provider.go

// Package miab implements a DNS record management client compatible
// with the libdns interfaces for https://mailinabox.email/ custom DNS Endpoints.
// The mailinabox DNS API is limited in that it only works with one zone.
package mailinabox

import (
	"context"
	"fmt"
	"strings"

	"github.com/libdns/libdns"
	"github.com/luv2code/gomiabdns"
	miab "github.com/luv2code/gomiabdns"
)

// Provider facilitates DNS record manipulation with Mail-In-A-Box.
type Provider struct {
	// APIURL is the URL provided by the mailinabox admin interface, found
	// on your box here: https://box.[your-domain.com]/admin#custom_dns
	// https://box.[your-domain.com]/admin/dns/custom
	APIURL string `json:"api_url,omitempty"`
	// EmailAddress of an admin account.
	// It's recommended that a dedicated account
	// be created especially for managing DNS.
	EmailAddress string `json:"email_address,omitempty"`
	// Password of the admin account that corresponds to the email.
	Password string `json:"password,omitempty"`
}

func (p *Provider) getClient() *miab.Client {
	return miab.New(p.APIURL, p.EmailAddress, p.Password)
}

func removeTrailingDot(zone string) string {
	return zone[:len(zone)-1]
}
func (p *Provider) zoneCheck(zone string) error {
	zone = removeTrailingDot(zone)
	if !strings.Contains(p.APIURL, removeTrailingDot(zone)) {
		return fmt.Errorf("This DNS provider (%s) does not control the specified zone (%s)", p.APIURL, zone)
	}
	return nil
}
func toLibDnsRecords(zone string, miabRecords []miab.DNSRecord) []libdns.Record {
	libDNSRecords := []libdns.Record{}
	zone = removeTrailingDot(zone)
	for _, mr := range miabRecords {
		partialName := strings.ReplaceAll(mr.QualifiedName, zone, "")
		partialName = removeTrailingDot(partialName)
		libDNSRecords = append(libDNSRecords, libdns.Record{
			ID:    mr.QualifiedName + ".",
			Type:  string(mr.RecordType),
			Name:  partialName,
			Value: mr.Value,
		})
	}
	return libDNSRecords
}

// GetRecords lists all the records in the zone.
func (p *Provider) GetRecords(ctx context.Context, zone string) ([]libdns.Record, error) {
	if err := p.zoneCheck(zone); err != nil {
		return nil, err
	}
	client := p.getClient()
	miabRecords, err := client.GetHosts(ctx, "", "")
	if err != nil {
		return nil, err
	}
	return toLibDnsRecords(zone, miabRecords), nil
}

// AppendRecords adds records to the zone. It returns the records that were added.
func (p *Provider) AppendRecords(ctx context.Context, zone string, records []libdns.Record) ([]libdns.Record, error) {
	if err := p.zoneCheck(zone); err != nil {
		return nil, err
	}
	zone = removeTrailingDot(zone)
	client := p.getClient()
	for _, r := range records {
		if err := client.AddHost(ctx, r.Name+"."+zone, gomiabdns.RecordType(r.Type), r.Value); err != nil {
			return nil, err
		}
	}
	return records, nil
}

// SetRecords sets the records in the zone, either by updating existing records or creating new ones.
// It returns the updated records.
func (p *Provider) SetRecords(ctx context.Context, zone string, records []libdns.Record) ([]libdns.Record, error) {
	if err := p.zoneCheck(zone); err != nil {
		return nil, err
	}
	zone = removeTrailingDot(zone)
	client := p.getClient()
	for _, r := range records {
		if err := client.UpdateHost(ctx, r.Name+"."+zone, gomiabdns.RecordType(r.Type), r.Value); err != nil {
			return nil, err
		}
	}
	return records, nil
}

// DeleteRecords deletes the records from the zone. It returns the records that were deleted.
func (p *Provider) DeleteRecords(ctx context.Context, zone string, records []libdns.Record) ([]libdns.Record, error) {
	if err := p.zoneCheck(zone); err != nil {
		return nil, err
	}
	zone = removeTrailingDot(zone)
	client := p.getClient()
	for _, r := range records {
		if err := client.DeleteHost(ctx, r.Name+"."+zone, gomiabdns.RecordType(r.Type), r.Value); err != nil {
			return nil, err
		}
	}
	return records, nil
}

// Interface guards
var (
	_ libdns.RecordGetter   = (*Provider)(nil)
	_ libdns.RecordAppender = (*Provider)(nil)
	_ libdns.RecordSetter   = (*Provider)(nil)
	_ libdns.RecordDeleter  = (*Provider)(nil)
)