using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;

using AxCopilot.Models;
using AxCopilot.Services;
using AxCopilot.Services.Agent;

namespace AxCopilot.Views;

public partial class ChatWindow
{
    // ── A-2: PermissionItems 이벤트 위임 ──
    private bool _permPanelDelegationInitialized;

    private sealed class PermissionItemTag
    {
        public required string Level { get; init; }
        public required bool IsActive { get; init; }
        public required Brush SelectedBackground { get; init; }
        public required Brush HoverBackground { get; init; }
    }

    private void InitPermissionPanelDelegation()
    {
        if (_permPanelDelegationInitialized || PermissionItems == null)
            return;
        _permPanelDelegationInitialized = true;

        PermissionItems.MouseMove += PermissionItems_DelegatedMouseMove;
        PermissionItems.MouseLeave += PermissionItems_DelegatedMouseLeave;
        PermissionItems.PreviewMouseLeftButtonDown += PermissionItems_DelegatedLeftButtonDown;
        PermissionItems.PreviewKeyDown += PermissionItems_DelegatedKeyDown;
    }

    private Border? _lastHoveredPermBorder;

    private void PermissionItems_DelegatedMouseMove(object sender, MouseEventArgs e)
    {
        var border = FindAncestorWithTag<Border>(e.OriginalSource as DependencyObject);
        if (ReferenceEquals(border, _lastHoveredPermBorder))
            return;

        if (_lastHoveredPermBorder?.Tag is PermissionItemTag prevTag)
            _lastHoveredPermBorder.Background = prevTag.IsActive ? prevTag.SelectedBackground : Brushes.Transparent;
        _lastHoveredPermBorder = border;

        if (border?.Tag is PermissionItemTag tag)
            border.Background = tag.IsActive ? tag.SelectedBackground : tag.HoverBackground;
    }

    private void PermissionItems_DelegatedMouseLeave(object sender, MouseEventArgs e)
    {
        if (_lastHoveredPermBorder?.Tag is PermissionItemTag prevTag)
            _lastHoveredPermBorder.Background = prevTag.IsActive ? prevTag.SelectedBackground : Brushes.Transparent;
        _lastHoveredPermBorder = null;
    }

    private void PermissionItems_DelegatedLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        var border = FindAncestorWithTag<Border>(e.OriginalSource as DependencyObject);
        if (border?.Tag is PermissionItemTag tag)
        {
            e.Handled = true;
            ApplyPermissionLevel(tag.Level);
        }
    }

    private void PermissionItems_DelegatedKeyDown(object sender, KeyEventArgs e)
    {
        if (e.Key is not (Key.Enter or Key.Space))
            return;
        var border = FindAncestorWithTag<Border>(e.OriginalSource as DependencyObject);
        if (border?.Tag is PermissionItemTag tag)
        {
            e.Handled = true;
            ApplyPermissionLevel(tag.Level);
        }
    }

    private void ApplyPermissionLevel(string level)
    {
        _settings.Settings.Llm.FilePermission = PermissionModeCatalog.NormalizeGlobalMode(level);
        ScheduleSettingsSave();
        _appState.LoadFromSettings(_settings);
        UpdatePermissionUI();
        SaveConversationSettings();
        RefreshInlineSettingsPanel();
        RefreshOverlayModeButtons();
        PermissionPopup.IsOpen = false;
    }

    private void BtnPermission_Click(object sender, RoutedEventArgs e)
    {
        if (PermissionPopup == null) return;

        // Dynamically retarget popup to whichever button was clicked (FolderBar or Inline)
        if (sender is UIElement clickedElement &&
            (ReferenceEquals(clickedElement, BtnPermissionInline) || ReferenceEquals(clickedElement, BtnPermission)))
        {
            PermissionPopup.PlacementTarget = clickedElement;
        }

        InitPermissionPanelDelegation();
        _lastHoveredPermBorder = null;
        PermissionItems.Children.Clear();

