using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Threading;

namespace AxCopilot.Views;

public partial class ChatWindow
{
    private static readonly HashSet<string> _ignoredDirs = new(StringComparer.OrdinalIgnoreCase)
    {
        "bin", "obj", "node_modules", ".git", ".vs", ".idea", ".vscode",
        "__pycache__", ".mypy_cache", ".pytest_cache", "dist", "build",
        ".cache", ".next", ".nuxt", "coverage", ".terraform",
    };

    private DispatcherTimer? _fileBrowserRefreshTimer;

    private void ToggleFileBrowser()
    {
        if (FileBrowserPanel.Visibility == Visibility.Visible)
        {
            FileBrowserPanel.Visibility = Visibility.Collapsed;
            _settings.Settings.Llm.ShowFileBrowser = false;
        }
        else
        {
            FileBrowserPanel.Visibility = Visibility.Visible;
            _settings.Settings.Llm.ShowFileBrowser = true;
            BuildFileTree();
        }

        _settings.Save();
    }

    private void BtnFileBrowserRefresh_Click(object sender, RoutedEventArgs e) => BuildFileTree();

    private void BtnFileBrowserOpenFolder_Click(object sender, RoutedEventArgs e)
    {
        var folder = GetCurrentWorkFolder();
        if (string.IsNullOrEmpty(folder) || !Directory.Exists(folder))
            return;

        try
        {
            Process.Start(new ProcessStartInfo { FileName = folder, UseShellExecute = true });
        }
        catch
        {
        }
    }

    private void BtnFileBrowserClose_Click(object sender, RoutedEventArgs e)
    {
        FileBrowserPanel.Visibility = Visibility.Collapsed;
    }

    private void BuildFileTree()
    {
        FileTreeView.Items.Clear();
        var folder = GetCurrentWorkFolder();
        if (string.IsNullOrEmpty(folder) || !Directory.Exists(folder))
        {
            FileTreeView.Items.Add(new TreeViewItem { Header = "작업 폴더를 선택하세요", IsEnabled = false });
            return;
        }

        FileBrowserTitle.Text = $"파일 탐색기 — {Path.GetFileName(folder)}";
        var count = 0;
        PopulateDirectory(new DirectoryInfo(folder), FileTreeView.Items, 0, ref count);
    }

    private void PopulateDirectory(DirectoryInfo dir, ItemCollection items, int depth, ref int count)
    {
        if (depth > 4 || count > 200)
            return;

        try
        {
            foreach (var subDir in dir.GetDirectories().OrderBy(d => d.Name))
            {
                if (count > 200)
                    break;
                if (_ignoredDirs.Contains(subDir.Name) || subDir.Name.StartsWith('.'))
                    continue;

                count++;
                var dirItem = new TreeViewItem
                {
                    Header = CreateSurfaceFileTreeHeader("\uED25", subDir.Name, null),
                    Tag = subDir.FullName,
                    IsExpanded = depth < 1,
                };

                if (depth < 3)
                {
                    dirItem.Items.Add(new TreeViewItem { Header = "로딩 중..." });
                    var capturedDir = subDir;
                    var capturedDepth = depth;
                    dirItem.Expanded += (s, _) =>
                    {
                        if (s is TreeViewItem ti && ti.Items.Count == 1 && ti.Items[0] is TreeViewItem d && d.Header?.ToString() == "로딩 중...")
                        {
                            ti.Items.Clear();
                            var c = 0;
                            PopulateDirectory(capturedDir, ti.Items, capturedDepth + 1, ref c);
                        }
                    };
                }
                else
                {
                    PopulateDirectory(subDir, dirItem.Items, depth + 1, ref count);
                }

                items.Add(dirItem);
            }
        }
        catch
        {
        }

        try
        {
            foreach (var file in dir.GetFiles().OrderBy(f => f.Name))
            {
                if (count > 200)
                    break;
                count++;

                var ext = file.Extension.ToLowerInvariant();
                var icon = GetFileIcon(ext);
                var size = FormatFileSize(file.Length);

                var fileItem = new TreeViewItem
                {
                    Header = CreateSurfaceFileTreeHeader(icon, file.Name, size),
                    Tag = file.FullName,
                };

                var capturedPath = file.FullName;
                fileItem.MouseDoubleClick += (_, e) =>
                {
                    e.Handled = true;
                    TryShowPreview(capturedPath);
                };

                fileItem.MouseRightButtonUp += (s, e) =>
                {
                    e.Handled = true;
                    if (s is TreeViewItem ti)
                        ti.IsSelected = true;
                    ShowFileTreeContextMenu(capturedPath);
                };

                items.Add(fileItem);
            }
        }
        catch
        {
        }
    }

