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;

namespace AxCopilot.Views;

public partial class ChatWindow
{
    private void UpdateInputBoxHeight()
    {
        if (InputBox == null)
            return;

        var text = InputBox.Text ?? string.Empty;
        var explicitLineCount = 1 + text.Count(ch => ch == '\n');
        var displayMode = (_settings.Settings.Llm.AgentUiExpressionLevel ?? "balanced").Trim().ToLowerInvariant();
        if (displayMode is not ("rich" or "balanced" or "simple"))
            displayMode = "balanced";

        var maxLines = displayMode switch
        {
            "rich" => 6,
            "simple" => 4,
            _ => 5,
        };
        const double baseHeight = 42;
        const double lineStep = 22;
        var visibleLines = Math.Clamp(explicitLineCount, 1, maxLines);
        var targetHeight = baseHeight + ((visibleLines - 1) * lineStep);

        InputBox.MinLines = 1;
        InputBox.MaxLines = maxLines;
        InputBox.Height = targetHeight;
        InputBox.VerticalScrollBarVisibility = explicitLineCount > maxLines
            ? ScrollBarVisibility.Auto
            : ScrollBarVisibility.Disabled;
    }

    private string BuildComposerDraftText()
    {
        var rawText = InputBox?.Text?.Trim() ?? "";
        return _slashPalette.ActiveCommand != null
            ? (_slashPalette.ActiveCommand + " " + rawText).Trim()
            : rawText;
    }

    private static string InferDraftKind(string text, string? explicitKind = null)
    {
        var trimmed = text?.Trim() ?? "";
        var requestedKind = explicitKind?.Trim().ToLowerInvariant();

        if (requestedKind is "followup" or "steering")
            return requestedKind;

        if (trimmed.StartsWith("/", StringComparison.OrdinalIgnoreCase))
            return "command";

        if (requestedKind is "direct" or "message")
            return requestedKind;

        if (trimmed.StartsWith("steer:", StringComparison.OrdinalIgnoreCase) ||
            trimmed.StartsWith("@steer ", StringComparison.OrdinalIgnoreCase) ||
            trimmed.StartsWith("조정:", StringComparison.OrdinalIgnoreCase))
            return "steering";

        return "message";
    }

    private void QueueComposerDraft(string priority = "next", string? explicitKind = null, bool startImmediatelyWhenIdle = true)
    {
        if (InputBox == null)
            return;

        var text = BuildComposerDraftText();
        if (string.IsNullOrWhiteSpace(text))
            return;

        if (_isStreaming && string.Equals(priority, "now", StringComparison.OrdinalIgnoreCase))
            priority = "next";

        HideSlashChip(restoreText: false);
        ClearPromptCardPlaceholder();

        var queuedItem = EnqueueDraftRequest(text, priority, explicitKind);

        InputBox.Clear();
        InputBox.Focus();
        UpdateInputBoxHeight();
        RefreshDraftQueueUi();

        if (queuedItem == null)
            return;

        if (!_isStreaming && startImmediatelyWhenIdle)
        {
            StartNextQueuedDraftIfAny(queuedItem.Id);
            return;
        }

        var toast = queuedItem.Kind switch
        {
            "command" => "명령이 대기열에 추가되었습니다.",
            "direct" => "직접 실행 요청이 대기열에 추가되었습니다.",
            "steering" => "조정 요청이 대기열에 추가되었습니다.",
            "followup" => "후속 작업이 대기열에 추가되었습니다.",
            _ => "메시지가 대기열에 추가되었습니다.",
        };
        ShowToast(toast);
    }

    private void RefreshDraftQueueUi()
    {
        if (DraftPreviewCard == null || DraftPreviewText == null || DraftQueuePanel == null || BtnDraftEnqueue == null)
            return;

        lock (_convLock)
        {
            var session = ChatSession;
            if (session != null)
                _draftQueueProcessor.PromoteReadyBlockedItems(session, _activeTab, _storage);
        }

        var items = _appState.GetDraftQueueItems(_activeTab);

        DraftPreviewCard.Visibility = Visibility.Collapsed;
        BtnDraftEnqueue.IsEnabled = false;
        DraftPreviewText.Text = string.Empty;