        ChatConversation? currentConversation;
        lock (_convLock) currentConversation = _currentConversation;
        var coreLevels = PermissionModePresentationCatalog.Ordered.ToList();
        var current = PermissionModeCatalog.NormalizeGlobalMode(_settings.Settings.Llm.FilePermission);

        void AddPermissionRows(Panel container, IEnumerable<PermissionModePresentation> levels)
        {
            var hoverBackground = TryFindResource("ItemHoverBackground") as Brush ?? BrushFromHex("#F8FAFC");
            var selectedBackground = TryFindResource("HintBackground") as Brush ?? BrushFromHex("#F8FAFC");
            var selectedBorder = TryFindResource("AccentColor") as Brush ?? BrushFromHex("#D6E4FF");
            foreach (var item in levels)
            {
                var level = item.Mode;
                var isActive = level.Equals(current, StringComparison.OrdinalIgnoreCase);
                var rowBorder = new Border
                {
                    Background = isActive ? selectedBackground : Brushes.Transparent,
                    BorderBrush = isActive ? selectedBorder : Brushes.Transparent,
                    BorderThickness = new Thickness(1),
                    CornerRadius = new CornerRadius(12),
                    Padding = new Thickness(10, 10, 10, 10),
                    Margin = new Thickness(0, 0, 0, 4),
                    Cursor = Cursors.Hand,
                    Focusable = true,
                };
                KeyboardNavigation.SetIsTabStop(rowBorder, true);

                var row = new Grid();
                row.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });
                row.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
                row.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });

                row.Children.Add(new TextBlock
                {
                    Text = item.Icon,
                    FontFamily = s_segoeIconFont,
                    FontSize = 15,
                    Foreground = BrushFromHex(item.ColorHex),
                    Margin = new Thickness(0, 0, 10, 0),
                    VerticalAlignment = VerticalAlignment.Center,
                });

                var textStack = new StackPanel();
                textStack.Children.Add(new TextBlock
                {
                    Text = item.Title,
                    FontSize = 13.5,
                    FontWeight = FontWeights.SemiBold,
                    Foreground = TryFindResource("PrimaryText") as Brush ?? Brushes.White,
                });
                textStack.Children.Add(new TextBlock
                {
                    Text = item.Description,
                    FontSize = 11.5,
                    Margin = new Thickness(0, 2, 0, 0),
                    Foreground = TryFindResource("SecondaryText") as Brush ?? Brushes.Gray,
                    TextWrapping = TextWrapping.Wrap,
                    LineHeight = 16,
                    MaxWidth = 220,
                });
                Grid.SetColumn(textStack, 1);
                row.Children.Add(textStack);

                var check = new TextBlock
                {
                    Text = isActive ? "\uE73E" : "",
                    FontFamily = s_segoeIconFont,
                    FontSize = 12,
                    FontWeight = FontWeights.Bold,
                    Foreground = BrushFromHex("#2563EB"),
                    VerticalAlignment = VerticalAlignment.Center,
                    Margin = new Thickness(12, 0, 0, 0),
                };
                Grid.SetColumn(check, 2);
                row.Children.Add(check);

                rowBorder.Child = row;

                // A-2: 이벤트 위임 — 개별 람다 대신 Tag에 메타 저장
                rowBorder.Tag = new PermissionItemTag
                {
                    Level = level,
                    IsActive = isActive,
                    SelectedBackground = selectedBackground,
                    HoverBackground = hoverBackground,
                };

                container.Children.Add(rowBorder);
            }
        }

        AddPermissionRows(PermissionItems, coreLevels);

