/**
 * Express validation middleware using Zod
 * Validates request body, query parameters, and path parameters
 */

import { Request, Response, NextFunction } from 'express';
import { ZodSchema, ZodError } from 'zod';

export interface ValidationOptions {
  body?: ZodSchema;
  query?: ZodSchema;
  params?: ZodSchema;
}

/**
 * Create validation middleware for Express routes
 */
export function validate(options: ValidationOptions) {
  return async (req: Request, res: Response, next: NextFunction) => {
    try {
      // Validate request body
      if (options.body) {
        req.body = options.body.parse(req.body);
      }

      // Validate query parameters
      if (options.query) {
        req.query = options.query.parse(req.query);
      }

      // Validate path parameters
      if (options.params) {
        req.params = options.params.parse(req.params);
      }

      next();
    } catch (error) {
      if (error instanceof ZodError) {
        const validationErrors = error.errors.map((err) => ({
          path: err.path.join('.'),
          message: err.message,
          code: err.code,
        }));

        return res.status(400).json({
          code: 'VALIDATION_ERROR',
          message: 'Request validation failed',
          errors: validationErrors,
        });
      }

      next(error);
    }
  };
}

/**
 * Validate request body only
 */
export function validateBody(schema: ZodSchema) {
  return validate({ body: schema });
}

/**
 * Validate query parameters only
 */
export function validateQuery(schema: ZodSchema) {
  return validate({ query: schema });
}

/**
 * Validate path parameters only
 */
export function validateParams(schema: ZodSchema) {
  return validate({ params: schema });
}