"use client";

import React, { useState, useCallback, useRef, useEffect } from "react";
import dynamic from "next/dynamic";
import { DashboardElement, QueryResult } from "./types";
import { ChartRenderer } from "./charts/ChartRenderer";
import { snapToGrid, snapSizeToGrid, GRID_CONFIG } from "./gridUtils";

// 위젯 동적 임포트
const WeatherWidget = dynamic(() => import("@/components/dashboard/widgets/WeatherWidget"), {
  ssr: false,
  loading: () => <div className="flex h-full items-center justify-center text-sm text-gray-500">로딩 중...</div>,
});

const ExchangeWidget = dynamic(() => import("@/components/dashboard/widgets/ExchangeWidget"), {
  ssr: false,
  loading: () => <div className="flex h-full items-center justify-center text-sm text-gray-500">로딩 중...</div>,
});

const CalculatorWidget = dynamic(() => import("@/components/dashboard/widgets/CalculatorWidget"), {
  ssr: false,
  loading: () => <div className="flex h-full items-center justify-center text-sm text-gray-500">로딩 중...</div>,
});

const VehicleMapWidget = dynamic(() => import("@/components/dashboard/widgets/VehicleMapWidget"), {
  ssr: false,
  loading: () => <div className="flex h-full items-center justify-center text-sm text-gray-500">로딩 중...</div>,
});

const DeliveryStatusWidget = dynamic(() => import("@/components/dashboard/widgets/DeliveryStatusWidget"), {
  ssr: false,
  loading: () => <div className="flex h-full items-center justify-center text-sm text-gray-500">로딩 중...</div>,
});

const RiskAlertWidget = dynamic(() => import("@/components/dashboard/widgets/RiskAlertWidget"), {
  ssr: false,
  loading: () => <div className="flex h-full items-center justify-center text-sm text-gray-500">로딩 중...</div>,
});

// 시계 위젯 임포트
import { ClockWidget } from "./widgets/ClockWidget";
// 달력 위젯 임포트
import { CalendarWidget } from "./widgets/CalendarWidget";
// 기사 관리 위젯 임포트
import { DriverManagementWidget } from "./widgets/DriverManagementWidget";

interface CanvasElementProps {
  element: DashboardElement;
  isSelected: boolean;
  cellSize: number;
  onUpdate: (id: string, updates: Partial<DashboardElement>) => void;
  onRemove: (id: string) => void;
  onSelect: (id: string | null) => void;
  onConfigure?: (element: DashboardElement) => void;
}

/**
 * 캔버스에 배치된 개별 요소 컴포넌트
 * - 드래그로 이동 가능 (그리드 스냅)
 * - 크기 조절 핸들 (그리드 스냅)
 * - 삭제 버튼
 */
export function CanvasElement({
  element,
  isSelected,
  cellSize,
  onUpdate,
  onRemove,
  onSelect,
  onConfigure,
}: CanvasElementProps) {
  const [isDragging, setIsDragging] = useState(false);
  const [isResizing, setIsResizing] = useState(false);
  const [dragStart, setDragStart] = useState({ x: 0, y: 0, elementX: 0, elementY: 0 });
  const [resizeStart, setResizeStart] = useState({
    x: 0,
    y: 0,
    width: 0,
    height: 0,
    elementX: 0,
    elementY: 0,
    handle: "",
  });
  const [chartData, setChartData] = useState<QueryResult | null>(null);
  const [isLoadingData, setIsLoadingData] = useState(false);
  const elementRef = useRef<HTMLDivElement>(null);

  // 드래그/리사이즈 중 임시 위치/크기 (스냅 전)
  const [tempPosition, setTempPosition] = useState<{ x: number; y: number } | null>(null);
  const [tempSize, setTempSize] = useState<{ width: number; height: number } | null>(null);

  // 요소 선택 처리
  const handleMouseDown = useCallback(
    (e: React.MouseEvent) => {
      // 닫기 버튼이나 리사이즈 핸들 클릭 시 무시
      if ((e.target as HTMLElement).closest(".element-close, .resize-handle")) {
        return;
      }

