package request

import (
	errors2 "errors"
	"github.com/go-playground/validator/v10"
	"reflect"
)

var validate *validator.Validate

func ValidateAndHandleError(req interface{}) error {
	validate = validator.New()

	if err := validate.Struct(req); err != nil {
		formattedError := formatValidationError(err)
		return errors2.New(formattedError)
	}
	return nil
}

func formatValidationError(err error) string {
	if _, ok := err.(*validator.InvalidValidationError); ok {
		return err.Error()
	}

	var errorMessage string
	for _, err := range err.(validator.ValidationErrors) {
		switch err.Tag() {
		case "required":
			errorMessage += "The field '" + err.Field() + "' is required."
		case "min":
			if err.Kind() == reflect.Slice {
				errorMessage += "The field '" + err.Field() + "' must contain at least " + err.Param() + " items."
			} else {
				errorMessage += "The field '" + err.Field() + "' must be at least " + err.Param() + "."
			}
		case "oneof":
			errorMessage += "The field '" + err.Field() + "' must be one of [" + err.Param() + "]."
		case "email":
			errorMessage += "The field '" + err.Field() + "' must be a valid email address."
		case "len":
			errorMessage += "The field '" + err.Field() + "' must be exactly " + err.Param() + " characters long."
		default:
			errorMessage += "The field '" + err.Field() + "' is invalid."
		}
		errorMessage += " "
	}

	return errorMessage
}