const BASE = "/api/v1";

function getToken(): string | null {
  return localStorage.getItem("rh_token");
}

export function setToken(token: string): void {
  localStorage.setItem("rh_token", token);
}

export function clearToken(): void {
  localStorage.removeItem("rh_token");
}

async function request<T>(
  path: string,
  options: RequestInit = {},
  isFormData = false
): Promise<T> {
  const token = getToken();
  const headers: Record<string, string> = {
    ...(options.headers as Record<string, string>),
  };
  if (!isFormData) {
    headers["Content-Type"] = "application/json";
  }
  if (token) {
    headers["Authorization"] = `Bearer ${token}`;
  }
  const resp = await fetch(`${BASE}${path}`, { ...options, headers });
  if (!resp.ok) {
    if (resp.status === 401) {
      clearToken();
      window.location.href = "/login";
      throw new Error("Session expired");
    }
    const error = await resp.json().catch(() => ({ detail: resp.statusText }));
    throw new Error(error.detail ?? resp.statusText);
  }
  if (resp.status === 204) return undefined as T;
  return resp.json();
}

export const api = {
  get: <T>(path: string) => request<T>(path),
  post: <T>(path: string, body: unknown) =>
    request<T>(path, { method: "POST", body: JSON.stringify(body) }),
  upload: <T>(path: string, formData: FormData) =>
    request<T>(path, { method: "POST", body: formData }, true),
  patch: <T>(path: string, body: unknown) =>
    request<T>(path, { method: "PATCH", body: JSON.stringify(body) }),
  delete: (path: string) => request<void>(path, { method: "DELETE" }),
};