package app

import (
	"context"
	"errors"
	"fmt"
	"os/exec"
	"strings"
	"time"
)

// ---------------------------------------------------------------------
// низкоуровневые helpers
// ---------------------------------------------------------------------

// EN: Low-level command execution adapters with timeout handling and small
// EN: policy-route verification helper used by higher-level handlers.
// RU: Низкоуровневые адаптеры запуска команд с таймаутами и вспомогательной
// RU: проверкой policy-route, используемой верхнеуровневыми обработчиками.

func runCommand(name string, args ...string) (string, string, int, error) {
	return runCommandTimeout(60*time.Second, name, args...)
}

// ---------------------------------------------------------------------
// policy route check
// ---------------------------------------------------------------------

func checkPolicyRoute(iface, table string) (bool, error) {
	stdout, _, exitCode, err := runCommand("ip", "route", "show", "table", table)
	if exitCode != 0 {
		if err == nil {
			err = fmt.Errorf("ip route show exited with %d", exitCode)
		}
		return false, err
	}
	want := fmt.Sprintf("default dev %s", iface)
	for _, line := range strings.Split(stdout, "\n") {
		line = strings.TrimSpace(line)
		if strings.HasPrefix(line, want) {
			return true, nil
		}
	}
	return false, nil
}

// ---------------------------------------------------------------------
// command timeout helper
// ---------------------------------------------------------------------

func runCommandTimeout(timeout time.Duration, name string, args ...string) (string, string, int, error) {
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	cmd := exec.CommandContext(ctx, name, args...)
	out, err := cmd.CombinedOutput()
	stdout := string(out)
	stderr := stdout

	exitCode := 0
	if err != nil {
		if ee, ok := err.(*exec.ExitError); ok {
			exitCode = ee.ExitCode()
		} else if errors.Is(err, context.DeadlineExceeded) {
			exitCode = -1
			err = fmt.Errorf("command timeout: %w", err)
		} else {
			exitCode = -1
		}
	}
	return stdout, stderr, exitCode, err
}