"use client";

import { useState, useCallback, useEffect } from "react";
import { DndProvider } from "react-dnd";
import { HTML5Backend } from "react-dnd-html5-backend";
import { ArrowLeft, Save, Smartphone, Tablet, Undo2, Redo2 } from "lucide-react";
import { Button } from "@/components/ui/button";
import { Tabs, TabsList, TabsTrigger } from "@/components/ui/tabs";
import {
  ResizableHandle,
  ResizablePanel,
  ResizablePanelGroup,
} from "@/components/ui/resizable";
import { toast } from "sonner";

import { PopCanvas } from "./PopCanvas";
import { PopCanvasV4 } from "./PopCanvasV4";
import { PopPanel } from "./panels/PopPanel";
import { ComponentPaletteV4 } from "./panels/ComponentPaletteV4";
import { ComponentEditorPanelV4 } from "./panels/ComponentEditorPanelV4";
import {
  PopLayoutDataV3,
  PopLayoutDataV4,
  PopLayoutModeKey,
  PopComponentType,
  GridPosition,
  PopComponentDefinition,
  PopComponentDefinitionV4,
  PopContainerV4,
  PopSizeConstraintV4,
  createEmptyPopLayoutV3,
  createEmptyPopLayoutV4,
  ensureV3Layout,
  addComponentToV3Layout,
  removeComponentFromV3Layout,
  updateComponentPositionInModeV3,
  addComponentToV4Layout,
  removeComponentFromV4Layout,
  updateComponentInV4Layout,
  updateContainerV4,
  findContainerV4,
  isV3Layout,
  isV4Layout,
} from "./types/pop-layout";
import { screenApi } from "@/lib/api/screen";
import { ScreenDefinition } from "@/types/screen";

// ========================================
// 레이아웃 모드 타입
// ========================================
type LayoutMode = "v3" | "v4";
type DeviceType = "mobile" | "tablet";

// ========================================
// Props
// ========================================
interface PopDesignerProps {
  selectedScreen: ScreenDefinition;
  onBackToList: () => void;
  onScreenUpdate?: (updatedScreen: Partial<ScreenDefinition>) => void;
}

// ========================================
// 메인 컴포넌트 (v3/v4 통합)
// - 새 화면: v4로 시작
// - 기존 v3 화면: v3로 로드 (하위 호환)
// ========================================
export default function PopDesigner({
  selectedScreen,
  onBackToList,
  onScreenUpdate,
}: PopDesignerProps) {
  // ========================================
  // 레이아웃 모드 (데이터에 따라 자동 결정)
  // ========================================
  const [layoutMode, setLayoutMode] = useState<LayoutMode>("v4");

  // ========================================
  // 레이아웃 상태 (데스크탑 모드와 동일한 방식)
  // ========================================
  const [layoutV4, setLayoutV4] = useState<PopLayoutDataV4>(createEmptyPopLayoutV4());
  const [layoutV3, setLayoutV3] = useState<PopLayoutDataV3>(createEmptyPopLayoutV3());

  // 히스토리 (v4용)
  const [historyV4, setHistoryV4] = useState<PopLayoutDataV4[]>([]);
  const [historyIndexV4, setHistoryIndexV4] = useState(-1);

  // 히스토리 (v3용)
  const [historyV3, setHistoryV3] = useState<PopLayoutDataV3[]>([]);
  const [historyIndexV3, setHistoryIndexV3] = useState(-1);

  const [idCounter, setIdCounter] = useState(1);
  
  const [isLoading, setIsLoading] = useState(true);
  const [isSaving, setIsSaving] = useState(false);
  const [hasChanges, setHasChanges] = useState(false);

  // ========================================
  // 히스토리 저장 함수
  // ========================================
  const saveToHistoryV4 = useCallback((newLayout: PopLayoutDataV4) => {
    setHistoryV4((prev) => {
      const newHistory = prev.slice(0, historyIndexV4 + 1);
      newHistory.push(JSON.parse(JSON.stringify(newLayout))); // 깊은 복사
      return newHistory.slice(-50); // 최대 50개
    });
    setHistoryIndexV4((prev) => Math.min(prev + 1, 49));
  }, [historyIndexV4]);

  const saveToHistoryV3 = useCallback((newLayout: PopLayoutDataV3) => {
    setHistoryV3((prev) => {
      const newHistory = prev.slice(0, historyIndexV3 + 1);
      newHistory.push(JSON.parse(JSON.stringify(newLayout)));
      return newHistory.slice(-50);
    });
    setHistoryIndexV3((prev) => Math.min(prev + 1, 49));
  }, [historyIndexV3]);

