import React, { useRef, useEffect, useState, useCallback } from 'react';
import { Stage, Layer, Image as KonvaImage, Line } from 'react-konva';
import type { KonvaEventObject } from 'konva/lib/Node';
import type { Stage as StageType } from 'konva/lib/Stage';
import { useAppStore } from '../store/useAppStore';
import { Button } from './ui/Button';
import { ZoomIn, ZoomOut, RotateCcw, Download } from 'lucide-react';
import { downloadImage } from '../utils/imageUtils';

export const ImageCanvas: React.FC = () => {
  const {
    canvasImage,
    canvasZoom,
    // canvasPan,
    setCanvasZoom,
    setCanvasPan,
    brushStrokes,
    addBrushStroke,
    showMasks,
    selectedTool,
    isGenerating,
    isContinuousGenerating,
    retryCount,
    brushSize,
    showHistory,
    showPromptPanel
  } = useAppStore();

  const stageRef = useRef<StageType>(null);
  const [image, setImage] = useState<HTMLImageElement | null>(null);
  const [stageSize, setStageSize] = useState({ width: 800, height: 600 });
  const [isDrawing, setIsDrawing] = useState(false);
  const [currentStroke, setCurrentStroke] = useState<number[]>([]);

  const handleZoom = useCallback((delta: number) => {
    const stage = stageRef.current;
    if (stage) {
      const currentZoom = stage.scaleX();
      const newZoom = Math.max(0.1, Math.min(3, currentZoom + delta));
      
      // 先更新React状态以确保Konva Image组件使用正确的缩放值
      setCanvasZoom(newZoom);
      
      // 使用setTimeout确保DOM已更新后再设置Stage
      setTimeout(() => {
        const stage = stageRef.current;
        if (stage) {
          // 直接通过stageRef控制Stage
          stage.scale({ x: newZoom, y: newZoom });
          stage.batchDraw();
        }
      }, 0);
    }
  }, [setCanvasZoom]);

  // 加载图像
  useEffect(() => {
    console.log('useEffect triggered, canvasImage:', canvasImage);
    
    // 如果没有图像URL，直接返回
    if (!canvasImage) {
      console.log('没有图像需要加载');
      setImage(null);
      return;
    }
    
    let img: HTMLImageElement | null = null;
    let isCancelled = false;
    
    console.log('开始加载图像，URL:', canvasImage);
    
    img = new window.Image();
    
    img.onload = () => {
      // 检查是否已取消
      if (isCancelled) {
        console.log('图像加载被取消');
        return;
      }
      
      console.log('图像加载成功，尺寸:', img.width, 'x', img.height);
      setImage(img);
      
      // 只在图像首次加载时自动适应画布
      if (!isCancelled && img) {
        const isMobile = window.innerWidth < 768;
        const padding = isMobile ? 0.9 : 0.8;
        
        const scaleX = (stageSize.width * padding) / img.width;
        const scaleY = (stageSize.height * padding) / img.height;
        
        const maxZoom = isMobile ? 0.3 : 0.8;
        const optimalZoom = Math.min(scaleX, scaleY, maxZoom);
        
        // 立即更新React状态以确保Konva Image组件使用正确的缩放值
        setCanvasZoom(optimalZoom);
        setCanvasPan({ x: 0, y: 0 });
        
        // 使用setTimeout确保DOM已更新后再设置Stage
        setTimeout(() => {
          // 检查是否已取消
          if (isCancelled) {
            return;
          }
          
          if (!isCancelled && img) {
            // 直接设置缩放，但保持Stage居中
            const stage = stageRef.current;
            if (stage) {
              stage.scale({ x: optimalZoom, y: optimalZoom });
              // 重置Stage位置以确保居中
              stage.position({ x: 0, y: 0 });
              stage.batchDraw();
            }
            
            console.log('图像自动适应画布完成，缩放:', optimalZoom);
          }
        }, 0);
      }
    };
    
    img.onerror = (error) => {
      // 检查是否已取消
      if (isCancelled) {
        return;
      }
      
      console.error('图像加载失败:', error);
      console.error('图像URL:', canvasImage);
      