      // 위젯 내부 (헤더 제외) 클릭 시 드래그 무시 - 인터랙티브 사용 가능
      if ((e.target as HTMLElement).closest(".widget-interactive-area")) {
        return;
      }

      onSelect(element.id);
      setIsDragging(true);
      setDragStart({
        x: e.clientX,
        y: e.clientY,
        elementX: element.position.x,
        elementY: element.position.y,
      });
      e.preventDefault();
    },
    [element.id, element.position.x, element.position.y, onSelect],
  );

  // 리사이즈 핸들 마우스다운
  const handleResizeMouseDown = useCallback(
    (e: React.MouseEvent, handle: string) => {
      e.stopPropagation();
      setIsResizing(true);
      setResizeStart({
        x: e.clientX,
        y: e.clientY,
        width: element.size.width,
        height: element.size.height,
        elementX: element.position.x,
        elementY: element.position.y,
        handle,
      });
    },
    [element.size.width, element.size.height, element.position.x, element.position.y],
  );

  // 마우스 이동 처리 (그리드 스냅 적용)
  const handleMouseMove = useCallback(
    (e: MouseEvent) => {
      if (isDragging) {
        const deltaX = e.clientX - dragStart.x;
        const deltaY = e.clientY - dragStart.y;

        // 임시 위치 계산 (스냅 안 됨)
        let rawX = Math.max(0, dragStart.elementX + deltaX);
        const rawY = Math.max(0, dragStart.elementY + deltaY);

        // X 좌표가 캔버스 너비를 벗어나지 않도록 제한
        const maxX = GRID_CONFIG.CANVAS_WIDTH - element.size.width;
        rawX = Math.min(rawX, maxX);

        setTempPosition({ x: rawX, y: rawY });
      } else if (isResizing) {
        const deltaX = e.clientX - resizeStart.x;
        const deltaY = e.clientY - resizeStart.y;

        let newWidth = resizeStart.width;
        let newHeight = resizeStart.height;
        let newX = resizeStart.elementX;
        let newY = resizeStart.elementY;

        // 최소 크기 설정: 달력은 2x3, 나머지는 2x2
        const minWidthCells = 2;
        const minHeightCells = element.type === "widget" && element.subtype === "calendar" ? 3 : 2;
        const minWidth = GRID_CONFIG.CELL_SIZE * minWidthCells;
        const minHeight = GRID_CONFIG.CELL_SIZE * minHeightCells;

        switch (resizeStart.handle) {
          case "se": // 오른쪽 아래
            newWidth = Math.max(minWidth, resizeStart.width + deltaX);
            newHeight = Math.max(minHeight, resizeStart.height + deltaY);
            break;
          case "sw": // 왼쪽 아래
            newWidth = Math.max(minWidth, resizeStart.width - deltaX);
            newHeight = Math.max(minHeight, resizeStart.height + deltaY);
            newX = resizeStart.elementX + deltaX;
            break;
          case "ne": // 오른쪽 위
            newWidth = Math.max(minWidth, resizeStart.width + deltaX);
            newHeight = Math.max(minHeight, resizeStart.height - deltaY);
            newY = resizeStart.elementY + deltaY;
            break;
          case "nw": // 왼쪽 위
            newWidth = Math.max(minWidth, resizeStart.width - deltaX);
            newHeight = Math.max(minHeight, resizeStart.height - deltaY);
            newX = resizeStart.elementX + deltaX;
            newY = resizeStart.elementY + deltaY;
            break;
        }

        // 가로 너비가 캔버스를 벗어나지 않도록 제한
        const maxWidth = GRID_CONFIG.CANVAS_WIDTH - newX;
        newWidth = Math.min(newWidth, maxWidth);

        // 임시 크기/위치 저장 (스냅 안 됨)
        setTempPosition({ x: Math.max(0, newX), y: Math.max(0, newY) });
        setTempSize({ width: newWidth, height: newHeight });
      }
    },
    [isDragging, isResizing, dragStart, resizeStart, element.size.width, element.type, element.subtype],
  );

