/json" },
      });

    if (url.startsWith(CF_AUTHORIZE_URL)) {
      if (opts.authorizeError) {
        return new Response(null, {
          status: 302,
          headers: { Location: `https://dash.cloudflare.com/oauth/error?error=${opts.authorizeError}&state=wmh_preflight` },
        });
      }
      if (opts.authorizeRedirect) {
        return new Response(null, { status: 302, headers: { Location: opts.authorizeRedirect } });
      }
      // 默认行为:只有 scopesAllowed 里的 scope 才放行,否则点名第一个被拒的
      const allowed = opts.scopesAllowed ?? [];
      const asked = (new URL(url).searchParams.get("scope") ?? "").split(" ").filter(Boolean);
      const rejected = asked.find((sc) => !allowed.includes(sc));
      if (rejected) {
        const desc = `The requested scope is invalid, unknown, or malformed. The OAuth 2.0 Client is not allowed to request scope '${rejected}'.`;
        return new Response(null, {
          status: 302,
          headers: {
            Location: `${REDIRECT_URI}?error=invalid_scope&error_description=${encodeURIComponent(desc)}&state=wmh_preflight`,
          },
        });
      }
      return new Response(null, { status: 302, headers: { Location: "https://dash.cloudflare.com/login" } });
    }
    if (url === TOKEN_URL) {
      // 复刻 Cloudflare 的客户端认证要求:只接受 HTTP Basic(client_secret_basic)。
      // 把 client_id/secret 放进 POST body(client_secret_post)会被 401 invalid_client 拒绝,
      // 且错误描述会点名 "method 'client_secret_post' was requested"(2026-09-30 线上踩过)。
      const auth = headers.get("authorization") ?? "";
      if (!auth.startsWith("Basic ")) {
        const desc =
          "Client authentication failed (e.g., unknown client, no client authentication included, " +
          "or unsupported authentication method). The OAuth 2.0 Client supports client authentication " +
          "method 'client_secret_basic', but method 'client_secret_post' was requested.";
        return new Response(JSON.stringify({ error: "invalid_client", error_description: desc }), {
          status: 401,
          headers: { "Content-Type": "application/json" },
        });
      }
      if ((opts.tokenStatus ?? 200) !== 200) {
        return new Response(JSON.stringify({ error: "invalid_grant" }), { status: opts.tokenStatus });
      }
      // OAuth token 端点是裸 JSON(不是 Cloudflare API 的 {success,result} 信封)
      return new Response(JSON.stringify({ access_token: accessToken, expires_in: 3600, token_type: "bearer" }), {
        status: 200,
        headers: { "Content-Type": "application/json" },
      });
    }
    if (url.startsWith(`${API_BASE}/zones`)) {
      if (url.includes("/email/routing/rules/catch_all")) return json({ id: "catch-all-rule" });
      if (url.includes("/email/routing")) return json({ enabled: true });
      return json(zones);
    }
    if (url.includes("/workers/scripts/")) return json({ id: url.split("/").pop() });
    return json(null, 404);
  }) as typeof globalThis.fetch;

  return {
    calls,
    restore: () => {
      globalThis.fetch = original;
    },
    hit: (method, pathPart) =>
      calls.some((c) => c.method === method.toUpperCase() && c.path.includes(pathPart)),
    bodyOf: (method, pathPart) =>
      calls.find((c) => c.method === method.toUpperCase() && c.path.includes(pathPart))?.body ?? null,
  };
}