  // ========================================
  // Undo/Redo 함수
  // ========================================
  const undoV4 = useCallback(() => {
    if (historyIndexV4 > 0) {
      const newIndex = historyIndexV4 - 1;
      const previousLayout = historyV4[newIndex];
      if (previousLayout) {
        setLayoutV4(JSON.parse(JSON.stringify(previousLayout)));
        setHistoryIndexV4(newIndex);
        console.log("[Undo V4] 복원됨, index:", newIndex);
      }
    }
  }, [historyIndexV4, historyV4]);

  const redoV4 = useCallback(() => {
    if (historyIndexV4 < historyV4.length - 1) {
      const newIndex = historyIndexV4 + 1;
      const nextLayout = historyV4[newIndex];
      if (nextLayout) {
        setLayoutV4(JSON.parse(JSON.stringify(nextLayout)));
        setHistoryIndexV4(newIndex);
        console.log("[Redo V4] 복원됨, index:", newIndex);
      }
    }
  }, [historyIndexV4, historyV4]);

  const undoV3 = useCallback(() => {
    if (historyIndexV3 > 0) {
      const newIndex = historyIndexV3 - 1;
      const previousLayout = historyV3[newIndex];
      if (previousLayout) {
        setLayoutV3(JSON.parse(JSON.stringify(previousLayout)));
        setHistoryIndexV3(newIndex);
      }
    }
  }, [historyIndexV3, historyV3]);

  const redoV3 = useCallback(() => {
    if (historyIndexV3 < historyV3.length - 1) {
      const newIndex = historyIndexV3 + 1;
      const nextLayout = historyV3[newIndex];
      if (nextLayout) {
        setLayoutV3(JSON.parse(JSON.stringify(nextLayout)));
        setHistoryIndexV3(newIndex);
      }
    }
  }, [historyIndexV3, historyV3]);

  // 현재 모드의 Undo/Redo
  const canUndo = layoutMode === "v4" ? historyIndexV4 > 0 : historyIndexV3 > 0;
  const canRedo = layoutMode === "v4" 
    ? historyIndexV4 < historyV4.length - 1 
    : historyIndexV3 < historyV3.length - 1;
  const handleUndo = layoutMode === "v4" ? undoV4 : undoV3;
  const handleRedo = layoutMode === "v4" ? redoV4 : redoV3;

  // ========================================
  // v3용 디바이스/모드 상태
  // ========================================
  const [activeDevice, setActiveDevice] = useState<DeviceType>("tablet");
  const [activeModeKey, setActiveModeKey] = useState<PopLayoutModeKey>("tablet_landscape");

  // ========================================
  // v4용 뷰포트 모드 상태
  // ========================================
  type ViewportMode = "mobile_portrait" | "mobile_landscape" | "tablet_portrait" | "tablet_landscape";
  const [currentViewportMode, setCurrentViewportMode] = useState<ViewportMode>("tablet_landscape");
  
  // v4: 임시 레이아웃 (고정 전 배치) - 다른 모드에서만 사용
  const [tempLayout, setTempLayout] = useState<PopContainerV4 | null>(null);

  // ========================================
  // 선택 상태
  // ========================================
  const [selectedComponentId, setSelectedComponentId] = useState<string | null>(null);
  const [selectedContainerId, setSelectedContainerId] = useState<string | null>(null);

  // 선택된 컴포넌트/컨테이너
  const selectedComponentV3: PopComponentDefinition | null = selectedComponentId
    ? layoutV3.components[selectedComponentId] || null
    : null;
  const selectedComponentV4: PopComponentDefinitionV4 | null = selectedComponentId
    ? layoutV4.components[selectedComponentId] || null
    : null;
  const selectedContainer: PopContainerV4 | null = selectedContainerId
    ? findContainerV4(layoutV4.root, selectedContainerId)
    : null;

  // ========================================
  // 레이아웃 로드
  // ========================================
  useEffect(() => {
    const loadLayout = async () => {
      if (!selectedScreen?.screenId) return;

      setIsLoading(true);
      try {
        const loadedLayout = await screenApi.getLayoutPop(selectedScreen.screenId);
        