        PermissionPopup.IsOpen = true;
        Dispatcher.BeginInvoke(() =>
        {
            TryFocusFirstPermissionElement(PermissionItems);
        }, System.Windows.Threading.DispatcherPriority.Input);
    }

    private static bool TryFocusFirstPermissionElement(DependencyObject root)
    {
        if (root is UIElement ui && ui.Focusable && ui.IsEnabled && ui.Visibility == Visibility.Visible)
            return ui.Focus();

        var childCount = VisualTreeHelper.GetChildrenCount(root);
        for (var i = 0; i < childCount; i++)
        {
            var child = VisualTreeHelper.GetChild(root, i);
            if (TryFocusFirstPermissionElement(child))
                return true;
        }

        return false;
    }

    private void SetToolPermissionOverride(string toolName, string? mode)
    {
        if (string.IsNullOrWhiteSpace(toolName)) return;
        var toolPermissions = _settings.Settings.Llm.ToolPermissions ??= new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
        var existingKey = toolPermissions.Keys.FirstOrDefault(x => string.Equals(x, toolName, StringComparison.OrdinalIgnoreCase));

        if (string.IsNullOrWhiteSpace(mode))
        {
            if (!string.IsNullOrWhiteSpace(existingKey))
                toolPermissions.Remove(existingKey!);
        }
        else
        {
            toolPermissions[existingKey ?? toolName] = PermissionModeCatalog.NormalizeToolOverride(mode);
        }

        ScheduleSettingsSave();
        _appState.LoadFromSettings(_settings);
        UpdatePermissionUI();
        SaveConversationSettings();
    }

    private void RefreshPermissionPopup()
    {
        if (PermissionPopup == null) return;
        BtnPermission_Click(this, new RoutedEventArgs());
    }

    private bool GetPermissionPopupSectionExpanded(string sectionKey, bool defaultValue = false)
    {
        var map = _settings.Settings.Llm.PermissionPopupSections;
        if (map != null && map.TryGetValue(sectionKey, out var expanded))
            return expanded;
        return defaultValue;
    }

    private void SetPermissionPopupSectionExpanded(string sectionKey, bool expanded)
    {
        var map = _settings.Settings.Llm.PermissionPopupSections ??= new Dictionary<string, bool>(StringComparer.OrdinalIgnoreCase);
        map[sectionKey] = expanded;
        ScheduleSettingsSave();
    }

    /// <summary>Shift+Tab으로 권한 모드를 순환합니다 (Claude Code 스타일).</summary>
    private void CyclePermissionMode()
    {
        var llm = _settings.Settings.Llm;
        llm.FilePermission = NextPermission(llm.FilePermission);
        ScheduleSettingsSave();
        _appState.LoadFromSettings(_settings);
        UpdatePermissionUI();
        SaveConversationSettings();
        RefreshInlineSettingsPanel();

        // Toast 알림
        var label = PermissionModeCatalog.ToDisplayLabel(llm.FilePermission);
        var icon = PermissionModeCatalog.NormalizeGlobalMode(llm.FilePermission) switch
        {
            "Plan" => "\uE769",
            "AcceptEdits" => "\uE73E",
            "BypassPermissions" => "\uE7BA",
            "Deny" => "\uE711",
            _ => "\uE8D7",
        };
        ShowToast(label, icon);
    }

    private void PlanModeBannerClose_Click(object sender, MouseButtonEventArgs e)
    {
        if (PlanModeBanner != null)
            PlanModeBanner.Visibility = Visibility.Collapsed;
    }

    private void BtnPermissionTopBannerClose_Click(object sender, RoutedEventArgs e)
    {
        if (PermissionTopBanner != null)
            PermissionTopBanner.Visibility = Visibility.Collapsed;
    }

    private void UpdatePermissionUI()
    {
        if (PermissionLabel == null || PermissionIcon == null) return;

        // 계획 모드 배너 기본 숨김 — Plan 분기에서만 표시
        if (PlanModeBanner != null)
            PlanModeBanner.Visibility = Visibility.Collapsed;

