using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using System.Net.NetworkInformation;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace NetworkSpeedTest
{
    public partial class MainForm : Form
    {
        private DataTable adapterTable;
        private PerformanceCounter netCounter;
        private Timer timer;

        private string networkCard;
        private int maxSpeed = 0;

        public MainForm()
        {
            InitializeComponent();

            InitInstance();
            
        }

        public void InitInstance()
        {
            NetworkInterface[] adapters = NetworkInterface.GetAllNetworkInterfaces();
            
            adapterTable = new DataTable();
            adapterTable.Columns.Add("Name", typeof(string));
            adapterTable.Columns.Add("Description", typeof(string));

            for (int i = 0; i < adapters.Length; i++)
            {
                adapterTable.Rows.Add(new string[] { adapters[i].Name, adapters[i].Description });
            }

            CardComboBox.DataSource = adapterTable.DefaultView;
            CardComboBox.ValueMember = "Description";
        }

        private void StartMeasuring()
        {
            StartButton.Text = "중지";
            maxSpeed = 0;
            SpeedBar.Value = 0;
            SpeedBar.Maximum = 0;

            timer = new Timer();
            timer.Interval = 1000;
            timer.Tick += new EventHandler(Timer_Tick);
            timer.Start();
        }

        private void StopMeasuring()
        {
            StartButton.Text = "측정";
            timer.Stop();
        }

        private void Timer_Tick(object sender, EventArgs e)
        {
            try
            {
                int speed = (int)netCounter.NextValue();
                if (speed > maxSpeed)
                {
                    maxSpeed = speed;
                    SpeedBar.Maximum = maxSpeed;
                    MaxSpeedLabel.Text = string.Format("{0} bps", maxSpeed.ToString("N0"));
                }
                
                SpeedBar.Value = speed;
                float percentage = maxSpeed == 0f ? 0f : (float)speed / (float)maxSpeed * 100f;
                SpeedLabel.Text = string.Format("{0} bps ({1}%)", speed.ToString("N0"), percentage.ToString("N2"));
            }
            catch (Exception ex)
            {
                StopMeasuring();
                MessageBox.Show("다음과 같은 이유로 측정할 수 없습니다." + Environment.NewLine + ex.Message);
            }
        }

        private void StartButton_Click(object sender, EventArgs e)
        {
            try
            {
                if (string.IsNullOrEmpty(networkCard))
                {
                    MessageBox.Show("네트워크 카드를 선택해 주십시오.");
                }

                if (StartButton.Text == "측정")
                {
                    StartMeasuring();
                }
                else
                {
                    StopMeasuring();
                }
                        
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }

        private void CardComboBox_SelectedIndexChanged(object sender, EventArgs e)
        {
            try
            {
                DataRowView rowView = CardComboBox.SelectedItem as DataRowView;
                if (rowView == null)
                    return;

                string description = rowView.Row["Description"].ToString();
                networkCard = description
                    .Replace('(', '[')
                    .Replace(')', ']')
                    .Replace('/', '_');

                netCounter = new PerformanceCounter();
                netCounter.CategoryName = "Network Interface";
                netCounter.CounterName = "Bytes Total/sec";
                netCounter.InstanceName = networkCard;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }
    }
}