using System.IO;
using System.Text;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media.Imaging;
using UglyToad.PdfPig;

namespace AxCopilot.Views;

public partial class QuickLookWindow : Window
{
    private static readonly HashSet<string> ImageExts = new(StringComparer.OrdinalIgnoreCase)
    {
        ".png", ".jpg", ".jpeg", ".gif", ".bmp", ".webp", ".ico", ".tiff", ".tif"
    };

    private static readonly HashSet<string> TextExts = new(StringComparer.OrdinalIgnoreCase)
    {
        ".txt", ".md", ".cs", ".vb", ".fs", ".py", ".js", ".ts", ".jsx", ".tsx",
        ".json", ".xml", ".xaml", ".yaml", ".yml", ".toml", ".ini", ".conf",
        ".log", ".csv", ".html", ".htm", ".css", ".scss", ".less",
        ".sql", ".sh", ".bash", ".bat", ".cmd", ".ps1",
        ".config", ".env", ".gitignore", ".editorconfig",
        ".java", ".cpp", ".c", ".h", ".hpp", ".rs", ".go", ".rb", ".php", ".swift",
        ".vue", ".svelte", ".dockerfile"
    };

    public QuickLookWindow(string path, Window owner)
    {
        InitializeComponent();
        Owner = owner;
        KeyDown += OnKeyDown;
        Loaded += (_, _) => LoadPreview(path);
    }

    private void OnKeyDown(object sender, KeyEventArgs e)
    {
        if (e.Key is Key.Escape or Key.F3)
        {
            Close();
            e.Handled = true;
        }
    }

    private void TitleBar_MouseDown(object sender, MouseButtonEventArgs e)
    {
        if (e.LeftButton == MouseButtonState.Pressed)
            DragMove();
    }

    private void BtnClose_Click(object sender, MouseButtonEventArgs e) => Close();

    private void LoadPreview(string path)
    {
        try
        {
            FileNameText.Text = Path.GetFileName(path);

            if (Directory.Exists(path))
            {
                ShowInfo("\uE838", "폴더", path);
                return;
            }

            if (!File.Exists(path))
            {
                ShowInfo("\uE783", "파일을 찾을 수 없습니다.", path);
                return;
            }

            var info = new FileInfo(path);
            var ext = Path.GetExtension(path);
            FooterPath.Text = path;
            FooterMeta.Text = $"{FormatSize(info.Length)} · {info.LastWriteTime:yyyy-MM-dd HH:mm}";

            if (ImageExts.Contains(ext))
            {
                using var fs = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
                var image = new BitmapImage();
                image.BeginInit();
                image.CacheOption = BitmapCacheOption.OnLoad;
                image.StreamSource = fs;
                image.EndInit();
                image.Freeze();

                PreviewImage.Source = image;
                ImageScrollViewer.Visibility = Visibility.Visible;
                FileTypeIcon.Text = "\uE91B";
                return;
            }

            if (string.Equals(ext, ".pdf", StringComparison.OrdinalIgnoreCase))
            {
                using var doc = PdfDocument.Open(path);
                var page = doc.NumberOfPages > 0 ? doc.GetPage(1).Text : "";
                PdfPreviewText.Text = page.Length > 1200 ? page[..1200] + "…" : page;
                PdfScrollViewer.Visibility = Visibility.Visible;
                FileTypeIcon.Text = "\uEA90";
                return;
            }

            if (TextExts.Contains(ext))
            {
                string text;
                try
                {
                    text = File.ReadAllText(path, Encoding.UTF8);
                }
                catch
                {
                    text = File.ReadAllText(path);
                }

                PreviewText.Text = text.Length > 4000 ? text[..4000] + "\n…" : text;
                TextScrollViewer.Visibility = Visibility.Visible;
                FileTypeIcon.Text = "\uE8A5";
                return;
            }

            ShowInfo("\uE7C3", $"파일 · {ext.TrimStart('.').ToUpperInvariant()}", path);
        }
        catch (Exception ex)
        {
            ShowInfo("\uEA39", "미리보기를 열지 못했습니다.", ex.Message);
        }
    }

    private void ShowInfo(string icon, string title, string detail)
    {
        InfoTypeIcon.Text = icon;
        InfoTypeName.Text = title;
        InfoSubText.Text = detail;
        InfoPanel.Visibility = Visibility.Visible;
    }

    private static string FormatSize(long bytes) => bytes switch
    {
        < 1024 => $"{bytes} B",
        < 1048576 => $"{bytes / 1024.0:F1} KB",
        < 1073741824 => $"{bytes / 1048576.0:F1} MB",
        _ => $"{bytes / 1073741824.0:F2} GB"
    };
}