        // 유효한 레이아웃인지 확인:
        // 1. version 필드 필수
        // 2. 컴포넌트가 있어야 함 (빈 레이아웃은 새 화면 취급)
        const hasValidLayout = loadedLayout && loadedLayout.version;
        const hasComponents = loadedLayout?.components && Object.keys(loadedLayout.components).length > 0;

        if (hasValidLayout && hasComponents) {
          if (isV4Layout(loadedLayout)) {
            // v4 레이아웃
            setLayoutV4(loadedLayout);
            setHistoryV4([loadedLayout]);
            setHistoryIndexV4(0);
            setLayoutMode("v4");
            console.log(`POP v4 레이아웃 로드: ${Object.keys(loadedLayout.components).length}개 컴포넌트`);
          } else {
            // v1/v2/v3 → v3로 변환
            const v3Layout = ensureV3Layout(loadedLayout);
            setLayoutV3(v3Layout);
            setHistoryV3([v3Layout]);
            setHistoryIndexV3(0);
            setLayoutMode("v3");
            console.log(`POP v3 레이아웃 로드: ${Object.keys(v3Layout.components).length}개 컴포넌트`);
          }
        } else {
          // 새 화면 또는 빈 레이아웃 → v4로 시작
          const emptyLayout = createEmptyPopLayoutV4();
          setLayoutV4(emptyLayout);
          setHistoryV4([emptyLayout]);
          setHistoryIndexV4(0);
          setLayoutMode("v4");
        }
      } catch (error) {
        console.error("레이아웃 로드 실패:", error);
        toast.error("레이아웃을 불러오는데 실패했습니다");
        const emptyLayout = createEmptyPopLayoutV4();
        setLayoutV4(emptyLayout);
        setHistoryV4([emptyLayout]);
        setHistoryIndexV4(0);
        setLayoutMode("v4");
      } finally {
        setIsLoading(false);
      }
    };

    loadLayout();
  }, [selectedScreen?.screenId]);

  // ========================================
  // 저장
  // ========================================
  const handleSave = useCallback(async () => {
    if (!selectedScreen?.screenId) return;

    setIsSaving(true);
    try {
      const layoutToSave = layoutMode === "v3" ? layoutV3 : layoutV4;
      await screenApi.saveLayoutPop(selectedScreen.screenId, layoutToSave);
      toast.success("저장되었습니다");
      setHasChanges(false);
    } catch (error) {
      console.error("저장 실패:", error);
      toast.error("저장에 실패했습니다");
    } finally {
      setIsSaving(false);
    }
  }, [selectedScreen?.screenId, layoutMode, layoutV3, layoutV4]);

  // ========================================
  // v3: 컴포넌트 핸들러
  // ========================================
  const handleDropComponentV3 = useCallback(
    (type: PopComponentType, gridPosition: GridPosition) => {
      const newId = `${type}-${Date.now()}`;
      const newLayout = addComponentToV3Layout(layoutV3, newId, type, gridPosition);
      setLayoutV3(newLayout);
      saveToHistoryV3(newLayout);
      setSelectedComponentId(newId);
      setHasChanges(true);
    },
    [layoutV3, saveToHistoryV3]
  );

  const handleUpdateComponentDefinitionV3 = useCallback(
    (componentId: string, updates: Partial<PopComponentDefinition>) => {
      const newLayout = {
        ...layoutV3,
        components: {
          ...layoutV3.components,
          [componentId]: { ...layoutV3.components[componentId], ...updates },
        },
      };
      setLayoutV3(newLayout);
      saveToHistoryV3(newLayout);
      setHasChanges(true);
    },
    [layoutV3, saveToHistoryV3]
  );

  const handleUpdateComponentPositionV3 = useCallback(
    (componentId: string, position: GridPosition, modeKey?: PopLayoutModeKey) => {
      const targetMode = modeKey || activeModeKey;
      const newLayout = updateComponentPositionInModeV3(layoutV3, targetMode, componentId, position);
      setLayoutV3(newLayout);
      saveToHistoryV3(newLayout);
      setHasChanges(true);
    },
    [layoutV3, activeModeKey, saveToHistoryV3]
  );

  const handleDeleteComponentV3 = useCallback((componentId: string) => {
    const newLayout = removeComponentFromV3Layout(layoutV3, componentId);
    setLayoutV3(newLayout);
    saveToHistoryV3(newLayout);
    setSelectedComponentId(null);
    setHasChanges(true);
  }, [layoutV3, saveToHistoryV3]);

