package firewall

import (
	"fmt"
	"os/exec"
	"strings"
)

func (m *FirewallManager) ResetRuleCounters(kind, id string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	found := false
	switch kind {
	case "filter":
		for _, r := range m.filterRules {
			found = found || r.ID == id
		}
	case "nat":
		for _, r := range m.natRules {
			found = found || r.ID == id
		}
	case "mangle":
		for _, r := range m.mangleRules {
			found = found || r.ID == id
		}
	default:
		return fmt.Errorf("unknown rule kind")
	}
	if !found {
		return fmt.Errorf("rule not found")
	}
	for _, binary := range []string{"iptables", "ip6tables"} {
		out, err := exec.Command(binary + "-save").Output()
		if err != nil {
			return err
		}
		table := ""
		numbers := map[string]int{}
		for _, line := range strings.Split(string(out), "\n") {
			if strings.HasPrefix(line, "*") {
				table = line[1:]
				numbers = map[string]int{}
			}
			if !strings.HasPrefix(line, "-A ") {
				continue
			}
			fields := strings.Fields(line)
			chain := fields[1]
			numbers[chain]++
			if table != kind && !(kind == "filter" && table == "filter") {
				continue
			}
			if !strings.HasPrefix(chain, "DT_") {
				continue
			}
			if strings.Contains(line, "--comment "+quote("id:"+id)) || strings.Contains(line, "--comment "+quote("id:"+id+":log")) {
				if out, err := exec.Command(binary, "-t", table, "-Z", chain, fmt.Sprint(numbers[chain])).CombinedOutput(); err != nil {
					return fmt.Errorf("reset counter: %s: %w", out, err)
				}
			}
		}
	}
	return nil
}