/**
 * Client for the SkateSpots push service (`push-service/`).
 *
 * The service watches relays for push-marked gift wraps and sends a CONTENT-FREE
 * Web Push. It never decrypts; the app fetches + decrypts the named wrap itself.
 *
 * Base URL mirrors `sasquatchAiBase()`: production (and native builds) use the
 * deployed host; dev points at the local service. `VITE_PUSH_SERVICE_BASE`
 * overrides both.
 */
import { isNativePlatform } from '@/lib/platform';

const PRODUCTION_PUSH_BASE = 'https://push.skate-spots.org';

export function pushServiceBase(): string {
  const override = (import.meta.env as Record<string, string | undefined>).VITE_PUSH_SERVICE_BASE;
  if (override) return override.replace(/\/+$/, '');
  if (import.meta.env.PROD || isNativePlatform()) return PRODUCTION_PUSH_BASE;
  return 'http://localhost:8788';
}

/** Standard `PushSubscription.toJSON()` shape the service expects. */
export interface PushSubscriptionJSON {
  endpoint: string;
  keys: { p256dh: string; auth: string };
}

async function post<T>(path: string, body: unknown): Promise<T> {
  const res = await fetch(`${pushServiceBase()}${path}`, {
    method: 'POST',
    headers: { 'content-type': 'application/json' },
    body: JSON.stringify(body),
  });
  const data = (await res.json().catch(() => ({}))) as T & { error?: string };
  if (!res.ok) throw new Error(data.error || `Push service error (${res.status})`);
  return data;
}

export async function fetchVapidPublicKey(): Promise<string> {
  const res = await fetch(`${pushServiceBase()}/vapid-public-key`);
  if (!res.ok) throw new Error('Could not reach the notification service.');
  const data = (await res.json()) as { key?: string };
  if (!data.key) throw new Error('Notification service returned no key.');
  return data.key;
}

export async function requestPushChallenge(pubkey: string): Promise<string> {
  const data = await post<{ challenge: string }>('/auth/challenge', { pubkey });
  return data.challenge;
}

export async function subscribeToPush(
  subscription: PushSubscriptionJSON,
  proof: unknown,
  categories?: string[],
): Promise<void> {
  await post('/subscribe', { subscription, proof, categories });
}

export async function unsubscribeFromPush(endpoint: string, proof: unknown): Promise<void> {
  await post('/unsubscribe', { endpoint, proof });
}