// dynamic domain no-name system service
//
// a simple dynamic dns record updating utility which fetches your
// ip address from a source, and lets a provider know of the fresh
// address.
package main

import (
	"flag"
	"fmt"
	"log/slog"
	"os"

	"git.rnrd.eu/ddnnss/provider"
	"git.rnrd.eu/ddnnss/source"
)

const version = "1.0.0"

func main() {
	configPath := flag.String("config", "/etc/ddnnss.json", "config file")
	showVersion := flag.Bool("version", false, "print the version and exit")
	flag.Parse()

	if *showVersion {
		fmt.Println("ddnnss", version)
		return
	}

	slog.Info("ddnnss!", slog.String("version", version))

	cfg, err := LoadConfig(*configPath)
	if err != nil {
		slog.Error("could not load config", slog.String("error", err.Error()))
		os.Exit(1)
	}

	providers := map[string]provider.Provider{}
	sources := map[string]source.Source{}

	slog.Info("starting new cycle", slog.Int("records", len(cfg.Records)))

	failed := false
	for _, r := range cfg.Records {
		fqdn := r.Name + "." + r.Zone
		log := slog.With("record", fqdn, "type", r.Type)

		log.Info(
			"ensuring record",
			slog.String("provider", r.Provider),
			slog.String("source", r.Source),
		)

		p, ok := providers[r.Provider]
		if !ok {
			p, err = provider.New(log, cfg.Providers[r.Provider])
			if err != nil {
				log.Error("provider setup failed", "provider", r.Provider, "error", err)
				failed = true
				continue
			}
			providers[r.Provider] = p
		}

		s, ok := sources[r.Source]
		if !ok {
			s, err = source.New(log, cfg.Sources[r.Source])
			if err != nil {
				log.Error("source setup failed", "source", r.Source, "error", err)
				failed = true
				continue
			}
			sources[r.Source] = s
		}

		family := source.IPv4
		if r.Type == provider.TypeAAAA {
			family = source.IPv6
		}
		if !s.Supports(family) {
			log.Error("source cannot provide the needed address family",
				"source", r.Source, "family", family)
			failed = true
			continue
		}

		addr, err := s.Lookup(family)
		if err != nil {
			log.Error("address lookup failed", "source", r.Source, "error", err)
			failed = true
			continue
		}

		prev, changed, err := p.Ensure(r.Zone, r.Name, r.Type, addr)
		switch {
		case err != nil:
			log.Error("update failed", "error", err)
			failed = true
		case changed && prev == "":
			log.Info("record created", "addr", addr)
		case changed:
			log.Info("record updated", "from", prev, "to", addr)
		default:
			log.Info("record unchanged", "addr", addr)
		}
	}

	slog.Info(
		"cycle finished",
		slog.Int("records", len(cfg.Records)),
		slog.Bool("failed", failed),
	)

	if failed {
		slog.Error("not all records were ensured successfully")
		os.Exit(1)
	}
}