using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Security.Principal;
using Microsoft.CodeAnalysis.CSharp;
using PureCrack.Panel;
using PureCrack.Setup;
using PureCrack.Util;

namespace PureCrack;

public static class Preflight
{
	public sealed class Result
	{
		public List<string> Problems { get; } = new List<string>();

		public string? PanelExePath { get; set; }

		public bool Ok => Problems.Count == 0;
	}

	public static Result Run()
	{
		Result result = new Result();
		if (!IsAdmin())
		{
			result.Problems.Add("not running as administrator (need admin to bind :443 + write hosts + install root cert)");
		}
		if (!IsTcpPortFree(443))
		{
			string text = LookupTcpListenerHolder(443);
			string arg = text ?? "another process";
			string arg2 = ((text != null && text.StartsWith("PID ")) ? (" (taskkill /F /PID " + text.Substring(4).Split(new char[1] { ' ' })[0] + " to stop it)") : "");
			result.Problems.Add($":{443} is already bound by {arg}{arg2}");
		}
		try
		{
			if (!HostsManager.IsWritable())
			{
				result.Problems.Add(HostsManager.Path + " is not writable (file marked read-only? AV blocking?)");
			}
		}
		catch (Exception ex)
		{
			result.Problems.Add("hosts file check threw: " + ex.Message);
		}
		try
		{
			result.PanelExePath = PanelLauncher.FindExe();
		}
		catch (FileNotFoundException ex2)
		{
			result.Problems.Add(ex2.Message);
		}
		try
		{
			_ = typeof(CSharpCompilation).Assembly.FullName;
		}
		catch (Exception ex3)
		{
			result.Problems.Add("Roslyn (Microsoft.CodeAnalysis.CSharp) not loadable: " + ex3.Message);
		}
		return result;
	}

	public static void Report(Result r)
	{
		if (r.Ok)
		{
			Log.Ok("preflight passed (panel at " + r.PanelExePath + ")");
			return;
		}
		Log.Err($"preflight: {r.Problems.Count} problem(s) — fix all then re-launch:");
		foreach (string problem in r.Problems)
		{
			Log.Bullet("  - " + problem);
		}
	}

	private static bool IsAdmin()
	{
		try
		{
			using WindowsIdentity ntIdentity = WindowsIdentity.GetCurrent();
			return new WindowsPrincipal(ntIdentity).IsInRole(WindowsBuiltInRole.Administrator);
		}
		catch
		{
			return false;
		}
	}

	private static bool IsTcpPortFree(int port)
	{
		TcpListener tcpListener = null;
		try
		{
			tcpListener = new TcpListener(IPAddress.Any, port);
			tcpListener.Start();
			return true;
		}
		catch (SocketException)
		{
			return false;
		}
		finally
		{
			try
			{
				tcpListener?.Stop();
			}
			catch
			{
			}
		}
	}

	private static string? LookupTcpListenerHolder(int port)
	{
		try
		{
			using Process process = Process.Start(new ProcessStartInfo("netstat", "-ano")
			{
				UseShellExecute = false,
				RedirectStandardOutput = true,
				CreateNoWindow = true
			});
			if (process == null)
			{
				return null;
			}
			string text = process.StandardOutput.ReadToEnd();
			process.WaitForExit(5000);
			string[] array = text.Split(new char[1] { '\n' });
			for (int i = 0; i < array.Length; i++)
			{
				string text2 = array[i].Trim();
				if (!text2.StartsWith("TCP", StringComparison.Ordinal))
				{
					continue;
				}
				string[] array2 = text2.Split(new char[2] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries);
				if (array2.Length >= 5 && !(array2[3] != "LISTENING") && array2[1].EndsWith(":" + port, StringComparison.Ordinal) && int.TryParse(array2[4], out var result))
				{
					try
					{
						Process processById = Process.GetProcessById(result);
						return $"PID {result} ({processById.ProcessName})";
					}
					catch
					{
						return $"PID {result}";
					}
				}
			}
		}
		catch
		{
		}
		return null;
	}
}