import { API_BASE } from "./config";

export class ApiClientError extends Error {
  status: number;
  code?: string;

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

async function request<T>(
  method: string,
  url: string,
  body?: unknown,
): Promise<T> {
  const headers: Record<string, string> = {};

  const token =
    typeof window !== "undefined" ? localStorage.getItem("token") : null;
  if (token) {
    headers["Authorization"] = `Bearer ${token}`;
  }

  if (body !== undefined) {
    headers["Content-Type"] = "application/json";
  }

  const res = await fetch(`${API_BASE}${url}`, {
    method,
    headers,
    body: body !== undefined ? JSON.stringify(body) : undefined,
  });

  if (!res.ok) {
    let message = `HTTP ${res.status}`;
    let code: string | undefined;
    try {
      const json = await res.json();
      message = json.message || json.error || json.detail || message;
      code = json.code;
    } catch {}
    throw new ApiClientError(res.status, message, code);
  }

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

  const json = await res.json();
  return json as T;
}

export const apiClient = {
  get: <T>(url: string) => request<T>("GET", url),
  post: <T>(url: string, body?: unknown) => request<T>("POST", url, body),
  patch: <T>(url: string, body?: unknown) => request<T>("PATCH", url, body),
  put: <T>(url: string, body?: unknown) => request<T>("PUT", url, body),
  delete: <T>(url: string) => request<T>("DELETE", url),
};

export const API_BASE_URL = API_BASE;