      // 检查是否是IndexedDB URL
      if (canvasImage.startsWith('indexeddb://')) {
        console.log('正在处理IndexedDB图像...');
        
        // 从IndexedDB获取图像并创建Blob URL
        const imageId = canvasImage.replace('indexeddb://', '');
        import('../services/referenceImageService').then((module) => {
          const referenceImageService = module;
          referenceImageService.getReferenceImage(imageId)
            .then(blob => {
              // 检查是否已取消
              if (isCancelled) {
                return;
              }
              
              if (blob) {
                const newUrl = URL.createObjectURL(blob);
                console.log('从IndexedDB创建新的Blob URL:', newUrl);
                // 更新canvasImage为新的URL
                // 检查是否已取消
                if (!isCancelled) {
                  useAppStore.getState().setCanvasImage(newUrl);
                }
              } else {
                console.error('IndexedDB中未找到图像');
              }
            })
            .catch(err => {
              // 检查是否已取消
              if (isCancelled) {
                return;
              }
              
              console.error('从IndexedDB获取图像时出错:', err);
            });
        }).catch(err => {
          // 检查是否已取消
          if (isCancelled) {
            return;
          }
          
          console.error('导入referenceImageService时出错:', err);
        });
      }
      // 检查是否是Blob URL
      else if (canvasImage.startsWith('blob:')) {
        console.log('正在检查Blob URL是否有效...');
        
        // 尝试从AppStore重新获取Blob并创建新的URL
        const blob = useAppStore.getState().getBlob(canvasImage);
        if (blob) {
          // 检查是否已取消
          if (isCancelled) {
            return;
          }
          
          console.log('从AppStore找到Blob，尝试重新创建URL...');
          // 重新创建Blob URL并重试加载
          const newUrl = URL.createObjectURL(blob);
          console.log('创建新的Blob URL:', newUrl);
          // 更新canvasImage为新的URL
          useAppStore.getState().setCanvasImage(newUrl);
        } else {
            // 检查是否已取消
            if (isCancelled) {
              return;
            }
            
            console.error('AppStore中未找到Blob');
            // 如果AppStore中也没有，尝试通过fetch检查URL
            fetch(canvasImage)
              .then(response => {
                // 检查是否已取消
                if (isCancelled) {
                  return;
                }
                
                if (!response.ok) {
                  console.error('Blob URL无法访问:', response.status, response.statusText);
                } else {
                  console.log('Blob URL可以访问，但图像加载仍然失败');
                }
              })
              .catch(fetchErr => {
                // 检查是否已取消
                if (isCancelled) {
                  return;
                }
                
                console.error('检查Blob URL时出错:', fetchErr);
              });
          }
        
      }
    };
    
    img.src = canvasImage;
    
    // 清理函数
    return () => {
      console.log('清理图像加载资源');
      // 标记为已取消
      isCancelled = true;
      // 取消图像加载
      if (img) {
        img.onload = null;
        img.onerror = null;
        // 清理图像源以释放内存
        img.src = '';
      }
    };
  }, [canvasImage, setCanvasZoom, setCanvasPan, stageSize.height, stageSize.width]); // 移除image依赖项

  // 处理舞台大小调整
  useEffect(() => {
    const updateSize = () => {
      const container = document.getElementById('canvas-container');
      if (container) {
        setStageSize({
          width: container.offsetWidth,
          height: container.offsetHeight
        });
      }
    };

    updateSize();
    window.addEventListener('resize', updateSize);
    return () => window.removeEventListener('resize', updateSize);
  }, [showPromptPanel, showHistory]);

  // 监听面板状态变化以调整画布大小
  useEffect(() => {
    // 使用 setTimeout 确保 DOM 已更新
    const timer = setTimeout(() => {
      const container = document.getElementById('canvas-container');
      if (container) {
        setStageSize({
          width: container.offsetWidth,
          height: container.offsetHeight
        });
      }
    }, 100);
    
    return () => clearTimeout(timer);
  }, [showPromptPanel, showHistory]);