  // ========================================
  // v4: 컴포넌트 핸들러
  // ========================================
  const handleDropComponentV4 = useCallback(
    (type: PopComponentType, containerId: string) => {
      const componentId = `comp_${idCounter}`;
      setIdCounter((prev) => prev + 1);
      const newLayout = addComponentToV4Layout(layoutV4, componentId, type, containerId, `${type} ${idCounter}`);
      setLayoutV4(newLayout);
      saveToHistoryV4(newLayout);
      setSelectedComponentId(componentId);
      setSelectedContainerId(null);
      setHasChanges(true);
      console.log("[V4] 컴포넌트 추가, 히스토리 저장됨");
    },
    [idCounter, layoutV4, saveToHistoryV4]
  );

  const handleUpdateComponentV4 = useCallback(
    (componentId: string, updates: Partial<PopComponentDefinitionV4>) => {
      const newLayout = updateComponentInV4Layout(layoutV4, componentId, updates);
      setLayoutV4(newLayout);
      saveToHistoryV4(newLayout);
      setHasChanges(true);
    },
    [layoutV4, saveToHistoryV4]
  );

  const handleUpdateContainerV4 = useCallback(
    (containerId: string, updates: Partial<PopContainerV4>) => {
      if (currentViewportMode === "tablet_landscape") {
        // 기본 모드 (태블릿 가로) → root 직접 수정 ✅
        const newLayout = {
          ...layoutV4,
          root: updateContainerV4(layoutV4.root, containerId, updates),
        };
        setLayoutV4(newLayout);
        saveToHistoryV4(newLayout);
        setHasChanges(true);
        console.log("[기본 모드] root 컨테이너 수정");
      } else {
        // 다른 모드 → 속성 패널에서 수정 차단됨 (UI에서 비활성화)
        toast.warning("기본 모드(태블릿 가로)에서만 속성을 변경할 수 있습니다");
        console.log("[다른 모드] 속성 수정 차단");
      }
    },
    [layoutV4, currentViewportMode, saveToHistoryV4]
  );

  const handleDeleteComponentV4 = useCallback((componentId: string) => {
    const newLayout = removeComponentFromV4Layout(layoutV4, componentId);
    setLayoutV4(newLayout);
    saveToHistoryV4(newLayout);
    setSelectedComponentId(null);
    setHasChanges(true);
    console.log("[V4] 컴포넌트 삭제, 히스토리 저장됨");
  }, [layoutV4, saveToHistoryV4]);

  // v4: 현재 모드 배치 고정 (오버라이드 저장) 🔥
  const handleLockLayoutV4 = useCallback(() => {
    if (currentViewportMode === "tablet_landscape") {
      toast.info("기본 모드는 고정할 필요가 없습니다");
      return;
    }

    if (!tempLayout) {
      toast.info("변경사항이 없습니다");
      return;
    }

    // 임시 레이아웃을 오버라이드에 저장 ✅
    const newLayout = {
      ...layoutV4,
      overrides: {
        ...layoutV4.overrides,
        [currentViewportMode]: {
          ...layoutV4.overrides?.[currentViewportMode as keyof typeof layoutV4.overrides],
          containers: {
            root: {
              direction: tempLayout.direction,
              wrap: tempLayout.wrap,
              gap: tempLayout.gap,
              alignItems: tempLayout.alignItems,
              justifyContent: tempLayout.justifyContent,
              padding: tempLayout.padding,
              children: tempLayout.children, // 순서 고정
            }
          }
        }
      }
    };

    setLayoutV4(newLayout);
    saveToHistoryV4(newLayout);
    setTempLayout(null); // 임시 레이아웃 초기화
    setHasChanges(true);
    toast.success(`${currentViewportMode} 모드 배치가 고정되었습니다`);
    console.log(`[V4] ${currentViewportMode} 배치 고정됨 (tempLayout → overrides)`);
  }, [layoutV4, currentViewportMode, tempLayout, saveToHistoryV4]);

