using System.Collections.ObjectModel;
using System.Diagnostics;
using FastSeek.Core;
using FastSeek.Core.Search;
using Microsoft.UI.Input;
using Microsoft.UI.Windowing;
using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;
using Microsoft.UI.Xaml.Input;
using Windows.System;

namespace FastSeek.WinUI;

public sealed partial class MainWindow : Window
{
    private readonly FastSeekEngine _engine = new();
    private readonly ObservableCollection<ResultItem> _items = new();

    public MainWindow()
    {
        this.InitializeComponent();
        ResultsList.ItemsSource = _items;
        ExtendsContentIntoTitleBar = true;
        this.Closed += (_, _) => _engine.Dispose();
        SetSpotlightSizing();
        _ = InitializeEngineAsync();
    }

    private async Task InitializeEngineAsync()
    {
        SearchBox.PlaceholderText = "Indexing NTFS drives...";
        try
        {
            await _engine.InitializeAsync();
            SearchBox.PlaceholderText = "Search files and folders...";
        }
        catch (Exception ex)
        {
            SearchBox.PlaceholderText = "Initialization failed";
            _items.Clear();
            _items.Add(new ResultItem { Kind = "ERR", Name = "Could not initialize index", FullPath = ex.Message, Raw = null });
        }
    }

    private void SetSpotlightSizing()
    {
        var hwnd = WinRT.Interop.WindowNative.GetWindowHandle(this);
        var id = Microsoft.UI.Win32Interop.GetWindowIdFromWindow(hwnd);
        var appWindow = AppWindow.GetFromWindowId(id);
        appWindow.Resize(new Windows.Graphics.SizeInt32(900, 560));
        if (appWindow.Presenter is OverlappedPresenter p)
        {
            p.IsMaximizable = false;
            p.IsMinimizable = true;
            p.IsResizable = true;
        }
    }

    private async void SearchBox_TextChanged(AutoSuggestBox sender, AutoSuggestBoxTextChangedEventArgs args)
    {
        if (args.Reason != AutoSuggestionBoxTextChangeReason.UserInput) return;
        var query = sender.Text;
        var results = await Task.Run(() => _engine.Search(query, 50));
        RenderResults(results);
    }

    private void RenderResults(List<SearchResult> results)
    {
        _items.Clear();
        foreach (var r in results)
        {
            _items.Add(new ResultItem
            {
                Kind = r.IsDir ? "DIR" : "FILE",
                Name = r.Name,
                FullPath = r.FullPath,
                Raw = r,
            });
        }
        if (_items.Count > 0) ResultsList.SelectedIndex = 0;
    }

    private void SearchBox_KeyDown(object sender, KeyRoutedEventArgs e)
    {
        if (e.Key == VirtualKey.Down)
        {
            if (_items.Count == 0) return;
            var i = Math.Min(ResultsList.SelectedIndex + 1, _items.Count - 1);
            ResultsList.SelectedIndex = i;
            ResultsList.ScrollIntoView(_items[i]);
            e.Handled = true;
        }
        else if (e.Key == VirtualKey.Up)
        {
            if (_items.Count == 0) return;
            var i = Math.Max(ResultsList.SelectedIndex - 1, 0);
            ResultsList.SelectedIndex = i;
            ResultsList.ScrollIntoView(_items[i]);
            e.Handled = true;
        }
        else if (e.Key == VirtualKey.Enter)
        {
            OpenSelected();
            e.Handled = true;
        }
        else if (e.Key == VirtualKey.Escape)
        {
            this.Close();
        }
    }

    private void ResultsList_ItemClick(object sender, ItemClickEventArgs e) => OpenSelected();

    private void OpenSelected()
    {
        if (ResultsList.SelectedItem is not ResultItem item) return;
        try
        {
            Process.Start(new ProcessStartInfo
            {
                FileName = item.FullPath,
                UseShellExecute = true,
            });
        }
        catch
        {
            try
            {
                Process.Start(new ProcessStartInfo
                {
                    FileName = "explorer.exe",
                    Arguments = $"/select,\"{item.FullPath}\"",
                    UseShellExecute = true,
                });
            }
            catch { }
        }
    }

    private sealed class ResultItem
    {
        public required string Kind { get; init; }
        public required string Name { get; init; }
        public required string FullPath { get; init; }
        public SearchResult? Raw { get; init; }
    }
}