using System.IO;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using Microsoft.Win32;

namespace AxCopilot.Views;

/// <summary>클립보드 이미지 전용 미리보기 창. 원본 해상도 기준 줌과 저장을 지원합니다.</summary>
public partial class ClipboardImagePreviewWindow : Window
{
    private const double MinZoom = 0.1;
    private const double MaxZoom = 8.0;
    private const double ZoomStep = 0.1;

    private readonly BitmapSource _image;
    private readonly string? _sourcePath;
    private double _zoom = 1.0;
    private bool _fitToViewport = true;

    public ClipboardImagePreviewWindow(BitmapSource image, string? sourcePath = null)
    {
        _image = image ?? throw new ArgumentNullException(nameof(image));
        _sourcePath = sourcePath;

        InitializeComponent();

        PreviewImage.Source = _image;
        TitleText.Text = string.IsNullOrWhiteSpace(sourcePath)
            ? "클립보드 이미지 미리보기"
            : Path.GetFileName(sourcePath);
        MetaText.Text = $"{_image.PixelWidth:N0} × {_image.PixelHeight:N0}px";

        Loaded += (_, _) =>
        {
            ApplyFitToViewport();
            UpdateStatusText();
        };
    }

    private void TitleBar_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        if (e.ClickCount == 2)
        {
            WindowState = WindowState == WindowState.Maximized ? WindowState.Normal : WindowState.Maximized;
            return;
        }

        try { DragMove(); } catch { }
    }

    private void Window_KeyDown(object sender, KeyEventArgs e)
    {
        switch (e.Key)
        {
            case Key.Escape:
                Close();
                e.Handled = true;
                return;
            case Key.Add:
            case Key.OemPlus:
                IncreaseZoom();
                e.Handled = true;
                return;
            case Key.Subtract:
            case Key.OemMinus:
                DecreaseZoom();
                e.Handled = true;
                return;
            case Key.D0:
            case Key.NumPad0:
                ResetZoom();
                e.Handled = true;
                return;
            case Key.F:
                ApplyFitToViewport();
                e.Handled = true;
                return;
            case Key.C when Keyboard.Modifiers == ModifierKeys.Control:
                CopyImageToClipboard();
                e.Handled = true;
                return;
        }
    }

    private void ImageScrollViewer_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
    {
        if ((Keyboard.Modifiers & ModifierKeys.Control) == 0)
            return;

        if (e.Delta > 0)
            IncreaseZoom();
        else if (e.Delta < 0)
            DecreaseZoom();

        e.Handled = true;
    }

    private void ImageScrollViewer_SizeChanged(object sender, SizeChangedEventArgs e)
    {
        if (_fitToViewport)
            ApplyFitToViewport();
    }

    private void BtnClose_MouseLeftButtonUp(object sender, MouseButtonEventArgs e) => Close();
    private void BtnResetZoom_MouseLeftButtonUp(object sender, MouseButtonEventArgs e) => ResetZoom();
    private void BtnZoomIn_Click(object sender, RoutedEventArgs e) => IncreaseZoom();
    private void BtnZoomOut_Click(object sender, RoutedEventArgs e) => DecreaseZoom();
    private void BtnFit_Click(object sender, RoutedEventArgs e) => ApplyFitToViewport();
    private void BtnCopyImage_Click(object sender, RoutedEventArgs e) => CopyImageToClipboard();
    private void BtnSavePng_Click(object sender, RoutedEventArgs e) => SaveImage("png");
    private void BtnSaveJpeg_Click(object sender, RoutedEventArgs e) => SaveImage("jpg");
    private void BtnSaveBmp_Click(object sender, RoutedEventArgs e) => SaveImage("bmp");

    private void IncreaseZoom() => SetZoom(_zoom + ZoomStep, false);
    private void DecreaseZoom() => SetZoom(_zoom - ZoomStep, false);
    private void ResetZoom() => SetZoom(1.0, false);

    private void ApplyFitToViewport()
    {
        if (ImageScrollViewer.ViewportWidth <= 0 || ImageScrollViewer.ViewportHeight <= 0)
            return;

        var availableWidth = Math.Max(1, ImageScrollViewer.ViewportWidth - 32);
        var availableHeight = Math.Max(1, ImageScrollViewer.ViewportHeight - 32);

        var scaleX = availableWidth / _image.PixelWidth;
        var scaleY = availableHeight / _image.PixelHeight;
        var fitScale = Math.Min(scaleX, scaleY);

        if (double.IsNaN(fitScale) || double.IsInfinity(fitScale) || fitScale <= 0)
            fitScale = 1.0;

