"use client";

import { useState, useEffect, useCallback, useMemo } from "react";
import { cn } from "@/lib/utils";
import {
  ChevronRight,
  ChevronDown,
  ChevronUp,
  Folder,
  FolderOpen,
  Monitor,
  Plus,
  MoreVertical,
  Edit,
  Trash2,
  Loader2,
  RefreshCw,
  FolderPlus,
  MoveRight,
  ArrowUp,
  ArrowDown,
  Search,
} from "lucide-react";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Badge } from "@/components/ui/badge";
import { ScrollArea } from "@/components/ui/scroll-area";
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuTrigger,
  DropdownMenuSeparator,
} from "@/components/ui/dropdown-menu";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
} from "@/components/ui/alert-dialog";
import { Label } from "@/components/ui/label";
import { toast } from "sonner";
import { ScreenDefinition } from "@/types/screen";
import { apiClient } from "@/lib/api/client";
import {
  PopScreenGroup,
  getPopScreenGroups,
  createPopScreenGroup,
  updatePopScreenGroup,
  deletePopScreenGroup,
  ensurePopRootGroup,
  buildPopGroupTree,
} from "@/lib/api/popScreenGroup";

// ============================================================
// 타입 정의
// ============================================================

interface PopCategoryTreeProps {
  screens: ScreenDefinition[]; // POP 레이아웃이 있는 화면 목록
  selectedScreen: ScreenDefinition | null;
  onScreenSelect: (screen: ScreenDefinition) => void;
  onScreenDesign: (screen: ScreenDefinition) => void;
  onGroupSelect?: (group: PopScreenGroup | null) => void;
  searchTerm?: string;
}

interface TreeNodeProps {
  group: PopScreenGroup;
  level: number;
  expandedGroups: Set<number>;
  onToggle: (groupId: number) => void;
  selectedGroupId: number | null;
  selectedScreenId: number | null;
  onGroupSelect: (group: PopScreenGroup) => void;
  onScreenSelect: (screen: ScreenDefinition) => void;
  onScreenDesign: (screen: ScreenDefinition) => void;
  onEditGroup: (group: PopScreenGroup) => void;
  onDeleteGroup: (group: PopScreenGroup) => void;
  onAddSubGroup: (parentGroup: PopScreenGroup) => void;
  screensMap: Map<number, ScreenDefinition>;
  // 화면 이동/삭제 관련
  onOpenMoveModal: (screen: ScreenDefinition, fromGroupId: number | null) => void;
  onRemoveScreenFromGroup: (screen: ScreenDefinition, groupId: number) => void;
  // 순서 변경 관련
  siblingGroups: PopScreenGroup[]; // 같은 레벨의 그룹들
  onMoveGroupUp: (group: PopScreenGroup) => void;
  onMoveGroupDown: (group: PopScreenGroup) => void;
  onMoveScreenUp: (screen: ScreenDefinition, groupId: number) => void;
  onMoveScreenDown: (screen: ScreenDefinition, groupId: number) => void;
  onDeleteScreen: (screen: ScreenDefinition) => void;
}

// ============================================================
// 트리 노드 컴포넌트
// ============================================================

function TreeNode({
  group,
  level,
  onOpenMoveModal,
  onRemoveScreenFromGroup,
  siblingGroups,
  onMoveGroupUp,
  onMoveGroupDown,
  onMoveScreenUp,
  onMoveScreenDown,
  onDeleteScreen,
  expandedGroups,
  onToggle,
  selectedGroupId,
  selectedScreenId,
  onGroupSelect,
  onScreenSelect,
  onScreenDesign,
  onEditGroup,
  onDeleteGroup,
  onAddSubGroup,
  screensMap,
}: TreeNodeProps) {
  const isExpanded = expandedGroups.has(group.id);
  const hasChildren = (group.children && group.children.length > 0) || (group.screens && group.screens.length > 0);
  const isSelected = selectedGroupId === group.id;

  // 그룹에 연결된 화면 목록
  const groupScreens = useMemo(() => {
    if (!group.screens) return [];
    return group.screens
      .map((gs) => screensMap.get(gs.screen_id))
      .filter((s): s is ScreenDefinition => s !== undefined);
  }, [group.screens, screensMap]);

  // 루트 레벨(POP 화면)인지 확인
  const isRootLevel = level === 0;

  // 그룹 순서 변경 가능 여부 계산
  const groupIndex = siblingGroups.findIndex((g) => g.id === group.id);
  const canMoveGroupUp = groupIndex > 0;
  const canMoveGroupDown = groupIndex < siblingGroups.length - 1;

  return (
    <div className="select-none">
      {/* 그룹 노드 */}
      <div
        className={cn(
          "flex items-center gap-1.5 py-1.5 px-2 rounded-md cursor-pointer transition-colors",
          isSelected ? "bg-primary/10 text-primary" : "hover:bg-muted",
          "group"
        )}
        style={{ paddingLeft: `${level * 24 + 8}px` }}
        onClick={() => onGroupSelect(group)}
      >
        {/* 트리 연결 표시 (하위 레벨만) */}
        {level > 0 && (
          <span className="text-muted-foreground/50 text-xs mr-1">ㄴ</span>
        )}