  // v4: 오버라이드 초기화 (자동 계산으로 되돌리기)
  const handleResetOverrideV4 = useCallback((mode: ViewportMode) => {
    if (mode === "tablet_landscape") {
      toast.info("기본 모드는 초기화할 수 없습니다");
      return;
    }

    const newOverrides = { ...layoutV4.overrides };
    delete newOverrides[mode as keyof typeof newOverrides];

    const newLayout = {
      ...layoutV4,
      overrides: Object.keys(newOverrides).length > 0 ? newOverrides : undefined
    };

    setLayoutV4(newLayout);
    saveToHistoryV4(newLayout);
    setHasChanges(true);
    toast.success(`${mode} 모드 오버라이드가 초기화되었습니다`);
    console.log(`[V4] ${mode} 오버라이드 초기화됨`);
  }, [layoutV4, saveToHistoryV4]);

  // v4: 컴포넌트 크기 조정 (드래그) - 리사이즈 중에는 히스토리 저장 안 함
  // 리사이즈 완료 시 별도로 저장해야 함 (TODO: 드래그 종료 시 저장)
  const handleResizeComponentV4 = useCallback(
    (componentId: string, sizeUpdates: Partial<PopSizeConstraintV4>) => {
      const existingComponent = layoutV4.components[componentId];
      if (!existingComponent) return;

      const newLayout = {
        ...layoutV4,
        components: {
          ...layoutV4.components,
          [componentId]: {
            ...existingComponent,
            size: {
              ...existingComponent.size,
              ...sizeUpdates,
            },
          },
        },
      };
      setLayoutV4(newLayout);
      // 리사이즈 중에는 히스토리 저장 안 함 (너무 많아짐)
      // saveToHistoryV4(newLayout);
      setHasChanges(true);
    },
    [layoutV4]
  );

  // v4: 컴포넌트 순서 변경 (드래그 앤 드롭)
  const handleReorderComponentV4 = useCallback(
    (containerId: string, fromIndex: number, toIndex: number) => {
      // 컨테이너 찾기 (재귀)
      const reorderInContainer = (container: PopContainerV4): PopContainerV4 => {
        if (container.id === containerId) {
          const newChildren = [...container.children];
          const [movedItem] = newChildren.splice(fromIndex, 1);
          newChildren.splice(toIndex, 0, movedItem);
          return { ...container, children: newChildren };
        }
        
        // 자식 컨테이너에서도 찾기
        return {
          ...container,
          children: container.children.map(child => {
            if (typeof child === "object") {
              return reorderInContainer(child);
            }
            return child;
          }),
        };
      };

      if (currentViewportMode === "tablet_landscape") {
        // 기본 모드 → root 직접 수정 ✅
        const newLayout = {
          ...layoutV4,
          root: reorderInContainer(layoutV4.root),
        };
        setLayoutV4(newLayout);
        saveToHistoryV4(newLayout);
        setHasChanges(true);
        console.log("[기본 모드] 컴포넌트 순서 변경 (root 저장)");
      } else {
        // 다른 모드 → 임시 레이아웃에만 저장 (화면에만 표시, layoutV4는 안 건드림) 🔥
        const reorderedRoot = reorderInContainer(layoutV4.root);
        setTempLayout(reorderedRoot);
        console.log(`[${currentViewportMode}] 컴포넌트 순서 변경 (임시, 고정 필요)`);
        toast.info("배치 변경됨. '고정' 버튼을 클릭하여 저장하세요", { duration: 2000 });
      }
    },
    [layoutV4, currentViewportMode, saveToHistoryV4]
  );

  // ========================================
  // v3: 디바이스/모드 전환
  // ========================================
  const handleDeviceChange = useCallback((device: DeviceType) => {
    setActiveDevice(device);
    setActiveModeKey(device === "tablet" ? "tablet_landscape" : "mobile_landscape");
  }, []);

  const handleModeKeyChange = useCallback((modeKey: PopLayoutModeKey) => {
    setActiveModeKey(modeKey);
  }, []);

  // ========================================
  // 뒤로가기
  // ========================================
  const handleBack = useCallback(() => {
    if (hasChanges) {
      if (confirm("저장하지 않은 변경사항이 있습니다. 나가시겠습니까?")) {
        onBackToList();
      }
    } else {
      onBackToList();
    }
  }, [hasChanges, onBackToList]);

