// Package updater runs one dynamic DNS update pass across all configured entries.
package updater

import (
	"fmt"
	"log"

	"git.aehoo.net/alphard/he-dydns/internal/config"
	"git.aehoo.net/alphard/he-dydns/internal/hedns"
	"git.aehoo.net/alphard/he-dydns/internal/network"
)

// Run discovers the current address(es) and updates every configured entry.
// It returns an error only when address discovery itself fails outright;
// per-entry update failures are logged and aggregated but do not stop other
// entries from being attempted.
func Run(cfg *config.Config) error {
	addrs, err := network.Discover(cfg.Interface)
	if err != nil {
		return fmt.Errorf("discovering address: %w", err)
	}

	if addrs.Empty() {
		log.Printf("no address found (interface=%q); skipping update", cfg.Interface)
		return nil
	}

	if addrs.IPv4 != nil {
		log.Printf("discovered IPv4 address %s", addrs.IPv4)
	}
	if addrs.IPv6 != nil {
		log.Printf("discovered IPv6 address %s", addrs.IPv6)
	}

	var failures int
	for _, entry := range cfg.Entries {
		if addrs.IPv4 != nil {
			if err := hedns.Update(entry.Hostname, entry.Token, addrs.IPv4); err != nil {
				log.Printf("error: %v", err)
				failures++
			} else {
				log.Printf("updated %s -> %s", entry.Hostname, addrs.IPv4)
			}
		}
		if addrs.IPv6 != nil {
			if err := hedns.Update(entry.Hostname, entry.Token, addrs.IPv6); err != nil {
				log.Printf("error: %v", err)
				failures++
			} else {
				log.Printf("updated %s -> %s", entry.Hostname, addrs.IPv6)
			}
		}
	}

	if failures > 0 {
		return fmt.Errorf("%d update(s) failed", failures)
	}
	return nil
}