/**
 * @fileoverview Express application factory for the Zapier-facing HTTP edge.
 * @module app
 */

import express from 'express';
import { sendError } from './errors.js';
import { createDebugger } from './debug/logger.js';
import { traceMiddleware } from './debug/trace.js';
import { apiRoutes } from './routes/index.js';
import { loadStore } from './store/db.js';
import { config } from './config.js';
import { isNatsConnected } from './nats/connection.js';

const log = createDebugger('app');

/**
 * Create the Express app (does not listen).
 *
 * @param {{ load?: boolean }} [options]
 * @returns {import('express').Express}
 */
export function createApp(options = {}) {
  if (options.load !== false) {
    loadStore();
  }

  const app = express();
  app.disable('x-powered-by');

  app.use(express.json({ limit: '12mb' }));
  app.use(traceMiddleware);

  /**
   * Liveness probe.
   */
  app.get('/health', (_req, res) => {
    res.json({
      status: 'ok',
      service: 'verae-zapier-middleware',
      mockVerae: config.mockVerae,
      natsEnabled: config.natsEnabled,
      natsConnected: isNatsConnected(),
    });
  });

  app.use('/zapier', apiRoutes);

  app.use((err, _req, res, _next) => {
    sendError(res, err);
  });

  log.info('express app created');
  return app;
}