        RebuildDraftQueuePanel(items);
    }

    private bool IsDraftQueueExpanded()
        => _expandedDraftQueueTabs.Contains(_activeTab);

    private void ToggleDraftQueueExpanded()
    {
        if (!_expandedDraftQueueTabs.Add(_activeTab))
            _expandedDraftQueueTabs.Remove(_activeTab);

        RefreshDraftQueueUi();
    }

    private void RebuildDraftQueuePanel(IReadOnlyList<DraftQueueItem> items)
    {
        if (DraftQueuePanel == null)
            return;

        DraftQueuePanel.Children.Clear();

        var visibleItems = items
            .OrderBy(GetDraftStateRank)
            .ThenBy(GetDraftPriorityRank)
            .ThenBy(x => x.CreatedAt)
            .ToList();

        if (visibleItems.Count == 0)
        {
            DraftQueuePanel.Visibility = Visibility.Collapsed;
            return;
        }

        var summary = _appState.GetDraftQueueSummary(_activeTab);
        var shouldShowQueue =
            IsDraftQueueExpanded()
            || summary.RunningCount > 0
            || summary.QueuedCount > 0
            || summary.FailedCount > 0;

        if (!shouldShowQueue)
        {
            DraftQueuePanel.Visibility = Visibility.Collapsed;
            return;
        }

        DraftQueuePanel.Visibility = Visibility.Visible;
        DraftQueuePanel.Children.Add(CreateDraftQueueSummaryStrip(summary, IsDraftQueueExpanded()));
        if (!IsDraftQueueExpanded())
        {
            DraftQueuePanel.Children.Add(CreateCompactDraftQueuePanel(visibleItems, summary));
            return;
        }

        const int maxPerSection = 3;
        var runningItems = visibleItems
            .Where(item => string.Equals(item.State, "running", StringComparison.OrdinalIgnoreCase))
            .Take(maxPerSection)
            .ToList();
        var queuedItems = visibleItems
            .Where(item => string.Equals(item.State, "queued", StringComparison.OrdinalIgnoreCase) && !IsDraftBlocked(item))
            .Take(maxPerSection)
            .ToList();
        var blockedItems = visibleItems
            .Where(IsDraftBlocked)
            .Take(maxPerSection)
            .ToList();
        var completedItems = visibleItems
            .Where(item => string.Equals(item.State, "completed", StringComparison.OrdinalIgnoreCase))
            .Take(maxPerSection)
            .ToList();
        var failedItems = visibleItems
            .Where(item => string.Equals(item.State, "failed", StringComparison.OrdinalIgnoreCase))
            .Take(maxPerSection)
            .ToList();

        AddDraftQueueSection("실행 중", runningItems, summary.RunningCount);
        AddDraftQueueSection("다음 작업", queuedItems, summary.QueuedCount);
        AddDraftQueueSection("보류", blockedItems, summary.BlockedCount);
        AddDraftQueueSection("완료", completedItems, summary.CompletedCount);
        AddDraftQueueSection("실패", failedItems, summary.FailedCount);

        if (summary.CompletedCount > 0 || summary.FailedCount > 0)
        {
            var footer = new StackPanel
            {
                Orientation = Orientation.Horizontal,
                Margin = new Thickness(0, 2, 0, 0),
            };

            if (summary.CompletedCount > 0)
                footer.Children.Add(CreateDraftQueueActionButton($"완료 정리 {summary.CompletedCount}", ClearCompletedDrafts, BrushFromHex("#ECFDF5")));

            if (summary.FailedCount > 0)
                footer.Children.Add(CreateDraftQueueActionButton($"실패 정리 {summary.FailedCount}", ClearFailedDrafts, BrushFromHex("#FEF2F2")));

