using System;
using System.Text;
using System.Windows.Forms;
using PKHeX.Core;

namespace PKHeX.WinForms;

public sealed partial class ErrorWindow : Form
{
    public static DialogResult ShowErrorDialog(string friendlyMessage, Exception ex, bool allowContinue)
    {
        string lang = GetDisplayLanguage();
        using var dialog = new ErrorWindow(lang);
        dialog.LoadException(ex, friendlyMessage, allowContinue);
        var dialogResult = dialog.ShowDialog();
        if (dialogResult == DialogResult.Abort)
            Environment.Exit(1);
        return dialogResult;
    }

    private static string GetDisplayLanguage()
    {
        try { return Main.CurrentLanguage; }
        catch { return System.Threading.Thread.CurrentThread.CurrentUICulture.TwoLetterISOLanguageName; }
    }

    public ErrorWindow(string? lang = GameLanguage.DefaultLanguage)
    {
        InitializeComponent();
        WinFormsUtil.TranslateInterface(this, lang ?? GetDisplayLanguage());
    }

    /// <summary>
    /// Gets or sets the visibility of the "Continue" button.
    /// </summary>
    /// <remarks>For UI exceptions, continuing could be safe.
    /// For application exceptions, continuing is not possible, so the button should not be shown.</remarks>
    private bool ShowContinue
    {
        set => B_Continue.Visible = value;
    }

    /// <summary>
    /// Friendly, context-specific method shown to the user.
    /// </summary>
    /// <remarks>This property is intended to be a user-friendly context-specific message about what went wrong.
    /// For example: "An error occurred while attempting to automatically load the save file."</remarks>
    private string Message
    {
        get => L_Message.Text;
        set => L_Message.Text = value;
    }

    private Exception? _error;

    public Exception Error
    {
        get => _error ?? throw new ArgumentNullException(nameof(_error));
        set
        {
            _error = value;
            UpdateExceptionDetailsMessage();
        }
    }

    public void LoadException(Exception ex, string friendlyMessage, bool allowContinue)
    {
        ShowContinue = allowContinue;
        Message = friendlyMessage;
        Error = ex;
    }

    private void UpdateExceptionDetailsMessage()
    {
        var details = new StringBuilder();
        details.AppendLine("Exception Details:");
        details.AppendLine(Error.ToString());
        details.AppendLine();

        details.AppendLine("Loaded Assemblies:");
        details.AppendLine("--------------------");
        try
        {
            foreach (var item in AppDomain.CurrentDomain.GetAssemblies())
            {
                details.AppendLine(item.FullName);
                details.AppendLine(item.Location);
                details.AppendLine();
            }
        }
        catch (Exception ex)
        {
            details.AppendLine("An error occurred while listing the Loaded Assemblies:");
            details.AppendLine(ex.ToString());
        }
        details.AppendLine("--------------------");

        // Include message in case it contains important information, like a file path.
        details.AppendLine("User Message:");
        details.AppendLine(Message);

        T_ExceptionDetails.Text = details.ToString();
    }

    private void ClickCopyException(object sender, EventArgs e) => WinFormsUtil.SetClipboardText(T_ExceptionDetails.Text);

    private void ClickContinue(object sender, EventArgs e)
    {
        DialogResult = DialogResult.OK;
        Close();
    }

    private void ClickAbort(object sender, EventArgs e)
    {
        DialogResult = DialogResult.Abort;
        Close();
    }
}