import type { Application } from "@oak/oak";

export type RequestOptions = {
  method?: string;
  path: string;
  headers?: HeadersInit;
  body?: unknown;
};

export type TestResponse = {
  status: number;
  headers: Headers;
  text: string;
  json: () => unknown;
};

export const requestApp = async (
  app: Application,
  opts: RequestOptions,
): Promise<TestResponse> => {
  const method = opts.method ?? "GET";
  const url = `http://test.local${opts.path}`;
  const init: RequestInit = {
    method,
    headers: opts.headers,
  };
  if (opts.body !== undefined && method !== "GET" && method !== "HEAD") {
    init.body = typeof opts.body === "string"
      ? opts.body
      : JSON.stringify(opts.body);
    const headers = new Headers(opts.headers);
    if (!headers.has("Content-Type")) {
      headers.set("Content-Type", "application/json");
    }
    init.headers = headers;
  }
  const req = new Request(url, init);
  const res = await app.handle(req);
  if (!res) {
    throw new Error("app.handle returned undefined");
  }
  const text = await res.text();
  return {
    status: res.status,
    headers: res.headers,
    text,
    json: () => JSON.parse(text),
  };
};