using System.Diagnostics;
using Avalonia.Controls;
using Avalonia.Interactivity;
using Avalonia.Platform.Storage;
using Avalonia.Threading;
using XSDVisualiser.Core;
using XSDVisualiser.Desktop.ViewModels;

namespace XSDVisualiser.Desktop.Views;

/// <summary>
/// Header area with actions to open an XSD file and perform file-related utilities.
/// </summary>
public partial class HeaderView : UserControl
{
    private readonly Button? _openBtn;

    public HeaderView()
    {
        InitializeComponent();
        _openBtn = this.FindControl<Button>("OpenBtn");
        if (_openBtn != null) _openBtn.Click += OpenBtn_Click;
    }

    private async void OpenBtn_Click(object? sender, RoutedEventArgs e)
    {
        if (TopLevel.GetTopLevel(this) is not Window topLevel)
            return;

        var storageProvider = topLevel.StorageProvider;
        var options = new FilePickerOpenOptions
        {
            AllowMultiple = false,
            Title = "Open XSD file",
            FileTypeFilter =
            [
                new FilePickerFileType("XSD schema")
                {
                    Patterns = ["*.xsd"]
                }
            ]
        };
        var results = await storageProvider.OpenFilePickerAsync(options);
        if (results.Count <= 0) return;

        var file = results[0];
        var path = file.TryGetLocalPath();
        if (!string.IsNullOrEmpty(path))
            await ParseAndShowAsync(path!, topLevel);
        else
            Dispatcher.UIThread.Post(() => topLevel.DataContext = new MainWindowViewModel(new SchemaModel
                { TargetNamespace = "Selected file is not a local file. Please choose a local .xsd." }));
    }

    private Task ParseAndShowAsync(string path, Window hostWindow)
    {
        return Task.Run(() =>
        {
            try
            {
                var parser = new XsdSchemaParser();
                var model = parser.Parse(path);
                Dispatcher.UIThread.Post(() =>
                {
                    var vm = new MainWindowViewModel(model)
                    {
                        CurrentFilePath = path
                    };
                    hostWindow.DataContext = vm;
                });
            }
            catch (Exception ex)
            {
                Dispatcher.UIThread.Post(() =>
                    hostWindow.DataContext = new MainWindowViewModel(new SchemaModel { TargetNamespace = ex.Message }));
            }
        });
    }

    private async void OnCopyPathClick(object? sender, RoutedEventArgs e)
    {
        var vm = DataContext as MainWindowViewModel;
        var path = vm?.CurrentFilePath;
        if (string.IsNullOrWhiteSpace(path)) return;

        var topLevel = TopLevel.GetTopLevel(this);
        if (topLevel?.Clipboard != null) await topLevel.Clipboard.SetTextAsync(path);
    }

    private void OnOpenContainingFolderClick(object? sender, RoutedEventArgs e)
    {
        var vm = DataContext as MainWindowViewModel;
        var path = vm?.CurrentFilePath;
        if (string.IsNullOrWhiteSpace(path)) return;
        var dir = Path.GetDirectoryName(path);
        if (string.IsNullOrWhiteSpace(dir) || !Directory.Exists(dir)) return;
        TryOpenFolder(dir);
    }

    private static void TryOpenFolder(string dir)
    {
        try
        {
            if (OperatingSystem.IsWindows())
            {
                var psi = new ProcessStartInfo("explorer.exe", dir)
                {
                    UseShellExecute = true
                };
                Process.Start(psi);
            }
            else if (OperatingSystem.IsMacOS())
            {
                Process.Start("open", dir);
            }
            else
            {
                // Linux
                Process.Start("xdg-open", dir);
            }
        }
        catch
        {
            try
            {
                var psi = new ProcessStartInfo
                {
                    FileName = dir,
                    UseShellExecute = true
                };
                Process.Start(psi);
            }
            catch
            {
                // ignored
            }
        }
    }
}