  // ========================================
  // 단축키 처리 (Delete, Undo, Redo)
  // ========================================
  useEffect(() => {
    const handleKeyDown = (e: KeyboardEvent) => {
      const target = e.target as HTMLElement;
      if (target.tagName === "INPUT" || target.tagName === "TEXTAREA" || target.isContentEditable) {
        return;
      }

      const key = e.key.toLowerCase();
      const isCtrlOrCmd = e.ctrlKey || e.metaKey;

      // Delete / Backspace: 컴포넌트 삭제
      if (e.key === "Delete" || e.key === "Backspace") {
        e.preventDefault();
        if (selectedComponentId) {
          layoutMode === "v3" ? handleDeleteComponentV3(selectedComponentId) : handleDeleteComponentV4(selectedComponentId);
        }
      }

      // Ctrl+Z / Cmd+Z: Undo (Shift 안 눌림)
      if (isCtrlOrCmd && key === "z" && !e.shiftKey) {
        e.preventDefault();
        console.log("Undo 시도:", { canUndo, layoutMode });
        if (canUndo) {
          handleUndo();
          setHasChanges(true);
          toast.success("실행 취소됨");
        } else {
          toast.info("실행 취소할 내용이 없습니다");
        }
        return;
      }

      // Ctrl+Shift+Z / Cmd+Shift+Z: Redo
      if (isCtrlOrCmd && key === "z" && e.shiftKey) {
        e.preventDefault();
        console.log("Redo 시도:", { canRedo, layoutMode });
        if (canRedo) {
          handleRedo();
          setHasChanges(true);
          toast.success("다시 실행됨");
        } else {
          toast.info("다시 실행할 내용이 없습니다");
        }
        return;
      }

      // Ctrl+Y / Cmd+Y: Redo (대체)
      if (isCtrlOrCmd && key === "y") {
        e.preventDefault();
        if (canRedo) {
          handleRedo();
          setHasChanges(true);
          toast.success("다시 실행됨");
        }
        return;
      }
    };

    window.addEventListener("keydown", handleKeyDown);
    return () => window.removeEventListener("keydown", handleKeyDown);
  }, [selectedComponentId, layoutMode, handleDeleteComponentV3, handleDeleteComponentV4, canUndo, canRedo, handleUndo, handleRedo]);

  // ========================================
  // 로딩
  // ========================================
  if (isLoading) {
    return (
      <div className="flex h-screen items-center justify-center">
        <div className="text-muted-foreground">로딩 중...</div>
      </div>
    );
  }

  // ========================================
  // 렌더링
  // ========================================
  return (
    <DndProvider backend={HTML5Backend}>
      <div className="flex h-screen flex-col bg-background">
        {/* 툴바 */}
        <div className="flex h-12 items-center justify-between border-b px-4">
          {/* 왼쪽: 뒤로가기 + 화면명 */}
          <div className="flex items-center gap-3">
            <Button variant="ghost" size="sm" onClick={handleBack}>
              <ArrowLeft className="mr-1 h-4 w-4" />
              목록
            </Button>
            <span className="text-sm font-medium">
              {selectedScreen?.screenName || "POP 화면"}
            </span>
            {hasChanges && <span className="text-xs text-orange-500">*변경됨</span>}
          </div>

          {/* 중앙: 레이아웃 버전 + v3 디바이스 전환 */}
          <div className="flex items-center gap-4">
            <span className="text-muted-foreground text-xs">
              {layoutMode === "v4" ? "자동 레이아웃 (v4)" : "4모드 레이아웃 (v3)"}
            </span>

            {layoutMode === "v3" && (
              <Tabs value={activeDevice} onValueChange={(v) => handleDeviceChange(v as DeviceType)}>
                <TabsList className="h-8">
                  <TabsTrigger value="tablet" className="h-7 px-3 text-xs">
                    <Tablet className="mr-1 h-3.5 w-3.5" />
                    태블릿
                  </TabsTrigger>
                  <TabsTrigger value="mobile" className="h-7 px-3 text-xs">
                    <Smartphone className="mr-1 h-3.5 w-3.5" />
                    모바일
                  </TabsTrigger>
                </TabsList>
              </Tabs>
            )}
          </div>

