package utils

import (
	"regexp"
	"strings"

	"github.com/go-playground/validator/v10"
)

var validate *validator.Validate

// InitValidator initializes the validator
func InitValidator() {
	validate = validator.New()
	
	// Register custom validators
	validate.RegisterValidation("phone", validatePhone)
	validate.RegisterValidation("nrp", validateNRP)
}

// ValidateStruct validates a struct
func ValidateStruct(s interface{}) error {
	if validate == nil {
		InitValidator()
	}
	return validate.Struct(s)
}

// validatePhone validates Indonesian phone numbers
func validatePhone(fl validator.FieldLevel) bool {
	phone := fl.Field().String()
	if phone == "" {
		return true // Allow empty (use required tag separately)
	}

	// Remove spaces and dashes
	phone = strings.ReplaceAll(phone, " ", "")
	phone = strings.ReplaceAll(phone, "-", "")

	// Check if starts with 0 or +62 or 62
	pattern := `^(0|\+?62)[0-9]{8,12}$`
	matched, _ := regexp.MatchString(pattern, phone)
	return matched
}

// validateNRP validates NRP (Nomor Registrasi Pokok)
func validateNRP(fl validator.FieldLevel) bool {
	nrp := fl.Field().String()
	if nrp == "" {
		return true // Allow empty (use required tag separately)
	}

	// NRP format: 10 digits
	pattern := `^[0-9]{10}$`
	matched, _ := regexp.MatchString(pattern, nrp)
	return matched
}

// IsValidEmail checks if email is valid
func IsValidEmail(email string) bool {
	pattern := `^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$`
	matched, _ := regexp.MatchString(pattern, email)
	return matched
}

// IsValidURL checks if URL is valid
func IsValidURL(url string) bool {
	pattern := `^https?://[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}(/.*)?$`
	matched, _ := regexp.MatchString(pattern, url)
	return matched
}

// SanitizeString removes potentially dangerous characters
func SanitizeString(s string) string {
	// Remove control characters
	s = strings.Map(func(r rune) rune {
		if r < 32 && r != '\n' && r != '\r' && r != '\t' {
			return -1
		}
		return r
	}, s)

	return strings.TrimSpace(s)
}