import { LoginForm, RegisterForm } from "@/types/auth";

export const API_URL = process.env.NEXT_PUBLIC_EXAMJAM_API_URL;

// Cookie utility function
const setCookie = (name: string, value: string | null, days: number = 7) => {
  if (typeof document === "undefined") return;

  if (value === null) {
    document.cookie = `${name}=; expires=Thu, 01 Jan 1970 00:00:00 UTC; path=/; SameSite=Strict; Secure`;
  } else {
    const expires = new Date();
    expires.setTime(expires.getTime() + days * 24 * 60 * 60 * 1000);
    document.cookie = `${name}=${encodeURIComponent(
      value
    )}; expires=${expires.toUTCString()}; path=/; SameSite=Strict; Secure`;
  }
};

type SetTokenFn = (token: string) => void;

// Optional: Create a custom error type to carry extra data
interface APIError extends Error {
  response?: any;
}

export const login = async (
  form: LoginForm,
  setToken: SetTokenFn
): Promise<void> => {
  const response = await fetch(`${API_URL}/auth/login/`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
    },
    body: JSON.stringify(form),
  });

  const data = await response.json();

  if (!response.ok) {
    throw new Error(data.message || "Login failed");
  }

  setCookie("authToken", data.token);
  setToken(data.token);
};

export const register = async (
  form: RegisterForm,
  setToken: SetTokenFn
): Promise<void> => {
  const response = await fetch(`${API_URL}/auth/register/`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
    },
    body: JSON.stringify(form),
  });

  const data = await response.json();

  if (!response.ok) {
    const error: APIError = new Error(data?.detail || "Registration failed");
    error.response = data;
    throw error;
  }

  setCookie("authToken", data.token);
  setToken(data.token);
};

export const getTokenFromCookie = (): string | null => {
  if (typeof document === "undefined") return null;

  const value = `; ${document.cookie}`;
  const parts = value.split(`; authToken=`);
  if (parts.length === 2) {
    return parts.pop()?.split(";").shift() || null;
  }
  return null;
};

export const clearAuthToken = (): void => {
  setCookie("authToken", null);
};

export const getToken = async (): Promise<string | null> => {
  if (typeof window === "undefined") {
    return null;
  }

  const match = document.cookie.match(/(?:^|;\s*)authToken=([^;]*)/);
  return match ? decodeURIComponent(match[1]) : null;
};