using Avalonia.Controls;
using Avalonia.Interactivity;
using Avalonia.Platform.Storage;
using Nonemm.Contests;

namespace Nonemm.App.Dialogs;

/// N1MM's goals editor, as the text the goals are kept in. It returns the
/// goals in `Goals.ToText` form, or null when cancelled.
public sealed partial class GoalsDialog : Window
{
    private readonly string exportFolder;

    public GoalsDialog(string goals, string exportFolder)
    {
        this.exportFolder = exportFolder;
        InitializeComponent();
        GoalsBox.Text = goals;
    }

    private void OnOk(object? sender, RoutedEventArgs e)
    {
        if (Checked() is { } text)
        {
            Close(text);
        }
    }

    private void OnCancel(object? sender, RoutedEventArgs e) => Close(null);

    /// Writes the goals to a file N1MM's Import Goals reads, keeping the
    /// dialog open.
    private async void OnExport(object? sender, RoutedEventArgs e)
    {
        if (Checked() is not { } text)
        {
            return;
        }
        IStorageFile? file = await StorageProvider.SaveFilePickerAsync(new FilePickerSaveOptions
        {
            Title = "Export goals",
            SuggestedFileName = "goals.txt",
            SuggestedStartLocation = await StorageProvider.TryGetFolderFromPathAsync(exportFolder),
        });
        if (file?.TryGetLocalPath() is not { } path)
        {
            return;
        }
        try
        {
            await File.WriteAllTextAsync(path, text);
            ProblemText.Text = $"{Path.GetFileName(path)} written.";
        }
        catch (IOException problem)
        {
            ProblemText.Text = $"could not write {path}: {problem.Message}";
        }
    }

    private string? Checked()
    {
        try
        {
            ProblemText.Text = "";
            return Goals.Parse(GoalsBox.Text ?? "").ToText();
        }
        catch (FormatException problem)
        {
            ProblemText.Text = problem.Message;
            return null;
        }
    }
}