          {/* 오른쪽: Undo/Redo + 저장 */}
          <div className="flex items-center gap-2">
            {/* Undo/Redo 버튼 */}
            <div className="flex items-center gap-1 border-r pr-2 mr-1">
              <Button
                variant="ghost"
                size="icon"
                className="h-8 w-8"
                onClick={() => {
                  handleUndo();
                  setHasChanges(true);
                  toast.success("실행 취소됨");
                }}
                disabled={!canUndo}
                title="실행 취소 (Ctrl+Z)"
              >
                <Undo2 className="h-4 w-4" />
              </Button>
              <Button
                variant="ghost"
                size="icon"
                className="h-8 w-8"
                onClick={() => {
                  handleRedo();
                  setHasChanges(true);
                  toast.success("다시 실행됨");
                }}
                disabled={!canRedo}
                title="다시 실행 (Ctrl+Shift+Z)"
              >
                <Redo2 className="h-4 w-4" />
              </Button>
            </div>
            
            {/* 저장 버튼 */}
            <Button size="sm" onClick={handleSave} disabled={isSaving || !hasChanges}>
              <Save className="mr-1 h-4 w-4" />
              {isSaving ? "저장 중..." : "저장"}
            </Button>
          </div>
        </div>

        {/* 메인 영역 */}
        <ResizablePanelGroup direction="horizontal" className="flex-1">
          {/* 왼쪽: 컴포넌트 패널 */}
          <ResizablePanel defaultSize={20} minSize={15} maxSize={30} className="border-r">
            {layoutMode === "v3" ? (
              <PopPanel
                layout={layoutV3}
                activeModeKey={activeModeKey}
                selectedComponentId={selectedComponentId}
                selectedComponent={selectedComponentV3}
                onUpdateComponentDefinition={handleUpdateComponentDefinitionV3}
                onDeleteComponent={handleDeleteComponentV3}
                activeDevice={activeDevice}
              />
            ) : (
              <ComponentPaletteV4 />
            )}
          </ResizablePanel>

          <ResizableHandle withHandle />

          {/* 중앙: 캔버스 */}
          <ResizablePanel defaultSize={layoutMode === "v3" ? 80 : 60}>
            {layoutMode === "v3" ? (
              <PopCanvas
                layout={layoutV3}
                activeDevice={activeDevice}
                activeModeKey={activeModeKey}
                onModeKeyChange={handleModeKeyChange}
                selectedComponentId={selectedComponentId}
                onSelectComponent={setSelectedComponentId}
                onUpdateComponentPosition={handleUpdateComponentPositionV3}
                onDropComponent={handleDropComponentV3}
                onDeleteComponent={handleDeleteComponentV3}
              />
            ) : (
              <PopCanvasV4
                layout={layoutV4}
                selectedComponentId={selectedComponentId}
                selectedContainerId={selectedContainerId}
                currentMode={currentViewportMode}
                tempLayout={tempLayout}
                onModeChange={setCurrentViewportMode}
                onSelectComponent={setSelectedComponentId}
                onSelectContainer={setSelectedContainerId}
                onDropComponent={handleDropComponentV4}
                onUpdateComponent={handleUpdateComponentV4}
                onUpdateContainer={handleUpdateContainerV4}
                onDeleteComponent={handleDeleteComponentV4}
                onResizeComponent={handleResizeComponentV4}
                onReorderComponent={handleReorderComponentV4}
                onLockLayout={handleLockLayoutV4}
                onResetOverride={handleResetOverrideV4}
              />
            )}
          </ResizablePanel>

          {/* 오른쪽: 속성 패널 (v4만) */}
          {layoutMode === "v4" && (
            <>
              <ResizableHandle withHandle />
              <ResizablePanel defaultSize={20} minSize={15} maxSize={30}>
                <ComponentEditorPanelV4
                  component={selectedComponentV4}
                  container={selectedContainer}
                  currentViewportMode={currentViewportMode}
                  onUpdateComponent={
                    selectedComponentId
                      ? (updates) => handleUpdateComponentV4(selectedComponentId, updates)
                      : undefined
                  }
                  onUpdateContainer={
                    selectedContainerId
                      ? (updates) => handleUpdateContainerV4(selectedContainerId, updates)
                      : undefined
                  }
                />
              </ResizablePanel>
            </>
          )}
        </ResizablePanelGroup>
      </div>
    </DndProvider>
  );
}