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package io.github.panxiaochao.captcha.utils;

import io.github.panxiaochao.core.utils.RandomUtil;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.stream.ImageOutputStream;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.concurrent.ThreadLocalRandom;

/**
 * 
 * 
 *
 * @author Lypxc
 * @since 2024-08-12
 * @version 1.0
 */
public class Graphics2DUtil {

	/**
	 * RGB颜色范围上限
	 */
	private static final int RGB_COLOR_BOUND = 256;

	/**
	 * 创建{@link Graphics2D}
	 * @param image {@link BufferedImage}
	 * @param color {@link Color}背景颜色以及当前画笔颜色，{@code null}表示不设置背景色
	 */
	public static Graphics2D createGraphics(BufferedImage image, Color color) {
		final Graphics2D graphics = image.createGraphics();
		if (null != color) {
			// 填充背景
			graphics.setColor(color);
			graphics.fillRect(0, 0, image.getWidth(), image.getHeight());
		}
		return graphics;
	}

	/**
	 * 绘制字符串，使用随机颜色，默认抗锯齿
	 * @param g {@link Graphics}画笔
	 * @param str 字符串
	 * @param font 字体
	 * @param width 字符串总宽度
	 * @param height 字符串背景高度
	 * @return 画笔对象
	 */
	public static Graphics drawString(Graphics g, String str, Font font, int width, int height) {
		return drawString(g, str, font, null, width, height);
	}

	/**
	 * 绘制字符串，默认抗锯齿
	 * @param g {@link Graphics}画笔
	 * @param str 字符串
	 * @param font 字体
	 * @param color 字体颜色，{@code null} 表示使用随机颜色（每个字符单独随机）
	 * @param width 字符串背景的宽度
	 * @param height 字符串背景的高度
	 * @return 画笔对象
	 */
	public static Graphics drawString(Graphics g, String str, Font font, Color color, int width, int height) {
		// 抗锯齿
		if (g instanceof Graphics2D) {
			((Graphics2D) g).setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
		}
		// 创建字体
		g.setFont(font);
		if (null != color) {
			g.setColor(color);
		}
		// 计算文字长度，计算居中的x点坐标，即字符串左边位置
		FontMetrics metrics = g.getFontMetrics(font);
		// 文字高度居中
		int y = (height - (metrics.getAscent() + metrics.getDescent())) / 2 + metrics.getAscent();
		// 根据字体算出字符串的占用宽度
		int textWidth = metrics.stringWidth(str);
		int len = str.length();
		// 文字的起始位置
		int x = (width - textWidth) / (len + 1);
		// 每个字符串的平均宽度
		int charWidth = textWidth / len;
		for (int i = 0; i < len; i++) {
			if (null == color) {
				// 产生随机的颜色值，让输出的每个字符的颜色值都将不同
				g.setColor(randomColor());
			}
			g.drawString(String.valueOf(str.charAt(i)), x + (x + charWidth) * i, y);
		}
		return g;
	}

	/**
	 * 生成随机颜色
	 */
	public static Color randomColor() {
		final ThreadLocalRandom random = RandomUtil.threadLocalRandom();
		return new Color(random.nextInt(RGB_COLOR_BOUND), random.nextInt(RGB_COLOR_BOUND),
				random.nextInt(RGB_COLOR_BOUND));
	}

	/**
	 * 通过{@link ImageWriter}写出图片到输出流
	 * @param image 图片
	 * @param out 输出的Image流{@link ImageOutputStream}
	 * @param quality 质量，数字为0~1（不包括0和1）表示质量压缩比，除此数字外设置表示不压缩
	 */
	public static void write(BufferedImage image, OutputStream out, String imageType, float quality) {
		ImageWriter writer = ImageIO.getImageWritersByFormatName(imageType).next();
		// 设置质量
		ImageWriteParam imgWriteParams = null;
		if (quality > 0.0 && quality < 1.0) {
			imgWriteParams = writer.getDefaultWriteParam();
			if (imgWriteParams.canWriteCompressed()) {
				imgWriteParams.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
				imgWriteParams.setCompressionQuality(quality);
			}
		}
		try (ImageOutputStream imageOutputStream = ImageIO.createImageOutputStream(out)) {
			writer.setOutput(imageOutputStream);
			if (null != imgWriteParams) {
				writer.write(null, new IIOImage(image, null, null), imgWriteParams);
			}
			else {
				writer.write(image);
			}
			imageOutputStream.flush();
		}
		catch (IOException e) {
			// skip
		}
		finally {
			writer.dispose();
		}
	}

}