            DraftQueuePanel.Children.Add(footer);
        }
    }

    private UIElement CreateCompactDraftQueuePanel(IReadOnlyList<DraftQueueItem> items, AppStateService.DraftQueueSummaryState summary)
    {
        var primaryText = TryFindResource("PrimaryText") as Brush ?? BrushFromHex("#111827");
        var secondaryText = TryFindResource("SecondaryText") as Brush ?? BrushFromHex("#6B7280");
        var background = TryFindResource("ItemBackground") as Brush ?? BrushFromHex("#F7F7F8");
        var borderBrush = TryFindResource("BorderColor") as Brush ?? BrushFromHex("#E4E4E7");
        var focusItem = items.FirstOrDefault(item => string.Equals(item.State, "running", StringComparison.OrdinalIgnoreCase))
            ?? items.FirstOrDefault(item => string.Equals(item.State, "queued", StringComparison.OrdinalIgnoreCase) && !IsDraftBlocked(item))
            ?? items.FirstOrDefault(IsDraftBlocked)
            ?? items.FirstOrDefault(item => string.Equals(item.State, "failed", StringComparison.OrdinalIgnoreCase))
            ?? items.FirstOrDefault(item => string.Equals(item.State, "completed", StringComparison.OrdinalIgnoreCase));

        var container = new Border
        {
            Background = background,
            BorderBrush = borderBrush,
            BorderThickness = new Thickness(1),
            CornerRadius = new CornerRadius(14),
            Padding = new Thickness(12, 10, 12, 10),
            Margin = new Thickness(0, 0, 0, 4),
        };

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

        var left = new StackPanel();
        left.Children.Add(new TextBlock
        {
            Text = focusItem == null
                ? "대기열 항목이 준비되면 여기에서 요약됩니다."
                : $"{GetDraftStateLabel(focusItem)} · {GetDraftKindLabel(focusItem)}",
            FontSize = 11,
            FontWeight = FontWeights.SemiBold,
            Foreground = primaryText,
        });
        left.Children.Add(new TextBlock
        {
            Text = focusItem?.Text ?? BuildDraftQueueCompactSummaryText(summary),
            FontSize = 10.5,
            Foreground = secondaryText,
            TextTrimming = TextTrimming.CharacterEllipsis,
            Margin = new Thickness(0, 4, 0, 0),
            MaxWidth = 520,
        });
        Grid.SetColumn(left, 0);
        root.Children.Add(left);

        var action = CreateDraftQueueActionButton("상세", ToggleDraftQueueExpanded);
        action.Margin = new Thickness(12, 0, 0, 0);
        Grid.SetColumn(action, 1);
        root.Children.Add(action);

        return container;
    }

    private static string BuildDraftQueueCompactSummaryText(AppStateService.DraftQueueSummaryState summary)
    {
        var parts = new List<string>();
        if (summary.RunningCount > 0) parts.Add($"실행 {summary.RunningCount}");
        if (summary.QueuedCount > 0) parts.Add($"다음 {summary.QueuedCount}");
        if (summary.FailedCount > 0) parts.Add($"실패 {summary.FailedCount}");
        return parts.Count == 0 ? "대기열 0" : string.Join(" · ", parts);
    }

    private void AddDraftQueueSection(string label, IReadOnlyList<DraftQueueItem> items, int totalCount)
    {
        if (DraftQueuePanel == null || totalCount <= 0)
            return;

        DraftQueuePanel.Children.Add(CreateDraftQueueSectionLabel($"{label} · {totalCount}"));
        foreach (var item in items)
            DraftQueuePanel.Children.Add(CreateDraftQueueCard(item));

        if (totalCount > items.Count)
        {
            DraftQueuePanel.Children.Add(new TextBlock
            {
                Text = $"추가 항목 {totalCount - items.Count}개",
                Margin = new Thickness(8, -2, 0, 8),
                FontSize = 10.5,
                Foreground = TryFindResource("SecondaryText") as Brush ?? BrushFromHex("#7A7F87"),
            });
        }
    }

    private UIElement CreateDraftQueueSummaryStrip(AppStateService.DraftQueueSummaryState summary, bool isExpanded)
    {
        var root = new Grid
        {
            Margin = new Thickness(0, 0, 0, 8),
        };
        root.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
        root.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });

        var wrap = new WrapPanel();

