using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Navigation;
using System.IO;
using System.Net;
using ModernWpf.Controls;
using System.Windows.Forms;
using System.Media;
using Path = System.IO.Path;
using File = System.IO.File;
using EZPPClient_Installer.Utils;
using IWshRuntimeLibrary;
using Semver;

#if DEBUG
using MessageBox = System.Windows.MessageBox;
#endif

namespace EZPPClient_Installer
{
  public partial class MainWindow : Window
  {

    public static MainWindow Instance { get; private set; }

    [DllImport("kernel32.dll")]
    private static extern bool CreateSymbolicLink(string lpSymlinkFileName, string lpTargetFileName, SymbolicLink dwFlags);

    private static SemVersion VERSION = new SemVersion(1, 1, 1);

    public static string RELEASESTREAM;

    public MainWindow()
    {
      var alreadyRunning = System.Diagnostics.Process.GetProcessesByName(System.IO.Path.GetFileNameWithoutExtension(System.Reflection.Assembly.GetEntryAssembly().Location)).Count() > 1;
      if (alreadyRunning)
      {
        this.Close();
        return;
      }
       
      Instance = this;
      InitializeComponent();
      Init();
    }

    private async void Init()
    {

      UpdateInstallButton(false);

      UpdateState status = await CheckForInstallerUpdates();

      switch (status)
      {
        case UpdateState.UpdateFound:
          ShowInstallerUpdateDialog();
          return;
        case UpdateState.Error:
          return;
      }


      string versionString = "v" + VERSION;
      InstallerWindow.Title = "EZPPClient Installer " + versionString.Replace(",", ".");

      await FetchReleaseStreams();

      string osuPath = OsuUtil.osuInstallDir();

      if (osuPath.EndsWith(@"\EZPPClient"))
      {
        osuPath = osuPath.Replace(@"\EZPPClient", "");
      }

      bool isValidFolder = await isValidOsuFolder(osuPath);
      UpdateInstallButton(!string.IsNullOrEmpty(osuPath));

      if(string.IsNullOrEmpty(osuPath))
        folderTextbox.Text = "";

      if (!string.IsNullOrEmpty(osuPath) && isValidFolder)
      {
        bool foundInstall = isEZPPClientInstallationFound(osuPath);
        if (foundInstall)
        {
          string osuEZPPPath = osuPath + @"\EZPPClient";

          Uninstall_Button.Visibility = Visibility.Visible;
          UpdateInstallButton(false);


          List<string> outdatedFiles = await DownloadUtil.FilesToDownload(osuEZPPPath, false);

          if (!IsEmpty(outdatedFiles))
          {
            UpdateInstallButton(true);
            InstallButton.Content = "Update";
            linkFoldersCheckbox.IsEnabled = false;
          }
        }

        folderTextbox.Text = osuPath;
      }
      else
        await new ContentDialog()
        {
          Title = "Hmmm..",
          Content = "We failed to locate your osu! Installation path, please define it manually qwq",
          PrimaryButtonText = "Okay qwq"
        }.ShowAsync();

    }

    private async Task FetchReleaseStreams()
    {
      List<string> releases = await ReleaseStreamUtil.GetAvailableReleaseStreams();
      foreach(string release in releases)
      {
        ReleaseStreamComboBox.Items.Add(release.UppercaseFirst().Trim());
      }

      string systemRelease = RegistryUtil.GetUsedReleaseStream("Stable");

      bool containsRelease = releases.Contains(systemRelease);

      ReleaseStreamComboBox.SelectedValue = systemRelease;
     
