using System;
using System.Linq;
using System.Windows.Forms;
using Microsoft.Extensions.DependencyInjection;
using PolyTrader.Core.Modularity;

namespace PolyTraderSharp.Ui
{
    /// <summary>
    /// Schlanke „Startleiste" der PolyTrader.App. Das Layout (ListView, Menü, Button) liegt
    /// im Designer (LauncherForm.Designer.cs). Zur Laufzeit werden ausschließlich die
    /// Listeneinträge (Daten) aus den registrierten Views befüllt — keine Steuerelemente.
    /// Kennt selbst kein Modul.
    /// </summary>
    public partial class LauncherForm : Form
    {
        private readonly ShellUiHost _uiHost;
        private readonly IServiceProvider _services;
        private frm_main? _legacyForm;

        public LauncherForm(ShellUiHost uiHost, IServiceProvider services)
        {
            _uiHost = uiHost;
            _services = services;

            InitializeComponent();

            PopulateViews();
            lstViews.DoubleClick += (_, _) => OpenSelected();
            btnOpen.Click += (_, _) => OpenSelected();
            miLegacy.Click += (_, _) => OpenLegacy();
            miBeenden.Click += (_, _) => Close();
        }

        private void PopulateViews()
        {
            lstViews.BeginUpdate();
            lstViews.Groups.Clear();
            lstViews.Items.Clear();

            foreach (var group in _uiHost.Views
                         .GroupBy(v => string.IsNullOrEmpty(v.Group) ? "Allgemein" : v.Group!)
                         .OrderBy(g => g.Key))
            {
                var lvGroup = new ListViewGroup(group.Key) { Header = group.Key };
                lstViews.Groups.Add(lvGroup);

                foreach (var view in group.OrderBy(v => v.Order).ThenBy(v => v.Title))
                {
                    lstViews.Items.Add(new ListViewItem(view.Title, lvGroup) { Tag = view });
                }
            }

            lstViews.EndUpdate();
        }

        private void OpenSelected()
        {
            if (lstViews.SelectedItems.Count == 0) return;
            if (lstViews.SelectedItems[0].Tag is ModuleView view)
                _uiHost.OpenView(view);
        }

        private void OpenLegacy()
        {
            if (_legacyForm != null && !_legacyForm.IsDisposed)
            {
                if (_legacyForm.WindowState == FormWindowState.Minimized)
                    _legacyForm.WindowState = FormWindowState.Normal;
                _legacyForm.BringToFront();
                _legacyForm.Activate();
                return;
            }

            _legacyForm = _services.GetRequiredService<frm_main>();
            _legacyForm.FormClosed += (_, _) => _legacyForm = null;
            _legacyForm.Show();
        }
    }
}