import { Router } from 'express';

import { getLookup, listLookups } from '../services/lookupService.js';
import { asyncHandler } from '../utils/asyncHandler.js';
import { validateParam } from '../middleware/validateParams.js';
import { lookupCache } from '../services/cacheService.js';

const router = Router();

router.get(
  '/',
  asyncHandler(async (_req, res) => {
    /*
     * The bulk lookup endpoint is convenient for client startup because dropdown
     * lists are small and reused across many dynamic fields. Fetching them in one
     * call keeps the frontend startup sequence short.
     */
    const cached = lookupCache.get('all-lookups');

    if (cached) {
      return res.json(cached);
    }

    const lookups = await listLookups();
    const payload = { items: lookups };
    lookupCache.set('all-lookups', payload);
    return res.json(payload);
  })
);

router.get(
  '/:lookupCode',
  validateParam('lookupCode'),
  asyncHandler(async (req, res) => {
    /*
     * The single-lookup endpoint is still useful for debugging and for possible
     * future optimization if the number of lookup sets grows and startup payloads
     * need to become more selective.
     */
    const cacheKey = `lookup-${req.params.lookupCode}`;
    const cached = lookupCache.get(cacheKey);

    if (cached) {
      return res.json(cached);
    }

    const lookup = await getLookup(req.params.lookupCode);

    if (!lookup) {
      return res.status(404).json({ message: 'Lookup not found.' });
    }

    lookupCache.set(cacheKey, lookup);
    return res.json(lookup);
  })
);

export default router;