        ChatConversation? currentConversation;
        lock (_convLock) currentConversation = _currentConversation;
        var summary = _appState.GetPermissionSummary(currentConversation);
        var perm = PermissionModeCatalog.NormalizeGlobalMode(summary.EffectiveMode);
        PermissionLabel.Text = PermissionModeCatalog.ToDisplayLabel(perm);
        if (PermissionLabelInline != null) PermissionLabelInline.Text = PermissionLabel.Text;
        PermissionIcon.Text = perm switch
        {
            "AcceptEdits" => "\uE73E",
            "Plan" => "\uE769",
            "BypassPermissions" => "\uE7BA",
            "Deny" => "\uE711",
            _ => "\uE8D7",
        };
        if (PermissionIconInline != null) PermissionIconInline.Text = PermissionIcon.Text;
        if (BtnPermission != null)
        {
            var operationMode = OperationModePolicy.Normalize(_settings.Settings.OperationMode);
            BtnPermission.ToolTip = $"{summary.Description}\n운영 모드: {operationMode}\n기본값: {PermissionModeCatalog.ToDisplayLabel(summary.DefaultMode)} · 예외 {summary.OverrideCount}개";
            BtnPermission.Background = Brushes.Transparent;
            BtnPermission.BorderThickness = new Thickness(1);
        }

        if (!string.Equals(_lastPermissionBannerMode, perm, StringComparison.OrdinalIgnoreCase))
            _lastPermissionBannerMode = perm;