    private static string GetFileIcon(string ext) => ext switch
    {
        ".html" or ".htm" => "\uEB41",
        ".xlsx" or ".xls" => "\uE9F9",
        ".docx" or ".doc" => "\uE8A5",
        ".pdf" => "\uEA90",
        ".csv" => "\uE80A",
        ".md" => "\uE70B",
        ".json" or ".xml" => "\uE943",
        ".png" or ".jpg" or ".jpeg" or ".gif" or ".svg" or ".webp" => "\uEB9F",
        ".cs" or ".py" or ".js" or ".ts" or ".java" or ".cpp" => "\uE943",
        ".bat" or ".cmd" or ".ps1" or ".sh" => "\uE756",
        ".txt" or ".log" => "\uE8A5",
        _ => "\uE7C3",
    };

    private static string FormatFileSize(long bytes) => bytes switch
    {
        < 1024 => $"{bytes} B",
        < 1024 * 1024 => $"{bytes / 1024.0:F1} KB",
        _ => $"{bytes / (1024.0 * 1024.0):F1} MB",
    };

    private void ShowFileTreeContextMenu(string filePath)
    {
        var primaryText = TryFindResource("PrimaryText") as Brush ?? Brushes.White;
        var secondaryText = TryFindResource("SecondaryText") as Brush ?? Brushes.Gray;
        var dangerBrush = new SolidColorBrush(Color.FromRgb(0xE7, 0x4C, 0x3C));

        var popup = new Popup
        {
            StaysOpen = false,
            AllowsTransparency = true,
            PopupAnimation = PopupAnimation.Fade,
            Placement = PlacementMode.MousePoint,
        };
        var panel = new StackPanel { Margin = new Thickness(2) };
        var container = CreateSurfacePopupContainer(panel, 200, new Thickness(6));
        popup.Child = container;

        void AddItem(string icon, string label, Action action, Brush? labelColor = null, Brush? iconColor = null)
        {
            var item = CreateSurfacePopupMenuItem(icon, iconColor ?? secondaryText, label, () =>
            {
                popup.IsOpen = false;
                action();
            }, labelColor ?? primaryText);
            panel.Children.Add(item);
        }

        void AddSep()
        {
            panel.Children.Add(CreateSurfacePopupSeparator());
        }

        var ext = Path.GetExtension(filePath).ToLowerInvariant();
        if (_previewableExtensions.Contains(ext))
            AddItem("\uE8A1", "미리보기", () => ShowPreviewPanel(filePath));

        AddItem("\uE8A7", "외부 프로그램으로 열기", () =>
        {
            try
            {
                Process.Start(new ProcessStartInfo { FileName = filePath, UseShellExecute = true });
            }
            catch
            {
            }
        });
        AddItem("\uED25", "폴더에서 보기", () =>
        {
            try
            {
                Process.Start("explorer.exe", $"/select,\"{filePath}\"");
            }
            catch
            {
            }
        });
        AddItem("\uE8C8", "경로 복사", () =>
        {
            try
            {
                Clipboard.SetText(filePath);
                ShowToast("경로 복사됨");
            }
            catch
            {
            }
        });

        AddSep();

        AddItem("\uE8AC", "이름 변경", () =>
        {
            var dir = Path.GetDirectoryName(filePath) ?? "";
            var oldName = Path.GetFileName(filePath);
            var dlg = new InputDialog("이름 변경", "새 파일 이름:", oldName) { Owner = this };
            if (dlg.ShowDialog() == true && !string.IsNullOrWhiteSpace(dlg.ResponseText))
            {
                var newPath = Path.Combine(dir, dlg.ResponseText.Trim());
                try
                {
                    File.Move(filePath, newPath);
                    BuildFileTree();
                    ShowToast($"이름 변경: {dlg.ResponseText.Trim()}");
                }
                catch (Exception ex)
                {
                    ShowToast($"이름 변경 실패: {ex.Message}", "\uE783");
                }
            }
        });

        AddItem("\uE74D", "삭제", () =>
        {
            var result = CustomMessageBox.Show(
                $"파일을 삭제하시겠습니까?\n{Path.GetFileName(filePath)}",
                "파일 삭제 확인", MessageBoxButton.YesNo, MessageBoxImage.Warning);
            if (result == MessageBoxResult.Yes)
            {
                try
                {
                    File.Delete(filePath);
                    BuildFileTree();
                    ShowToast("파일 삭제됨");
                }
                catch (Exception ex)
                {
                    ShowToast($"삭제 실패: {ex.Message}", "\uE783");
                }
            }
        }, dangerBrush, dangerBrush);

        Dispatcher.BeginInvoke(() => { popup.IsOpen = true; }, DispatcherPriority.Input);
    }

    private void RefreshFileTreeIfVisible()
    {
        if (FileBrowserPanel.Visibility != Visibility.Visible)
            return;

        _fileBrowserRefreshTimer?.Stop();
        _fileBrowserRefreshTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(500) };
        _fileBrowserRefreshTimer.Tick += (_, _) =>
        {
            _fileBrowserRefreshTimer.Stop();
            BuildFileTree();
        };
        _fileBrowserRefreshTimer.Start();
    }
}