package main

import (
	"context"
	"encoding/json"
	"flag"
	"fmt"
	"log"
	"net"
	"os"

	"github.com/libdns/cloudflare"
	"github.com/libdns/libdns"
)

var (
	domain = os.Getenv("DOMAIN")
	token  = os.Getenv("CF_TOKEN")
)

func main() {
	ctx := context.TODO()
	ip := net.IPv4(127, 0, 0, 1)
	var cname string
	sub := "<UNSET>"
	var path string

	flag.StringVar(&domain, "d", domain, "Domain name, e.g. example.com")
	flag.StringVar(&sub, "s", sub, "Subdomain to add dns entry for, e.g. blog")
	flag.StringVar(&token, "a", token, "Cloudflare API Token")
	flag.TextVar(&ip, "i", ip, "IP address")
	flag.StringVar(&cname, "c", cname, "CNAME target")
	flag.StringVar(&path, "o", path, "path to save all records as json, e.g. ./records.json")
	flag.Parse()

	provider := cloudflare.Provider{APIToken: token}
	zone := domain + "."
	fmt.Println(zone, sub, cname)
	makeRecord := func() (libdns.Record, error) {
		switch {
		case cname != "":
			return libdns.Record{
				Type:  "CNAME",
				Name:  sub,
				Value: cname,
			}, nil
		case len(ip) == net.IPv4len:
			return libdns.Record{
				Type:  "A",
				Name:  sub,
				Value: ip.To4().String(),
			}, nil
		case len(ip) == net.IPv6len:
			return libdns.Record{
				Type:  "AAAA",
				Name:  sub,
				Value: ip.To16().String(),
			}, nil
		}
		return libdns.Record{}, fmt.Errorf("neither cname nor valid ip is set")
	}

	if sub != "<UNSET>" {
		record, err := makeRecord()
		if err != nil {
			panic(err)
		}
		log.Printf("setting record, %+v", record)
		newRecs, err := provider.SetRecords(ctx, zone, []libdns.Record{record})
		if err != nil {
			panic(err)
		}
		fmt.Println(newRecs)
	}

	if path != "" {
		recs, err := provider.GetRecords(ctx, zone)
		if err != nil {
			panic(err)
		}
		data, err := json.Marshal(recs)

		if err != nil {
			panic(err)
		}
		err = os.WriteFile(path, data, 0644)
		if err != nil {
			panic(err)
		}
	}
}