    }

    private async Task<UpdateState> CheckForInstallerUpdates()
    {
#if !DEBUG
      try
      {
        using (WebClient client = new WebClient())
        {
          client.Headers.Add("user-agent", "EZPPClientInstaller");
          string newVersionString = await client.DownloadStringTaskAsync("https://new.ez-pp.farm/ezppclient?version");
          SemVersion newVersion = new SemVersion(9, 9, 9);

          try
          {
            newVersion = SemVersion.Parse(newVersionString);
          }
          catch (Exception e){
            ShowErrorDialog(e.Message);
          }

          int versionsBehind = newVersion.CompareTo(VERSION);
          
          if (versionsBehind > 0)
            return UpdateState.UpdateFound;
        }
      }
      catch (WebException e)
      {
        ShowErrorDialog(e.Message);
        return UpdateState.Error;
      }
#endif
      return UpdateState.UpToDate;
    }

    private async void ShowErrorDialog(string error)
    {
      var dialog = new ContentDialog()
      {
        Title = "Oops...",
        Content = "Failed to connect to the EZPPFarm Website.\n" + error,
        PrimaryButtonText = "Exit"
      };
      await dialog.ShowAsync();
      this.Close();
    }

    private async void ShowInstallerUpdateDialog()
    {
      UpdateInstallButton(false);
      var dialog = new ContentDialog()
      {
        Title = "New version available.",
        Content = "Please download the latest version.",
        PrimaryButtonText = "Download"
      };
      var result = await dialog.ShowAsync();

      if (result == ContentDialogResult.Primary)
      {
        System.Diagnostics.Process.Start("https://ez-pp.farm/download");
        ShowInstallerUpdateDialog();
      }
    }

    private void UpdateInstallButton(bool enable)
    {
      InstallButton.Content = enable ? "Install" : "Reinstall";
      linkFoldersCheckbox.IsEnabled = enable;
    }

    private async void Install_Click(object sender, RoutedEventArgs e)
    {
      string osuFolder = folderTextbox.Text;
      bool isValid = await isValidOsuFolder(osuFolder);
      if (!isValid)
      {
        SystemSounds.Asterisk.Play();
        await new ContentDialog()
        {
          Title = "Hmmm..",
          Content = "It seems like the selected folder is not a osu! installation.",
          PrimaryButtonText = "Okay qwq"
        }.ShowAsync();
        return;
      }

      var type = InstallButton.Content;

      RegistryUtil.SetUsedReleaseStream(RELEASESTREAM);

      if (!Directory.Exists(osuFolder + "\\EZPPClient"))
      {
        Directory.CreateDirectory(osuFolder + "\\EZPPClient");
      }

      string EZPPFolder = osuFolder + @"\EZPPClient";

      if (ProcessUtil.ProgramIsRunning(folderTextbox.Text + @"\EZPPClient.exe"))
      {
        _ = new ContentDialog()
        {
          Title = "Oops..",
          Content = "The EZPPClient is currently running.",
          PrimaryButtonText = "Oh"
        }.ShowAsync();
        return;
      }

      if (InstallButton.Content.Equals("Install"))
      {
        if (linkFoldersCheckbox.IsChecked.Value)
        {
          if (!Directory.Exists(string.Format(@"{0}\Skins\", EZPPFolder)) && Directory.Exists(string.Format(@"{0}\Skins\", osuFolder)))
          {
            if (!CreateSymbolicLink(string.Format(@"{0}\Skins\", EZPPFolder), string.Format(@"{0}\Skins\", osuFolder), SymbolicLink.Directory))
            {
              ContentDialog dg = new ContentDialog()
              {
                Title = "Hmmm..",
                Content = "Failed to create Symlink to Skins folder.",
                PrimaryButtonText = "Okay :/"
              };
              await dg.ShowAsync();
            }
          }
          else
          {
            ContentDialog dg = new ContentDialog()
            {
              Title = "Hmmm..",
              Content = "Failed to locate Skins folder.",
              PrimaryButtonText = "Okay :/"
            };
            await dg.ShowAsync();
          }

          if (!Directory.Exists(string.Format(@"{0}\Songs\", EZPPFolder)) && Directory.Exists(string.Format(@"{0}\Songs\", osuFolder)))
          {
            if (!CreateSymbolicLink(string.Format(@"{0}\Songs\", EZPPFolder), string.Format(@"{0}\Songs\", osuFolder), SymbolicLink.Directory))
            {
              ContentDialog dg = new ContentDialog()
              {
                Title = "Hmmm..",
                Content = "Failed to create Symlink to Songs folder.",
                PrimaryButtonText = "Okay :/"
              };
              await dg.ShowAsync();
            }

