package models

import "strings"

// blank clears each optional text column whose value is empty or only
// whitespace, so an emptied admin text input stores NULL rather than "".
func blank(fields ...**string) {
	for _, f := range fields {
		if *f != nil && strings.TrimSpace(**f) == "" {
			*f = nil
		}
	}
}

// temporalErrors is a field-to-messages map in the shape of lagoon.Validate.
type temporalErrors map[string][]string

func (e temporalErrors) add(field, msg string) { e[field] = append(e[field], msg) }

func (e temporalErrors) result() map[string][]string {
	if len(e) == 0 {
		return nil
	}
	return e
}

// TemporalValidator is implemented by models whose dates must be in order.
// The admin controllers call it before a save, because lagoon.Validate
// cannot compare two fields.
type TemporalValidator interface {
	TemporalErrors() map[string][]string
}