package com.mes.print.template;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsEnvironment;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.awt.print.PageFormat;
import java.awt.print.Printable;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardCopyOption;
import java.util.HashMap;
import java.util.Map;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.ImageType;
import org.apache.pdfbox.rendering.PDFRenderer;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import com.mes.print.model.FlowCardData;

/**
 * 流转卡渲染器（支持 PDF 模板 + 二维码）
 * 复用 OP40 的 LaserCardPrintUtil 渲染逻辑
 */
public class FlowCardRenderer {

	// PDF 模板尺寸（A5 纵向 148x210mm）
	private static final float PDF_PAGE_W_PT = 419.5f;
	private static final float PDF_PAGE_H_PT = 595.25f;

	// 三个动态元素在 PDF 坐标系里的位置（pt，左上原点）
	private static final float QR_X = 194.5f;
	private static final float QR_Y = 65.4f;
	private static final float QR_W = 35.7f;
	private static final float QR_H = 34.6f;

	// 文字 baseline（Graphics2D.drawString 的 y 参数）
	private static final float STEEL_TEXT_X = 291.5f;
	private static final float STEEL_TEXT_Y = 85.5f;
	private static final float SN_TEXT_X = 291.5f;
	private static final float SN_TEXT_Y = 96.4f;

	private static final int TEXT_FONT_SIZE = 8;

	// 中文字体候选，按顺序找到系统里第一个可用的
	private static final String[] FONT_CANDIDATES = {"SimSun", "宋体", "Microsoft YaHei", "微软雅黑", Font.SANS_SERIF};

	// 打印用的底图 DPI；越高越清晰但内存/耗时越大，300 是常规打印标准
	private static final float PRINT_TEMPLATE_DPI = 300f;

	// 模板 PDF 缓存
	private static volatile PDDocument templateDoc;
	private static volatile PDFRenderer templateRenderer;
	private static volatile BufferedImage templateImage;
	private static final Object LOCK = new Object();

	public static Printable render(final FlowCardData data) {
		try {
			BufferedImage bgImage = getTemplateImage();
			BufferedImage qr = generateQrCode(data.getSn(), 600);

			return new Printable() {
				@Override
				public int print(Graphics g, PageFormat pf, int idx) {
					if (idx > 0) return NO_SUCH_PAGE;
					Graphics2D g2 = (Graphics2D) g;

					g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
					g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
					g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);

					// 把 PDF 页面尺寸（pt）等比缩放到打印区域，居中
					double sx = pf.getImageableWidth() / PDF_PAGE_W_PT;
					double sy = pf.getImageableHeight() / PDF_PAGE_H_PT;
					double scale = Math.min(sx, sy);
					double tx = pf.getImageableX() + (pf.getImageableWidth() - PDF_PAGE_W_PT * scale) / 2.0;
					double ty = pf.getImageableY() + (pf.getImageableHeight() - PDF_PAGE_H_PT * scale) / 2.0;

					g2.translate(tx, ty);
					g2.scale(scale, scale);

					// 底图 BufferedImage 是 A5 @ 300dpi ≈ 1747x2480 像素，drawImage 到 pt 坐标 419.5x595.25
					g2.drawImage(bgImage, 0, 0, (int) Math.ceil(PDF_PAGE_W_PT), (int) Math.ceil(PDF_PAGE_H_PT), null);

					drawDynamic(g2, qr, data);
					return PAGE_EXISTS;
				}
			};
		} catch (Exception e) {
			throw new RuntimeException("流转卡渲染失败: " + e.getMessage(), e);
		}
	}

	private static void drawDynamic(Graphics2D g2, BufferedImage qr, FlowCardData d) {
		// 白底盖一下原模板上的二维码占位图
		g2.setColor(Color.WHITE);
		g2.fill(new java.awt.geom.Rectangle2D.Float(QR_X, QR_Y, QR_W, QR_H));
		if (qr != null) {
			g2.drawImage(qr, (int) QR_X, (int) QR_Y, (int) QR_W, (int) QR_H, null);
		}

		g2.setColor(Color.BLACK);
		g2.setFont(pickChineseFont(TEXT_FONT_SIZE));
		String steelSn = d.getSteelSn();
		String customerSn = d.getSn();
		if (steelSn != null) {
			g2.drawString(steelSn, STEEL_TEXT_X, STEEL_TEXT_Y);
		}
		if (customerSn != null) {
			g2.drawString(customerSn, SN_TEXT_X, SN_TEXT_Y);
		}
	}

	private static BufferedImage getTemplateImage() throws IOException {
		if (templateImage != null) return templateImage;
		synchronized (LOCK) {
			if (templateImage == null) {
				PDFRenderer r = getRenderer();
				templateImage = r.renderImageWithDPI(0, PRINT_TEMPLATE_DPI, ImageType.RGB);
				System.out.println("[流转卡] 底图已预渲染 " + templateImage.getWidth() + "x" + templateImage.getHeight()
						+ " @" + PRINT_TEMPLATE_DPI + "dpi");
			}
		}
		return templateImage;
	}

	private static PDFRenderer getRenderer() throws IOException {
		if (templateRenderer != null) return templateRenderer;
		synchronized (LOCK) {
			if (templateRenderer == null) {
				String path = "config/liuzhuanka_template.pdf";
				File pdfFile = extractToTemp(path);
				PDDocument doc = PDDocument.load(pdfFile);
				templateDoc = doc;
				templateRenderer = new PDFRenderer(doc);
				System.out.println("[流转卡] 已加载模板：" + pdfFile.getAbsolutePath());
			}
		}
		return templateRenderer;
	}

	private static File extractToTemp(String cpPath) throws IOException {
		File direct = new File(cpPath);
		if (direct.isFile()) {
			return direct;
		}
		try (InputStream is = ClassLoader.getSystemResourceAsStream(cpPath)) {
			if (is == null) {
				throw new IOException("找不到流转卡模板：" + cpPath);
			}
			Path tmp = Files.createTempFile("liuzhuanka_template_", ".pdf");
			tmp.toFile().deleteOnExit();
			Files.copy(is, tmp, StandardCopyOption.REPLACE_EXISTING);
			return tmp.toFile();
		}
	}

	private static Font pickChineseFont(int size) {
		String[] available = GraphicsEnvironment.getLocalGraphicsEnvironment().getAvailableFontFamilyNames();
		for (String name : FONT_CANDIDATES) {
			for (String a : available) {
				if (a.equalsIgnoreCase(name)) {
					return new Font(name, Font.BOLD, size);
				}
			}
		}
		return new Font(Font.SANS_SERIF, Font.BOLD, size);
	}

	private static BufferedImage generateQrCode(String content, int pixelSize) {
		if (content == null || content.isEmpty()) return null;
		try {
			Map<EncodeHintType, Object> hints = new HashMap<>();
			hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
			hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
			hints.put(EncodeHintType.MARGIN, 0);

			BitMatrix bm = new QRCodeWriter().encode(content, BarcodeFormat.QR_CODE, pixelSize, pixelSize, hints);
			BufferedImage img = new BufferedImage(pixelSize, pixelSize, BufferedImage.TYPE_INT_RGB);
			for (int x = 0; x < pixelSize; x++) {
				for (int y = 0; y < pixelSize; y++) {
					img.setRGB(x, y, bm.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
				}
			}
			return img;
		} catch (WriterException e) {
			e.printStackTrace();
			return null;
		}
	}
}