package com.klp.utils;

import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Base64;

/**
 * 图片处理工具类
 *
 * @author klp
 * @date 2025-01-27
 */
@Slf4j
@Component
public class ImageProcessingUtils {

    /**
     * 将图片URL转换为Base64 Data URI
     *
     * @param imageUrl 图片URL
     * @param maxDimension 最大尺寸
     * @param quality 图片质量
     * @return Base64 Data URI
     */
    public String imageUrlToDataUri(String imageUrl, int maxDimension, int quality) {
        try {
            // 下载图片
            BufferedImage originalImage = downloadImage(imageUrl);
            if (originalImage == null) {
                throw new RuntimeException("无法下载图片: " + imageUrl);
            }

            // 调整图片尺寸
            BufferedImage resizedImage = resizeImage(originalImage, maxDimension);

            // 转换为Base64
            String base64 = imageToBase64(resizedImage, quality);

            return "data:image/jpeg;base64," + base64;
        } catch (Exception e) {
            log.error("图片转换失败: {}", e.getMessage(), e);
            throw new RuntimeException("图片转换失败: " + e.getMessage());
        }
    }

    /**
     * 下载图片
     *
     * @param imageUrl 图片URL
     * @return BufferedImage对象
     */
    private BufferedImage downloadImage(String imageUrl) {
        try {
            URL url = new URL(imageUrl);
            try (InputStream inputStream = url.openStream()) {
                return ImageIO.read(inputStream);
            }
        } catch (IOException e) {
            log.error("下载图片失败: {}", e.getMessage(), e);
            return null;
        }
    }

    /**
     * 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 BufferedImage resizeImage(BufferedImage originalImage, int maxDimension) {
        int originalWidth = originalImage.getWidth();
        int originalHeight = originalImage.getHeight();

        // 计算新的尺寸
        int newWidth, newHeight;
        if (originalWidth > originalHeight) {
            newWidth = Math.min(originalWidth, maxDimension);
            newHeight = (int) ((double) originalHeight * newWidth / originalWidth);
        } else {
            newHeight = Math.min(originalHeight, maxDimension);
            newWidth = (int) ((double) originalWidth * newHeight / originalHeight);
        }

        // 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;
    }

    /**
     * 将图片转换为Base64字符串
     *
     * @param image 图片对象
     * @param quality 图片质量
     * @return Base64字符串
     */
    private String imageToBase64(BufferedImage image, int quality) {
        try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
            // 使用JPEG格式输出
            ImageIO.write(image, "JPEG", baos);
            byte[] imageBytes = baos.toByteArray();
            return Base64.getEncoder().encodeToString(imageBytes);
        } catch (IOException e) {
            log.error("图片转Base64失败: {}", e.getMessage(), e);
            throw new RuntimeException("图片转Base64失败: " + e.getMessage());
        }
    }

    /**
     * 验证图片URL是否有效
     *
     * @param imageUrl 图片URL
     * @return 是否有效
     */
    public boolean isValidImageUrl(String imageUrl) {
        try {
            URL url = new URL(imageUrl);
            String protocol = url.getProtocol();
            return "http".equals(protocol) || "https".equals(protocol);
        } catch (Exception e) {
            log.warn("无效的图片URL: {}", imageUrl);
            return false;
        }
    }
}