backend/src/middleware/validate.js

import { ZodError } from 'zod';

/**
 * Validate request body against a Zod schema
 * @param {import('zod').ZodSchema} schema
 */
export const validateBody = (schema) => (req, res, next) => {
  try {
    req.body = schema.parse(req.body);
    next();
  } catch (err) {
    if (err instanceof ZodError) {
      const errors = err.errors.map((e) => ({
        field: e.path.join('.'),
        message: e.message,
      }));
      return res.status(400).json({
        success: false,
        error: 'Validation failed',
        details: errors,
      });
    }
    next(err);
  }
};

/**
 * Validate request params against a Zod schema
 * @param {import('zod').ZodSchema} schema
 */
export const validateParams = (schema) => (req, res, next) => {
  try {
    req.params = schema.parse(req.params);
    next();
  } catch (err) {
    if (err instanceof ZodError) {
      return res.status(400).json({
        success: false,
        error: 'Invalid parameters',
        details: err.errors.map((e) => ({ field: e.path.join('.'), message: e.message })),
      });
    }
    next(err);
  }
};