        if (summary.RunningCount > 0)
            wrap.Children.Add(CreateQueueSummaryPill("실행 중", summary.RunningCount.ToString(), "#EFF6FF", "#BFDBFE", "#1D4ED8"));
        if (summary.QueuedCount > 0)
            wrap.Children.Add(CreateQueueSummaryPill("다음", summary.QueuedCount.ToString(), "#F5F3FF", "#DDD6FE", "#6D28D9"));
        if (isExpanded && summary.BlockedCount > 0)
            wrap.Children.Add(CreateQueueSummaryPill("보류", summary.BlockedCount.ToString(), "#FFF7ED", "#FDBA74", "#C2410C"));
        if (isExpanded && summary.CompletedCount > 0)
            wrap.Children.Add(CreateQueueSummaryPill("완료", summary.CompletedCount.ToString(), "#ECFDF5", "#BBF7D0", "#166534"));
        if (summary.FailedCount > 0)
            wrap.Children.Add(CreateQueueSummaryPill("실패", summary.FailedCount.ToString(), "#FEF2F2", "#FECACA", "#991B1B"));

        if (wrap.Children.Count == 0)
            wrap.Children.Add(CreateQueueSummaryPill("대기열", "0", "#F8FAFC", "#E2E8F0", "#475569"));

        Grid.SetColumn(wrap, 0);
        root.Children.Add(wrap);

        var toggle = CreateDraftQueueActionButton(isExpanded ? "간단히" : "상세 보기", ToggleDraftQueueExpanded);
        toggle.Margin = new Thickness(10, 0, 0, 0);
        Grid.SetColumn(toggle, 1);
        root.Children.Add(toggle);

        return root;
    }

    private Border CreateQueueSummaryPill(string label, string value, string bgHex, string borderHex, string fgHex)
    {
        return new Border
        {
            Background = BrushFromHex(bgHex),
            BorderBrush = BrushFromHex(borderHex),
            BorderThickness = new Thickness(1),
            CornerRadius = new CornerRadius(999),
            Padding = new Thickness(8, 3, 8, 3),
            Margin = new Thickness(0, 0, 6, 0),
            Child = new StackPanel
            {
                Orientation = Orientation.Horizontal,
                Children =
                {
                    new TextBlock
                    {
                        Text = label,
                        FontSize = 10,
                        Foreground = BrushFromHex(fgHex),
                    },
                    new TextBlock
                    {
                        Text = $" {value}",
                        FontSize = 10,
                        FontWeight = FontWeights.SemiBold,
                        Foreground = BrushFromHex(fgHex),
                    }
                }
            }
        };
    }

    private TextBlock CreateDraftQueueSectionLabel(string text)
    {
        return new TextBlock
        {
            Text = text,
            FontSize = 10.5,
            FontWeight = FontWeights.SemiBold,
            Margin = new Thickness(8, 0, 8, 6),
            Foreground = TryFindResource("SecondaryText") as Brush ?? BrushFromHex("#64748B"),
        };
    }

    private Border CreateDraftQueueCard(DraftQueueItem item)
    {
        var background = TryFindResource("ItemBackground") as Brush ?? BrushFromHex("#F7F7F8");
        var borderBrush = TryFindResource("BorderColor") as Brush ?? BrushFromHex("#E4E4E7");
        var primaryText = TryFindResource("PrimaryText") as Brush ?? BrushFromHex("#111827");
        var secondaryText = TryFindResource("SecondaryText") as Brush ?? BrushFromHex("#6B7280");
        var neutralSurface = BrushFromHex("#F5F6F8");
        var (kindIcon, kindForeground) = GetDraftKindVisual(item);
        var (stateBackground, stateBorder, stateForeground) = GetDraftStateBadgeColors(item);
        var (priorityBackground, priorityBorder, priorityForeground) = GetDraftPriorityBadgeColors(item.Priority);

        var container = new Border
        {
            Background = background,
            BorderBrush = borderBrush,
            BorderThickness = new Thickness(1),
            CornerRadius = new CornerRadius(14),
            Padding = new Thickness(12, 10, 12, 10),
            Margin = new Thickness(0, 0, 0, 8),
        };

