package firewall

import (
	"fmt"
	"net"
	"strings"
)

// SyncAddressLists updates Linux ipsets to match the configured AddressList entries and referenced lists
func SyncAddressLists(entries []AddressListEntry, referencedLists ...string) 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)
	}

	// Ensure any custom list explicitly referenced in rules exists even if empty
	for _, ref := range referencedLists {
		ref = strings.TrimPrefix(ref, "!")
		if ref != "" && !strings.HasPrefix(ref, "geo:") && !strings.HasPrefix(ref, "geo_") {
			if _, ok := listMap[ref]; !ok {
				listMap[ref] = []string{}
			}
		}
	}

	for name, addrs := range listMap {
		var v4, v6 []string
		for _, address := range addrs {
			ip := net.ParseIP(address)
			if ip == nil {
				ip, _, _ = net.ParseCIDR(address)
			}
			if ip == nil {
				return fmt.Errorf("invalid address: %s", address)
			}
			if ip.To4() != nil {
				v4 = append(v4, address)
			} else {
				v6 = append(v6, address)
			}
		}
		if err := replaceSet(GetIPSetName(name), "inet", v4); err != nil {
			return err
		}
		if err := replaceSet(GetIPSetName(name)+"_v6", "inet6", v6); err != nil {
			return err
		}
	}

	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, " ", "_")
}

// GetGeoIPSetName returns the internal ipset name for a Geo-Location country or preset
func GetGeoIPSetName(code string) string {
	if code == "" {
		return ""
	}
	clean := strings.TrimPrefix(code, "!")
	clean = strings.TrimPrefix(clean, "geo:")
	clean = strings.TrimPrefix(clean, "geo_")
	return "mk_geo_" + strings.ToUpper(clean)
}