package com.klp.utils;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Base64;

/**
 * 图片处理工具类
 */
@Component
public class ImageUtils {
    
    private static final Logger logger = LoggerFactory.getLogger(ImageUtils.class);
    
    /**
     * 将图片转换为data URI格式
     * @param imagePath 图片路径
     * @param maxDimension 最大尺寸
     * @param quality 质量 (1-100)
     * @return data URI字符串
     */
    public static String imageToDataUri(String imagePath, int maxDimension, int quality) {
        try {
            File file = new File(imagePath);
            if (!file.exists()) {
                throw new RuntimeException("图片文件不存在: " + imagePath);
            }
            
            BufferedImage originalImage = ImageIO.read(file);
            if (originalImage == null) {
                throw new RuntimeException("无法读取图片文件: " + imagePath);
            }
            
            // 调整图片尺寸
            BufferedImage resizedImage = resizeImage(originalImage, maxDimension);
            
            // 转换为JPEG格式
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            ImageIO.write(resizedImage, "JPEG", baos);
            
            // 转换为base64
            byte[] imageBytes = baos.toByteArray();
            String base64 = Base64.getEncoder().encodeToString(imageBytes);
            
            return "data:image/jpeg;base64," + base64;
            
        } catch (IOException e) {
            logger.error("处理图片失败: {}", imagePath, e);
            throw new RuntimeException("处理图片失败: " + imagePath, e);
        }
    }
    
    /**
     * 调整图片尺寸
     * @param originalImage 原始图片
     * @param maxDimension 最大尺寸
     * @return 调整后的图片
     */
    private static BufferedImage resizeImage(BufferedImage originalImage, int maxDimension) {
        int originalWidth = originalImage.getWidth();
        int originalHeight = originalImage.getHeight();
        
        // 计算缩放比例
        double scale = Math.min((double) maxDimension / originalWidth, (double) maxDimension / originalHeight);
        
        if (scale >= 1.0) {
            // 如果原图小于最大尺寸，直接返回原图
            return originalImage;
        }
        
        int newWidth = (int) (originalWidth * scale);
        int newHeight = (int) (originalHeight * scale);
        
        // 创建新图片
        BufferedImage resizedImage = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2d = resizedImage.createGraphics();
        
        // 设置渲染质量
        g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
        g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        
        // 绘制调整后的图片
        g2d.drawImage(originalImage, 0, 0, newWidth, newHeight, null);
        g2d.dispose();
        
        return resizedImage;
    }
    
    /**
     * 检查文件是否为有效的图片文件
     * @param filePath 文件路径
     * @return 是否为有效图片
     */
    public static boolean isValidImageFile(String filePath) {
        try {
            File file = new File(filePath);
            if (!file.exists() || file.length() == 0) {
                return false;
            }
            
            // 检查文件扩展名
            String fileName = file.getName().toLowerCase();
            if (!fileName.endsWith(".png") && !fileName.endsWith(".jpg") && !fileName.endsWith(".jpeg")) {
                return false;
            }
            
            // 尝试读取图片
            BufferedImage image = ImageIO.read(file);
            return image != null;
            
        } catch (Exception e) {
            logger.warn("检查图片文件失败: {}", filePath, e);
            return false;
        }
    }
    
    /**
     * 获取目录下的所有有效图片文件
     * @param directoryPath 目录路径
     * @return 图片文件路径列表
     */
    public static java.util.List<String> getValidImageFiles(String directoryPath) {
        java.util.List<String> validImages = new java.util.ArrayList<>();
        
        try {
            File directory = new File(directoryPath);
            if (!directory.exists() || !directory.isDirectory()) {
                return validImages;
            }
            
            File[] files = directory.listFiles((dir, name) -> {
                String lowerName = name.toLowerCase();
                return lowerName.endsWith(".png") || lowerName.endsWith(".jpg") || lowerName.endsWith(".jpeg");
            });
            
            if (files != null) {
                for (File file : files) {
                    if (isValidImageFile(file.getAbsolutePath())) {
                        validImages.add(file.getAbsolutePath());
                    }
                }
            }
            
        } catch (Exception e) {
            logger.error("获取图片文件列表失败: {}", directoryPath, e);
        }
        
        return validImages;
    }
}