  // 处理鼠标滚轮缩放
  useEffect(() => {
    const container = document.getElementById('canvas-container');
    if (!container) return;

    const handleWheel = (e: WheelEvent) => {
      e.preventDefault();
      const delta = e.deltaY > 0 ? -0.1 : 0.1;
      handleZoom(delta);
    };

    container.addEventListener('wheel', handleWheel, { passive: false });
    return () => container.removeEventListener('wheel', handleWheel);
  }, [canvasZoom, handleZoom]);

  const handleMouseDown = (e: KonvaEventObject<MouseEvent>) => {
    if (selectedTool !== 'mask' || !image) return;
    
    setIsDrawing(true);
    const stage = e.target.getStage();
    if (!stage) return;
    
    // 使用 Konva 的 getRelativePointerPosition 获取准确坐标
    const relativePos = stage.getRelativePointerPosition();
    if (!relativePos) return;
    
    // 计算图像在舞台上的边界
    const imageX = (stageSize.width / canvasZoom - image.width) / 2;
    const imageY = (stageSize.height / canvasZoom - image.height) / 2;
    
    // 转换为相对于图像的坐标
    const relativeX = relativePos.x - imageX;
    const relativeY = relativePos.y - imageY;
    
    // 检查点击是否在图像边界内
    if (relativeX >= 0 && relativeX <= image.width && relativeY >= 0 && relativeY <= image.height) {
      setCurrentStroke([relativeX, relativeY]);
    }
  };

  const handleMouseMove = (e: KonvaEventObject<MouseEvent>) => {
    if (!isDrawing || selectedTool !== 'mask' || !image) return;
    
    const stage = e.target.getStage();
    if (!stage) return;
    
    // 使用 Konva 的 getRelativePointerPosition 获取准确坐标
    const relativePos = stage.getRelativePointerPosition();
    if (!relativePos) return;
    
    // 计算图像在舞台上的边界
    const imageX = (stageSize.width / canvasZoom - image.width) / 2;
    const imageY = (stageSize.height / canvasZoom - image.height) / 2;
    
    // 转换为相对于图像的坐标
    const relativeX = relativePos.x - imageX;
    const relativeY = relativePos.y - imageY;
    
    // 检查是否在图像边界内
    if (relativeX >= 0 && relativeX <= image.width && relativeY >= 0 && relativeY <= image.height) {
      setCurrentStroke([...currentStroke, relativeX, relativeY]);
    }
  };

  const handleMouseUp = () => {
    if (!isDrawing || currentStroke.length < 4) {
      setIsDrawing(false);
      setCurrentStroke([]);
      return;
    }
    
    setIsDrawing(false);
    addBrushStroke({
      id: `stroke-${Date.now()}`,
      points: currentStroke,
      brushSize,
      color: '#A855F7',
    });
    setCurrentStroke([]);
  };

  const handleReset = () => {
    if (image) {
      const isMobile = window.innerWidth < 768;
      const padding = isMobile ? 0.9 : 0.8;
      const scaleX = (stageSize.width * padding) / image.width;
      const scaleY = (stageSize.height * padding) / image.height;
      const maxZoom = isMobile ? 0.3 : 0.8;
      const optimalZoom = Math.min(scaleX, scaleY, maxZoom);
      
      // 同时更新React状态以确保Konva Image组件使用正确的缩放值
      setCanvasZoom(optimalZoom);
      setCanvasPan({ x: 0, y: 0 });
      
      // 使用setTimeout确保DOM已更新后再设置Stage
      setTimeout(() => {
        // 直接通过stageRef控制Stage
        const stage = stageRef.current;
        if (stage) {
          stage.scale({ x: optimalZoom, y: optimalZoom });
          stage.position({ x: 0, y: 0 });
          stage.batchDraw();
        }
      }, 0);
    }
  };

  const handleDownload = async () => {
    // 首先尝试从当前选中的生成记录或编辑记录中获取上传后的URL
    const { selectedGenerationId, selectedEditId, currentProject } = useAppStore.getState();
    
