Program.cs

using CommandLine;

namespace MiniHping;

/// <summary>
/// Main program class for MiniHping, an educational network tool for sending TCP/ICMP packets.
/// </summary>
class Program
{
    /// <summary>
    /// Main entry point for the MiniHping application.
    /// </summary>
    /// <param name="args"></param>
    /// <returns></returns>
    static async Task<int> Main(string[] args)
    {
        Console.WriteLine("MiniHping v0.1.0 - by z0rimo");
        Console.WriteLine("==========================================");

        return await Parser.Default.ParseArguments<Options>(args)
            .MapResult(
                async (Options opts) => await RunProgram(opts),
                errs => Task.FromResult(1)
            );
    }

    /// <summary>
    /// Main program logic to run MiniHping with the provided options.
    /// </summary>
    /// <param name="opts"></param>
    /// <returns></returns>
    static async Task<int> RunProgram(Options opts)
    {
        try
        {
            // 1. 시스템 체크
            if (!NetworkManager.CheckSystemRequirements())
                return 1;

            // 2. 네트워크 인터페이스 선택
            var device = NetworkManager.SelectNetworkInterface(opts.InterfaceIndex);
            if (device == null)
            {
                Console.WriteLine("❌ Failed to select network interface");
                return 1;
            }

            // 3. 대상 IP 주소 해석
            var targetIP = await NetworkManager.ResolveHostnameAsync(opts.Target);
            if (targetIP == null)
            {
                Console.WriteLine($"❌ Cannot resolve hostname '{opts.Target}'");
                return 1;
            }

            // 4. 정보 출력
            Console.WriteLine($"Target: {opts.Target} ({targetIP})");
            Console.WriteLine($"Mode: {opts.Mode.ToUpper()}");
            if (opts.Mode.Equals("tcp", StringComparison.OrdinalIgnoreCase))
                Console.WriteLine($"Port: {opts.Port}");
            Console.WriteLine($"Interface: {device.Name}");
            Console.WriteLine($"Packets: {(opts.Count == -1 ? "unlimited" : opts.Count.ToString())}");
            Console.WriteLine();

            // 5. 서비스 시작
            var hpingService = new HpingService(device);

            if (opts.Mode.Equals("tcp", StringComparison.OrdinalIgnoreCase))
                await hpingService.StartTcpHpingAsync(targetIP, opts);
            else if (opts.Mode.Equals("icmp", StringComparison.OrdinalIgnoreCase))
                await hpingService.StartIcmpHpingAsync(targetIP, opts);
            else
            {
                Console.WriteLine($"❌ Unsupported mode: {opts.Mode}");
                return 1;
            }

            return 0;
        }
        catch (Exception ex)
        {
            Console.WriteLine($"❌ Error: {ex.Message}");
            if (opts.Verbose)
                Console.WriteLine($"Stack trace: {ex.StackTrace}");
            return 1;
        }
    }
}