const router = require('express').Router();
const { body } = require('express-validator');
const prisma = require('../lib/prisma');
const auditMiddleware = require('../middleware/auditMiddleware');
const { validateRequest } = require('../middleware/errorHandler');

const experimentValidation = [
  body('title').trim().notEmpty().withMessage('Title is required').isLength({ max: 255 }).withMessage('Title must be ≤255 characters'),
];

// GET /api/experiments — list all
router.get('/', async (req, res, next) => {
  try {
    const experiments = await prisma.experiment.findMany({
      orderBy: { created_at: 'desc' },
      include: { _count: { select: { animals: true } } },
    });
    res.json(experiments);
  } catch (err) {
    next(err);
  }
});

// GET /api/experiments/:id — get one with animals
router.get('/:id', async (req, res, next) => {
  try {
    const experiment = await prisma.experiment.findUnique({
      where: { id: req.params.id },
      include: { animals: true },
    });
    if (!experiment) return res.status(404).json({ error: 'Experiment not found' });
    res.json(experiment);
  } catch (err) {
    next(err);
  }
});

// POST /api/experiments — create
router.post('/', experimentValidation, validateRequest, async (req, res, next) => {
  try {
    const { title } = req.body;
    const experiment = await prisma.experiment.create({ data: { title } });

    // Write CREATE audit log
    await prisma.auditLog.create({
      data: {
        table_name: 'experiments',
        record_id: experiment.id,
        action: 'CREATE',
        changes: { before: null, after: experiment },
      },
    });

    res.status(201).json(experiment);
  } catch (err) {
    next(err);
  }
});

// PUT /api/experiments/:id — update
router.put(
  '/:id',
  auditMiddleware('experiments', prisma.experiment),
  experimentValidation,
  validateRequest,
  async (req, res, next) => {
    try {
      const { title } = req.body;
      const experiment = await prisma.experiment.update({
        where: { id: req.params.id },
        data: { title },
      });
      res.json(experiment);
    } catch (err) {
      next(err);
    }
  }
);

// DELETE /api/experiments/:id — delete
router.delete(
  '/:id',
  auditMiddleware('experiments', prisma.experiment),
  async (req, res, next) => {
    try {
      await prisma.experiment.delete({ where: { id: req.params.id } });
      res.status(204).send();
    } catch (err) {
      next(err);
    }
  }
);

module.exports = router;