          }
          else
          {
            ContentDialog dg = new ContentDialog()
            {
              Title = "Hmmm..",
              Content = "Failed to locate Songs folder.",
              PrimaryButtonText = "Okay :/"
            };
            await dg.ShowAsync();
          }
        }
        string userName = Environment.UserName;
        if(File.Exists(string.Format(@"{0}\osu!.{1}.cfg", osuFolder, userName)) && !File.Exists(string.Format(@"{0}\osu!.{1}.cfg", EZPPFolder, userName)))
        {
          try
          {
            if (!CreateSymbolicLink(string.Format(@"{0}\osu!.{1}.cfg", EZPPFolder, userName), string.Format(@"{0}\osu!.{1}.cfg", osuFolder, userName), SymbolicLink.File))
            {
              ContentDialog dg = new ContentDialog()
              {
                Title = "Hmmm..",
                Content = "Failed to create Symlink to cfg file.",
                PrimaryButtonText = "Okay :/"
              };
              await dg.ShowAsync();
            }
          }
          catch (Exception)
          {
            ContentDialog dg = new ContentDialog()
            {
              Title = "Hmmm..",
              Content = string.Format("Failed to link osu!.{0}.cfg", userName),
              PrimaryButtonText = "Okay :/"
            };
            await dg.ShowAsync();
          }
        }
        if (File.Exists(string.Format(@"{0}\scores.db", osuFolder)) && !File.Exists(string.Format(@"{0}\scores.db", EZPPFolder)))
        {
          try
          {
            if (!CreateSymbolicLink(string.Format(@"{0}\scores.db", EZPPFolder), string.Format(@"{0}\scores.db", osuFolder), SymbolicLink.File))
            {
              ContentDialog dg = new ContentDialog()
              {
                Title = "Hmmm..",
                Content = "Failed to create Symlink to scores.db file.",
                PrimaryButtonText = "Okay :/"
              };
              await dg.ShowAsync();
            }
          }
          catch (Exception)
          {
            ContentDialog dg = new ContentDialog()
            {
              Title = "Hmmm..",
              Content = "Failed to link scores.db",
              PrimaryButtonText = "Okay :/"
            };
            await dg.ShowAsync();
          }
        }
        if (File.Exists(string.Format(@"{0}\collection.db", osuFolder)) && !File.Exists(string.Format(@"{0}\collection.db", EZPPFolder)))
        {
          try
          {
            if (!CreateSymbolicLink(string.Format(@"{0}\collection.db", EZPPFolder), string.Format(@"{0}\collection.db", osuFolder), SymbolicLink.File))
            {
              ContentDialog dg = new ContentDialog()
              {
                Title = "Hmmm..",
                Content = "Failed to create Symlink to collection.db file.",
                PrimaryButtonText = "Okay :/"
              };
              await dg.ShowAsync();
            }
          }
          catch (Exception)
          {
            ContentDialog dg = new ContentDialog()
            {
              Title = "Hmmm..",
              Content = "Failed to link collection.db",
              PrimaryButtonText = "Okay :/"
            };
            await dg.ShowAsync();
          }
        }
        if (File.Exists(string.Format(@"{0}\osu!.db", osuFolder)) && !File.Exists(string.Format(@"{0}\osu!.db", EZPPFolder)))
        {
          try
          {
            if (!CreateSymbolicLink(string.Format(@"{0}\osu!.db", EZPPFolder), string.Format(@"{0}\osu!.db", osuFolder), SymbolicLink.File))
            {
              ContentDialog dg = new ContentDialog()
              {
                Title = "Hmmm..",
                Content = "Failed to create Symlink to osu!.db file.",
                PrimaryButtonText = "Okay :/"
              };
              await dg.ShowAsync();
            }
          }
          catch (Exception)
          {
            ContentDialog dg = new ContentDialog()
            {
              Title = "Hmmm..",
              Content = "Failed to link osu!.db",
              PrimaryButtonText = "Okay :/"
            };
            await dg.ShowAsync();
          }
        }
      }