        if (perm == PermissionModeCatalog.AcceptEdits)
        {
            var activeColor = new SolidColorBrush(Color.FromRgb(0x10, 0x7C, 0x10));
            PermissionLabel.Foreground = activeColor;
            if (PermissionLabelInline != null) PermissionLabelInline.Foreground = activeColor;
            PermissionIcon.Foreground = activeColor;
            if (PermissionIconInline != null) PermissionIconInline.Foreground = activeColor;
            if (BtnPermission != null)
                BtnPermission.BorderBrush = BrushFromHex("#86EFAC");
            if (PermissionTopBanner != null)
            {
                PermissionTopBanner.BorderBrush = BrushFromHex("#86EFAC");
                PermissionTopBannerIcon.Text = "\uE73E";
                PermissionTopBannerIcon.Foreground = activeColor;
                PermissionTopBannerTitle.Text = "현재 권한 모드 · 편집 자동 승인";
                PermissionTopBannerTitle.Foreground = BrushFromHex("#166534");
                PermissionTopBannerText.Text = "모든 파일 편집은 자동 승인하고, 명령 실행만 계속 확인합니다.";
                PermissionTopBanner.Visibility = Visibility.Collapsed;
            }
        }
        else if (perm == PermissionModeCatalog.Deny)
        {
            var denyColor = new SolidColorBrush(Color.FromRgb(0x10, 0x7C, 0x10));
            PermissionLabel.Foreground = denyColor;
            if (PermissionLabelInline != null) PermissionLabelInline.Foreground = denyColor;
            PermissionIcon.Foreground = denyColor;
            if (PermissionIconInline != null) PermissionIconInline.Foreground = denyColor;
            if (BtnPermission != null)
                BtnPermission.BorderBrush = BrushFromHex("#86EFAC");
            if (PermissionTopBanner != null)
            {
                PermissionTopBanner.BorderBrush = BrushFromHex("#86EFAC");
                PermissionTopBannerIcon.Text = "\uE73E";
                PermissionTopBannerIcon.Foreground = denyColor;
                PermissionTopBannerTitle.Text = "현재 권한 모드 · 읽기 전용";
                PermissionTopBannerTitle.Foreground = denyColor;
                PermissionTopBannerText.Text = "기존 파일은 읽기만 가능하며 수정/삭제가 차단되고, 새 파일 생성은 가능합니다.";
                PermissionTopBanner.Visibility = Visibility.Collapsed;
            }
        }
        else if (perm == PermissionModeCatalog.Plan)
        {
            var planColor = new SolidColorBrush(Color.FromRgb(0xD9, 0x77, 0x06));
            PermissionLabel.Foreground = planColor;
            if (PermissionLabelInline != null) PermissionLabelInline.Foreground = planColor;
            PermissionIcon.Foreground = planColor;
            if (PermissionIconInline != null) PermissionIconInline.Foreground = planColor;
            if (BtnPermission != null)
                BtnPermission.BorderBrush = BrushFromHex("#FDE68A");
            if (PermissionTopBanner != null)
            {
                PermissionTopBanner.BorderBrush = BrushFromHex("#FDE68A");
                PermissionTopBannerIcon.Text = "\uE769";
                PermissionTopBannerIcon.Foreground = planColor;
                PermissionTopBannerTitle.Text = "현재 권한 모드 · 계획 모드";
                PermissionTopBannerTitle.Foreground = planColor;
                PermissionTopBannerText.Text = "파일을 읽고 분석한 뒤, 실행 전에 계획을 먼저 보여줍니다.";
                PermissionTopBanner.Visibility = Visibility.Collapsed;
            }
            // 계획 모드 배너 표시
            if (PlanModeBanner != null)
                PlanModeBanner.Visibility = Visibility.Visible;
        }
        else if (perm == PermissionModeCatalog.BypassPermissions)
        {
            var autoColor = new SolidColorBrush(Color.FromRgb(0xC2, 0x41, 0x0C));
            PermissionLabel.Foreground = autoColor;
            if (PermissionLabelInline != null) PermissionLabelInline.Foreground = autoColor;
            PermissionIcon.Foreground = autoColor;
            if (PermissionIconInline != null) PermissionIconInline.Foreground = autoColor;
            if (BtnPermission != null)
                BtnPermission.BorderBrush = BrushFromHex("#FDBA74");
            if (PermissionTopBanner != null)
            {
                PermissionTopBanner.BorderBrush = BrushFromHex("#FDBA74");
                PermissionTopBannerIcon.Text = "\uE814";
                PermissionTopBannerIcon.Foreground = autoColor;
                PermissionTopBannerTitle.Text = "현재 권한 모드 · 권한 건너뛰기";
                PermissionTopBannerTitle.Foreground = autoColor;
                PermissionTopBannerText.Text = "파일 편집과 명령 실행까지 모두 자동 허용합니다. 민감한 작업 전에는 설정을 다시 확인하세요.";
                PermissionTopBanner.Visibility = Visibility.Collapsed;
            }
        }
        else
        {
            var defaultFg = BrushFromHex("#2563EB");
            var iconFg = new SolidColorBrush(Color.FromRgb(0x25, 0x63, 0xEB));
            PermissionLabel.Foreground = defaultFg;
            if (PermissionLabelInline != null) PermissionLabelInline.Foreground = defaultFg;
            PermissionIcon.Foreground = iconFg;
            if (PermissionIconInline != null) PermissionIconInline.Foreground = iconFg;
            if (BtnPermission != null)
                BtnPermission.BorderBrush = BrushFromHex("#BFDBFE");
            if (PermissionTopBanner != null)
            {
                if (perm == PermissionModeCatalog.Default)
                {
                    PermissionTopBanner.BorderBrush = BrushFromHex("#BFDBFE");
                    PermissionTopBannerIcon.Text = "\uE8D7";
                    PermissionTopBannerIcon.Foreground = BrushFromHex("#1D4ED8");
                    PermissionTopBannerTitle.Text = "현재 권한 모드 · 권한 요청";
                    PermissionTopBannerTitle.Foreground = BrushFromHex("#1D4ED8");
                    PermissionTopBannerText.Text = "변경하기 전에 항상 확인합니다.";
                    PermissionTopBanner.Visibility = Visibility.Collapsed;
                }
                else
                {
                    PermissionTopBanner.Visibility = Visibility.Collapsed;
                }
            }
        }
    }
}