  // 마우스 업 처리 (그리드 스냅 적용)
  const handleMouseUp = useCallback(() => {
    if (isDragging && tempPosition) {
      // 드래그 종료 시 그리드에 스냅 (동적 셀 크기 사용)
      let snappedX = snapToGrid(tempPosition.x, cellSize);
      const snappedY = snapToGrid(tempPosition.y, cellSize);

      // X 좌표가 캔버스 너비를 벗어나지 않도록 최종 제한
      const maxX = GRID_CONFIG.CANVAS_WIDTH - element.size.width;
      snappedX = Math.min(snappedX, maxX);

      onUpdate(element.id, {
        position: { x: snappedX, y: snappedY },
      });

      setTempPosition(null);
    }

    if (isResizing && tempPosition && tempSize) {
      // 리사이즈 종료 시 그리드에 스냅 (동적 셀 크기 사용)
      const snappedX = snapToGrid(tempPosition.x, cellSize);
      const snappedY = snapToGrid(tempPosition.y, cellSize);
      let snappedWidth = snapSizeToGrid(tempSize.width, 2, cellSize);
      const snappedHeight = snapSizeToGrid(tempSize.height, 2, cellSize);

      // 가로 너비가 캔버스를 벗어나지 않도록 최종 제한
      const maxWidth = GRID_CONFIG.CANVAS_WIDTH - snappedX;
      snappedWidth = Math.min(snappedWidth, maxWidth);

      onUpdate(element.id, {
        position: { x: snappedX, y: snappedY },
        size: { width: snappedWidth, height: snappedHeight },
      });

      setTempPosition(null);
      setTempSize(null);
    }

    setIsDragging(false);
    setIsResizing(false);
  }, [isDragging, isResizing, tempPosition, tempSize, element.id, element.size.width, onUpdate, cellSize]);

  // 전역 마우스 이벤트 등록
  React.useEffect(() => {
    if (isDragging || isResizing) {
      document.addEventListener("mousemove", handleMouseMove);
      document.addEventListener("mouseup", handleMouseUp);

      return () => {
        document.removeEventListener("mousemove", handleMouseMove);
        document.removeEventListener("mouseup", handleMouseUp);
      };
    }
  }, [isDragging, isResizing, handleMouseMove, handleMouseUp]);

  // 데이터 로딩
  const loadChartData = useCallback(async () => {
    if (!element.dataSource?.query || element.type !== "chart") {
      return;
    }

    setIsLoadingData(true);
    try {
      let result;

      // 외부 DB vs 현재 DB 분기
      if (element.dataSource.connectionType === "external" && element.dataSource.externalConnectionId) {
        // 외부 DB
        const { ExternalDbConnectionAPI } = await import("@/lib/api/externalDbConnection");
        const externalResult = await ExternalDbConnectionAPI.executeQuery(
          parseInt(element.dataSource.externalConnectionId),
          element.dataSource.query,
        );

        if (!externalResult.success) {
          throw new Error(externalResult.message || "외부 DB 쿼리 실행 실패");
        }

        setChartData({
          columns: externalResult.data?.[0] ? Object.keys(externalResult.data[0]) : [],
          rows: externalResult.data || [],
          totalRows: externalResult.data?.length || 0,
          executionTime: 0,
        });
      } else {
        // 현재 DB
        const { dashboardApi } = await import("@/lib/api/dashboard");
        result = await dashboardApi.executeQuery(element.dataSource.query);

        setChartData({
          columns: result.columns || [],
          rows: result.rows || [],
          totalRows: result.rowCount || 0,
          executionTime: 0,
        });
      }
    } catch (error) {
      console.error("Chart data loading error:", error);
      setChartData(null);
    } finally {
      setIsLoadingData(false);
    }
  }, [
    element.dataSource?.query,
    element.dataSource?.connectionType,
    element.dataSource?.externalConnectionId,
    element.type,
  ]);

  // 컴포넌트 마운트 시 및 쿼리 변경 시 데이터 로딩
  useEffect(() => {
    loadChartData();
  }, [loadChartData]);

  // 자동 새로고침 설정
  useEffect(() => {
    if (!element.dataSource?.refreshInterval || element.dataSource.refreshInterval === 0) {
      return;
    }

    const interval = setInterval(loadChartData, element.dataSource.refreshInterval);
    return () => clearInterval(interval);
  }, [element.dataSource?.refreshInterval, loadChartData]);