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

        var left = new StackPanel();
        Grid.SetColumn(left, 0);
        root.Children.Add(left);

        var header = new StackPanel
        {
            Orientation = Orientation.Horizontal,
        };
        header.Children.Add(new TextBlock
        {
            Text = kindIcon,
            FontFamily = new FontFamily("Segoe MDL2 Assets"),
            FontSize = 11,
            Foreground = kindForeground,
            VerticalAlignment = VerticalAlignment.Center,
            Margin = new Thickness(0, 0, 6, 0),
        });
        header.Children.Add(CreateDraftQueueBadge(GetDraftKindLabel(item), BrushFromHex("#F8FAFC"), borderBrush, kindForeground));
        header.Children.Add(CreateDraftQueueBadge(GetDraftStateLabel(item), stateBackground, stateBorder, stateForeground));
        header.Children.Add(CreateDraftQueueBadge(GetDraftPriorityLabel(item.Priority), priorityBackground, priorityBorder, priorityForeground));
        left.Children.Add(header);

        left.Children.Add(new TextBlock
        {
            Text = item.Text,
            FontSize = 12.5,
            Foreground = primaryText,
            Margin = new Thickness(0, 6, 0, 0),
            TextWrapping = TextWrapping.Wrap,
            TextTrimming = TextTrimming.CharacterEllipsis,
            MaxWidth = 520,
        });

        var meta = $"{item.CreatedAt:HH:mm}";
        if (item.AttemptCount > 0)
            meta += $" · 시도 {item.AttemptCount}";
        if (item.NextRetryAt.HasValue && item.NextRetryAt.Value > DateTime.Now)
            meta += $" · 재시도 {item.NextRetryAt.Value:HH:mm:ss}";
        if (!string.IsNullOrWhiteSpace(item.LastError))
            meta += $" · {TruncateForStatus(item.LastError, 36)}";

        left.Children.Add(new TextBlock
        {
            Text = meta,
            FontSize = 10.5,
            Foreground = secondaryText,
            Margin = new Thickness(0, 6, 0, 0),
        });

        var actions = new StackPanel
        {
            Orientation = Orientation.Horizontal,
            VerticalAlignment = VerticalAlignment.Top,
        };
        Grid.SetColumn(actions, 1);
        root.Children.Add(actions);

        if (!string.Equals(item.State, "running", StringComparison.OrdinalIgnoreCase))
            actions.Children.Add(CreateDraftQueueActionButton("실행", () => QueueDraftForImmediateRun(item.Id)));

        if (string.Equals(item.State, "failed", StringComparison.OrdinalIgnoreCase) ||
            string.Equals(item.State, "completed", StringComparison.OrdinalIgnoreCase))
        {
            actions.Children.Add(CreateDraftQueueActionButton("대기", () => ResetDraftInQueue(item.Id), neutralSurface));
        }

        actions.Children.Add(CreateDraftQueueActionButton("삭제", () => RemoveDraftFromQueue(item.Id), neutralSurface));
        return container;
    }

    private Border CreateDraftQueueBadge(string text, Brush background, Brush borderBrush, Brush foreground)
    {
        return new Border
        {
            Background = background,
            BorderBrush = borderBrush,
            BorderThickness = new Thickness(1),
            CornerRadius = new CornerRadius(999),
            Padding = new Thickness(7, 2, 7, 2),
            Margin = new Thickness(0, 0, 6, 0),
            Child = new TextBlock
            {
                Text = text,
                FontSize = 10,
                FontWeight = FontWeights.SemiBold,
                Foreground = foreground,
            }
        };
    }

    private Button CreateDraftQueueActionButton(string label, Action onClick, Brush? background = null)
    {
        var btn = new Button
        {
            Content = label,
            Margin = new Thickness(6, 0, 0, 0),
            Padding = new Thickness(10, 5, 10, 5),
            MinWidth = 48,
            FontSize = 11,
            Background = background ?? BrushFromHex("#EEF2FF"),
            BorderBrush = TryFindResource("BorderColor") as Brush ?? BrushFromHex("#D4D4D8"),
            BorderThickness = new Thickness(1),
            Foreground = TryFindResource("PrimaryText") as Brush ?? BrushFromHex("#111827"),
            Cursor = Cursors.Hand,
        };
        btn.Click += (_, _) => onClick();
        return btn;
    }

