export interface PushSubscriptionData {
  endpoint: string;
  keys: {
    p256dh: string;
    auth: string;
  };
}

export interface VapidPublicKeyResponse {
  publicKey: string | null;
}

const API_BASE_URL = import.meta.env.VITE_API_URL || 'http://localhost:3000/api/v1';

export async function getVapidPublicKey(): Promise<string | null> {
  try {
    const response = await fetch(`${API_BASE_URL}/push/vapid-public-key`);
    if (!response.ok) {
      throw new Error('Failed to fetch VAPID public key');
    }
    const data: VapidPublicKeyResponse = await response.json();
    return data.publicKey;
  } catch {
    return null;
  }
}

export async function subscribeToPush(
  subscription: PushSubscriptionData,
): Promise<boolean> {
  try {
    const response = await fetch(`${API_BASE_URL}/push/subscribe`, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        endpoint: subscription.endpoint,
        p256dh: subscription.keys.p256dh,
        auth: subscription.keys.auth,
      }),
    });

    return response.ok;
  } catch {
    return false;
  }
}

export async function unsubscribeFromPush(
  endpoint: string,
): Promise<boolean> {
  try {
    const response = await fetch(`${API_BASE_URL}/push/unsubscribe`, {
      method: 'DELETE',
      headers: {
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({ endpoint }),
    });
    return response.ok;
  } catch {
    return false;
  }
}

export function urlBase64ToUint8Array(base64String: string): Uint8Array {
  const padding = '='.repeat((4 - (base64String.length % 4)) % 4);
  const base64 = (base64String + padding)
    .replace(/-/g, '+')
    .replace(/_/g, '/');

  const rawData = window.atob(base64);
  const outputArray = new Uint8Array(rawData.length);

  for (let i = 0; i < rawData.length; ++i) {
    outputArray[i] = rawData.charCodeAt(i);
  }
  return outputArray;
}