        SetZoom(Math.Min(1.0, fitScale), true);
    }

    private void SetZoom(double zoom, bool fitToViewport)
    {
        _fitToViewport = fitToViewport;
        _zoom = Math.Max(MinZoom, Math.Min(MaxZoom, zoom));
        ImageScaleTransform.ScaleX = _zoom;
        ImageScaleTransform.ScaleY = _zoom;
        UpdateStatusText();
    }

    private void UpdateStatusText()
    {
        var mode = _fitToViewport ? "창 맞춤" : "수동 줌";
        var source = string.IsNullOrWhiteSpace(_sourcePath) ? "원본 경로 없음" : _sourcePath;
        StatusText.Text = $"{_image.PixelWidth:N0} × {_image.PixelHeight:N0}px · 확대 {Math.Round(_zoom * 100)}% · {mode} · {source}";
    }

    private void CopyImageToClipboard()
    {
        try
        {
            var app = Application.Current as App;
            app?.ClipboardHistoryService?.SuppressNextCapture();
            Clipboard.SetImage(_image);
            CustomMessageBox.Show("이미지를 클립보드에 복사했습니다.", "AX Commander", MessageBoxButton.OK, MessageBoxImage.Information);
        }
        catch (Exception ex)
        {
            Services.LogService.Warn($"클립보드 이미지 복사 실패: {ex.Message}");
            CustomMessageBox.Show($"이미지 복사에 실패했습니다.\n{ex.Message}", "AX Commander", MessageBoxButton.OK, MessageBoxImage.Warning);
        }
    }

    private void SaveImage(string format)
    {
        try
        {
            var dialog = new SaveFileDialog
            {
                FileName = BuildDefaultFileName(format),
                Filter = format switch
                {
                    "png" => "PNG 이미지|*.png",
                    "jpg" => "JPEG 이미지|*.jpg;*.jpeg",
                    "bmp" => "BMP 이미지|*.bmp",
                    _ => "이미지 파일|*.*",
                },
                AddExtension = true,
                OverwritePrompt = true,
            };

            if (dialog.ShowDialog(this) != true)
                return;

            BitmapEncoder encoder = format switch
            {
                "jpg" => new JpegBitmapEncoder { QualityLevel = 95 },
                "bmp" => new BmpBitmapEncoder(),
                _ => new PngBitmapEncoder(),
            };

            encoder.Frames.Add(BitmapFrame.Create(_image));
            using var stream = new FileStream(dialog.FileName, FileMode.Create, FileAccess.Write);
            encoder.Save(stream);

            CustomMessageBox.Show($"이미지를 저장했습니다.\n{dialog.FileName}", "AX Commander", MessageBoxButton.OK, MessageBoxImage.Information);
        }
        catch (Exception ex)
        {
            Services.LogService.Warn($"클립보드 이미지 저장 실패: {ex.Message}");
            CustomMessageBox.Show($"이미지 저장에 실패했습니다.\n{ex.Message}", "AX Commander", MessageBoxButton.OK, MessageBoxImage.Warning);
        }
    }

    private string BuildDefaultFileName(string format)
    {
        var sourceName = !string.IsNullOrWhiteSpace(_sourcePath)
            ? Path.GetFileNameWithoutExtension(_sourcePath)
            : $"clipboard-image-{DateTime.Now:yyyyMMdd-HHmmss}";

        var extension = format switch
        {
            "jpg" => ".jpg",
            "bmp" => ".bmp",
            _ => ".png",
        };

        return sourceName + extension;
    }
}