    // 获取当前选中的记录
    let selectedRecord = null;
    if (selectedGenerationId && currentProject) {
      selectedRecord = currentProject.generations.find(g => g.id === selectedGenerationId);
    } else if (selectedEditId && currentProject) {
      selectedRecord = currentProject.edits.find(e => e.id === selectedEditId);
    }
    
    // 如果有选中的记录且有上传结果，尝试下载上传后的图像
    if (selectedRecord && selectedRecord.uploadResults && selectedRecord.uploadResults.length > 0) {
      // 下载第一个上传结果（通常是生成的图像）
      const uploadResult = selectedRecord.uploadResults[0];
      if (uploadResult.success && uploadResult.url) {
        try {
          await downloadImage(uploadResult.url, `nano-banana-${Date.now()}.png`);
        } catch (error) {
          console.error('下载图像失败:', error);
        }
        // 立即返回
        return;
      }
    }
    
    // 如果没有上传后的URL或下载失败，回退到下载当前画布内容
    const stage = stageRef.current;
    if (stage) {
      try {
        // 使用Konva的toDataURL方法获取画布内容
        const dataURL = stage.toDataURL();
        
        // 创建下载链接
        const link = document.createElement('a');
        link.href = dataURL;
        link.download = `nano-banana-${Date.now()}.png`;
        document.body.appendChild(link);
        link.click();
        document.body.removeChild(link);
        
        console.log('画布内容下载成功');
      } catch (error) {
        console.error('下载画布内容时出错:', error);
        
        // 如果Konva下载失败，回退到下载原始图像
        if (canvasImage) {
          try {
            await downloadImage(canvasImage, `nano-banana-${Date.now()}.png`);
          } catch (error) {
            console.error('下载图像失败:', error);
          }
        }
      }
    }
  };;

  return (
    <div className="flex flex-col h-full">
      {/* 工具栏 */}
      

      {/* 画布区域 */}
      <div 
        id="canvas-container" 
        className="flex-1 relative overflow-hidden bg-gray-100 rounded-lg"
      >
        {!image && !isGenerating && (
          <div className="absolute inset-0 flex items-center justify-center z-0">
            <div className="text-center max-w-xs">
              <div className="text-5xl mb-3">🍌</div>
              <h2 className="text-lg font-medium text-gray-400 mb-1">
                Nano Banana AI
              </h2>
              <p className="text-gray-500 text-sm">
                {selectedTool === 'generate' 
                  ? '在提示框中描述您想要创建的内容'
                  : '上传图像开始编辑'
                }
              </p>
            </div>
          </div>
        )}

        {isGenerating && (
          <div className="absolute inset-0 flex items-center justify-center bg-gray-900/40 z-50 backdrop-blur-sm rounded-lg animate-in fade-in duration-300">
            <div className="text-center bg-white/90 rounded-xl p-6 card-lg backdrop-blur-sm animate-in scale-in duration-200">
              <div className="animate-spin rounded-full h-10 w-10 border-2 border-yellow-400 border-t-transparent mx-auto mb-3" />
              <p className="text-gray-700 text-sm font-medium">正在创建图像...</p>
              {/* 显示重试次数 */}
              {isContinuousGenerating && (
                <p className="text-gray-500 text-xs mt-2">
                  重试次数: {retryCount}
                </p>
              )}
            </div>
          </div>
        )}