      List<string> filesToDownload = await DownloadUtil.FilesToDownload(EZPPFolder, InstallButton.Content.Equals("Reinstall"));

      Visibility prevInstallBtnVis = InstallButton.Visibility;
      Visibility prevUninstallBtnVis = Uninstall_Button.Visibility;
      Visibility prevLinkFCVis = linkFoldersCheckbox.Visibility;

      BrowseButton.IsEnabled = false;
      InstallButton.Visibility = Visibility.Hidden;
      Uninstall_Button.Visibility = Visibility.Hidden;
      linkFoldersCheckbox.Visibility = Visibility.Hidden;
      ReleaseStreamComboBox.IsEnabled = false;

      Download_Text.Visibility = Visibility.Visible;
      Download_Progressbar.Visibility = Visibility.Visible;

      await DownloadUtil.DownloadFiles(filesToDownload, EZPPFolder);

      if (type.Equals("Install"))
      {
        string desktopPath = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory);
        string desktopLinkFile = Path.Combine(desktopPath, "Start EZPPClient.lnk");

        string startMenuPath = Environment.GetFolderPath(Environment.SpecialFolder.StartMenu);
        string startMenuPathPrograms = Path.Combine(startMenuPath, "Programs");
        string startMenuLinkFile = Path.Combine(startMenuPathPrograms, "Start EZPPClient.lnk");

        if (!File.Exists(desktopLinkFile))
        {
          WshShell shell = new WshShell();
          IWshShortcut shortcut = (IWshShortcut)shell.CreateShortcut(desktopLinkFile);
          shortcut.Description = $"Starts the EZPPClient";
          shortcut.TargetPath = Path.Combine(EZPPFolder, "EZPPClient.exe");
          shortcut.Save();
        }

        if (!File.Exists(startMenuLinkFile))
        {
          WshShell shell = new WshShell();
          IWshShortcut shortcut = (IWshShortcut)shell.CreateShortcut(startMenuLinkFile);
          shortcut.Description = $"Starts the EZPPClient";
          shortcut.TargetPath = Path.Combine(EZPPFolder, "EZPPClient.exe");
          shortcut.Save();
        }
      }

      InstallButton.Visibility = prevInstallBtnVis;
      Uninstall_Button.Visibility = prevUninstallBtnVis;
      linkFoldersCheckbox.Visibility = prevLinkFCVis;
      BrowseButton.IsEnabled = true;
      ReleaseStreamComboBox.IsEnabled = true;

      Download_Text.Visibility = Visibility.Hidden;
      Download_Progressbar.Visibility = Visibility.Hidden;

      Uninstall_Button.Visibility = Visibility.Visible;
      UpdateInstallButton(false);
      
      List<string> outdatedFiles = await DownloadUtil.FilesToDownload(EZPPFolder, false);

      if (!IsEmpty(outdatedFiles))
      {
        UpdateInstallButton(true);
        InstallButton.Content = "Update";
        linkFoldersCheckbox.IsEnabled = false;
        string updateText = "It seems like the installation was faulty, please hit Update to repair the EZPPClient.";

        switch (type)
        {
          case "Update":
            updateText = "It seems like the update was faulty, please hit Update to repair the EZPPClient.";
            break;
          case "Reinstall":
            updateText = "It seems like the reinstallation was faulty, please hit Update to repair the EZPPClient.";
            break;
        }