    private static int GetDraftStateRank(DraftQueueItem item)
        => string.Equals(item.State, "running", StringComparison.OrdinalIgnoreCase) ? 0
            : IsDraftBlocked(item) ? 1
            : string.Equals(item.State, "queued", StringComparison.OrdinalIgnoreCase) ? 2
            : string.Equals(item.State, "failed", StringComparison.OrdinalIgnoreCase) ? 3
            : 4;

    private static int GetDraftPriorityRank(DraftQueueItem item)
        => item.Priority?.ToLowerInvariant() switch
        {
            "now" => 0,
            "next" => 1,
            _ => 2,
        };

    private static string GetDraftPriorityLabel(string? priority)
        => priority?.ToLowerInvariant() switch
        {
            "now" => "지금",
            "later" => "나중",
            _ => "다음",
        };

    private static string GetDraftKindLabel(DraftQueueItem item)
        => item.Kind?.ToLowerInvariant() switch
        {
            "followup" => "후속 작업",
            "steering" => "조정",
            "command" => "명령",
            "direct" => "직접 실행",
            _ => "메시지",
        };

    private (string Icon, Brush Foreground) GetDraftKindVisual(DraftQueueItem item)
        => item.Kind?.ToLowerInvariant() switch
        {
            "followup" => ("\uE8A5", BrushFromHex("#0F766E")),
            "steering" => ("\uE7C3", BrushFromHex("#B45309")),
            "command" => ("\uE756", BrushFromHex("#7C3AED")),
            "direct" => ("\uE8A7", BrushFromHex("#2563EB")),
            _ => ("\uE8BD", BrushFromHex("#475569")),
        };

    private static string GetDraftStateLabel(DraftQueueItem item)
        => IsDraftBlocked(item) ? "재시도 대기"
        : item.State?.ToLowerInvariant() switch
        {
            "running" => "실행 중",
            "failed" => "실패",
            "completed" => "완료",
            _ => "대기",
        };

    private Brush GetDraftStateBrush(DraftQueueItem item)
        => IsDraftBlocked(item) ? BrushFromHex("#B45309")
        : item.State?.ToLowerInvariant() switch
        {
            "running" => BrushFromHex("#2563EB"),
            "failed" => BrushFromHex("#DC2626"),
            "completed" => BrushFromHex("#059669"),
            _ => BrushFromHex("#7C3AED"),
        };

    private (Brush Background, Brush Border, Brush Foreground) GetDraftStateBadgeColors(DraftQueueItem item)
        => IsDraftBlocked(item)
            ? (BrushFromHex("#FFF7ED"), BrushFromHex("#FDBA74"), BrushFromHex("#C2410C"))
            : item.State?.ToLowerInvariant() switch
            {
                "running" => (BrushFromHex("#EFF6FF"), BrushFromHex("#BFDBFE"), BrushFromHex("#1D4ED8")),
                "failed" => (BrushFromHex("#FEF2F2"), BrushFromHex("#FECACA"), BrushFromHex("#991B1B")),
                "completed" => (BrushFromHex("#ECFDF5"), BrushFromHex("#BBF7D0"), BrushFromHex("#166534")),
                _ => (BrushFromHex("#F5F3FF"), BrushFromHex("#DDD6FE"), BrushFromHex("#6D28D9")),
            };

    private static (Brush Background, Brush Border, Brush Foreground) GetDraftPriorityBadgeColors(string? priority)
        => priority?.ToLowerInvariant() switch
        {
            "now" => (BrushFromHex("#EEF2FF"), BrushFromHex("#C7D2FE"), BrushFromHex("#3730A3")),
            "later" => (BrushFromHex("#F8FAFC"), BrushFromHex("#E2E8F0"), BrushFromHex("#475569")),
            _ => (BrushFromHex("#FEF3C7"), BrushFromHex("#FDE68A"), BrushFromHex("#92400E")),
        };

    private static bool IsDraftBlocked(DraftQueueItem item)
        => string.Equals(item.State, "queued", StringComparison.OrdinalIgnoreCase)
           && item.NextRetryAt.HasValue
           && item.NextRetryAt.Value > DateTime.Now;
}