        <Stage
          ref={stageRef}
          width={stageSize.width}
          height={stageSize.height}
          draggable={selectedTool !== 'mask'}
          onDragEnd={() => {
            // 通过stageRef直接获取和设置位置
            const stage = stageRef.current;
            if (stage) {
              const scale = stage.scaleX();
              setCanvasPan({ 
                x: stage.x() / scale, 
                y: stage.y() / scale 
              });
            }
          }}
          onMouseDown={handleMouseDown}
          onMouseMove={handleMouseMove}
          onMouseUp={handleMouseUp}
          style={{ 
            cursor: selectedTool === 'mask' ? 'crosshair' : 'default',
            zIndex: 10
          }}
        >
          <Layer>
            {image && (
              <KonvaImage
                image={image}
                x={(stageSize.width / canvasZoom - image.width) / 2}
                y={(stageSize.height / canvasZoom - image.height) / 2}
                onRender={() => {
                  console.log('KonvaImage组件渲染完成');
                }}
              />
            )}
            
            {/* 画笔描边 */}
            {showMasks && brushStrokes.map((stroke) => (
              <Line
                key={stroke.id}
                points={stroke.points}
                stroke="#A855F7"
                strokeWidth={stroke.brushSize}
                tension={0.5}
                lineCap="round"
                lineJoin="round"
                globalCompositeOperation="source-over"
                opacity={0.6}
                x={(stageSize.width / canvasZoom - (image?.width || 0)) / 2}
                y={(stageSize.height / canvasZoom - (image?.height || 0)) / 2}
              />
            ))}
            
            {/* 正在绘制的当前描边 */}
            {isDrawing && currentStroke.length > 2 && (
              <Line
                points={currentStroke}
                stroke="#A855F7"
                strokeWidth={brushSize}
                tension={0.5}
                lineCap="round"
                lineJoin="round"
                globalCompositeOperation="source-over"
                opacity={0.6}
                x={(stageSize.width / canvasZoom - (image?.width || 0)) / 2}
                y={(stageSize.height / canvasZoom - (image?.height || 0)) / 2}
              />
            )}
          </Layer>
        </Stage>

        {/* 悬浮操作按钮 */}
        {image && !isGenerating && (
          <div className="absolute bottom-4 left-1/2 transform -translate-x-1/2 bg-white/80 backdrop-blur-sm rounded-full card border border-gray-200 px-3 py-2 flex items-center space-x-2">
            <Button 
              variant="ghost" 
              size="sm" 
              onClick={() => handleZoom(-0.1)} 
              className="h-8 w-8 p-0 text-gray-600 hover:text-gray-900 hover:bg-gray-100 rounded-full card"
            >
              <ZoomOut className="h-4 w-4" />
            </Button>
            <span className="text-xs text-gray-500 min-w-[40px] text-center">
              {Math.round(canvasZoom * 100)}%
            </span>
            <Button 
              variant="ghost" 
              size="sm" 
              onClick={() => handleZoom(0.1)} 
              className="h-8 w-8 p-0 text-gray-600 hover:text-gray-900 hover:bg-gray-100 rounded-full card"
            >
              <ZoomIn className="h-4 w-4" />
            </Button>
            <Button 
              variant="ghost" 
              size="sm" 
              onClick={handleReset} 
              className="h-8 w-8 p-0 text-gray-600 hover:text-gray-900 hover:bg-gray-100 rounded-full card"
            >
              <RotateCcw className="h-4 w-4" />
            </Button>
            <div className="w-px h-6 bg-gray-200"></div>
            <Button 
              variant="ghost" 
              size="sm" 
              onClick={handleDownload} 
              className="h-8 w-8 p-0 text-gray-600 hover:text-gray-900 hover:bg-gray-100 rounded-full card"
            >
              <Download className="h-4 w-4" />
            </Button>
          </div>
        )}
      </div>

      {/* 状态栏 */}
      <div className="p-2 border-t border-gray-200 bg-white">
        <div className="flex items-center justify-between text-xs text-gray-500">
          <div className="flex items-center space-x-2">
            {brushStrokes.length > 0 && (
              <span className="text-yellow-400">{brushStrokes.length} 个描边</span>
            )}
          </div>
          
          <div className="flex items-center space-x-1">
            <span className="text-xs text-gray-500">
              © 2025 Mark Fulton
            </span>
          </div>
        </div>
      </div>
    </div>
  );
};