  // 요소 삭제
  const handleRemove = useCallback(() => {
    onRemove(element.id);
  }, [element.id, onRemove]);

  // 스타일 클래스 생성
  const getContentClass = () => {
    if (element.type === "chart") {
      switch (element.subtype) {
        case "bar":
          return "bg-gradient-to-br from-indigo-400 to-purple-600";
        case "pie":
          return "bg-gradient-to-br from-pink-400 to-red-500";
        case "line":
          return "bg-gradient-to-br from-blue-400 to-cyan-400";
        default:
          return "bg-gray-200";
      }
    } else if (element.type === "widget") {
      switch (element.subtype) {
        case "exchange":
          return "bg-gradient-to-br from-pink-400 to-yellow-400";
        case "weather":
          return "bg-gradient-to-br from-cyan-400 to-indigo-800";
        case "clock":
          return "bg-gradient-to-br from-teal-400 to-cyan-600";
        case "calendar":
          return "bg-gradient-to-br from-indigo-400 to-purple-600";
        case "driver-management":
          return "bg-gradient-to-br from-blue-400 to-indigo-600";
        default:
          return "bg-gray-200";
      }
    }
    return "bg-gray-200";
  };

  // 드래그/리사이즈 중일 때는 임시 위치/크기 사용, 아니면 실제 값 사용
  const displayPosition = tempPosition || element.position;
  const displaySize = tempSize || element.size;

  return (
    <div
      ref={elementRef}
      className={`absolute min-h-[120px] min-w-[120px] cursor-move rounded-lg border-2 bg-white shadow-lg ${isSelected ? "border-blue-500 shadow-blue-200" : "border-gray-400"} ${isDragging || isResizing ? "transition-none" : "transition-all duration-150"} `}
      style={{
        left: displayPosition.x,
        top: displayPosition.y,
        width: displaySize.width,
        height: displaySize.height,
        padding: `${GRID_CONFIG.ELEMENT_PADDING}px`,
        boxSizing: "border-box",
      }}
      onMouseDown={handleMouseDown}
    >
      {/* 헤더 */}
      <div className="flex cursor-move items-center justify-between border-b border-gray-200 bg-gray-50 p-3">
        <span className="text-sm font-bold text-gray-800">{element.title}</span>
        <div className="flex gap-1">
          {/* 설정 버튼 (시계, 달력, 기사관리 위젯은 자체 설정 UI 사용) */}
          {onConfigure &&
            !(
              element.type === "widget" &&
              (element.subtype === "clock" || element.subtype === "calendar" || element.subtype === "driver-management")
            ) && (
              <button
                className="hover:bg-accent0 flex h-6 w-6 items-center justify-center rounded text-gray-400 transition-colors duration-200 hover:text-white"
                onClick={() => onConfigure(element)}
                title="설정"
              >
                ⚙️
              </button>
            )}
          {/* 삭제 버튼 */}
          <button
            className="element-close hover:bg-destructive/100 flex h-6 w-6 items-center justify-center rounded text-gray-400 transition-colors duration-200 hover:text-white"
            onClick={handleRemove}
            title="삭제"
          >
            ×
          </button>
        </div>
      </div>