        {/* 확장/축소 버튼 */}
        <button
          className="p-0.5 hover:bg-muted-foreground/10 rounded shrink-0"
          onClick={(e) => {
            e.stopPropagation();
            onToggle(group.id);
          }}
        >
          {hasChildren ? (
            isExpanded ? (
              <ChevronDown className="h-4 w-4 text-muted-foreground" />
            ) : (
              <ChevronRight className="h-4 w-4 text-muted-foreground" />
            )
          ) : (
            <div className="w-4 h-4" />
          )}
        </button>

        {/* 폴더 아이콘 - 루트는 다른 색상 */}
        {isExpanded && hasChildren ? (
          <FolderOpen className={cn("h-4 w-4 shrink-0", isRootLevel ? "text-orange-500" : "text-amber-500")} />
        ) : (
          <Folder className={cn("h-4 w-4 shrink-0", isRootLevel ? "text-orange-500" : "text-amber-500")} />
        )}

        {/* 그룹명 - 루트는 볼드체 */}
        <span className={cn("flex-1 text-sm truncate", isRootLevel && "font-semibold")}>{group.group_name}</span>

        {/* 화면 수 배지 */}
        {group.screen_count && group.screen_count > 0 && (
          <Badge variant="secondary" className="text-[10px] px-1.5 py-0 h-4 shrink-0">
            {group.screen_count}
          </Badge>
        )}

        {/* 더보기 메뉴 */}
        <DropdownMenu>
          <DropdownMenuTrigger asChild>
            <Button
              variant="ghost"
              size="icon"
              className="h-6 w-6 opacity-0 group-hover:opacity-100 shrink-0"
              onClick={(e) => e.stopPropagation()}
            >
              <MoreVertical className="h-3.5 w-3.5" />
            </Button>
          </DropdownMenuTrigger>
          <DropdownMenuContent align="end" className="w-40">
            <DropdownMenuItem onClick={() => onAddSubGroup(group)}>
              <FolderPlus className="h-4 w-4 mr-2" />
              하위 그룹 추가
            </DropdownMenuItem>
            <DropdownMenuItem onClick={() => onEditGroup(group)}>
              <Edit className="h-4 w-4 mr-2" />
              수정
            </DropdownMenuItem>
            <DropdownMenuSeparator />
            <DropdownMenuItem 
              onClick={() => onMoveGroupUp(group)}
              disabled={!canMoveGroupUp}
            >
              <ArrowUp className="h-4 w-4 mr-2" />
              위로 이동
            </DropdownMenuItem>
            <DropdownMenuItem 
              onClick={() => onMoveGroupDown(group)}
              disabled={!canMoveGroupDown}
            >
              <ArrowDown className="h-4 w-4 mr-2" />
              아래로 이동
            </DropdownMenuItem>
            <DropdownMenuSeparator />
            <DropdownMenuItem
              className="text-destructive"
              onClick={() => onDeleteGroup(group)}
            >
              <Trash2 className="h-4 w-4 mr-2" />
              삭제
            </DropdownMenuItem>
          </DropdownMenuContent>
        </DropdownMenu>
      </div>

      {/* 확장된 경우 하위 요소 렌더링 */}
      {isExpanded && (
        <>
          {/* 하위 그룹 */}
          {group.children?.map((child) => (
            <TreeNode
              key={`group-${child.id}`}
              group={child}
              level={level + 1}
              expandedGroups={expandedGroups}
              onToggle={onToggle}
              selectedGroupId={selectedGroupId}
              selectedScreenId={selectedScreenId}
              onGroupSelect={onGroupSelect}
              onScreenSelect={onScreenSelect}
              onScreenDesign={onScreenDesign}
              onEditGroup={onEditGroup}
              onDeleteGroup={onDeleteGroup}
              onAddSubGroup={onAddSubGroup}
              screensMap={screensMap}
              onOpenMoveModal={onOpenMoveModal}
              onRemoveScreenFromGroup={onRemoveScreenFromGroup}
              siblingGroups={group.children || []}
              onMoveGroupUp={onMoveGroupUp}
              onMoveGroupDown={onMoveGroupDown}
              onMoveScreenUp={onMoveScreenUp}
              onMoveScreenDown={onMoveScreenDown}
              onDeleteScreen={onDeleteScreen}
            />
          ))}

          {/* 그룹에 연결된 화면 */}
          {groupScreens.map((screen, screenIndex) => {
            const canMoveScreenUp = screenIndex > 0;
            const canMoveScreenDown = screenIndex < groupScreens.length - 1;
            
            return (
              <div
                key={`screen-${screen.screenId}`}
                className={cn(
                  "flex items-center gap-1.5 py-1.5 px-2 rounded-md cursor-pointer transition-colors",
                  selectedScreenId === screen.screenId
                    ? "bg-primary/10 text-primary"
                    : "hover:bg-muted",
                  "group"
                )}
                style={{ paddingLeft: `${(level + 1) * 24 + 8}px` }}
                onClick={() => onScreenSelect(screen)}
                onDoubleClick={() => onScreenDesign(screen)}
              >
                {/* 트리 연결 표시 */}
                <span className="text-muted-foreground/50 text-xs mr-1">ㄴ</span>
                <Monitor className="h-4 w-4 text-blue-500 shrink-0" />
                <span className="flex-1 text-sm truncate">{screen.screenName}</span>
                <span className="text-[10px] text-muted-foreground shrink-0">#{screen.screenId}</span>
                
