package validator

import (
	"regexp"

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

var (
	validate *validator.Validate
	uuidRegex    = regexp.MustCompile(`^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$`)
	slugRegex    = regexp.MustCompile(`^[a-z0-9-]+$`)
	currencyRegex = regexp.MustCompile(`^[A-Z]{3}$`)
)

func init() {
	validate = validator.New()

	// Custom validators
	_ = validate.RegisterValidation("uuid", validateUUID)
	_ = validate.RegisterValidation("slug", validateSlug)
	_ = validate.RegisterValidation("latitude", validateLatitude)
	_ = validate.RegisterValidation("longitude", validateLongitude)
	_ = validate.RegisterValidation("place_type", validatePlaceType)
	_ = validate.RegisterValidation("user_role", validateUserRole)
	_ = validate.RegisterValidation("currency", validateCurrency)
	_ = validate.RegisterValidation("user_status", validateUserStatus)
	_ = validate.RegisterValidation("place_status", validatePlaceStatus)
	_ = validate.RegisterValidation("service_status", validateServiceStatus)
	_ = validate.RegisterValidation("booking_status", validateBookingStatus)
}

// Validate validates a struct and returns ValidationErrors if any
func Validate(s interface{}) error {
	return validate.Struct(s)
}

// ValidateVar validates a single variable
func ValidateVar(field interface{}, tag string) error {
	return validate.Var(field, tag)
}

// ValidationErrors wraps validator.ValidationErrors for easier handling
type ValidationErrors validator.ValidationErrors

func (ve ValidationErrors) Error() string {
	return validator.ValidationErrors(ve).Error()
}

// FieldErrors returns a map of field -> error message
func (ve ValidationErrors) FieldErrors() map[string]string {
	errs := make(map[string]string)
	for _, fe := range ve {
		errs[fe.Field()] = fe.Tag()
	}
	return errs
}

// Custom validators

func validateUUID(fl validator.FieldLevel) bool {
	return uuidRegex.MatchString(fl.Field().String())
}

func validateSlug(fl validator.FieldLevel) bool {
	return slugRegex.MatchString(fl.Field().String())
}

func validateLatitude(fl validator.FieldLevel) bool {
	lat := fl.Field().Float()
	return lat >= -90 && lat <= 90
}

func validateLongitude(fl validator.FieldLevel) bool {
	lng := fl.Field().Float()
	return lng >= -180 && lng <= 180
}

func validatePlaceType(fl validator.FieldLevel) bool {
	v := fl.Field().String()
	return v == "place" || v == "studio"
}

func validateUserRole(fl validator.FieldLevel) bool {
	roles := map[string]bool{
		"customer": true, "landlord": true, "executor": true,
		"moderator": true, "superadmin": true,
	}
	return roles[fl.Field().String()]
}

func validateCurrency(fl validator.FieldLevel) bool {
	return currencyRegex.MatchString(fl.Field().String())
}

func validateUserStatus(fl validator.FieldLevel) bool {
	statuses := map[string]bool{"active": true, "banned": true, "pending_verification": true}
	return statuses[fl.Field().String()]
}

func validatePlaceStatus(fl validator.FieldLevel) bool {
	statuses := map[string]bool{
		"draft": true, "pending_moderation": true, "published": true,
		"rejected": true, "archived": true,
	}
	return statuses[fl.Field().String()]
}

func validateServiceStatus(fl validator.FieldLevel) bool {
	statuses := map[string]bool{"draft": true, "published": true, "archived": true}
	return statuses[fl.Field().String()]
}

func validateBookingStatus(fl validator.FieldLevel) bool {
	statuses := map[string]bool{"pending": true, "confirmed": true, "cancelled": true, "completed": true}
	return statuses[fl.Field().String()]
}