export class ApiError extends Error {
  readonly status: number;

  constructor(message: string, status: number) {
    super(message);
    this.name = "ApiError";
    this.status = status;
  }
}

type RequestInitWithJson = RequestInit & {
  json?: unknown;
};

async function request<TResponse>(
  input: string,
  init: RequestInitWithJson = {},
): Promise<TResponse> {
  const headers = new Headers(init.headers);
  const body =
    init.json === undefined ? init.body : JSON.stringify(init.json, null, 2);

  if (init.json !== undefined) {
    headers.set("Content-Type", "application/json");
  }

  const response = await fetch(input, {
    ...init,
    headers,
    body,
  });

  if (!response.ok) {
    let message = `${response.status} ${response.statusText}`;

    try {
      const errorPayload = (await response.json()) as {
        error?: { message?: string };
      };
      message = errorPayload.error?.message ?? message;
    } catch {
      message = `${response.status} ${response.statusText}`;
    }

    throw new ApiError(message, response.status);
  }

  const contentType = response.headers.get("Content-Type") ?? "";
  if (contentType.includes("application/yaml")) {
    return (await response.text()) as TResponse;
  }

  return (await response.json()) as TResponse;
}

export function getJson<TResponse>(input: string) {
  return request<TResponse>(input);
}

export function getText(input: string) {
  return request<string>(input);
}

export function postJson<TResponse>(input: string, json?: unknown) {
  return request<TResponse>(input, {
    method: "POST",
    json,
  });
}

export function postText<TResponse>(input: string, text: string) {
  return request<TResponse>(input, {
    method: "POST",
    headers: {
      "Content-Type": "application/yaml",
    },
    body: text,
  });
}