                {/* 더보기 메뉴 (폴더와 동일한 스타일) */}
                <DropdownMenu>
                  <DropdownMenuTrigger asChild>
                    <Button
                      variant="ghost"
                      size="icon"
                      className="h-6 w-6 opacity-0 group-hover:opacity-100 shrink-0"
                      onClick={(e) => e.stopPropagation()}
                    >
                      <MoreVertical className="h-3.5 w-3.5" />
                    </Button>
                  </DropdownMenuTrigger>
                  <DropdownMenuContent align="end" className="w-48">
                    <DropdownMenuItem onClick={() => onScreenDesign(screen)}>
                      <Edit className="h-4 w-4 mr-2" />
                      설계
                    </DropdownMenuItem>
                    <DropdownMenuSeparator />
                    <DropdownMenuItem 
                      onClick={() => onMoveScreenUp(screen, group.id)}
                      disabled={!canMoveScreenUp}
                    >
                      <ArrowUp className="h-4 w-4 mr-2" />
                      위로 이동
                    </DropdownMenuItem>
                    <DropdownMenuItem 
                      onClick={() => onMoveScreenDown(screen, group.id)}
                      disabled={!canMoveScreenDown}
                    >
                      <ArrowDown className="h-4 w-4 mr-2" />
                      아래로 이동
                    </DropdownMenuItem>
                    <DropdownMenuSeparator />
                    <DropdownMenuItem onClick={() => onOpenMoveModal(screen, group.id)}>
                      <MoveRight className="h-4 w-4 mr-2" />
                      다른 카테고리로 이동
                    </DropdownMenuItem>
                    <DropdownMenuSeparator />
                    <DropdownMenuItem 
                      onClick={() => onRemoveScreenFromGroup(screen, group.id)}
                    >
                      <MoveRight className="h-4 w-4 mr-2" />
                      그룹에서 제거
                    </DropdownMenuItem>
                    <DropdownMenuItem 
                      className="text-destructive"
                      onClick={() => onDeleteScreen(screen)}
                    >
                      <Trash2 className="h-4 w-4 mr-2" />
                      화면 삭제
                    </DropdownMenuItem>
                  </DropdownMenuContent>
                </DropdownMenu>
              </div>
            );
          })}
        </>
      )}
    </div>
  );
}

// ============================================================
// 메인 컴포넌트
// ============================================================

export function PopCategoryTree({
  screens,
  selectedScreen,
  onScreenSelect,
  onScreenDesign,
  onGroupSelect,
  searchTerm = "",
}: PopCategoryTreeProps) {
  // 상태 관리
  const [groups, setGroups] = useState<PopScreenGroup[]>([]);
  const [loading, setLoading] = useState(true);
  const [expandedGroups, setExpandedGroups] = useState<Set<number>>(new Set());
  const [selectedGroupId, setSelectedGroupId] = useState<number | null>(null);

  // 그룹 모달 상태
  const [isGroupModalOpen, setIsGroupModalOpen] = useState(false);
  const [editingGroup, setEditingGroup] = useState<PopScreenGroup | null>(null);
  const [parentGroupId, setParentGroupId] = useState<number | null>(null);
  const [groupFormData, setGroupFormData] = useState({
    group_name: "",
    group_code: "",
    description: "",
    icon: "",
  });

  // 그룹 삭제 다이얼로그 상태
  const [isDeleteDialogOpen, setIsDeleteDialogOpen] = useState(false);
  const [deletingGroup, setDeletingGroup] = useState<PopScreenGroup | null>(null);

  // 화면 삭제 다이얼로그 상태
  const [isScreenDeleteDialogOpen, setIsScreenDeleteDialogOpen] = useState(false);
  const [deletingScreen, setDeletingScreen] = useState<ScreenDefinition | null>(null);

  // 이동 모달 상태
  const [isMoveModalOpen, setIsMoveModalOpen] = useState(false);
  const [movingScreen, setMovingScreen] = useState<ScreenDefinition | null>(null);
  const [movingFromGroupId, setMovingFromGroupId] = useState<number | null>(null);
  const [moveSearchTerm, setMoveSearchTerm] = useState("");

  // 화면 맵 생성 (screen_id로 빠르게 조회)
  const screensMap = useMemo(() => {
    const map = new Map<number, ScreenDefinition>();
    screens.forEach((s) => map.set(s.screenId, s));
    return map;
  }, [screens]);

  // 그룹 데이터 로드
  const loadGroups = useCallback(async () => {
    try {
      setLoading(true);
      
      // 먼저 POP 루트 그룹 확보
      await ensurePopRootGroup();
      
      // 그룹 목록 조회
      const data = await getPopScreenGroups(searchTerm);
      setGroups(data);

