package app

import (
	"fmt"
	"net"

	"dnsupdater/dns"
	"dnsupdater/dns/service"
)

type Updater struct {
	service service.Service
	// cache   map[string][]dns.Record
	cache dns.DomainRecordCache
}

func NewUpdater(service service.Service) *Updater {
	return &Updater{
		service: service,
		cache:   *dns.NewDomainRecordCache(service.List),
	}
}

func (u Updater) find(domain string, record_name string) (*dns.Record, error) {
	records, err := u.cache.Get(domain)
	if err != nil {
		return nil, err
	}
	if rec, found := records.FindByName(record_name); found {
		return &rec, nil
	}
	return nil, fmt.Errorf("could not find record %s", record_name)
}

func (u Updater) Update(domain, record string, ip net.IP) error {
	var err error
	var r *dns.Record
	if r, err = u.find(domain, record); err == nil {
		// Update if needed.
		if r.Ip == nil || !r.Ip.Equal(ip) {
			return u.service.Update(domain, r.Id, ip.String())
		}
	}
	return err
}