        _ = new ContentDialog()
        {
          Title = "Hmmm..",
          Content = updateText,
          PrimaryButtonText = "Okay qwq"
        }.ShowAsync();
        SystemSounds.Asterisk.Play();
        this.Focus();
      }
      else
      {
        string updateText = "The EZPPClient was successfully installed!";

        switch (type)
        {
          case "Update":
            updateText = "The EZPPClient was successfully updated!";
            break;
          case "Reinstall":
            updateText = "The EZPPClient was successfully reinstalled!";
            break;
        }

        _ = new ContentDialog()
        {
          Title = "Success!",
          Content = updateText,
          PrimaryButtonText = "Yaaay :3"
        }.ShowAsync();
        SystemSounds.Asterisk.Play();
        this.Focus();
        UpdateInstallButton(false);
      }

    }

    private void Hyperlink_RequestNavigate(object sender, RequestNavigateEventArgs e)
    {
      System.Diagnostics.Process.Start("https://ez-pp.farm/");
      e.Handled = true;
    }

    private async void Browse_Click(object sender, RoutedEventArgs e)
    {
      if (InstallButton.Visibility == Visibility.Hidden)
        return;
      using (var fbd = new FolderBrowserDialog())
      {
        DialogResult result = fbd.ShowDialog();

        if (result == System.Windows.Forms.DialogResult.OK && !string.IsNullOrWhiteSpace(fbd.SelectedPath))
        {
          bool isValid = await isValidOsuFolder(fbd.SelectedPath);

          if (!isValid)
          {
            SystemSounds.Asterisk.Play();
            await new ContentDialog()
            {
              Title = "Hmmm..",
              Content = "It seems like this location is not an osu! installation.",
              PrimaryButtonText = "Okay qwq"
            }.ShowAsync();
          }
          else
          {
            bool foundInstall = isEZPPClientInstallationFound(fbd.SelectedPath);
            folderTextbox.Text = fbd.SelectedPath;

            if (foundInstall)
            {
              Uninstall_Button.Visibility = Visibility.Visible;
              UpdateInstallButton(false);

              string osuEZPPPath = folderTextbox.Text + @"\EZPPClient";
              List<string> outdatedFiles = await DownloadUtil.FilesToDownload(osuEZPPPath, false);

              if (!IsEmpty(outdatedFiles))
              {
                UpdateInstallButton(true);
                InstallButton.Content = "Update";
              }
              else
              {
                UpdateInstallButton(true);
              }
            }
            else
            {
              UpdateInstallButton(true);
            }
          }
        }
      }
    }

    private async void Uninstall_Button_Click(object sender, RoutedEventArgs e)
    {
      if(ProcessUtil.ProgramIsRunning(folderTextbox.Text + @"\EZPPClient.exe"))
      {
        _ = new ContentDialog()
        {
          Title = "Oops..",
          Content = "The EZPPClient is currently running.",
          PrimaryButtonText = "Oh"
        }.ShowAsync();
        return;
      }
      SystemSounds.Asterisk.Play();
      ContentDialog cd = new ContentDialog()
      {
        Title = "Confirm uninstall",
        Content = "Are you sure you want to remove the EZPPClient?",
        PrimaryButtonText = "Yes",
        SecondaryButtonText = "No"
      };
      ContentDialogResult result = await cd.ShowAsync();
      if (result == ContentDialogResult.Primary)
      {
        string osuEZPPPath = folderTextbox.Text + @"\EZPPClient";
        if (Directory.Exists(osuEZPPPath))
          Directory.Delete(osuEZPPPath, true);

        
        string desktopPath = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory);
        string linkFile = Path.Combine(desktopPath, "Start EZPPClient.lnk");
        if (File.Exists(linkFile))
          File.Delete(linkFile);

        string startMenuPath = Environment.GetFolderPath(Environment.SpecialFolder.StartMenu);
        string startMenuPathPrograms = Path.Combine(startMenuPath, "Programs");
        string startMenuLinkFile = Path.Combine(startMenuPathPrograms, "Start EZPPClient.lnk");
        if (File.Exists(startMenuLinkFile))
          File.Delete(startMenuLinkFile);