      // 첫 로드 시 루트 그룹들 자동 확장
      if (expandedGroups.size === 0 && data.length > 0) {
        const rootIds = data
          .filter((g) => g.hierarchy_path === "POP" || g.hierarchy_path?.split("/").length === 2)
          .map((g) => g.id);
        setExpandedGroups(new Set(rootIds));
      }
    } catch (error) {
      console.error("POP 그룹 로드 실패:", error);
      toast.error("그룹 목록 로드에 실패했습니다.");
    } finally {
      setLoading(false);
    }
  }, [searchTerm]);

  useEffect(() => {
    loadGroups();
  }, [loadGroups]);

  // 트리 구조로 변환
  const treeData = useMemo(() => buildPopGroupTree(groups), [groups]);

  // 그룹 토글
  const handleToggle = (groupId: number) => {
    setExpandedGroups((prev) => {
      const next = new Set(prev);
      if (next.has(groupId)) {
        next.delete(groupId);
      } else {
        next.add(groupId);
      }
      return next;
    });
  };

  // 그룹 선택
  const handleGroupSelect = (group: PopScreenGroup) => {
    setSelectedGroupId(group.id);
    onGroupSelect?.(group);
  };

  // 그룹 생성/수정 모달 열기
  const openGroupModal = (parentGroup?: PopScreenGroup, editGroup?: PopScreenGroup) => {
    if (editGroup) {
      setEditingGroup(editGroup);
      setParentGroupId(editGroup.parent_group_id || null);
      setGroupFormData({
        group_name: editGroup.group_name,
        group_code: editGroup.group_code,
        description: editGroup.description || "",
        icon: editGroup.icon || "",
      });
    } else {
      setEditingGroup(null);
      setParentGroupId(parentGroup?.id || null);
      setGroupFormData({
        group_name: "",
        group_code: "",
        description: "",
        icon: "",
      });
    }
    setIsGroupModalOpen(true);
  };

  // 그룹 저장
  const handleSaveGroup = async () => {
    if (!groupFormData.group_name || !groupFormData.group_code) {
      toast.error("그룹명과 그룹코드는 필수입니다.");
      return;
    }

    try {
      if (editingGroup) {
        // 수정
        const result = await updatePopScreenGroup(editingGroup.id, {
          group_name: groupFormData.group_name,
          description: groupFormData.description,
          icon: groupFormData.icon,
        });
        if (result.success) {
          toast.success("그룹이 수정되었습니다.");
          loadGroups();
        } else {
          toast.error(result.message || "수정에 실패했습니다.");
        }
      } else {
        // 생성
        const result = await createPopScreenGroup({
          group_name: groupFormData.group_name,
          group_code: groupFormData.group_code,
          description: groupFormData.description,
          icon: groupFormData.icon,
          parent_group_id: parentGroupId,
        });
        if (result.success) {
          toast.success("그룹이 생성되었습니다.");
          loadGroups();
        } else {
          toast.error(result.message || "생성에 실패했습니다.");
        }
      }
      setIsGroupModalOpen(false);
    } catch (error) {
      console.error("그룹 저장 실패:", error);
      toast.error("그룹 저장에 실패했습니다.");
    }
  };

  // 그룹 삭제
  const handleDeleteGroup = async () => {
    if (!deletingGroup) return;

    try {
      const result = await deletePopScreenGroup(deletingGroup.id);
      if (result.success) {
        toast.success("그룹이 삭제되었습니다.");
        loadGroups();
        if (selectedGroupId === deletingGroup.id) {
          setSelectedGroupId(null);
          onGroupSelect?.(null);
        }
      } else {
        toast.error(result.message || "삭제에 실패했습니다.");
      }
    } catch (error) {
      console.error("그룹 삭제 실패:", error);
      toast.error("그룹 삭제에 실패했습니다.");
    } finally {
      setIsDeleteDialogOpen(false);
      setDeletingGroup(null);
    }
  };

  // 화면을 그룹으로 이동 (기존 연결 삭제 후 새 연결 추가)
  const handleMoveScreenToGroup = async (screen: ScreenDefinition, targetGroup: PopScreenGroup) => {
    try {
      // 1. 기존 연결 정보 찾기 (모든 그룹에서 해당 화면의 연결 찾기)
      let existingLinkId: number | null = null;
      for (const g of groups) {
        const screenLink = g.screens?.find((s) => s.screen_id === screen.screenId);
        if (screenLink) {
          existingLinkId = screenLink.id;
          break;
        }
      }

      // 2. 기존 연결이 있으면 삭제
      if (existingLinkId) {
        await apiClient.delete(`/screen-groups/group-screens/${existingLinkId}`);
      }

      // 3. 새 그룹에 연결 추가
      const response = await apiClient.post("/screen-groups/group-screens", { 
        group_id: targetGroup.id, 
        screen_id: screen.screenId,
        screen_role: "main",
        display_order: 0,
        is_default: false,
      });
      
      if (response.data.success) {
        toast.success(`"${screen.screenName}"을(를) "${(targetGroup as any)._displayName || targetGroup.group_name}"으로 이동했습니다.`);
        loadGroups(); // 그룹 목록 새로고침
      } else {
        throw new Error(response.data.message || "이동 실패");
      }
    } catch (error: any) {
      console.error("화면 이동 실패:", error);
      toast.error(error.response?.data?.message || error.message || "화면 이동에 실패했습니다.");
    }
  };