      {/* 내용 */}
      <div className="relative h-[calc(100%-45px)]">
        {element.type === "chart" ? (
          // 차트 렌더링
          <div className="h-full w-full bg-white">
            {isLoadingData ? (
              <div className="flex h-full w-full items-center justify-center text-gray-500">
                <div className="text-center">
                  <div className="border-primary mx-auto mb-2 h-6 w-6 animate-spin rounded-full border-2 border-t-transparent" />
                  <div className="text-sm">데이터 로딩 중...</div>
                </div>
              </div>
            ) : (
              <ChartRenderer
                element={element}
                data={chartData || undefined}
                width={element.size.width}
                height={element.size.height - 45}
              />
            )}
          </div>
        ) : element.type === "widget" && element.subtype === "weather" ? (
          // 날씨 위젯 렌더링
          <div className="widget-interactive-area h-full w-full">
            <WeatherWidget city="서울" refreshInterval={600000} />
          </div>
        ) : element.type === "widget" && element.subtype === "exchange" ? (
          // 환율 위젯 렌더링
          <div className="widget-interactive-area h-full w-full">
            <ExchangeWidget baseCurrency="KRW" targetCurrency="USD" refreshInterval={600000} />
          </div>
        ) : element.type === "widget" && element.subtype === "clock" ? (
          // 시계 위젯 렌더링
          <div className="h-full w-full">
            <ClockWidget
              element={element}
              onConfigUpdate={(newConfig) => {
                onUpdate(element.id, { clockConfig: newConfig });
              }}
            />
          </div>
        ) : element.type === "widget" && element.subtype === "calculator" ? (
          // 계산기 위젯 렌더링
          <div className="widget-interactive-area h-full w-full">
            <CalculatorWidget />
          </div>
        ) : element.type === "widget" && element.subtype === "vehicle-map" ? (
          // 차량 위치 지도 위젯 렌더링
          <div className="widget-interactive-area h-full w-full">
            <VehicleMapWidget />
          </div>
        ) : element.type === "widget" && element.subtype === "delivery-status" ? (
          // 배송/화물 현황 위젯 렌더링
          <div className="widget-interactive-area h-full w-full">
            <DeliveryStatusWidget />
          </div>
        ) : element.type === "widget" && element.subtype === "risk-alert" ? (
          // 리스크/알림 위젯 렌더링
          <div className="widget-interactive-area h-full w-full">
            <RiskAlertWidget />
          </div>
        ) : element.type === "widget" && element.subtype === "calendar" ? (
          // 달력 위젯 렌더링
          <div className="h-full w-full">
            <CalendarWidget
              element={element}
              onConfigUpdate={(newConfig) => {
                onUpdate(element.id, { calendarConfig: newConfig });
              }}
            />
          </div>
        ) : element.type === "widget" && element.subtype === "driver-management" ? (
          // 기사 관리 위젯 렌더링
          <div className="h-full w-full">
            <DriverManagementWidget
              element={element}
              onConfigUpdate={(newConfig) => {
                onUpdate(element.id, { driverManagementConfig: newConfig });
              }}
            />
          </div>
        ) : (
          // 기타 위젯 렌더링
          <div
            className={`flex h-full w-full items-center justify-center p-5 text-center text-sm font-medium text-white ${getContentClass()} `}
          >
            <div>
              <div className="mb-2 text-4xl">🔧</div>
              <div className="whitespace-pre-line">{element.content}</div>
            </div>
          </div>
        )}
      </div>

      {/* 리사이즈 핸들 (선택된 요소에만 표시) */}
      {isSelected && (
        <>
          <ResizeHandle position="nw" onMouseDown={handleResizeMouseDown} />
          <ResizeHandle position="ne" onMouseDown={handleResizeMouseDown} />
          <ResizeHandle position="sw" onMouseDown={handleResizeMouseDown} />
          <ResizeHandle position="se" onMouseDown={handleResizeMouseDown} />
        </>
      )}
    </div>
  );
}

interface ResizeHandleProps {
  position: "nw" | "ne" | "sw" | "se";
  onMouseDown: (e: React.MouseEvent, handle: string) => void;
}

/**
 * 크기 조절 핸들 컴포넌트
 */
function ResizeHandle({ position, onMouseDown }: ResizeHandleProps) {
  const getPositionClass = () => {
    switch (position) {
      case "nw":
        return "top-[-5px] left-[-5px] cursor-nw-resize";
      case "ne":
        return "top-[-5px] right-[-5px] cursor-ne-resize";
      case "sw":
        return "bottom-[-5px] left-[-5px] cursor-sw-resize";
      case "se":
        return "bottom-[-5px] right-[-5px] cursor-se-resize";
    }
  };

  return (
    <div
      className={`resize-handle absolute h-3 w-3 border border-white bg-green-500 ${getPositionClass()} `}
      onMouseDown={(e) => onMouseDown(e, position)}
    />
  );
}