BetterDiscordApp-v2/Installers/dotNet/BetterDiscordWI/panels/Panel1.cs

using System;
using System.Diagnostics;
using System.IO;
using System.Windows.Forms;

namespace BetterDiscordWI.panels {
    public partial class Panel1: UserControl, IPanel {
        public Panel1() {
            InitializeComponent();
        }

        public void SetVisible() {

            GetParent().btnBack.Visible = true;
            GetParent().btnNext.Enabled = true;
            GetParent().btnBack.Enabled = true;
            GetParent().btnNext.Text = @"Install";
            GetParent().lblPanelTitle.Text = @"BetterDiscord Installation";

            PickVersion();
        }

        public FormMain GetParent() {
            return (FormMain)ParentForm;
        }

        public void BtnNext() {
            GetParent().DiscordPath = tbPath.Text;
            GetParent().RestartDiscord = cbRestart.Checked;
            GetParent().SwitchPanel(2);
        }

        public void BtnPrev() {
            GetParent().SwitchPanel(0);
        }

        private void btnBrowser_Click(object sender, EventArgs e) {
            FolderBrowserDialog fbd = new FolderBrowserDialog { SelectedPath = tbPath.Text };
            fbd.ShowDialog(GetParent());

            tbPath.Text = fbd.SelectedPath;
        }

        private void checkBox1_CheckedChanged(object sender, EventArgs e) {
            PickVersion();
        }

        private void checkBox2_CheckedChanged(object sender, EventArgs e) {
            PickVersion();
        }

        private void PickVersion() {
            string dirPath;
            if(checkBox1.Checked) {
                dirPath = $"{Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData)}\\DiscordCanary";
                if(!Directory.Exists(dirPath)) checkBox1.Checked = false;
                
                checkBox2.Checked = false;
            } else if(checkBox2.Checked) {
                dirPath = $"{Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData)}\\DiscordPTB";
                if(!Directory.Exists(dirPath)) checkBox2.Checked = false;

                checkBox1.Checked = false;
            } else {
                dirPath = $"{Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData)}\\Discord";
            }

            if (!Directory.Exists(dirPath)) return;
            string[] directories = Directory.GetDirectories(dirPath);

            string highestVersion = null;

            foreach(string s in directories) {
                Debug.Print(s);
                if(!s.Contains("app-"))
                    continue;
                if(string.IsNullOrEmpty(highestVersion)) {
                    highestVersion = s;
                    continue;
                }

                if(string.CompareOrdinal(s, highestVersion) > 0) {
                    highestVersion = s;
                }
            }

            tbPath.Text = highestVersion;
        }
    }
}