  // 그룹에서 화면 제거
  const handleRemoveScreenFromGroup = async (screen: ScreenDefinition, groupId: number) => {
    try {
      // 해당 그룹에서 화면 연결 정보 찾기
      const targetGroup = groups.find((g) => g.id === groupId);
      const screenLink = targetGroup?.screens?.find((s) => s.screen_id === screen.screenId);
      
      if (!screenLink) {
        toast.error("연결 정보를 찾을 수 없습니다.");
        return;
      }

      await apiClient.delete(`/screen-groups/group-screens/${screenLink.id}`);
      toast.success(`"${screen.screenName}"을(를) 그룹에서 제거했습니다.`);
      loadGroups();
    } catch (error: any) {
      console.error("화면 제거 실패:", error);
      toast.error(error.response?.data?.message || error.message || "화면 제거에 실패했습니다.");
    }
  };

  // 화면 삭제 다이얼로그 열기
  const handleDeleteScreen = (screen: ScreenDefinition) => {
    setDeletingScreen(screen);
    setIsScreenDeleteDialogOpen(true);
  };

  // 화면 삭제 확인
  const confirmDeleteScreen = async () => {
    if (!deletingScreen) return;

    try {
      // 화면 삭제 API 호출 (휴지통으로 이동)
      await apiClient.delete(`/screen-management/screens/${deletingScreen.screenId}`);
      toast.success(`"${deletingScreen.screenName}" 화면이 휴지통으로 이동되었습니다.`);
      
      // 화면 목록 새로고침 (부모 컴포넌트에서 처리해야 함)
      loadGroups();
      
      // 삭제된 화면이 선택된 상태였다면 선택 해제
      if (selectedScreen?.screenId === deletingScreen.screenId) {
        onScreenSelect(null as any); // 선택 해제
      }
    } catch (error: any) {
      console.error("화면 삭제 실패:", error);
      toast.error(error.response?.data?.message || error.message || "화면 삭제에 실패했습니다.");
    } finally {
      setIsScreenDeleteDialogOpen(false);
      setDeletingScreen(null);
    }
  };

  // 그룹 순서 위로 이동
  const handleMoveGroupUp = async (targetGroup: PopScreenGroup) => {
    try {
      // 같은 부모의 형제 그룹들 찾기
      const parentId = targetGroup.parent_id;
      const siblingGroups = groups
        .filter((g) => g.parent_id === parentId)
        .sort((a, b) => (a.display_order || 0) - (b.display_order || 0));
      
      const currentIndex = siblingGroups.findIndex((g) => g.id === targetGroup.id);
      if (currentIndex <= 0) return;

      const prevGroup = siblingGroups[currentIndex - 1];
      
      // 두 그룹의 display_order 교환
      await Promise.all([
        apiClient.put(`/screen-groups/groups/${targetGroup.id}`, { 
          display_order: prevGroup.display_order || currentIndex - 1 
        }),
        apiClient.put(`/screen-groups/groups/${prevGroup.id}`, { 
          display_order: targetGroup.display_order || currentIndex 
        }),
      ]);
      
      loadGroups();
    } catch (error: any) {
      console.error("그룹 순서 변경 실패:", error);
      toast.error("순서 변경에 실패했습니다.");
    }
  };

  // 그룹 순서 아래로 이동
  const handleMoveGroupDown = async (targetGroup: PopScreenGroup) => {
    try {
      // 같은 부모의 형제 그룹들 찾기
      const parentId = targetGroup.parent_id;
      const siblingGroups = groups
        .filter((g) => g.parent_id === parentId)
        .sort((a, b) => (a.display_order || 0) - (b.display_order || 0));
      
      const currentIndex = siblingGroups.findIndex((g) => g.id === targetGroup.id);
      if (currentIndex >= siblingGroups.length - 1) return;

      const nextGroup = siblingGroups[currentIndex + 1];
      
      // 두 그룹의 display_order 교환
      await Promise.all([
        apiClient.put(`/screen-groups/groups/${targetGroup.id}`, { 
          display_order: nextGroup.display_order || currentIndex + 1 
        }),
        apiClient.put(`/screen-groups/groups/${nextGroup.id}`, { 
          display_order: targetGroup.display_order || currentIndex 
        }),
      ]);
      
      loadGroups();
    } catch (error: any) {
      console.error("그룹 순서 변경 실패:", error);
      toast.error("순서 변경에 실패했습니다.");
    }
  };

  // 화면 순서 위로 이동
  const handleMoveScreenUp = async (screen: ScreenDefinition, groupId: number) => {
    try {
      const targetGroup = groups.find((g) => g.id === groupId);
      if (!targetGroup?.screens) return;
      
      const sortedScreens = [...targetGroup.screens].sort(
        (a, b) => (a.display_order || 0) - (b.display_order || 0)
      );
      const currentIndex = sortedScreens.findIndex((s) => s.screen_id === screen.screenId);
      if (currentIndex <= 0) return;

      const currentLink = sortedScreens[currentIndex];
      const prevLink = sortedScreens[currentIndex - 1];
      
