import type { AuthUser } from "@/domain/auth/types/auth-user";

const AUTH_STORAGE_KEY = "auth";

function parseExpiration(expiration: string): number | null {
  const asNumber = Number(expiration);
  if (!Number.isNaN(asNumber) && asNumber > 0) {
    return asNumber > 1e12 ? asNumber : asNumber * 1000;
  }

  const parsed = Date.parse(expiration);
  return Number.isNaN(parsed) ? null : parsed;
}

export function setAuthUser(user: AuthUser): void {
  if (typeof window === "undefined") {
    return;
  }

  localStorage.setItem(AUTH_STORAGE_KEY, JSON.stringify(user));
}

export function getAuthUser(): AuthUser | null {
  if (typeof window === "undefined") {
    return null;
  }

  const raw = localStorage.getItem(AUTH_STORAGE_KEY);
  if (!raw) {
    return null;
  }

  try {
    return JSON.parse(raw) as AuthUser;
  } catch {
    return null;
  }
}

export function getAccessToken(): string | null {
  const user = getAuthUser();
  if (!user?.token || typeof user.token !== "string") {
    return null;
  }

  return `Bearer ${user.token}`;
}

export function clearAuth(): void {
  if (typeof window === "undefined") {
    return;
  }

  localStorage.removeItem(AUTH_STORAGE_KEY);
}

export function isSessionValid(user: AuthUser | null): boolean {
  if (!user?.token || !user.expiration) {
    return false;
  }

  const expiresAt = parseExpiration(user.expiration);
  if (expiresAt === null) {
    return false;
  }

  return Date.now() < expiresAt;
}