using System;
using System.Diagnostics;
using System.Linq;

namespace ToolLibrary
{
    public static class PortProcessManager
    {
        /// <summary>
        /// 获取指定端口占用的进程 PID
        /// </summary>
        /// <param name="port">指定的端口号</param>
        /// <returns>占用端口的进程 PID，失败时返回 -1</returns>
        public static int GetProcessIdByPort(int port)
        {
            try
            {
                // 使用 netstat 命令获取端口信息
                var startInfo = new ProcessStartInfo
                {
                    FileName = "netstat",
                    Arguments = $"-ano | findstr :{port}", // 查找指定端口的占用情况
                    RedirectStandardOutput = true,
                    UseShellExecute = false,
                    CreateNoWindow = true
                };

                using (var process = Process.Start(startInfo))
                using (var reader = process.StandardOutput)
                {
                    string output = reader.ReadToEnd();
                    if (!string.IsNullOrEmpty(output))
                    {
                        // 输出格式: TCP    0.0.0.0:2403          0.0.0.0:0              LISTENING       1234
                        var columns = output.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
                        if (columns.Length > 4)
                        {
                            int pid = int.Parse(columns[columns.Length - 1]); // 获取 PID
                            return pid;
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("查询端口进程失败: " + ex.Message);
            }

            return -1; // 返回无效的 PID
        }

        /// <summary>
        /// 根据 PID 杀死指定的进程
        /// </summary>
        /// <param name="pid">进程 ID</param>
        /// <returns>是否成功杀死进程</returns>
        public static bool KillProcessById(int pid)
        {
            try
            {
                var process = Process.GetProcessById(pid);
                process.Kill();
                Console.WriteLine($"进程 PID {pid} 已成功结束。");
                return true;
            }
            catch (Exception ex)
            {
                Console.WriteLine("结束进程失败: " + ex.Message);
                return false;
            }
        }

        /// <summary>
        /// 查询端口占用的进程并杀死该进程
        /// </summary>
        /// <param name="port">指定的端口号</param>
        /// <returns>是否成功杀死进程</returns>
        public static bool KillProcessByPort(int port)
        {
            int pid = GetProcessIdByPort(port);
            if (pid > 0)
            {
                return KillProcessById(pid);
            }
            else
            {
                Console.WriteLine($"端口 {port} 没有被占用或未找到相关进程。");
                return false;
            }
        }
    }

}