      // 두 화면의 display_order 교환
      await Promise.all([
        apiClient.put(`/screen-groups/group-screens/${currentLink.id}`, { 
          display_order: prevLink.display_order || currentIndex - 1 
        }),
        apiClient.put(`/screen-groups/group-screens/${prevLink.id}`, { 
          display_order: currentLink.display_order || currentIndex 
        }),
      ]);
      
      loadGroups();
    } catch (error: any) {
      console.error("화면 순서 변경 실패:", error);
      toast.error("순서 변경에 실패했습니다.");
    }
  };

  // 화면 순서 아래로 이동
  const handleMoveScreenDown = async (screen: ScreenDefinition, groupId: number) => {
    try {
      const targetGroup = groups.find((g) => g.id === groupId);
      if (!targetGroup?.screens) return;
      
      const sortedScreens = [...targetGroup.screens].sort(
        (a, b) => (a.display_order || 0) - (b.display_order || 0)
      );
      const currentIndex = sortedScreens.findIndex((s) => s.screen_id === screen.screenId);
      if (currentIndex >= sortedScreens.length - 1) return;

      const currentLink = sortedScreens[currentIndex];
      const nextLink = sortedScreens[currentIndex + 1];
      
      // 두 화면의 display_order 교환
      await Promise.all([
        apiClient.put(`/screen-groups/group-screens/${currentLink.id}`, { 
          display_order: nextLink.display_order || currentIndex + 1 
        }),
        apiClient.put(`/screen-groups/group-screens/${nextLink.id}`, { 
          display_order: currentLink.display_order || currentIndex 
        }),
      ]);
      
      loadGroups();
    } catch (error: any) {
      console.error("화면 순서 변경 실패:", error);
      toast.error("순서 변경에 실패했습니다.");
    }
  };

  // 미분류 화면 (그룹에 연결되지 않은 화면)
  const ungroupedScreens = useMemo(() => {
    const groupedScreenIds = new Set<number>();
    groups.forEach((g) => {
      g.screens?.forEach((gs) => groupedScreenIds.add(gs.screen_id));
    });
    return screens.filter((s) => !groupedScreenIds.has(s.screenId));
  }, [groups, screens]);

  // 전체 그룹 평탄화 (이동 드롭다운용)
  const flattenedGroups = useMemo(() => {
    const result: PopScreenGroup[] = [];
    const flatten = (groups: PopScreenGroup[], parentName?: string) => {
      groups.forEach((g) => {
        // 표시 이름에 부모 경로 추가
        const displayGroup = { 
          ...g, 
          _displayName: parentName ? `${parentName} > ${g.group_name}` : g.group_name 
        };
        result.push(displayGroup);
        if (g.children && g.children.length > 0) {
          flatten(g.children, displayGroup._displayName);
        }
      });
    };
    flatten(treeData);
    return result;
  }, [treeData]);

  // 이동 모달 열기
  const openMoveModal = (screen: ScreenDefinition, fromGroupId: number | null) => {
    setMovingScreen(screen);
    setMovingFromGroupId(fromGroupId);
    setMoveSearchTerm("");
    setIsMoveModalOpen(true);
  };

  // 이동 모달에서 그룹 선택 처리
  const handleMoveToSelectedGroup = async (targetGroup: PopScreenGroup) => {
    if (!movingScreen) return;
    
    await handleMoveScreenToGroup(movingScreen, targetGroup);
    setIsMoveModalOpen(false);
    setMovingScreen(null);
    setMovingFromGroupId(null);
  };

  // 이동 모달용 필터링된 그룹 목록
  const filteredMoveGroups = useMemo(() => {
    if (!moveSearchTerm) return flattenedGroups;
    const searchLower = moveSearchTerm.toLowerCase();
    return flattenedGroups.filter((g: any) => 
      (g._displayName || g.group_name).toLowerCase().includes(searchLower)
    );
  }, [flattenedGroups, moveSearchTerm]);

  if (loading) {
    return (
      <div className="flex items-center justify-center h-full">
        <Loader2 className="h-6 w-6 animate-spin text-muted-foreground" />
      </div>
    );
  }

  return (
    <div className="flex flex-col h-full">
      {/* 헤더 */}
      <div className="shrink-0 p-3 border-b flex items-center justify-between">
        <h3 className="text-sm font-medium">POP 카테고리</h3>
        <div className="flex items-center gap-1">
          <Button variant="ghost" size="icon" className="h-7 w-7" onClick={loadGroups}>
            <RefreshCw className="h-3.5 w-3.5" />
          </Button>
          <Button variant="ghost" size="icon" className="h-7 w-7" onClick={() => openGroupModal()}>
            <Plus className="h-3.5 w-3.5" />
          </Button>
        </div>
      </div>

