package firewall

import (
	"os/exec"
	"strings"
)

// SyncAddressLists updates Linux ipsets to match the configured AddressList entries
func SyncAddressLists(entries []AddressListEntry) error {
	// Group addresses by list name
	listMap := make(map[string][]string)
	for _, e := range entries {
		if e.Disabled || e.Name == "" || e.Address == "" {
			continue
		}
		listMap[e.Name] = append(listMap[e.Name], e.Address)
	}

	// Clean up any mk_ sets that no longer exist or are now empty (ignoring mk_geo_ sets managed by GeoIP)
	if out, err := exec.Command("ipset", "list", "-name").Output(); err == nil {
		lines := strings.Split(string(out), "\n")
		for _, line := range lines {
			line = strings.TrimSpace(line)
			if strings.HasPrefix(line, "mk_") && !strings.HasPrefix(line, "mk_geo_") {
				name := strings.TrimPrefix(line, "mk_")
				if _, ok := listMap[name]; !ok {
					_ = exec.Command("ipset", "flush", line).Run()
					_ = exec.Command("ipset", "destroy", line).Run()
				}
			}
		}
	}

	for name, addrs := range listMap {
		setName := "mk_" + strings.ReplaceAll(name, " ", "_")
		// Create set if not exists
		_ = exec.Command("ipset", "create", setName, "hash:net", "-exist").Run()
		_ = exec.Command("ipset", "flush", setName).Run()

		for _, a := range addrs {
			_ = exec.Command("ipset", "add", setName, a, "-exist").Run()
		}
	}

	return nil
}

// GetIPSetName returns the internal ipset name for an address list
func GetIPSetName(listName string) string {
	if listName == "" {
		return ""
	}
	clean := strings.TrimPrefix(listName, "!")
	if strings.HasPrefix(clean, "geo:") {
		code := strings.ToUpper(strings.TrimPrefix(clean, "geo:"))
		return "mk_geo_" + code
	}
	if strings.HasPrefix(clean, "geo_") {
		return "mk_" + clean
	}
	return "mk_" + strings.ReplaceAll(clean, " ", "_")
}