        _ = new ContentDialog()
        {
          Title = "Success!",
          Content = "The EZPPClient was successfully uninstalled!",
          PrimaryButtonText = "Okay"
        }.ShowAsync();
        SystemSounds.Asterisk.Play();
        this.Focus();
        Uninstall_Button.Visibility = Visibility.Hidden;
        UpdateInstallButton(true);
      }
    }

    private bool isEZPPClientInstallationFound(string folder)
    {
      return Directory.Exists(folder + @"\EZPPClient");
    }

    private async Task<bool> isValidOsuFolder(string folder)
    {
      if (string.IsNullOrEmpty(folder) || string.IsNullOrWhiteSpace(folder))
        return false;
      string[] files = Directory.GetFiles(folder, "*");
      string[] subDirs = Directory.GetDirectories(folder, "*");
      bool hasSongsFolder = false;
      bool hasSkinsFolder = false;
      bool hasOsuExecutable = false;
      foreach (string file in files)
      {
        if (file.Contains("osu!.exe"))
        {
          hasOsuExecutable = true;
          break;
        }
      }

      foreach (string dir in subDirs)
      {
        if (dir.Contains("Songs") && !hasSongsFolder)
          hasSongsFolder = true;
        if (dir.Contains("Skins") && !hasSkinsFolder)
          hasSkinsFolder = true;

        if (hasSkinsFolder && hasSongsFolder)
          break;
      }

      return hasOsuExecutable && hasSkinsFolder && hasSongsFolder;
    }

    public static bool IsEmpty<T>(List<T> list)
    {
      if (list == null)
      {
        return true;
      }

      return !list.Any();
    }

    private enum SymbolicLink
    {
      File,
      Directory
    }

    public static void updateProgress(string file, double progress)
    {
      Instance.Download_Progressbar.IsIndeterminate = (progress == 100);
      Instance.Download_Progressbar.Value = progress;
      Instance.Download_Text.Content = "Downloading: " + file;
    }

    private async void ReleaseStreamComboBox_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
    {

      bool init = string.IsNullOrEmpty(RELEASESTREAM);

      RELEASESTREAM = (string)ReleaseStreamComboBox.SelectedValue;

      if (init)
        return;

      ReleaseStreamComboBox.IsEnabled = false;
      BrowseButton.IsEnabled = false;
      InstallButton.IsEnabled = false;
      Uninstall_Button.IsEnabled = false;

      string osuPath = folderTextbox.Text;

      bool isValidFolder = await isValidOsuFolder(osuPath);
      UpdateInstallButton(!string.IsNullOrEmpty(osuPath));

      if (!string.IsNullOrEmpty(osuPath) && isValidFolder)
      {
        bool foundInstall = isEZPPClientInstallationFound(osuPath);
        if (foundInstall)
        {
          string osuEZPPPath = osuPath + @"\EZPPClient";

          Uninstall_Button.Visibility = Visibility.Visible;
          UpdateInstallButton(false);


          List<string> outdatedFiles = await DownloadUtil.FilesToDownload(osuEZPPPath, false);

          if (!IsEmpty(outdatedFiles))
          {
            UpdateInstallButton(true);
            InstallButton.Content = "Update";
            linkFoldersCheckbox.IsEnabled = false;
          }
        }

        folderTextbox.Text = osuPath;
      }

      _ = new ContentDialog()
      {
        Title = "Success!",
        Content = "ReleaseStream changed to " + RELEASESTREAM,
        PrimaryButtonText = "Okay"
      }.ShowAsync();

      ReleaseStreamComboBox.IsEnabled = true;
      BrowseButton.IsEnabled = true;
      InstallButton.IsEnabled = true;
      Uninstall_Button.IsEnabled = true;

    }
  }
}