import { isAuthResponseMessage } from "./auth-messages";

interface FetchResponseLike {
  json(): Promise<unknown>;
  ok: boolean;
  status: number;
}

type FetchLike = (
  input: string,
  init?: RequestInit
) => Promise<FetchResponseLike>;

type SendMessageLike = (message: unknown) => Promise<unknown>;

export function createProtectedApiClient(options: {
  baseUrl: string;
  fetchImpl?: FetchLike;
  sendMessage: SendMessageLike;
}) {
  const fetchImpl = options.fetchImpl ?? fetch;

  return {
    async loadProtectedMockData() {
      const token = await readAccessToken(options.sendMessage);
      const response = await fetchImpl(
        new URL("/api/mock/protected", options.baseUrl).toString(),
        {
          headers: {
            Authorization: `Bearer ${token}`
          },
          method: "GET"
        }
      );

      if (response.status === 401 || response.status === 403) {
        throw new Error("protected api unauthorized");
      }

      if (!response.ok) {
        throw new Error(`protected api request failed: ${response.status}`);
      }

      return response.json();
    }
  };
}

async function readAccessToken(sendMessage: SendMessageLike): Promise<string> {
  const response = await sendMessage({ type: "auth:get-access-token" });

  if (
    !isAuthResponseMessage(response) ||
    !response.ok ||
    response.type !== "auth:token" ||
    !response.value.accessToken.trim()
  ) {
    throw new Error("protected api token unavailable");
  }

  return response.value.accessToken;
}