      {/* 트리 영역 */}
      <ScrollArea className="flex-1">
        <div className="p-2">
          {treeData.length === 0 && ungroupedScreens.length === 0 ? (
            <div className="text-center text-sm text-muted-foreground py-8">
              카테고리가 없습니다.
              <br />
              <Button variant="link" className="text-xs" onClick={() => openGroupModal()}>
                새 카테고리 추가
              </Button>
            </div>
          ) : (
            <>
              {/* 트리 렌더링 */}
              {treeData.map((group) => (
                <TreeNode
                  key={`group-${group.id}`}
                  group={group}
                  level={0}
                  expandedGroups={expandedGroups}
                  onToggle={handleToggle}
                  selectedGroupId={selectedGroupId}
                  selectedScreenId={selectedScreen?.screenId || null}
                  onGroupSelect={handleGroupSelect}
                  onScreenSelect={onScreenSelect}
                  onScreenDesign={onScreenDesign}
                  onEditGroup={(g) => openGroupModal(undefined, g)}
                  onDeleteGroup={(g) => {
                    setDeletingGroup(g);
                    setIsDeleteDialogOpen(true);
                  }}
                  onAddSubGroup={(g) => openGroupModal(g)}
                  screensMap={screensMap}
                  onOpenMoveModal={openMoveModal}
                  onRemoveScreenFromGroup={handleRemoveScreenFromGroup}
                  siblingGroups={treeData}
                  onMoveGroupUp={handleMoveGroupUp}
                  onMoveGroupDown={handleMoveGroupDown}
                  onMoveScreenUp={handleMoveScreenUp}
                  onMoveScreenDown={handleMoveScreenDown}
                  onDeleteScreen={handleDeleteScreen}
                />
              ))}

              {/* 미분류 화면 */}
              {ungroupedScreens.length > 0 && (
                <div className="mt-4 pt-4 border-t">
                  <div className="text-xs text-muted-foreground px-2 mb-2">
                    미분류 ({ungroupedScreens.length})
                  </div>
                  {ungroupedScreens.map((screen) => (
                    <div
                      key={`ungrouped-${screen.screenId}`}
                      className={cn(
                        "flex items-center gap-2 py-1.5 px-2 rounded-md cursor-pointer transition-colors",
                        selectedScreen?.screenId === screen.screenId
                          ? "bg-primary/10 text-primary"
                          : "hover:bg-muted",
                        "group"
                      )}
                      onClick={() => onScreenSelect(screen)}
                      onDoubleClick={() => onScreenDesign(screen)}
                    >
                      <Monitor className="h-4 w-4 text-gray-400 shrink-0" />
                      <span className="flex-1 text-sm truncate">{screen.screenName}</span>
                      <span className="text-[10px] text-muted-foreground shrink-0">#{screen.screenId}</span>
                      
                      {/* 더보기 메뉴 */}
                      <DropdownMenu>
                        <DropdownMenuTrigger asChild>
                          <Button
                            variant="ghost"
                            size="icon"
                            className="h-6 w-6 opacity-0 group-hover:opacity-100 shrink-0"
                            onClick={(e) => e.stopPropagation()}
                          >
                            <MoreVertical className="h-3.5 w-3.5" />
                          </Button>
                        </DropdownMenuTrigger>
                        <DropdownMenuContent align="end" className="w-48">
                          <DropdownMenuItem onClick={() => onScreenDesign(screen)}>
                            <Edit className="h-4 w-4 mr-2" />
                            설계
                          </DropdownMenuItem>
                          <DropdownMenuSeparator />
                          <DropdownMenuItem onClick={() => openMoveModal(screen, null)}>
                            <MoveRight className="h-4 w-4 mr-2" />
                            카테고리로 이동
                          </DropdownMenuItem>
                          <DropdownMenuSeparator />
                          <DropdownMenuItem 
                            className="text-destructive"
                            onClick={() => handleDeleteScreen(screen)}
                          >
                            <Trash2 className="h-4 w-4 mr-2" />
                            화면 삭제
                          </DropdownMenuItem>
                        </DropdownMenuContent>
                      </DropdownMenu>
                    </div>
                  ))}
                </div>
              )}
            </>
          )}
        </div>
      </ScrollArea>

      {/* 그룹 생성/수정 모달 */}
      <Dialog open={isGroupModalOpen} onOpenChange={setIsGroupModalOpen}>
        <DialogContent className="max-w-[95vw] sm:max-w-[400px]">
          <DialogHeader>
            <DialogTitle className="text-base sm:text-lg">
              {editingGroup ? "카테고리 수정" : "새 카테고리"}
            </DialogTitle>
            <DialogDescription className="text-xs sm:text-sm">
              {editingGroup ? "카테고리 정보를 수정합니다." : "POP 화면을 분류할 카테고리를 추가합니다."}
            </DialogDescription>
          </DialogHeader>

          <div className="space-y-3 sm:space-y-4">
            <div>
              <Label htmlFor="group_name" className="text-xs sm:text-sm">
                카테고리명 *
              </Label>
              <Input
                id="group_name"
                value={groupFormData.group_name}
                onChange={(e) => setGroupFormData((prev) => ({ ...prev, group_name: e.target.value }))}
                placeholder="예: 생산관리"
                className="h-8 text-xs sm:h-10 sm:text-sm"
              />
            </div>

            {!editingGroup && (
              <div>
                <Label htmlFor="group_code" className="text-xs sm:text-sm">
                  카테고리코드 *
                </Label>
                <Input
                  id="group_code"
                  value={groupFormData.group_code}
                  onChange={(e) => setGroupFormData((prev) => ({ ...prev, group_code: e.target.value.toUpperCase() }))}
                  placeholder="예: PRODUCTION"
                  className="h-8 text-xs sm:h-10 sm:text-sm"
                />
                <p className="text-muted-foreground mt-1 text-[10px] sm:text-xs">
                  영문 대문자와 밑줄만 사용 가능합니다.
                </p>
              </div>
            )}

