/**
 * @fileoverview REST Hook subscribe/unsubscribe and HTTP delivery.
 * @module services/webhookService
 */

import { createWebhook, deleteWebhook } from '../store/webhooks.js';
import { createDebugger } from '../debug/logger.js';

const log = createDebugger('webhooks');

const ALLOWED_EVENTS = new Set(['timestamp.completed', 'timestamp.failed']);

/**
 * @param {object} ctx - auth context
 * @param {{ targetUrl: string, event: string }} params
 */
export function subscribe(ctx, { targetUrl, event }) {
  if (!targetUrl) {
    throw new Error('targetUrl is required');
  }
  if (!ALLOWED_EVENTS.has(event)) {
    throw new Error(`Unsupported event: ${event}`);
  }

  return createWebhook({
    tenantId: ctx.tenantId,
    targetUrl,
    event,
  });
}

/**
 * @param {object} ctx
 * @param {{ hookId?: string, targetUrl?: string }} params
 */
export function unsubscribe(ctx, { hookId, targetUrl }) {
  const removed = deleteWebhook({
    tenantId: ctx.tenantId,
    hookId,
    targetUrl,
  });

  if (!removed) {
    throw new Error('Webhook subscription not found');
  }

  return { removed: true };
}

/**
 * POST payload to Zapier target URL.
 * @param {string} targetUrl
 * @param {object} payload
 * @returns {Promise<{ ok: boolean, status: number }>}
 */
export async function deliverWebhook(targetUrl, payload) {
  log.debug('deliverWebhook', { targetUrl, event: payload?.event });

  const response = await fetch(targetUrl, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'User-Agent': 'Verae-Zapier-Middleware/1.0',
    },
    body: JSON.stringify(payload),
  });

  log.debug('deliverWebhook result', { status: response.status, ok: response.ok });
  return { ok: response.ok, status: response.status };
}