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

namespace XSDVisualiser.Desktop.Views;

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(() => hostWindow.DataContext = new MainWindowViewModel(model));
            }
            catch (Exception ex)
            {
                Dispatcher.UIThread.Post(() => hostWindow.DataContext = new MainWindowViewModel(new SchemaModel { TargetNamespace = ex.Message }));
            }
        });
    }
}