            <div>
              <Label htmlFor="description" className="text-xs sm:text-sm">
                설명
              </Label>
              <Input
                id="description"
                value={groupFormData.description}
                onChange={(e) => setGroupFormData((prev) => ({ ...prev, description: e.target.value }))}
                placeholder="카테고리에 대한 설명"
                className="h-8 text-xs sm:h-10 sm:text-sm"
              />
            </div>
          </div>

          <DialogFooter className="gap-2 sm:gap-0">
            <Button
              variant="outline"
              onClick={() => setIsGroupModalOpen(false)}
              className="h-8 flex-1 text-xs sm:h-10 sm:flex-none sm:text-sm"
            >
              취소
            </Button>
            <Button
              onClick={handleSaveGroup}
              className="h-8 flex-1 text-xs sm:h-10 sm:flex-none sm:text-sm"
            >
              {editingGroup ? "수정" : "생성"}
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>

      {/* 삭제 확인 다이얼로그 */}
      <AlertDialog open={isDeleteDialogOpen} onOpenChange={setIsDeleteDialogOpen}>
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogTitle>카테고리 삭제</AlertDialogTitle>
            <AlertDialogDescription>
              "{deletingGroup?.group_name}" 카테고리를 삭제하시겠습니까?
              <br />
              이 작업은 되돌릴 수 없습니다.
            </AlertDialogDescription>
          </AlertDialogHeader>
          <AlertDialogFooter>
            <AlertDialogCancel>취소</AlertDialogCancel>
            <AlertDialogAction
              className="bg-destructive text-destructive-foreground hover:bg-destructive/90"
              onClick={handleDeleteGroup}
            >
              삭제
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>

      {/* 화면 이동 모달 */}
      <Dialog open={isMoveModalOpen} onOpenChange={setIsMoveModalOpen}>
        <DialogContent className="max-w-[95vw] sm:max-w-[450px]">
          <DialogHeader>
            <DialogTitle className="text-base sm:text-lg">
              카테고리로 이동
            </DialogTitle>
            <DialogDescription className="text-xs sm:text-sm">
              "{movingScreen?.screenName}" 화면을 이동할 카테고리를 선택하세요.
            </DialogDescription>
          </DialogHeader>

          {/* 검색 입력 */}
          <div className="relative">
            <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
            <Input
              placeholder="카테고리 검색..."
              value={moveSearchTerm}
              onChange={(e) => setMoveSearchTerm(e.target.value)}
              className="pl-9 h-9 text-sm"
            />
          </div>

          {/* 카테고리 트리 목록 */}
          <ScrollArea className="h-64 border rounded-md">
            <div className="p-2 space-y-0.5">
              {filteredMoveGroups.length === 0 ? (
                <div className="text-center text-sm text-muted-foreground py-8">
                  검색 결과가 없습니다.
                </div>
              ) : (
                filteredMoveGroups.map((group: any) => {
                  const isCurrentGroup = group.id === movingFromGroupId;
                  const displayName = group._displayName || group.group_name;
                  const depth = (displayName.match(/>/g) || []).length;
                  
                  return (
                    <button
                      key={group.id}
                      disabled={isCurrentGroup}
                      onClick={() => handleMoveToSelectedGroup(group)}
                      className={cn(
                        "w-full flex items-center gap-2 py-2 px-3 rounded-md text-left transition-colors",
                        isCurrentGroup 
                          ? "opacity-50 cursor-not-allowed bg-muted" 
                          : "hover:bg-muted cursor-pointer"
                      )}
                      style={{ paddingLeft: `${depth * 16 + 12}px` }}
                    >
                      <Folder className={cn(
                        "h-4 w-4 shrink-0",
                        depth === 0 ? "text-orange-500" : "text-amber-500"
                      )} />
                      <span className="text-sm truncate flex-1">
                        {group.group_name}
                      </span>
                      {isCurrentGroup && (
                        <span className="text-xs text-muted-foreground">(현재)</span>
                      )}
                    </button>
                  );
                })
              )}
            </div>
          </ScrollArea>

          <DialogFooter className="gap-2 sm:gap-0">
            <Button
              variant="outline"
              onClick={() => setIsMoveModalOpen(false)}
              className="h-8 flex-1 text-xs sm:h-10 sm:flex-none sm:text-sm"
            >
              취소
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>

      {/* 화면 삭제 확인 다이얼로그 */}
      <AlertDialog open={isScreenDeleteDialogOpen} onOpenChange={setIsScreenDeleteDialogOpen}>
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogTitle>화면 삭제</AlertDialogTitle>
            <AlertDialogDescription>
              "{deletingScreen?.screenName}" 화면을 삭제하시겠습니까?
              <br />
              <span className="text-muted-foreground text-xs">
                삭제된 화면은 휴지통으로 이동되며, 나중에 복원할 수 있습니다.
              </span>
            </AlertDialogDescription>
          </AlertDialogHeader>
          <AlertDialogFooter>
            <AlertDialogCancel>취소</AlertDialogCancel>
            <AlertDialogAction
              onClick={confirmDeleteScreen}
              className="bg-destructive text-destructive-foreground hover:bg-destructive/90"
            >
              삭제
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>
    </div>
  );
}