import type { ErrorResponse } from "./types";

export class ApiError extends Error {
  constructor(
    public status: number,
    public error: string,
    message?: string,
  ) {
    super(message ?? error);
    this.name = "ApiError";
  }
}

async function request<T>(url: string, options?: RequestInit): Promise<T> {
  const res = await fetch(url, {
    ...options,
    credentials: "include",
    headers: {
      "Content-Type": "application/json",
      ...options?.headers,
    },
  });

  if (res.status === 401) {
    throw new ApiError(401, "unauthorized");
  }

  if (!res.ok) {
    let body: ErrorResponse | undefined;
    try {
      body = (await res.json()) as ErrorResponse;
    } catch {
      // non-JSON error response
    }
    throw new ApiError(
      res.status,
      body?.error ?? `HTTP ${res.status}`,
      body?.message,
    );
  }

  if (res.status === 204) {
    return undefined as T;
  }

  return res.json() as Promise<T>;
}

export function get<T>(url: string): Promise<T> {
  return request<T>(url);
}

export function post<T>(url: string, body?: unknown): Promise<T> {
  return request<T>(url, {
    method: "POST",
    body: body != null ? JSON.stringify(body) : undefined,
  });
}

export function put<T>(url: string, body?: unknown): Promise<T> {
  return request<T>(url, {
    method: "PUT",
    body: body != null ? JSON.stringify(body) : undefined,
  });
}

export function del(url: string): Promise<void> {
  return request<void>(url, { method: "DELETE" });
}