const { body, param, query, validationResult } = require("express-validator");
const logger = require("../config/logger");

// Validation error handler middleware
const handleValidationErrors = (req, res, next) => {
  const errors = validationResult(req);
  if (!errors.isEmpty()) {
    logger.warn("Validation error", {
      path: req.path,
      errors: errors.array(),
      body: req.body,
    });
    return res.status(400).json({
      success: false,
      message: "Validation failed",
      errors: errors.array().map((err) => ({
        field: err.param,
        message: err.msg,
      })),
    });
  }
  next();
};

// Common validation rules
const validators = {
  // Auth validators
  login: [
    body("email")
      .isEmail()
      .withMessage("Valid email is required")
      .normalizeEmail()
      .trim(),
    body("password")
      .isLength({ min: 8 })
      .withMessage("Password must be at least 8 characters"),
  ],

  // User validators
  createUser: [
    body("email")
      .isEmail()
      .withMessage("Valid email is required")
      .normalizeEmail()
      .trim(),
    body("username")
      .isLength({ min: 3, max: 50 })
      .matches(/^[a-zA-Z0-9_-]+$/)
      .withMessage(
        "Username must be 3-50 characters and contain only letters, numbers, hyphens, and underscores"
      )
      .trim(),
    body("password")
      .isLength({ min: 8 })
      .matches(/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)/)
      .withMessage(
        "Password must be at least 8 characters with uppercase, lowercase, and number"
      ),
    body("role_id").notEmpty().withMessage("Role is required").trim(),
  ],

  updateUser: [
    param("id")
      .matches(/^user-[a-f0-9-]+$/)
      .withMessage("Invalid user ID format"),
    body("email")
      .optional()
      .isEmail()
      .withMessage("Valid email is required")
      .normalizeEmail()
      .trim(),
    body("username")
      .optional()
      .isLength({ min: 3, max: 50 })
      .withMessage("Username must be 3-50 characters")
      .matches(/^[a-zA-Z0-9_-]+$/)
      .trim(),
  ],

  // Product validators
  createProduct: [
    body("name")
      .isLength({ min: 1, max: 255 })
      .withMessage("Product name is required (max 255 characters)")
      .trim()
      .escape(),
    body("description")
      .optional()
      .isString()
      .withMessage("Description must be text")
      .trim(),
    body("price")
      .isFloat({ min: 0 })
      .withMessage("Price must be a positive number"),
    body("stockquantity")
      .optional()
      .isInt({ min: 0 })
      .withMessage("Stock quantity must be a non-negative integer"),
    body("category")
      .optional()
      .isString()
      .withMessage("Category must be text")
      .trim()
      .escape(),
  ],

  updateProduct: [
    param("id").isUUID().withMessage("Invalid product ID"),
    body("name")
      .optional()
      .isLength({ min: 1, max: 255 })
      .withMessage("Product name must be 1-255 characters")
      .trim()
      .escape(),
    body("price")
      .optional()
      .isFloat({ min: 0 })
      .withMessage("Price must be a positive number"),
    body("stockquantity")
      .optional()
      .isInt({ min: 0 })
      .withMessage("Stock quantity must be a non-negative integer"),
  ],

  // Blog validators
  createBlogPost: [
    body("title")
      .isLength({ min: 1, max: 255 })
      .withMessage("Title is required (max 255 characters)")
      .trim()
      .escape(),
    body("slug")
      .isLength({ min: 1, max: 255 })
      .matches(/^[a-z0-9-]+$/)
      .withMessage(
        "Slug must contain only lowercase letters, numbers, and hyphens"
      )
      .trim(),
    body("content").notEmpty().withMessage("Content is required").trim(),
  ],

  // Generic ID validator
  idParam: [param("id").notEmpty().withMessage("ID is required").trim()],

  // Pagination validators
  pagination: [
    query("page")
      .optional()
      .isInt({ min: 1 })
      .withMessage("Page must be a positive integer"),
    query("limit")
      .optional()
      .isInt({ min: 1, max: 100 })
      .withMessage("Limit must be between 1 and 100"),
  ],
};

module.exports = {
  validators,
  handleValidationErrors,
};